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1.
J Eur Acad Dermatol Venereol ; 35(1): 211-215, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32216136

RESUMO

BACKGROUND: Granuloma annulare (GA) and the related annular elastolytic giant cell granuloma (AEGCG) and interstitial granulomatous dermatitis (IGD) are idiopathic histiocytic inflammatory disorders, which are frequently recalcitrant to treatment. OBJECTIVES: Evaluate the efficacy of sulphasalazine in treating GA, AEGCG and IGD. METHODS: Sixteen patients were identified with granulomatous disease who were treated with sulphasalazine between September 2015 and September 2019. Outcomes were based on patients' and providers' subjective evaluations. RESULTS: Sixteen patients were included in the study (ages 56-89, four male and twelve female). Previous treatments were attempted in fifteen patients. Clinical improvement was seen in fourteen patients (87.5%). Initial improvement was noted within a mean (SD) of 66.4 (35.1) days after starting therapy, with increasing benefits over time. Ten patients (62.5%) reported complete or near-complete clearance, three patients (18.8%) reported significant improvement, and one (6.3%) reported partial improvement. Twelve patients elected to stop or reduce therapy, resulting in relapse or worsening in five patients. CONCLUSIONS: Sulphasalazine may be considered as treatment for GA and GA-related conditions.


Assuntos
Dermatite , Granuloma Anular , Granuloma de Células Gigantes , Idoso , Idoso de 80 Anos ou mais , Dermatite/tratamento farmacológico , Feminino , Granuloma , Granuloma Anular/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Sulfassalazina/uso terapêutico
2.
Phys Chem Chem Phys ; 20(8): 5942-5951, 2018 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-29423491

RESUMO

The solvent-dependent excited state behavior of the molecular push-pull system 2-diethylamino-7-nitrofluorene has been explored using femtosecond transient absorption spectroscopy in combination with density functional theory calculations. Several excited state minima have been identified computationally, all possessing significant intramolecular charge transfer character. The experimentally observed dual fluorescence is suggested to arise from a planar excited state minimum and another minimum reached by twisting of the aryl-nitrogen bond of the amino group. The majority of the excited state population, however, undergo non-radiative transitions and potential excited state deactivation pathways are assessed in the computational investigation. A third excited state conformer, characterized by twisting around the aryl-nitrogen bond of the nitro group, is reasoned to be responsible for the majority of the non-radiative decays and a crossing between the excited state and ground state is localized. Additionally, ultrafast intersystem crossing is observed in the apolar solvent cyclohexane and rationalized to occur via an El-Sayed assisted transition from one of the identified excited state minima. The solvent thus determines more than just the fluorescence lifetime and shapes the potential energy landscape, thereby dictating the available excited state pathways.

4.
Br J Dermatol ; 172(2): 412-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25597261

RESUMO

BACKGROUND: Itching, burning, numbness and tingling of the skin are frequent reasons for dermatology consultation. We hypothesized that these sensations may be attributable to a small-fibre neuropathy. Sweating, which is mediated by small nerve fibres, may be a surrogate marker of small-fibre neuropathy. OBJECTIVES: To investigate the results of thermoregulatory sweat testing (TST), which depicts and estimates whole-body sweating, in patients with itching, burning, numbness and tingling sensations. METHODS: We retrospectively reviewed the medical records of 227 patients with itching, burning, numbness and tingling sensations involving the skin who were seen at our institution during 2008 and also underwent TST. RESULTS: The mean age of the cohort was 54 years (range 3-89), and 58% were female. In all, 149 patients (66%) had abnormal TST results; in 119 (80%) of these patients the areas of anhidrosis on TST corresponded to their symptomatic areas. For each symptom analysed separately, the area of anhidrosis correlated with the area of symptoms in most patients. CONCLUSIONS: Patients with burning, itching, numbness and tingling have abnormal sweating patterns and often do not sweat in the symptomatic areas. These novel findings suggest that a small-fibre neuropathy may underlie many cutaneous symptoms and that the neuropathy can be estimated using TST.


