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1.
Br J Dermatol ; 184(2): 226-236, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32956489

RESUMO

Chronic urticaria (CU) affects about 1% of the world population of all ages, mostly young and middle-aged women. It usually lasts for several years (> 1 year in 25-75% of patients) and often takes > 1 year before effective management is implemented. It presents as chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU) or both in the same person. More than 25% of cases are resistant to H1 -antihistamines, even at higher doses, and third- and fourth-line therapies (omalizumab and ciclosporin) control the disease only in two-thirds of H1 -antihistamine-resistant patients. Here we review the impact of CU on different aspects of patients' quality of life and the burden of this chronic disease for the patient and society. CU may have a strong impact on health-related quality of life (HRQoL), particularly when CSU is associated with angio-oedema and/or CIndU (Dermatology Life Quality Index > 10 in 30% of patients). Comorbidities, such as anxiety and depression, which are present in more than 30% of patients with CSU, compound HRQoL impairment. Severe pruritus and the unpredictable occurrence of weals and angio-oedema are responsible for sleep disorders; sexual dysfunction; limitations on daily life, work and sports activities; interfering with life within the family and in society; and patients' performance at school and work (6% absenteeism and 25% presenteeism). Apart from treatment costs, with annual values between 900 and 2400 purchasing power parity dollars (PPP$) in Europe and the USA, CU is associated with a high consumption of medical resources and other indirect costs, which may reach a total annual cost of PPP$ 15 550.


Assuntos
Urticária Crônica , Urticária , Doença Crônica , Europa (Continente) , Feminino , Humanos , Pessoa de Meia-Idade , Omalizumab/uso terapêutico , Qualidade de Vida , Urticária/tratamento farmacológico , Urticária/epidemiologia
3.
Clin Exp Dermatol ; 43(5): 573-576, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29451318

RESUMO

Omalizumab (Xolair® ) is an anti-IgE monoclonal antibody, which may benefit adults with systemic mastocytosis. We report effective treatment with omalizumab in two toddlers with severe diffuse cutaneous mastocytosis. Our cases offer preliminary evidence to support the safe use of omalizumab in paediatric patients with cutaneous mastocytosis.


Assuntos
Antialérgicos/uso terapêutico , Mastocitose Cutânea/tratamento farmacológico , Omalizumab/uso terapêutico , Pré-Escolar , Humanos , Masculino
4.
Paediatr Child Health ; 21(2): e10-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27095888

RESUMO

Primary immunodeficiencies are a group of heterogeneous disorders resulting from defects affecting the function of ≥1 parts of the immune system. Current estimates of the prevalence of primary immunodeficiency disease are one in 1200 patients. In Ontario, where the average general practitioner follows 1300 to 2000 patients, an estimated two patients will have primary immunodeficiency. With new primary immunodeficiencies being described at an exponential rate, and those previously described becoming better understood, it is challenging for health care providers to stay up to date. Knowledge gaps delay diagnosis and treatment, leading to increased morbidity and mortality. The present review aims to provide the primary care provider with the tools necessary to recognize primary immunodeficiency and assist in establishing diagnoses.


Les immunodéficiences primaires désignent un groupe de troubles hétérogènes causés par des déficits de la fonction d'au moins une partie du système immunitaire. Les évaluations actuelles de la prévalence des immunodéficiences primaires sont de un cas sur 1 200 patients. En Ontario, où l'omnipraticien moyen suit de 1 300 à 2 000 patients, on estime que deux de ces patients seront atteints d'une immunodéficience primaire. Puisque de nouvelles immunodéficiences primaires sont décrites à un taux exponentiel et que celles qui sont déjà décrites sont de mieux en mieux comprises, il est difficile pour les professionnels de la santé de demeurer à jour. Les lacunes sur le plan du savoir retardent le diagnostic et le traitement, ce qui accroît la morbidité et la mortalité. La présente analyse vise à fournir au dispensateur de soins de première ligne les outils nécessaires pour identifier les immunodéficiences primaires et contribuer à poser les diagnostics.

