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1.
Med J Malaysia ; 76(4): 594-596, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34305128

RESUMO

Post Endoscopic Retrograde Cholangiopancreatography (ERCP) pneumoperitoneum is commonly associated with perforated viscus but is rarely associated with benign causes. We present a case of 29 years old lady who underwent ERCP, who was found to have benign pneumoperitoneum subsequently. She was treated conservatively and recovered without complication. Although rare, post ERCP pneumoperitoneum of benign causes should be investigated as the course of treatment and outcome differ largely.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica , Pneumoperitônio , Adulto , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Feminino , Humanos , Pneumoperitônio/diagnóstico por imagem , Pneumoperitônio/etiologia
2.
Clin Exp Dermatol ; 44(4): 411-413, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30239029

RESUMO

Allergic contact dermatitis (ACD) is an increasing problem in children. We sought to investigate the extent of haptens or contact allergens present in baby cosmetic products. Computer programming scripts were written to web-scrape UK supermarkets and pharmacies. In total, 438 unique 'baby products' were identified, and constituent ingredient information was extracted. Data were cross-referenced against 10 standardized patch test reference series. We found that 88% of products had at least one reference contact allergen. There was a mean of 2.21 (range 1-15) reference allergens per product. The most abundant compounds were parabens, fragrances, cetyl/steryl alcohol, methylisothiazolinone, sodium lauryl sulfate and lanolin alcohol. Branded products and those marketed as 'sensitive/gentle/organic/fragrance-free' appeared to contain a greater number of reference allergens than those not marketed as such. This study highlights the increasing number of cosmetic products targeted to children in the UK, and the extent of potential allergens present in these products.


Assuntos
Alérgenos/imunologia , Cosméticos/efeitos adversos , Dermatite Alérgica de Contato/epidemiologia , Haptenos/imunologia , Dermatite Alérgica de Contato/imunologia , Desinfetantes/efeitos adversos , Humanos , Lactente , Parabenos/efeitos adversos , Conservantes Farmacêuticos/efeitos adversos , Prevalência , Tiazóis/efeitos adversos , Reino Unido/epidemiologia
3.
Clin Exp Allergy ; 47(2): 200-207, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27664415

RESUMO

BACKGROUND: Abnormal vocal cord movements can cause laryngeal extrathoracic airway obstruction (often called vocal cord dysfunction - VCD) leading to asthma-like symptoms. These aberrant movements are characteristically present during inspiration and termed paradoxical vocal cord movement (PVCM). We have reported PVCM in up to 40% of severe asthmatics, but it is not known if PVCM is detectable in all patients with asthma-like symptoms and if the condition is more often associated with abnormal lung function. OBJECTIVE: We hypothesized that PVCM is frequently associated with asthma symptoms accompanied by airflow limitation. Studies examined whether PVCM is solely linked to experiencing asthma symptoms, or if PVCM is related to airflow limitation and/or other disease characteristics. METHODS: Patients with asthma symptoms were recruited from general practice and severe asthma clinics (n = 155). Pulmonary function measurements were conducted, asthma control and Nijmegen (dysfunctional breathing) questionnaires were administered and skin prick testing was carried out. PVCM was quantified using dynamic 320-slice computerized tomography of the larynx. Groups were divided into patients with FEV1 ≥ 80% predicted or FEV1 < 80% predicted and FEV1 /FVC < 0.7. ATS/ERS definitions of severity were also applied and evaluated. Detection of PVCM in the groups was compared and analyses performed to identify features associated with PVCM. RESULTS: Overall (n = 155), PVCM was detected in 42 cases (27.1%). Patients with FEV1 < 80% predicted had PVCM more often (25/68, 36.8%) than individuals with normal spirometry (17/87, 19.5%; P = 0.016). PVCM was associated with older age (P = 0.003) and with Nijmegen scores > 20 (P = 0.04). Patients with FEV1 < 80% predicted plus Nijmegen scores > 20 were more likely to have PVCM (OR = 9.3, P = 0.02). CONCLUSIONS AND CLINICAL RELEVANCE: Paradoxical vocal cord movement is more often associated with asthma symptoms accompanied by airflow limitation and dysfunctional breathing. Further studies are needed to determine whether PVCM is induced by dysfunctional breathing practices and/or airway obstruction. How PVCM links with symptomatic asthma and VCD also requires evaluation.