Assuntos
Hipestesia/etiologia , Hipo-Hidrose/etiologia , Parestesia/etiologia , Doenças do Sistema Nervoso Periférico/complicações , Prurido/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
6.
Br J Dermatol ; 170(5): 1130-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24472115

RESUMO

BACKGROUND: Delusional infestation (DI) is a well-recognized clinical entity but there is a paucity of reliable data concerning its epidemiology. Knowledge of the epidemiology is fundamental to an understanding of any disease and its implications. Epidemiology is most accurately assessed using population-based studies, which are most generalizable to the wider population in the U.S. and worldwide. To our knowledge, no population-based study of the epidemiology (particularly incidence) of DI has been reported to date. OBJECTIVES: To determine the incidence of delusional infestation (DI) using a population-based study. METHODS: Medical records of Olmsted County residents were reviewed using the resources of the Rochester Epidemiology Project to confirm the patient's status as a true incident case of DI and to gather demographic information. Patients with a first-time diagnosis of DI or synonymous conditions between 1 January 1976 and 31 December 2010 were considered incident cases. RESULTS: Of 470 identified possible diagnoses, 64 were true incident cases of DI in this population-based study. The age- and sex-adjusted incidence was 1·9 [95% confidence interval (CI) 1·5-2·4] per 100 000 person-years. Mean age at diagnosis was 61·4 years (range 9-92 years). The incidence of DI increased over the four decades from 1·6 (95% CI 0·6-2·6) per 100 000 person-years in 1976-1985 to 2·6 (95% CI 1·4-3·8) per 100 000 person-years in 2006-2010. CONCLUSIONS: Our data indicate that DI is a rare disease, with incidence increasing across the life span, especially after the age of 40 years.


Assuntos
Delírio de Parasitose/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Minnesota/epidemiologia , Distribuição por Sexo , Adulto Jovem
7.
Nat Genet ; 7(4): 485-90, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7524919

RESUMO

Ichthyosis bullosa of Siemens (IBS) is an autosomal dominant skin disorder that resembles epidermolytic hyperkeratosis (EHK). We have identified mutations in two families originally diagnosed with EHK and in four families diagnosed with IBS at the same codon in the highly conserved carboxy terminal of the rod domain of keratin 2e, thus revealing a mutational hot spot. Our results allow a differential diagnosis to be made between IBS and EHK at the genetic level and we suggest that patients diagnosed with EHK, but lacking keratin K1 or K10 mutations, should be re-examined for mutations in their K2e genes.


Assuntos
Hiperceratose Epidermolítica/genética , Ictiose/genética , Queratinas/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , DNA/genética , Primers do DNA/genética , Diagnóstico Diferencial , Feminino , Genes Dominantes , Humanos , Hiperceratose Epidermolítica/diagnóstico , Hiperceratose Epidermolítica/patologia , Ictiose/diagnóstico , Ictiose/patologia , Queratina-2 , Queratinas/química , Masculino , Dados de Sequência Molecular , Estrutura Molecular , Mutação , Linhagem
8.
R Soc Open Sci ; 10(7): 230448, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37476516

RESUMO

Theoretical arguments and empirical investigations indicate that a high proportion of published findings do not replicate and are likely false. The current position paper provides a broad perspective on scientific error, which may lead to replication failures. This broad perspective focuses on reform history and on opportunities for future reform. We organize our perspective along four main themes: institutional reform, methodological reform, statistical reform and publishing reform. For each theme, we illustrate potential errors by narrating the story of a fictional researcher during the research cycle. We discuss future opportunities for reform. The resulting agenda provides a resource to usher in an era that is marked by a research culture that is less error-prone and a scientific publication landscape with fewer spurious findings.

9.
Clin Exp Dermatol ; 37(6): 639-41, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22300412

RESUMO

Pityriasis amiantacea (PA; also known as tinea amiantacea) is a relatively rare but distinctive scalp condition characterized by thick scales that adhere to each other and to the hair shaft, resulting in agglomeration and matting of hair. Temporary alopecia is a common complication. Although a specific cause remains unclear, PA is associated with several inflammatory diseases such as psoriasis and seborrhoeic dermatitis. We present a case of PA as a complication of underlying psoriasis, which developed during tumour necrosis factor (TNF)-α inhibitor therapy for Crohn disease. This paradoxical cutaneous reaction to anti-TNF-α therapy has been recently described as an emerging and perplexing cause of psoriasis and psoriasiform eruptions.