5.
Clin Exp Allergy ; 45(1): 249-54, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25207855

RESUMO

BACKGROUND: Studies suggest that siblings of children with peanut allergy (PNA) have a higher prevalence of PNA than the general population. OBJECTIVES: The Canadian Peanut Allergy Registry was used to assess the percentage of siblings of registered index PNA children who were 1) never exposed to peanut or 2) reportedly diagnosed with PNA by a physician without either a history of allergic reaction or a confirmatory testing. Sociodemographic and clinical factors that may be associated with either outcome were evaluated. METHODS: Parents completed a questionnaire on siblings' sociodemographic characteristics, exposure and reaction to peanut, confirmatory tests performed and whether PNA had been diagnosed. RESULTS: Of 932 Registry families, 748 families responded, representing 922 siblings. 13.6% of siblings had never been exposed to peanut, 70.4% (n = 88) of which were born after the index child. Almost 9% of siblings (80) were reported as PNA, but almost half of this group had no history of an allergic reaction to peanut, including five children who also had no testing to confirm PNA. Of these 5, 4 were born after PNA diagnosis in the index child. In a multivariate regression analysis for siblings at least 3 years old, those born after PNA diagnosis in the index child were more likely to have never been exposed to peanut. In a univariate analysis, siblings born after the diagnosis of PNA in the index child were more likely to be diagnosed with PNA without supportive history or confirmatory testing. CONCLUSIONS AND CLINICAL RELEVANCE: These data estimate that more than 10% of siblings of PNA patients will avoid peanut and that siblings born after the diagnosis of PNA in an index child are more likely to have never been exposed. Educational programs and guidelines that caution against unnecessary avoidance are required.


Assuntos
Arachis , Hipersensibilidade a Amendoim/diagnóstico , Hipersensibilidade a Amendoim/epidemiologia , Sistema de Registros , Irmãos , Inquéritos e Questionários , Adolescente , Canadá/epidemiologia , Criança , Feminino , Humanos , Masculino
6.
Allergy ; 68(2): 131-41, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23157275

RESUMO

BACKGROUND: Chronic spontaneous urticaria (CSU) is one of the most costly allergic conditions challenging physicians as well as patients and their families. Despite evident lacunae in the understanding of the pathogenesis, at least some findings suggest that psychosocial factors likely contribute to the development and exacerbation of CSU. We aim to assess the contribution of psychological factors to CSU. METHODS: Systematic search of PubMed and OVID/Medline databases was conducted from 1 January 1935 to 1 January 2012. Studies selected include original research in English, Spanish and French exploring the association between CSU and psychosocial factors. Two investigators independently reviewed all titles and abstracts to identify potentially relevant articles and resolved discrepancies by repeated review and discussion and arbitration of a third reviewer. Quality of systematic reviews and meta-analyses was assessed using a measure based on the Newcastle-Ottawa Scale and psychological conditions of CSU patients. RESULTS: We identified 114 eligible studies spanning 77 years and featuring 17 reviews, 67 studies related to neither CSU nor psychosocial factors, and eight studies that provided either no prevalence estimates or insufficient sample size. Pooling effect sizes using random effects, analyses revealed that, despite large heterogeneity (I(2) of 97.60%), psychosocial factors had a prevalence of 46.09% (95% confidence interval, 44.01%, 48.08%). CONCLUSION: Future research needs to better establish the contribution of psychosocial factors to the pathogenesis and exacerbation of CSU, and explore the possible benefit of behavioural interventions to the development of new management strategies.


