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1.
PeerJ ; 7: e7783, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31592350

RESUMO

Live trapping is a common tool used to assess demography of small mammals. However, live-trapping is often expensive and stressful to captured individuals. Thus, assessing the relative tradeoffs among study goals, project expenses, and animal well-being is necessary. Here, we evaluated how apparent bias and precision of estimates for apparent annual survival, abundance, capture probability, and recapture probability of Humboldt's flying squirrels (Glaucomys oregonensis) varied with the number of secondary trapping occasions. We used data from forested sites trapped on 12 consecutive occasions annually in the HJ Andrews Experimental Forest (9 sites, 6 years) and the Siuslaw National Forest (seven sites, three years) in Oregon. We used Huggins robust design models to estimate parameters of interest for the first 4, 8, and 12 trapping occasions. We also estimated the effect of attaching Tomahawk traps to tree boles on site- and year-specific flying squirrel capture frequencies. Our estimates with 12 occasions were similar to those from previous studies. Abundances and capture probabilities were variable among years on both sites; however, variation was much lower on the Siuslaw sites. Reducing the length of primary trapping occasions from 12 to 8 nights had very little impact on parameter estimates, but further reducing the length of primary trapping occasions to four nights caused substantial apparent bias in parameter estimates and decreased precision. We found that attaching Tomahawk traps to tree boles increased the site- and year-specific capture frequency of flying squirrels. Our results suggest that live-trapping studies targeting Humboldt's flying squirrels in the Pacific Northwest of the United States could reduce per-site costs and stress to captured individuals without biasing estimates by reducing the length of primary trapping occasions to 8 nights. We encourage similar analyses for other commonly-trapped species in these and other ecosystems.

2.
J Allergy Clin Immunol ; 141(1): 180-188.e3, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28629749

RESUMO

BACKGROUND: Clonal mast cell disorders are known to occur in a subset of patients with systemic reactions to Hymenoptera stings. This observation has prompted the question of whether clonal mast cell disorders also occur in patients with idiopathic anaphylaxis (IA). OBJECTIVE: We sought to determine the prevalence of clonal mast cell disorders among patients with IA, criteria to identify those patients who require a bone marrow biopsy, and whether the pathogenesis of IA involves a hyperresponsive mast cell compartment. METHODS: We prospectively enrolled patients with IA (≥3 episodes/y) who then underwent a medical evaluation that included a serum tryptase determination, allele-specific quantitative PCR (ASqPCR) for the KIT D816V mutation, and a bone marrow examination. Mast cells were cultured from peripheral blood CD34+ cells and examined for releasability after FcεRI aggregation. RESULTS: Clonal mast cell disease was diagnosed in 14% of patients referred with IA. ASqPCR for the KIT D816V mutation was a useful adjunct in helping identify those with systemic mastocytosis but not monoclonal mast cell activation syndrome. A modified overall clonal prediction model was developed by using clinical findings, a serum tryptase determination, and ASqPCR. There was no evidence of a hyperresponsive mast cell phenotype in patients with IA. CONCLUSION: Patients with clonal mast cell disease can present as having IA. Distinct clinical and laboratory features can be used to select those patients more likely to have an underlying clonal mast cell disorder (monoclonal mast cell activation syndrome or systemic mastocytosis) and thus candidates for a bone marrow biopsy.


Assuntos
Anafilaxia/genética , Anafilaxia/imunologia , Mastócitos/imunologia , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/imunologia , Mutação de Sentido Incorreto , Proteínas Proto-Oncogênicas c-kit , Adolescente , Adulto , Idoso , Substituição de Aminoácidos , Anafilaxia/patologia , Feminino , Humanos , Masculino , Mastócitos/patologia , Mastocitose Sistêmica/patologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/imunologia
3.
Nat Genet ; 48(12): 1564-1569, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27749843