Assuntos
Anti-Inflamatórios/efeitos adversos , Toxidermias/etiologia , Pitiríase/induzido quimicamente , Dermatoses do Couro Cabeludo/induzido quimicamente , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Doença de Crohn/tratamento farmacológico , Humanos , Masculino , Adulto Jovem
10.
Am J Transplant ; 10(3): 558-62, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20055804

RESUMO

Nephrogenic systemic fibrosis (NSF) is a debilitating disease in patients with severely diminished kidney function. Currently, no standard treatment exists but improvement has been reported after restoration of kidney function. We retrospectively studied 17 NSF patients with and without successful kidney transplantation (KTx) to evaluate the effects of KTx on NSF. Nine of the 11 KTx developed NSF pretransplant whereas two developed NSF immediately after KTx with delayed graft function. Two of the six dialysis patients had previous failed kidney transplants. Age and sex were well matched. All but one patient was dialysis dependent at the time of NSF. Median follow-up was 35 months for KTx patients and 9 months for dialysis patients. Kidney transplants achieved adequate renal function with median serum creatinine of 1.4 (0.9-2.8) mg/dL and a glomerular filtration rate of 42 (19-60) mL/min/1.73 m(2). NSF improved in 54.6% of the transplanted patients and 50% of the nontransplanted patients (p = 0.86). Two KTx patients had complete resolution of their symptoms whereas four had partial improvement. Improvement in the dialysis patients was all partial. Successful KTx did not insure improvement in NSF and in fact appeared to have no significant benefit over dialysis.


Assuntos
Transplante de Rim/métodos , Dermopatia Fibrosante Nefrogênica/terapia , Adulto , Idoso , Creatinina/sangue , Progressão da Doença , Feminino , Seguimentos , Taxa de Filtração Glomerular , Sobrevivência de Enxerto , Humanos , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
11.
Br J Dermatol ; 163(5): 1095-8, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20716222

RESUMO

BACKGROUND: Eruptive melanocytic naevi (EMN) are melanocytic proliferations developing rapidly on previously unaffected skin in association with various clinical scenarios, most commonly systemic immunosuppression. However, the exact mechanism leading to development of EMN is not understood. In particular, it is not known whether EMN harbour the BRAF mutations which occur frequently in melanoma and most common naevi. OBJECTIVES: To evaluate whether activating BRAF mutations may play a role in genesis of EMN. METHODS: Genomic DNA was isolated from 20 EMN from a patient treated with 6-mercaptopurine (6-MP). Primary BRAF genotyping was performed by allelespecific polymerase chain reaction, followed by validation using direct sequencing. RESULTS: The BRAF V600E mutation was identified in 85% of EMN examined. CONCLUSIONS: Our results implicate mutational activation of the BRAF­MAPK pathway as a factor in development of EMN in the setting of 6-MP treatment. The mechanism leading to development of EMN in this, and potentially other patients, may relate to synergistic mutagenic effects of thioguanines and ultraviolet (UV) A. Together with the documented importance of BRAF mutations in melanoma development and maintenance, these findings highlight the importance of UVA protection, especially in patients treated with thiopurines such as 6-MP.


Assuntos
DNA de Neoplasias/genética , Melanoma/genética , Nevo Pigmentado/genética , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/genética , Adulto , Genótipo , Humanos , Masculino , Melanoma/patologia , Nevo Pigmentado/patologia , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA , Neoplasias Cutâneas/patologia , Adulto Jovem
12.
Lupus ; 19(7): 815-29, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20142296

RESUMO

To investigate the role of HLA-DQ2 in the pathogenesis of associated immune disorders, we generated transgenic mice that expressed HLA-DQ2 in the absence of endogenous murine class II molecules (AE(0)DQ2). These AE(0)DQ2 mice with a mixed genetic background spontaneously developed skin lesions on their ears, whereas control AE(0)DQ6 genotype control mice (also with a mixed genetic background) did not. The skin lesions were characterized by deep subepidermal blistering with hydropic degeneration and lymphoid infiltration in the subepidermal area as determined by histopathology. Immunofluorescence analysis revealed thick band-like granular deposition of IgG, IgM, and a thin band of IgA deposition along the basement membrane. AE(0)DQ2 mice also developed significant and progressive hematuria and proteinuria as compared with the AE(0)DQ6 mice (p < 0.05). Histopathology showed immune complex deposits in the glomeruli of AE(0)DQ2 mice. Immunofluorescence analysis showed progressive mesangial and capillary wall deposition of IgA, IgM, IgG and C1q in the kidney. With electron microscopy, the deposits showed a 'fingerprint' substructure; and tubuloreticular structures were identified within endothelial cells. Conversely, these changes were not observed in AE(0)DQ6 mice. Serum anti-double stranded (ds)DNA IgM and IgG levels were also significantly elevated among AE(0)DQ2 mice compared with AE(0)DQ6 mice (p < 0.001). In conclusion, AE(0)DQ2 mice spontaneously develop an autoimmune lupus-like syndrome and are useful model for this disease. It remains to be determined whether genetic admixture played a role in the development of this systemic lupus erythematosus-like syndrome in HLA-DQ2 transgenic mice. Lupus (2010) 19, 815-829.