Assuntos
Urticária/epidemiologia , Urticária/psicologia , Terapia Comportamental , Estudos de Casos e Controles , Doença Crônica , Intervalos de Confiança , Estudos Transversais , Progressão da Doença , Feminino , Humanos , Masculino , Avaliação das Necessidades , Razão de Chances , Prevalência , Prognóstico , Psicologia , Quebeque/epidemiologia , Valores de Referência , Índice de Gravidade de Doença , Urticária/fisiopatologia , Urticária/terapia
7.
Allergy ; 68(12): 1605-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24410784

RESUMO

Prompt epinephrine administration is crucial in managing anaphylaxis, but epinephrine auto-injectors (EAIs) are underutilized by patients and their families. Children with peanut allergy were recruited from the Allergy Clinics at the Montreal Children's Hospital, food allergy advocacy organizations and organizations providing products to allergic individuals. Parents of children who had been prescribed an EAI were queried on whether they were fearful of using it and on factors that may contribute to fear. A majority of parents (672/1209 = 56%) expressed fear regarding the use of the EAI. Parents attributed the fear to hurting the child, using the EAI incorrectly or a bad outcome. Parents whose child had longer disease duration or a severe reaction and parents who were satisfied with the EAI training or found it easy to use were less likely to be afraid. Families may benefit from simulation training and more education on the recognition and management of anaphylaxis.


Assuntos
Epinefrina/administração & dosagem , Medo , Hipersensibilidade a Amendoim/tratamento farmacológico , Hipersensibilidade a Amendoim/psicologia , Adolescente , Anafilaxia/prevenção & controle , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Injeções Intramusculares , Masculino , Hipersensibilidade a Amendoim/epidemiologia , Fatores de Risco
8.
Allergy ; 66(1): 1-14, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20560905

RESUMO

Anaphylaxis is a clinical emergency, and recent reports suggest increased prevalence. A diverse set of primary genetic and environmental influences may confer susceptibility to anaphylactic reactions. Anaphylaxis presents diagnostic and therapeutic challenges. It often manifests with a broad array of symptoms and signs that might be similar to other diseases. The management of anaphylaxis consists of emergency treatment of acute episodes as well as preventive strategies to avoid recurrences. Treatment is complicated by its rapid onset and progression, presence of concurrent diseases or medications, and need for long-term allergen avoidance. Health care professionals must be able to recognize the signs of anaphylaxis, treat an episode promptly and appropriately, and provide preventive recommendations. Recognizing the gaps in our understanding and management of anaphylaxis may help identify promising targets for future treatment and prevention and areas that require further study.


Assuntos
Anafilaxia , Epinefrina/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alérgenos/efeitos adversos , Alérgenos/imunologia , Anafilaxia/tratamento farmacológico , Anafilaxia/epidemiologia , Anafilaxia/genética , Anafilaxia/fisiopatologia , Criança , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Prevalência , Pesquisa/tendências , Fatores de Risco , Adulto Jovem
9.
Artigo em Inglês | MEDLINE | ID: mdl-32206067

RESUMO

BACKGROUND: Oral immunotherapy (OIT) is an emerging approach to the treatment of patients with IgE-mediated food allergy and is in the process of transitioning to clinical practice. OBJECTIVE: To develop patient-oriented clinical practice guidelines on oral immunotherapy based on evidence and ethical imperatives for the provision of safe and efficient food allergy management. MATERIALS AND METHODS: Recommendations were developed using a reflective patient-centered multicriteria approach including 22 criteria organized in five dimensions (clinical, populational, economic, organizational and sociopolitical). Data was obtained from: (1) a review of scientific and ethic literature; (2) consultations of allergists, other healthcare professionals (pediatricians, family physicians, nurses, registered dieticians, psychologists, peer supporters), patients and caregivers; and patient associations through structured consultative panels, interviews and on-line questionnaire; and (3) organizational and economic data from the milieu of care. All data was synthesized by criteria in a multicriteria deliberative guide that served as a platform for structured discussion and development of recommendations for each dimension, based on evidence, ethical imperatives and other considerations. RESULTS: The deliberative grid included 162 articles from the literature and media reviews and data from consultations involving 85 individuals. Thirty-eight (38) recommendations were made for the practice of oral immunotherapy for the treatment of IgE mediated food allergy, based on evidence and a diversity of ethical imperatives. All recommendations were aimed at fostering a context conducive to achieving objectives identified by patients and caregivers with food allergy. Notably, specific recommendations were developed to promote a culture of shared responsibility between patients and healthcare system, equity in access, patient empowerment, shared decision making and personalization of OIT protocols to reflect patients' needs. It also provides recommendations to optimize organization of care to generate capacity to meet demand according to patient choice, e.g. OIT or avoidance. These recommendations were made acknowledging the necessity of ensuring sustainability of the clinical offer in light of various economic considerations. CONCLUSIONS: This innovative CPG methodology was guided by patients' perspectives, clinical evidence as well as ethical and other rationales. This allowed for the creation of a broad set of recommendations that chart optimal clinical practice and define the conditions required to bring about changes to food allergy care that will be sustainable, equitable and conducive to the well-being of all patients in need.