Assuntos
Obstrução das Vias Respiratórias/complicações , Obstrução das Vias Respiratórias/fisiopatologia , Asma/complicações , Asma/fisiopatologia , Disfunção da Prega Vocal/etiologia , Adulto , Idoso , Obstrução das Vias Respiratórias/diagnóstico , Asma/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória , Testes Cutâneos , Avaliação de Sintomas , Tomografia Computadorizada por Raios X
4.
Med Vet Entomol ; 28 Suppl 1: 104-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25171613

RESUMO

Rickettsioses are emerging zoonotic diseases reported worldwide. In spite of the serological evidence of spotted fever group rickettsioses in febrile patients in Malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. This study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. Using PCR assays targeting the citrate synthase gene (gltA), rickettsial DNA was detected in the tissue homogenates of 13 (13.7%) wild rats. Sequence analysis of the gltA amplicons showed 98.6-100% similarity with those of Rickettsia honei/R. conorii/R. raoultii (Rickettsiales: Rickettsiaceae). Sequence analysis of outer membrane protein A gene (ompA) identified Rickettsia sp. TCM1 strain from two rats. No rickettsia was detected from Laelaps mites, Rhipicephalus sanguineus and Haemaphysalis bispinosa ticks, and Felicola subrostratus lice in this study. R. felis was identified from 32.2% of 177 Ctenocephalides felis fleas. Sequence analysis of the gltA amplicons revealed two genotypes of R. felis (Rf31 and RF2125) in the fleas. As wild rats and cat fleas play an important role in the enzoonotic maintenance of rickettsiae, control of rodent and flea populations may be able to reduce transmission of rickettsioses in the local setting.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Citrato (si)-Sintase/genética , Ctenocephalides/microbiologia , Ratos , Infecções por Rickettsia/veterinária , Rickettsia/genética , Doenças dos Roedores/epidemiologia , Animais , Feminino , Malásia , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/veterinária , Rickettsia/classificação , Rickettsia/isolamento & purificação , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Doenças dos Roedores/microbiologia , Análise de Sequência de DNA/veterinária
5.
Gene Ther ; 17(5): 577-91, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20200564

RESUMO

The identification of axon growth-promoting genes, and overexpression of these genes in central nervous system (CNS) neurons projecting to the spinal cord, has emerged as one potential approach to enhancing CNS regeneration. Assessment of the regenerative potential of candidate genes usually requires axonal tracing of spinal projections, ideally limited to neurons that express the candidate gene. Alternatively, coexpression of a reporter gene such as enhanced green fluorescent protein (GFP) from an internal ribosomal entry site can be used to identify neurons expressing the candidate gene, but this strategy does not label corticospinal axons in the spinal cord. We therefore developed a dual promoter lentiviral vector in which a potentially therapeutic transgene is expressed from the cytomegalovirus-enhanced chicken beta-actin promoter and the fluorescent protein copGFP is expressed from the elongation factor-1alpha promoter. The vector was constructed to be compatible with the Gateway recombination system for efficient introduction of transgenes through entry shuttle vectors. We show both simultaneous expression of a candidate and reporter gene in corticospinal and red nucleus neurons, and efficient labeling of their axons after lesions in the cervical spinal cord. This expression system is therefore an accurate and efficient means of screening candidate genes in vivo for enhancement of axonal growth.


Assuntos
Axônios/fisiologia , Terapia Genética/métodos , Vetores Genéticos , Lentivirus , Regeneração Nervosa , Traumatismos da Medula Espinal/terapia , Actinas/genética , Animais , Feminino , Camundongos , Fator 1 de Elongação de Peptídeos/genética , Regiões Promotoras Genéticas , Ratos
7.
Water Sci Technol ; 61(12): 3041-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20555200

RESUMO

This work comprised of the comparative study of arsenic (As) uptake efficiency by Pteris vittata and Pityrogramma calomelanos grown in (i) As amended soils (0-600 ppm) and (ii) As tainted water (40 ppb) using a new compact continuous flow phytofiltration system in a tropical greenhouse. The As hyperaccumulation efficiency was dependent on the growth medium for the two fern species. The highest level of As detected in the fronds of P. vittata was 19,300+/-190 ppm (dry weight basis) and 11,600+/-230 ppm for Pityrogramma calomelanos, after growing for 78 days in soils amended with As. In the compact continuous flow As phytofiltration system experiments, Pityrogramma calomelanos was found to perform better than P. vittata in phytofiltrating As contaminated water under waterlogged conditions. During the 167 h of phytofiltration experiment, the removal efficiency was approximately 99% and 67% for Pityrogramma calomelanos and P. vittata systems respectively, based on an initial 40 ppb As. Pityrogramma calomelanos also required a shorter acclimatization time than P. vittata under waterlogged conditions.