Assuntos
Modelos Animais de Doenças , Antígenos HLA-DQ/genética , Lúpus Eritematoso Sistêmico/genética , Animais , DNA/sangue , Feminino , Imunofluorescência , Antígenos HLA-DQ/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Microscopia Eletrônica
13.
Science ; 263(5152): 1444-6, 1994 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-8128228

RESUMO

The participation of (6R) 5,6,7,8-tetrahydrobiopterin (6-BH4) in regulating the tyrosine supply for melanin biosynthesis was investigated by the examination of human keratinocytes, melanocytes, and epidermal suction blisters from normal human skin and from patients with the depigmentation disorder vitiligo. Cells, as well as total epidermis, contained high phenylalanine hydroxylase activities and also displayed the capacity to synthesize and recycle 6-BH4, the essential cofactor for this enzyme. In vitiligo, 4a-hydroxy-BH4 dehydratase activity was extremely low or absent, yielding an accumulation of the nonenzymatic by-product 7-tetrahydrobiopterin (7-BH4) at concentrations up to 8 x 10(-6) M in the epidermis. This by-product is a potent competitive inhibitor in the phenylalanine hydroxylase reaction with an inhibition constant of 10(-6) M. Thus, 6-BH4 seems to control melanin biosynthesis in the human epidermis, whereas 7-BH4 may initiate depigmentation in patients with vitiligo.


Assuntos
Biopterinas/análogos & derivados , Epiderme/metabolismo , Melaninas/biossíntese , Vitiligo/metabolismo , Biopterinas/biossíntese , Biopterinas/metabolismo , Biopterinas/farmacologia , Diferenciação Celular , Células Cultivadas , GTP Cicloidrolase/metabolismo , Humanos , Queratinócitos/metabolismo , Melanócitos/metabolismo , Fenilalanina Hidroxilase/antagonistas & inibidores , Fenilalanina Hidroxilase/metabolismo , Tirosina/biossíntese
14.
Science ; 243(4892): 811-4, 1989 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-2916128

RESUMO

Transforming growth factor alpha (TGF-alpha) is produced by and required for the growth of epithelial cells and is angiogenic in vivo. Since epidermal hyperplasia and angiogenesis are hallmarks of psoriasis, TGF-alpha gene expression was analyzed in epidermal biopsies of normal and psoriatic skin. TGF-alpha messenger RNA and protein are much more abundant in lesional psoriatic epidermis than in normal-appearing skin of psoriatic patients or in normal epidermis. In contrast, messenger RNA levels of transforming growth factor beta 1 (TGF-beta 1), which inhibits epithelial cell growth, are not significantly different in normal, uninvolved, and lesional psoriatic epidermis. Thus, psoriatic epidermal hyperplasia may involve increased expression of a keratinocyte mitogen (TGF-alpha) rather than deficient expression of a growth inhibitor (TGF-beta 1).


Assuntos
Psoríase/genética , Fatores de Crescimento Transformadores/genética , Northern Blotting , Epiderme/fisiopatologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imunoensaio , Fatores de Crescimento Transformadores/metabolismo
16.
G Ital Dermatol Venereol ; 144(1): 1-26, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19218908

RESUMO

Metastatic malignant melanoma is an incurable malignancy with extremely poor prognosis. Patients bearing this diagnosis face a median survival time of approximately 9 months with a probability of surviving 5 years after initial presentation at less than 5%. This is contrasted by the curative nature of surgical resection of early melanoma detected in the skin. To date, no systemic therapy has consistently and predictably impacted the overall survival of patients with metastatic melanoma. However, in recent years, a resurgence of innovative diagnostic and therapeutic developments have broadened our understanding of the natural history of melanoma and identified rational therapeutic targets/strategies that seem poised to significantly change the clinical outcomes in these patients. Herein we review the state-of-the-art in metastatic melanoma diagnostics and therapeutics with particular emphasis on multi-disciplinary clinical management.