10.
Mol Cell Biol ; 21(11): 3684-91, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11340162

RESUMO

In a panel of four human melanoma cell lines, equitoxic doses of cisplatin induced the proapoptotic conformation of the Bcl-2 family protein Bak prior to the execution phase of apoptosis. Because cisplatin-induced modulation of the related Bax protein was seen in only one cell line, a degree of specificity in the signal to Bak is indicated. Little is known about upstream regulation of Bak activity. In this study, we examined whether the apoptosis-specific pathway mediated by a kinase fragment of MEKK1 (DeltaMEKK1) is involved in the observed Bak modulation. We report that expression of a kinase-inactive fragment of MEKK1 (dominant negative MEKK [dnMEKK]) efficiently blocked cisplatin-induced modulation of Bak and cytochrome c release and consequently also reduced DEVDase activation and nuclear fragmentation. Accordingly, expression of a kinase-active MEKK1 fragment (dominant positive MEKK) was sufficient to induce modulation of Bak in three cell lines and to induce apoptosis in two of these. dnMEKK did not block cisplatin-induced c-Jun N-terminal kinase (JNK) activation, in agreement with a specifically proapoptotic role for the DeltaMEKK1 pathway. Finally, we show that reduction of Bak expression by antisense Bak reduced cisplatin-induced loss of mitochondrial integrity and caspase cleavage activity in breast cancer cell lines. In summary, we have identified Bak as a cisplatin-regulated component downstream in a proapoptotic, JNK-independent DeltaMEKK1 pathway.


Assuntos
Antineoplásicos/metabolismo , Apoptose , Cisplatino/metabolismo , MAP Quinase Quinase Quinase 1 , Proteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Antineoplásicos/farmacologia , Cisplatino/farmacologia , Grupo dos Citocromos c/metabolismo , Ativação Enzimática , Humanos , Proteína Quinase 8 Ativada por Mitógeno , Proteína Quinase 9 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Células Tumorais Cultivadas , Proteína Killer-Antagonista Homóloga a bcl-2 , Proteína X Associada a bcl-2
11.
Oncogene ; 9(12): 3655-63, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7970724

RESUMO

We here report the spontaneous loss of both homologues of the c-jun gene in two cell lines, isolated after transfection of rat embryo fibroblasts with single ras-oncogenes. These cells lines (designated A14 and B25) grow rapidly in vitro, have transformed morphologies and are invasive through reconstituted basal membranes. Both c-jun defective cell lines were found to be tumorigenic and metastatic in athymic mice. Loss of c-jun was paralleled by a dramatic decrease in interstitial collagenase expression, whereas stromelysin mRNA expression in c-jun- A14 and B25 cells was similar to that observed in c-jun+ transformed cell lines. Transient transfection experiments using reporter plasmids showed that stromelysin promoter activity in A14 cells was severely impaired by a point mutation in the -71 to -65 AP-1 motif, and was inhibited by a Jun dominant negative mutant. Gel mobility shift studies demonstrated the presence of a factor in A14 nuclear extracts capable of binding the stromelysin TRE. This factor bound JunB, JunD and Fos antibodies. Our findings suggest that c-Jun is not required for the tumorigenic and metastatic potential of ras-transformed fibrosarcoma cells, and that AP-1 protein(s) lacking c-Jun are capable of activating the stromelysin gene promoter.