RESUMO

Elevated basal serum tryptase levels are present in 4-6% of the general population, but the cause and relevance of such increases are unknown. Previously, we described subjects with dominantly inherited elevated basal serum tryptase levels associated with multisystem complaints including cutaneous flushing and pruritus, dysautonomia, functional gastrointestinal symptoms, chronic pain, and connective tissue abnormalities, including joint hypermobility. Here we report the identification of germline duplications and triplications in the TPSAB1 gene encoding α-tryptase that segregate with inherited increases in basal serum tryptase levels in 35 families presenting with associated multisystem complaints. Individuals harboring alleles encoding three copies of α-tryptase had higher basal serum levels of tryptase and were more symptomatic than those with alleles encoding two copies, suggesting a gene-dose effect. Further, we found in two additional cohorts (172 individuals) that elevated basal serum tryptase levels were exclusively associated with duplication of α-tryptase-encoding sequence in TPSAB1, and affected individuals reported symptom complexes seen in our initial familial cohort. Thus, our findings link duplications in TPSAB1 with irritable bowel syndrome, cutaneous complaints, connective tissue abnormalities, and dysautonomia.


Assuntos
Dor Crônica/genética , Doenças do Tecido Conjuntivo/genética , Variações do Número de Cópias de DNA/genética , Disautonomia Familiar/genética , Gastroenteropatias/genética , Prurido/genética , Dermatopatias/genética , Triptases/sangue , Triptases/genética , Adolescente , Adulto , Idoso , Criança , Dor Crônica/sangue , Dor Crônica/enzimologia , Doenças do Tecido Conjuntivo/sangue , Doenças do Tecido Conjuntivo/enzimologia , Disautonomia Familiar/sangue , Disautonomia Familiar/enzimologia , Feminino , Gastroenteropatias/sangue , Gastroenteropatias/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Prurido/sangue , Prurido/enzimologia , Dermatopatias/sangue , Dermatopatias/enzimologia , Adulto Jovem
4.
Stem Cell Res ; 15(1): 42-53, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26001169

RESUMO

Patients with systemic mastocytosis (SM) have a wide variety of problems, including skeletal abnormalities. The disease results from a mutation of the stem cell receptor (c-kit) in mast cells and we wondered if the function of bone marrow stromal cells (BMSCs; also known as MSCs or mesenchymal stem cells) might be affected by the invasion of bone marrow by mutant mast cells. As expected, BMSCs from SM patients do not have a mutation in c-kit, but they proliferate poorly. In addition, while osteogenic differentiation of the BMSCs seems to be deficient, their adipogenic potential appears to be increased. Since the hematopoietic supportive abilities of BMSCs are also important, we also studied the engraftment in NSG mice of human CD34(+) hematopoietic progenitors, after being co-cultured with BMSCs of healthy volunteers vs. BMSCs derived from patients with SM. BMSCs derived from the bone marrow of patients with SM could not support hematopoiesis to the extent that healthy BMSCs do. Finally, we performed an expression analysis and found significant differences between healthy and SM derived BMSCs in the expression of genes with a variety of functions, including the WNT signaling, ossification, and bone remodeling. We suggest that some of the symptoms associated with SM might be driven by epigenetic changes in BMSCs caused by dysfunctional mast cells in the bone marrow of the patients.


Assuntos
Células da Medula Óssea/patologia , Mastocitose Sistêmica/patologia , Adipogenia/genética , Adulto , Idoso , Animais , Estudos de Casos e Controles , Proliferação de Células , Forma Celular , Ensaio de Unidades Formadoras de Colônias , Feminino , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Hematopoese/genética , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Mutação/genética , Osteogênese/genética , Proteínas Proto-Oncogênicas c-kit/genética , Células Estromais/patologia , Doadores de Tecidos
5.
Environ Manage ; 55(4): 930-42, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25694035

RESUMO

We assessed the effects of the elimination of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the removal of cattle grazing, using 64 photos taken before grazing was removed compared with later retake photos. Two methods were used for this assessment: (1) a qualitative visual method comparing seven cover types and processes and (2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64 and 73% of sites, respectively. We found a 90% decrease in the amount of bare soil (P < 0.001) and a 63% decrease in exposed channel (P < 0.001) as well as a significant increase in the cover of grasses/sedges/forbs (15% increase, P = 0.037), rushes (389% increase, P = 0.014), and willow (388% increase, P < 0.001). We also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91% (kappa 83%) suggests that digital line transects can be a useful tool for quantifying vegetation cover from photos. Our results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without replanting or other active restoration efforts.