Assuntos
Melanoma/secundário , Melanoma/terapia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapia , Antineoplásicos/uso terapêutico , Quimioterapia Adjuvante , Diagnóstico Diferencial , Medicina Baseada em Evidências , Fluordesoxiglucose F18 , Humanos , Imunoterapia , Imageamento por Ressonância Magnética , Melanoma/diagnóstico , Melanoma/tratamento farmacológico , Melanoma/mortalidade , Melanoma/radioterapia , Melanoma/cirurgia , Tomografia por Emissão de Pósitrons , Prognóstico , Radioterapia Adjuvante , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/radioterapia , Neoplasias Cutâneas/cirurgia , Análise de Sobrevida , Tomografia Computadorizada por Raios X , Resultado do Tratamento
17.
J Clin Invest ; 106(12): 1467-79, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11120754

RESUMO

Pemphigus is an autoimmune disease of skin adhesion associated with autoantibodies against a number of keratinocyte antigens, such as the adhesion molecules desmoglein (Dsg) 1 and 3 and acetylcholine receptors. The notion that anti-Dsg antibodies alone are responsible for blisters in patients with pemphigus vulgaris (PV) stems from the ability of rDsg1 and rDsg3 to absorb antibodies that cause PV-like skin blisters in neonatal mice. Here, we demonstrate that PV IgGs eluted from rDsg1-Ig-His and rDsg3-Ig-His show similar antigenic profiles, including the 38-, 43-, 115-, and 190-kDa keratinocyte proteins and a non-Dsg 3 130-kDa polypeptide present in keratinocytes from Dsg 3 knockout mouse. We injected into Dsg 3-lacking mice the PV IgGs that did not cross-react with the 160-kDa Dsg 1 or its 45-kDa immunoreactive fragment and that showed no reactivity with recombinant Dsg 1. We used both the Dsg3(null) mice with a targeted mutation of the Dsg3 gene and the "balding" Dsg3(bal)/Dsg3(bal) mice that carry a spontaneous null mutation in Dsg3. These PV IgGs caused gross skin blisters with PV-like suprabasal acantholysis and stained perilesional epidermis in a fishnet-like pattern, indicating that the PV phenotype can be induced without anti-Dsg 3 antibody. The anti-Dsg 1 antibody also was not required, as its presence in PV IgG does not alter the PV-like phenotype in skin organ cultures and because pemphigus foliaceus IgGs produce a distinct phenotype in Dsg3(null) mice. Therefore, mucocutaneous lesions in PV patients could be caused by non-Dsg antibodies.


Assuntos
Autoanticorpos/imunologia , Caderinas/genética , Caderinas/imunologia , Queratinócitos/imunologia , Pênfigo/imunologia , Pênfigo/patologia , Acantólise/imunologia , Animais , Animais Recém-Nascidos , Autoanticorpos/sangue , Baculoviridae/genética , Vesícula/imunologia , Vesícula/patologia , Desmogleína 1 , Desmogleína 3 , Deleção de Genes , Histocitoquímica , Humanos , Imunização Passiva , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos , Camundongos Knockout , Pênfigo/sangue , Pênfigo/genética , Fenótipo , Proteínas Recombinantes de Fusão/imunologia , Pele/imunologia , Pele/patologia
18.
J Clin Invest ; 100(9): 2286-94, 1997 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9410906

RESUMO

Amphiregulin (AR) is a heparin-binding, heparin-inhibited member of the epidermal growth factor (EGF) family and an autocrine growth factor for human keratinocytes. Previous studies have shown that AR expression is increased in psoriatic epidermis. To test the hypothesis that aberrant AR expression is central to the development of psoriatic lesions, we constructed a transgene (K14-ARGE) encoding a human keratin 14 promoter-driven AR gene. Our results indicate that transgene integration and subsequent expression of AR in basal keratinocytes correlated with a psoriasis-like skin phenotype. Afflicted mice demonstrated shortened life spans, prominent scaling and erythematous skin with alopecia, and occasional papillomatous epidermal growths. Histologic examination revealed extensive areas of marked hyperkeratosis with focal parakeratosis, acanthosis, dermal and epidermal lymphocytic and neutrophilic infiltration, and dilated blood vessels within the papillary dermis. Our results reveal that AR exerts activity in the skin that is distinct from that of transgenic transforming growth factor-alpha or other cytokines, and induces skin pathology with striking similarities to psoriasis. Our observations also link the keratinocyte EGF receptor-ligand system to psoriatic inflammation, and suggest that aberrant expression of AR in the epidermis may represent a critical step in the development or propagation of psoriatic lesions.