Assuntos
Fibrossarcoma/genética , Genes jun , Genes ras , Metástase Neoplásica/genética , Animais , Sítios de Ligação , Colagenases/genética , Metaloproteinase 3 da Matriz , Metaloendopeptidases/genética , Camundongos , Camundongos Nus , Neoplasias Experimentais/etiologia , Osteopontina , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Sialoglicoproteínas/genética , Fator de Transcrição AP-1/metabolismo , Transfecção , Células Tumorais Cultivadas
12.
Cell Signal ; 8(3): 191-5, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8736703

RESUMO

Cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) regulates the activity of growth-factor-induced pathways at the level of cytoplasmic kinases and nuclear transcription factors. We observed that H-89, an inhibitor of PKA, induced mitogen-activated protein (MAP) kinase activity in a 12V-ras-transformed fibroblast cell line. In contrast, H-89 inhibited phorbol-ester-mediated induction of MAP kinase, junB messenger ribonucleic acid (mRNA), and collagenase mRNA in these cells. Phorbol-ester stimulation of a collagenase-promoter reporter construct was also inhibited by H-89. However, stimulation of the collagenase promoter was not inhibited by overexpression of the PKA-inhibitory protein PKI. These data suggest that H-89 inhibits the activity of an enzyme required for phorbol-ester induction of collagenase mRNA, but that this inhibition does not occur at the level of PKA.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Isoquinolinas/farmacologia , Inibidores de Metaloproteinases de Matriz , Sulfonamidas , Acetato de Tetradecanoilforbol/farmacologia , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Linhagem Celular Transformada , Colagenases/metabolismo , Genes jun , RNA Mensageiro , Ratos
13.
Eur J Cell Biol ; 53(2): 357-63, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2081549

RESUMO

The effects of Clostridium difficile toxin B on some actin-dependent cellular functions were studied. A three-day incubation of intoxicated B-lymphocytes and transformed 3T3 fibroblasts resulted in dose-dependent multinucleation. Using vimentin-negative Daudi cells we showed that this effect of toxin B does not involve vimentin. As DNA and protein syntheses are not impaired in the cells used, the results suggest that toxin B has an effect on the actin-containing contractile ring during mitosis, in a manner similar to that of the microfilament-disrupting agent cytochalasin B. Toxin B is the first bacterial toxin shown to have this effect. It was also found that the capping of surface IgM on B-lymphocytes was not inhibited by toxin B, whereas cytochalasin B did inhibit capping. These results suggest that capping is dependent on a specific membrane-associated actin structure, which is not affected by toxin B.


Assuntos
Citoesqueleto de Actina/ultraestrutura , Linfócitos B/imunologia , Proteínas de Bactérias , Toxinas Bacterianas/farmacologia , Núcleo Celular/ultraestrutura , Clostridioides difficile , Citotoxinas/farmacologia , Capeamento Imunológico/efeitos dos fármacos , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Linfócitos B/efeitos dos fármacos , Linhagem Celular Transformada , Núcleo Celular/efeitos dos fármacos , Citocalasina B/farmacologia , Camundongos , Células Tumorais Cultivadas
14.
FEBS Lett ; 417(1): 17-20, 1997 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-9395066

RESUMO

Two-dimensional gel electrophoresis was used to identify polypeptides differentially expressed between normal and c-jun transformed rat fibroblasts. The level of a 49 kDa polypeptide was 3-fold elevated in c-jun transformed cells. Sequence analysis by ion trap mass spectrometry identified the polypeptide as rat alpha-enolase. Enolase functions as a cell surface receptor for plasminogen, suggesting that upregulation may increase plasminogen activation and cell surface proteolysis important for tumor growth. However, no difference was observed between normal and transformed cells in formation of plasmin, suggesting that upregulation of alpha-enolase may contribute to an increased metabolic capacity, but not to increased plasminogen activation.