Assuntos
Criação de Animais Domésticos , Bovinos , Conservação dos Recursos Naturais , Ecossistema , Plantas , Animais , Oregon , Pesquisa Qualitativa , Solo
6.
J Allergy Clin Immunol ; 134(1): 178-87, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24582309

RESUMO

BACKGROUND: Mastocytosis associated with germline KIT activating mutations is exceedingly rare. We report the unique clinicopathologic features of a patient with systemic mastocytosis caused by a de novo germline KIT K509I mutation. OBJECTIVES: We sought to investigate the effect of the germline KIT K509I mutation on human mast cell development and function. METHODS: Primary human mast cells derived from CD34(+) peripheral blood progenitors were examined for growth, development, survival, and IgE-mediated activation. In addition, a mast cell transduction system that stably expressed the KIT K509I mutation was established. RESULTS: KIT K509I biopsied mast cells were round, CD25(-), and well differentiated. KIT K509I progenitors cultured in stem cell factor (SCF) demonstrated a 10-fold expansion compared with progenitors from healthy subjects and developed into mature hypergranular mast cells with enhanced antigen-mediated degranulation. KIT K509I progenitors cultured in the absence of SCF survived but lacked expansion and developed into hypogranular mast cells. A KIT K509I mast cell transduction system revealed SCF-independent survival to be reliant on the preferential splicing of KIT at the adjacent exonic junction. CONCLUSION: Germline KIT mutations associated with mastocytosis drive a well-differentiated mast cell phenotype distinct to that of somatic KIT D816V disease, the oncogenic potential of which might be influenced by SCF and selective KIT splicing.


Assuntos
Mutação em Linhagem Germinativa , Mastócitos/patologia , Mastocitose Sistêmica/genética , Fenótipo , Proteínas Proto-Oncogênicas c-kit/genética , Adulto , Processamento Alternativo , Degranulação Celular/efeitos dos fármacos , Diferenciação Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Feminino , Expressão Gênica , Humanos , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Mastocitose Sistêmica/imunologia , Mastocitose Sistêmica/patologia , Fator de Células-Tronco/farmacologia , Transdução Genética
8.
Exp Hematol ; 41(10): 870-881.e2, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23743299

RESUMO

Stem cell factor-dependent KIT activation is an essential process for mast cell homeostasis. The two major splice variants of KIT differ by the presence or absence of four amino acids (GNNK) at the juxta-membrane region of the extracellular domain. We hypothesized that the expression pattern of these variants differs in systemic mastocytosis and that transcripts containing the KIT D816V mutation segregate preferentially to one GNNK variant. A quantitative real-time PCR assay to assess GNNK(-) and GNNK(+) transcripts from bone marrow mononuclear cells was developed. The GNNK(-)/GNNK(+) copy number ratio showed a trend toward a positive correlation with the percentage of neoplastic mast cell involvement, and KIT D816V containing transcripts displayed a significantly elevated GNNK(-)/GNNK(+) copy number ratio. Relative expression of only the GNNK(-) variant correlated with increasing percentage of neoplastic mast cell involvement. A mast cell transfection system revealed that the GNNK(-) isoform of wild type KIT was associated with increased granule formation, histamine content, and growth. When accompanying the KIT D816V mutation, the GNNK(-) isoform enhanced cytokine-free metabolism and moderately reduced sensitivity to the tyrosine kinase inhibitor, PKC412. These data suggest that neoplastic mast cells favor a GNNK(-) variant predominance, which in turn enhances the activating potential of the KIT D816V mutation and thus could influence therapeutic sensitivity in systemic mastocytosis.