Assuntos
Glicoproteínas/genética , Substâncias de Crescimento/genética , Peptídeos e Proteínas de Sinalização Intercelular , Psoríase/genética , Anfirregulina , Animais , Complexo CD3/metabolismo , Família de Proteínas EGF , Epiderme/fisiologia , Regulação da Expressão Gênica , Humanos , Queratinas/genética , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Transgênicos , Psoríase/patologia
19.
Mol Cell Biol ; 11(5): 2547-57, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2017164

RESUMO

A novel human keratinocyte-derived autocrine factor (KAF) was purified from conditioned medium by using heparin affinity chromatography as the first step. Purified KAF stimulated the growth of normal human keratinocytes, mouse AKR-2B cells, and a mouse keratinocyte cell line (BALB/MK). Heparin sulfate inhibited KAF mitogenic activity on all cell types tested and inhibited the ability of KAF to compete with epidermal growth factor for cell surface binding. Interestingly, KAF stimulated the growth of BALB/MK cells at high cell density but failed to stimulate these cells at clonal density. Protein microsequencing of the first 20 NH2-terminal amino acid residues of purified KAF revealed identity to the NH2 terminus of human amphiregulin (AR). Northern (RNA) blot analysis with AR-specific cRNA demonstrated that human keratinocytes, as well as mammary epithelial cell cultures, expressed high levels of AR mRNA. In contrast, AR mRNA was not detected in normal human fibroblasts or melanocytes and was present at reduced levels in several mammary tumor cell lines. The mitogenic activity of purified AR was also shown to be inhibited by heparin sulfate, and an AR-specific enzyme-linked immunosorbent assay (ELISA) revealed that KAF and AR are antigenically related. We have previously shown that human keratinocytes can grow in an autocrine manner. Our present study demonstrates that one of the growth factors responsible for this autocrine growth (KAF) is similar or identical to AR and that KAF and AR bioactivity can be negatively regulated by heparin sulfate.


Assuntos
Glicoproteínas/genética , Substâncias de Crescimento/genética , Heparitina Sulfato/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular , Queratinócitos/fisiologia , Sequência de Aminoácidos , Anfirregulina , Animais , Sequência de Bases , Ligação Competitiva , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Replicação do DNA/efeitos dos fármacos , Família de Proteínas EGF , Fator de Crescimento Epidérmico/metabolismo , Glicoproteínas/isolamento & purificação , Glicoproteínas/farmacologia , Substâncias de Crescimento/isolamento & purificação , Substâncias de Crescimento/farmacologia , Humanos , Queratinócitos/efeitos dos fármacos , Masculino , Camundongos , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , RNA Mensageiro/genética , Homologia de Sequência do Ácido Nucleico , Pele/citologia
20.
Leukemia ; 20(9): 1593-601, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16838023

RESUMO

Ahi-1 (Abelson helper integration site 1) is a novel gene frequently activated by provirus insertional mutagenesis in murine leukemias and lymphomas. Its involvement in human leukemogenesis is demonstrated by gross perturbations in its expression in human leukemia cells, particularly in cutaneous T-cell lymphoma cell lines where increases in AHI-1 transcripts of 40-fold are seen. To test directly whether deregulated expression of AHI-1 contributes to their transformed properties, knockdown of AHI-1 expression in Hut78 cells, a cell line derived from a patient with Sezary syndrome (SS), was performed using retroviral-mediated RNA interference. Retroviral-mediated suppression specifically inhibited expression of AHI-1 and its isoforms in transduced cells by 80% and also reduced autocrine production of interleukin (IL)-2, IL-4 and tumor necrosis factor-alpha (TNFalpha) by up to 85%. It further significantly reduced their growth factor independence in vitro and the ability to produce tumors in immunodeficient mice. Interestingly, aberrant expression of AHI-1, particularly truncated isoforms, was present in CD4+CD7- Sezary cells from some patients with SS. Elevated expression of IL-2 and TNFalpha was also found in these cells. These findings provide strong evidence of the oncogenic activity of AHI-1 in human leukemogenesis and demonstrate that its deregulation may contribute to the development of SS.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Linfoma de Células T/fisiopatologia , Síndrome de Sézary/fisiopatologia , Neoplasias Cutâneas/fisiopatologia , Proteínas Adaptadoras de Transporte Vesicular , Animais , Sequência de Bases , Western Blotting , Linhagem Celular , Citocinas/biossíntese , Primers do DNA , Vetores Genéticos , Humanos , Linfoma de Células T/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Interferência de RNA , Retroviridae/genética , Neoplasias Cutâneas/patologia
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