Assuntos
Transformação Celular Neoplásica , Genes jun , Fosfopiruvato Hidratase/biossíntese , Plasminogênio/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Animais , Linhagem Celular Transformada , Fibroblastos/citologia , Fibroblastos/metabolismo , Expressão Gênica , Humanos , Proteínas Proto-Oncogênicas c-jun/genética , Ratos
15.
Clin Exp Metastasis ; 17(8): 649-54, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10919709

RESUMO

Increased urokinase plasminogen activator (u-PA) production is associated with tumor invasion and metastasis in several malignancies, including breast cancer. The mechanisms underlying constitutive u-PA expression are not well understood. We examined the relationship between the signal strength of the ERK pathway and the level of u-PA expression in the metastatic human breast cancer cell line MDA-MB-231. Treatment with the MEK1 inhibitor PD98059 resulted in decreased ERK1/2 phosphorylation and decreased u-PA mRNA and protein expression. Inhibition of ERK1/2 activity also led to decreased cell proliferation and to decreased cyclin D1 expression. Less than 5% of total ERK1/2 was phosphorylated in exponentially growing MDA-MB-231 cells, and ERK1/2 activity could be stimulated by okadaic acid. Okadaic acid did not stimulate u-PA expression, but induced strong expression of the cdk-inhibitor p21Cip1. These findings suggest that ERK1/2 signaling is tuned to a level which results in high u-PA expression and rapid cell proliferation.


Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , MAP Quinase Quinase Quinase 1 , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/biossíntese , Neoplasias da Mama/secundário , Divisão Celular/fisiologia , Ciclina D1/biossíntese , Ciclina D1/genética , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Ciclinas/genética , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Metástase Neoplásica , Ácido Okadáico/farmacologia , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Proto-Oncogênicas c-jun/biossíntese , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-raf/metabolismo , Proteínas Proto-Oncogênicas c-raf/fisiologia , Células Tumorais Cultivadas
17.
Toxicon ; 31(7): 845-52, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8212030

RESUMO

The potent cytotoxin of Clostridium difficile, toxin B, is internalized by endocytosis and activated intracellularly by an unidentified mechanism. Here it is shown that dithiothreitol treatment of toxin B resulted in (1) a mol. wt of 250,000 which is the smallest species of this toxin shown to be cytotoxic; (2) an increased endpoint titre; and (3) translocation of plasma membrane-bound toxin across the membrane at pH 4.5. Treatment with dithiothreitol can thus mimic intracellular activation of the toxin. Radiolabelling of highly purified toxin with retained activity, as well as the 32 N-terminal amino acids and the amino acid composition, is also presented.


Assuntos
Proteínas de Bactérias , Toxinas Bacterianas/metabolismo , Clostridioides difficile , Citotoxinas/metabolismo , Ditiotreitol/farmacologia , Sequência de Aminoácidos , Toxinas Bacterianas/química , Toxinas Bacterianas/toxicidade , Células Cultivadas , Cromatografia em Gel , Citotoxinas/toxicidade , Eletroforese em Gel de Poliacrilamida , Endocitose , Humanos , Dados de Sequência Molecular , Peso Molecular
18.
Melanoma Res ; 11(1): 11-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11254111