Assuntos
Regulação Neoplásica da Expressão Gênica , Mastócitos/metabolismo , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/fisiopatologia , Mutação , Proteínas Proto-Oncogênicas c-kit/genética , Adulto , Idoso , Resistencia a Medicamentos Antineoplásicos/genética , Ativação Enzimática/genética , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/enzimologia , Mastocitose Sistêmica/enzimologia , Pessoa de Meia-Idade , Isoformas de Proteínas/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Estaurosporina/análogos & derivados , Estaurosporina/farmacologia
10.
Blood ; 118(26): 6803-13, 2011 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-22053105

RESUMO

Increased mast cell burden is observed in the inflamed tissues and affected organs and tissues of patients with mast cell proliferative disorders. However, normal mast cells participate in host defense, so approaches to preferentially target clonally expanding mast cells are needed. We found that mammalian target of rapamycin complex 1 (mTORC1) and 2 (mTORC2) are up-regulated in neoplastic and developing immature mast cells compared with their terminally differentiated counterparts. Elevated mTOR mRNA was also observed in bone marrow mononuclear cells of patients exhibiting mast-cell hyperplasia. Selective inhibition of mTORC1 and mTORC2 through genetic and pharmacologic manipulation revealed that, whereas mTORC1 may contribute to mast-cell survival, mTORC2 was only critical for homeostasis of neoplastic and dividing immature mast cells. The cytostatic effect of mTORC2 down-regulation in proliferating mast cells was determined to be via inhibition of cell-cycle progression. Because mTORC2 was observed to play little role in the homeostasis of differentiated, nonproliferating, mature mast cells, these data provide a rationale for adopting a targeted approaching selectively inhibiting mTORC2 to effectively reduce the proliferation of mast cells associated with inflammation and disorders of mast cell proliferation while leaving normal differentiated mast cells largely unaffected.


Assuntos
Homeostase , Mastócitos/metabolismo , Mastocitose Sistêmica/metabolismo , Proteínas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Western Blotting , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Perfilação da Expressão Gênica , Humanos , Mastócitos/efeitos dos fármacos , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Transgênicos , Complexos Multiproteicos , Naftiridinas/farmacologia , Proteínas/antagonistas & inibidores , Proteínas/genética , Interferência de RNA , Proteína Companheira de mTOR Insensível à Rapamicina , Proteína Regulatória Associada a mTOR , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Células Tumorais Cultivadas
11.
Blood ; 118(20): 5466-75, 2011 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21926349

RESUMO

Kit regulation of mast cell proliferation and differentiation has been intimately linked to the activation of phosphatidylinositol 3-OH kinase (PI3K). The activating D816V mutation of Kit, seen in the majority of mastocytosis patients, causes a robust activation of PI3K signals. However, whether increased PI3K signaling in mast cells is a key element for their in vivo hyperplasia remains unknown. Here we report that dysregulation of PI3K signaling in mice by deletion of the phosphatase and tensin homolog (Pten) gene (which regulates the levels of the PI3K product, phosphatidylinositol 3,4,5-trisphosphate) caused mast cell hyperplasia and increased numbers in various organs. Selective deletion of Pten in the mast cell compartment revealed that the hyperplasia was intrinsic to the mast cell. Enhanced STAT5 phosphorylation and increased expression of survival factors, such as Bcl-XL, were observed in PTEN-deficient mast cells, and these were further enhanced by stem cell factor stimulation. Mice carrying PTEN-deficient mast cells also showed increased hypersensitivity as well as increased vascular permeability. Thus, Pten deletion in the mast cell compartment results in a mast cell proliferative phenotype in mice, demonstrating that dysregulation of PI3K signals is vital to the observed mast cell hyperplasia.


Assuntos
Permeabilidade Capilar/imunologia , Hipersensibilidade/patologia , Mastócitos/patologia , Mastócitos/fisiologia , Mastocitose/patologia , PTEN Fosfo-Hidrolase/genética , Transferência Adotiva , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Degranulação Celular/imunologia , Divisão Celular/imunologia , Sobrevivência Celular/imunologia , Células Cultivadas , Modelos Animais de Doenças , Hipersensibilidade/imunologia , Hipersensibilidade/fisiopatologia , Mastocitose/imunologia , Mastocitose/fisiopatologia , Camundongos , Camundongos Mutantes , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/imunologia
12.
J Allergy Clin Immunol ; 128(5): 1086-92.e1-3, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21762978