RESUMO

The regulation of apoptosis is believed to be dependent on the balance of the activities of different intracellular signalling systems. Activation of the SAPK/JNK pathway is implied in pro-apoptotic signalling, while activation of the MEK1/ERK pathway may have a viability-promoting effect. We show here that treatment with the MEK1 inhibitor PD98059 sensitizes the human melanoma cell line C8161 to cisplatin-induced apoptosis. In these cells, cisplatin at 40 microM did not elicit significant cell death, whereas massive cell death was seen when cells were pretreated for 20 h with 40 microM PD98059 before the addition of cisplatin. Concomitant addition of PD98059 and cisplatin did not have any sensitizing effect, and PD98059 on its own did not induce apoptosis. However, in three other human melanoma cell lines PD98059 did not potentiate cisplatin-induced apoptosis. Instead, in one of these cell lines (AA), PD98059 protected against cisplatin-induced cytotoxicity. We conclude that blocking of the MEK1/ERK pathway may, in some instances, potentiate the cytotoxic effect of cisplatin on human melanoma cell lines, whereas in other instances it may have a protective effect. Thus it cannot be regarded as a general approach to sensitizing melanoma cells to drug-induced apoptosis.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Melanoma/tratamento farmacológico , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Western Blotting , Caspase 3 , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Humanos , MAP Quinase Quinase 1 , Proteína Quinase 8 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Fatores de Tempo , Células Tumorais Cultivadas
19.
Anticancer Res ; 17(4A): 2347-52, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9252645

RESUMO

Ras proteins have been implicated in transducing cellular responses to DNA damaging agents. We used BZA-5B, an inhibitor of Ras-farnesylation, to examine the role of Ras in cellular sensitivity to cisplatin. A human melanoma cell line (224) with a Gln61Arg mutation in N-ras was used for these studies. We report that BZA-5B treated cells show an increased resistance to cisplatin. BZA-5B treatment decreased the number of cells showing in situ DNA fragmentation and increased cell viability and clonogenic survival after cisplatin treatment. Further experiments showed that cisplatin induction of the immediate early genes c-jun and p21cip1 was not affected by BZA-5B. Finally, we show that cisplatin causes only weak activation of Jun N-terminal kinase (JNK) in a human melanoma cell line. We conclude that inhibition of Ras function decreases the sensitivity of human melanoma cells to cisplatin-induced cell death.


Assuntos
Alquil e Aril Transferases , Benzodiazepinas/farmacologia , Cisplatino/farmacologia , Oligopeptídeos/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Apoptose , Fragmentação do DNA , Resistencia a Medicamentos Antineoplásicos , Inibidores Enzimáticos/farmacologia , Farnesiltranstransferase , Genes ras , Humanos , Melanoma , Transferases/antagonistas & inibidores , Células Tumorais Cultivadas
20.
J Allergy (Cairo) ; 2012: 858306, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22187574

RESUMO

Background. Studies suggest that the rising prevalence of food allergy during recent decades may have stabilized. Although genetics undoubtedly contribute to the emergence of food allergy, it is likely that other factors play a crucial role in mediating such short-term changes. Objective. To identify potential demographic predictors of food allergies. Methods. We performed a cross-Canada, random telephone survey. Criteria for food allergy were self-report of convincing symptoms and/or physician diagnosis of allergy. Multivariate logistic regressions were used to assess potential determinants. Results. Of 10,596 households surveyed in 2008/2009, 3666 responded, representing 9667 individuals. Peanut, tree nut, and sesame allergy were more common in children (odds ratio (OR) 2.24 (95% CI, 1.40, 3.59), 1.73 (95% CI, 1.11, 2.68), and 5.63 (95% CI, 1.39, 22.87), resp.) while fish and shellfish allergy were less common in children (OR 0.17 (95% CI, 0.04, 0.72) and 0.29 (95% CI, 0.14, 0.61)). Tree nut and shellfish allergy were less common in males (OR 0.55 (95% CI, 0.36, 0.83) and 0.63 (95% CI, 0.43, 0.91)). Shellfish allergy was more common in urban settings (OR 1.55 (95% CI, 1.04, 2.31)). There was a trend for most food allergies to be more prevalent in the more educated (tree nut OR 1.90 (95% CI, 1.18, 3.04)) and less prevalent in immigrants (shellfish OR 0.49 (95% CI, 0.26, 0.95)), but wide CIs preclude definitive conclusions for most foods. Conclusions. Our results reveal that in addition to age and sex, place of residence, socioeconomic status, and birth place may influence the development of food allergy.

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