RESUMO

BACKGROUND: IL-5 plays a central role in the development and maintenance of eosinophilia (EO) and eosinophil activation in a wide variety of eosinophilic disorders. Although IL-5, IL-3, and GM-CSF can modulate the expression of IL-5 receptor α (IL-5Rα) on eosinophils in vitro, little is known about soluble and surface IL-5Rα levels in vivo. OBJECTIVE: To assess soluble and surface IL-5Rα levels in patients with EO and/or mastocytosis. METHODS: Surface IL-5Rα expression was assessed by flow cytometry in blood and/or bone marrow from subjects with EO (n = 39) and systemic mastocytosis (n = 8) and from normal volunteers (n = 28). Soluble IL-5Rα (sIL-5Rα) level was measured in a cohort of 177 untreated subjects and correlated with EO, eosinophil activation, and serum tryptase and cytokine levels. RESULTS: IL-5Rα expression on eosinophils inversely correlated with EO (r = -0.48; P < .0001), whereas serum levels of sIL-5Rα increased with the eosinophil count (r = 0.56; P < .0001) and serum IL-5 (r = 0.40; P < .0001) and IL-13 (r = 0.29; P = .004) levels. Of interest, sIL-5Rα level was significantly elevated in patients with systemic mastocytosis without EO. Although sIL-5Rα levels correlated with serum tryptase levels in these patients, eosinophil activation, assessed by CD69 expression on eosinophils and serum eosinophil-derived neurotoxin levels, was increased compared with that in normal subjects. CONCLUSIONS: These data are consistent with an in vivo IL-5Rα regulatory pathway in human eosinophils similar to that described in vitro and involving a balance between soluble and surface receptor levels. This may have implications with respect to the use of novel therapeutic agents targeting IL-5 and its receptor in patients with EO and/or mastocytosis.


Assuntos
Eosinofilia/metabolismo , Subunidade alfa de Receptor de Interleucina-5/biossíntese , Mastocitose Sistêmica/metabolismo , Adulto , Idoso , Separação Celular , Citocinas/análise , Citocinas/biossíntese , Citocinas/imunologia , Ensaio de Imunoadsorção Enzimática , Neurotoxina Derivada de Eosinófilo/análise , Neurotoxina Derivada de Eosinófilo/biossíntese , Neurotoxina Derivada de Eosinófilo/imunologia , Eosinofilia/imunologia , Eosinófilos/imunologia , Eosinófilos/metabolismo , Feminino , Citometria de Fluxo , Humanos , Subunidade alfa de Receptor de Interleucina-5/imunologia , Masculino , Mastocitose Sistêmica/imunologia , Pessoa de Meia-Idade , Triptases/sangue , Adulto Jovem
13.
Haematologica ; 96(3): 459-63, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21134978

RESUMO

Cooperating genetic events are likely to contribute to the phenotypic diversity of KIT-D816V systemic mastocytosis. In this study, 44 patients with KIT-D816V systemic mastocytosis were evaluated for coexisting NRAS, KRAS, HRAS or MRAS mutations. Activating NRAS mutations were identified in 2 of 8 patients with advanced disease. NRAS mutations were not found in patients with indolent systemic mastocytosis. To better understand the clonal evolution of mastocytosis, we evaluated the cell compartments impacted by the NRAS and KIT mutations. Clonal mast cells harbored both mutations. KIT-D816V was not detected in bone marrow CD34(+) progenitors, whereas the NRAS mutation was present. These findings suggest that NRAS mutations may have the potential to precede KIT-D816V in clonal development. Unlike other mature lineages, mast cell survival is dependent on KIT and the presence of these two activating mutations may have a greater impact on the expansion of this cell compartment and in resultant disease severity.


Assuntos
Mastocitose Sistêmica/genética , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Idoso , Anticorpos/imunologia , Anticorpos/metabolismo , Antígenos CD34/genética , Antígenos CD34/imunologia , Medula Óssea/metabolismo , Medula Óssea/patologia , Células Clonais/metabolismo , Células Clonais/patologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Mastócitos/imunologia , Mastócitos/metabolismo , Mastócitos/patologia , Mastocitose Sistêmica/metabolismo , Mastocitose Sistêmica/patologia , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-kit/metabolismo
14.
J Immunol ; 182(9): 5770-7, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19380825

RESUMO

Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation. We used alpha(2)-macroglobulin capture to develop a sensitive, microtiter plate-based assay for serum chymase, assisted by a novel substrate synthesized based on results of combinatorial screening of peptide substrates. The substrate has low background hydrolysis in serum and is chymase-selective, with minimal cleavage by the chymotryptic peptidases cathepsin G and chymotrypsin. The assay detects activity in chymase-spiked serum with a threshold of approximately 1 pM (30 pg/ml), and reveals native chymase activity in serum of most subjects with systemic mastocytosis. alpha(2)-Macroglobulin-bound chymase generates angiotensin II in chymase-spiked serum, and it appears in native serum as chymostatin-inhibited activity, which can exceed activity of captopril-sensitive angiotensin-converting enzyme. These findings suggest that chymase bound to alpha(2)-macroglobulin is active, that the complex is an angiotensin-converting enzyme inhibitor-resistant reservoir of angiotensin II-generating activity, and that alpha(2)-macroglobulin capture may be exploited in assessing systemic release of secreted peptidases.


Assuntos
Angiotensina II/biossíntese , Quimases/sangue , Mastócitos/enzimologia , Soro/enzimologia , alfa-Macroglobulinas/metabolismo , Adulto , Criança , Quimases/isolamento & purificação , Quimases/metabolismo , Ativação Enzimática , Estabilidade Enzimática , Humanos , Mastócitos/metabolismo , Mastocitose/sangue , Mastocitose/enzimologia , Projetos Piloto , Ligação Proteica , Proteínas Recombinantes/sangue , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , alfa-Macroglobulinas/isolamento & purificação
15.
Haematologica ; 93(1): 49-56, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18166785

RESUMO

BACKGROUND: Translocations involving region 5q31-32 (PDGFRB) have been reported in a variety of myeloproliferative diseases and are often associated with significant peripheral eosinophilia. We report an unusual case of a patient presenting with peripheral basophilia and systemic mastocytosis in whom cytogenetic analysis revealed a t(4;5)(q21.1;q31.3). DESIGN AND METHODS: We used molecular analyses to determine the role of PDGFRB in this case. The patient was treated with imatinib. RESULTS: Fluorescence in situ hybridization (FISH) documented a breakpoint in PDGFRB. In agreement with this, the patient responded very well to imatinib with resolution of clinical symptoms, basophilia, and mast cell disease. Molecular analyses revealed that PDGFRB, encoding an imatinib-sensitive tyrosine kinase, was fused to PRKG2. The fusion gene incorporates the first two exons of PRKG2 fused to the truncated exon 12 of PDGFRB, resulting in the disruption of its juxtamembrane domain. Functional studies confirmed that the activity and transforming properties of PRKG2-PDGFRbeta were dependent on the disruption of the auto-inhibitory juxtamembrane domain. CONCLUSIONS: Our results identify a second case of the PRKG2-PDGFRB fusion and confirm the unusual PDGFRB breakpoint associated with this fusion. This work also illustrates the use of imatinib for the treatment of specific cases of systemic mastocytosis.


Assuntos
Regulação Leucêmica da Expressão Gênica , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Mastocitose Sistêmica/tratamento farmacológico , Mastocitose Sistêmica/genética , Proteínas de Fusão Oncogênica/genética , Piperazinas/farmacologia , Pirimidinas/farmacologia , Receptor beta de Fator de Crescimento Derivado de Plaquetas/química , Animais , Benzamidas , Medula Óssea/patologia , Citogenética , Humanos , Mesilato de Imatinib , Imunofenotipagem , Hibridização in Situ Fluorescente , Leucemia Mielogênica Crônica BCR-ABL Positiva/complicações , Masculino , Mastocitose Sistêmica/complicações , Camundongos , Pessoa de Meia-Idade
16.
Immunol Allergy Clin North Am ; 26(3): 549-73, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16931293

RESUMO

It is an exciting time in the treatment of systemic mastocytosis. Major advances in the past 2 decades have helped to define the molecular abnormalities associated with this disease and to delineate pathways involved in its pathogenesis. This has directly translated into the development of novel targeted therapies. These therapies hold great promise to patients and health care providers that a "cure" for systemic mastocytosis may someday be obtainable.


Assuntos
Mastocitose Sistêmica/terapia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Aconselhamento , Humanos , Mediadores da Inflamação/imunologia , Educação de Pacientes como Assunto
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