Assuntos
Arsênio/metabolismo , Fungos Mitospóricos/metabolismo , Pteris/metabolismo , Poluentes do Solo/isolamento & purificação , Poluentes da Água/isolamento & purificação , Biodegradação Ambiental , Gleiquênias/crescimento & desenvolvimento , Gleiquênias/metabolismo , Filtração/métodos , Purificação da Água/métodos
8.
Food Chem ; 307: 125631, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31634761

RESUMO

Lutein available in the current market is derived from marigold petals. However, extensive studies showed that microalgae are rich in lutein content and potentially exploitable for its dietary and other industrial applications. In this study, microwave assisted binary phase solvent extraction method (MABS) was the novel protocol being developed and optimized to achieve maximum lutein recovery from microalgae Scenedesmus sp. biomass. Results showed that 60% potassium hydroxide solution with acetone in the ratio of 0.1 (ml/ml) was the ideal binary phase solvent composition. Empirical model developed using response surface methodology revealed highest lutein content can be recovered through MABS extraction method at 55 °C treatment temperature, 36 min in extraction time, 0.7 (mg/ml) for biomass to solvent ratio, 250 Watt microwave power and 250 rpm stirring speed. This optimized novel protocol had increased the amount of lutein recovered by 130% and shorten the overall extraction time by 3-folds.


Assuntos
Aditivos Alimentares , Extração Líquido-Líquido/métodos , Luteína/isolamento & purificação , Scenedesmus/química , Temperatura Alta , Microalgas/química , Solventes
9.
BMC Microbiol ; 9: 170, 2009 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-19689794

RESUMO

BACKGROUND: Pathogens tolerate stress conditions that include low pH, oxidative stress, high salt and high temperature in order to survive inside and outside their hosts. Lipopolysaccharide (LPS), which forms the outer-leaflet of the outer membrane in Gram-negative bacteria, acts as a permeability barrier. The lipid A moiety of LPS anchors it to the outer membrane bilayer. The MsbB enzyme myristoylates the lipid A precursor and loss of this enzyme, in Salmonella, is correlated with reduced virulence and severe growth defects that can both be compensated with extragenic suppressor mutations. RESULTS: We report here that msbB (or msbB somA) Salmonella are highly sensitive to physiological CO2 (5%), resulting in a 3-log reduction in plating efficiency. Under these conditions, msbB Salmonella form long filaments, bulge and lyse. These bacteria are also sensitive to acidic pH and high osmolarity. Although CO2 acidifies LB broth media, buffering LB to pH 7.5 did not restore growth of msbB mutants in CO2, indicating that the CO2-induced growth defects are not due to the effect of CO2 on the pH of the media. A transposon insertion in the glucose metabolism gene zwf compensates for the CO2 sensitivity of msbB Salmonella. The msbB zwf mutants grow on agar, or in broth, in the presence of 5% CO2. In addition, msbB zwf strains show improved growth in low pH or high osmolarity media compared to the single msbB mutant. CONCLUSION: These results demonstrate that msbB confers acute sensitivity to CO2, acidic pH, and high osmolarity. Disruption of zwf in msbB mutants restores growth in 5% CO2 and results in improved growth in acidic media or in media with high osmolarity. These results add to a growing list of phenotypes caused by msbB and mutations that suppress specific growth defects.


Assuntos
Aciltransferases/genética , Dióxido de Carbono/farmacologia , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/genética , Proteínas de Bactérias/genética , Meios de Cultura , Regulação Bacteriana da Expressão Gênica , Glucosefosfato Desidrogenase/genética , Concentração de Íons de Hidrogênio , Mutagênese Insercional , Mutação , Salmonella typhimurium/efeitos dos fármacos
10.
Science ; 290(5489): 131-4, 2000 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-11021797

RESUMO

Benzodiazepine tranquilizers are used in the treatment of anxiety disorders. To identify the molecular and neuronal target mediating the anxiolytic action of benzodiazepines, we generated and analyzed two mouse lines in which the alpha2 or alpha3 GABAA (gamma-aminobutyric acid type A) receptors, respectively, were rendered insensitive to diazepam by a knock-in point mutation. The anxiolytic action of diazepam was absent in mice with the alpha2(H101R) point mutation but present in mice with the alpha3(H126R) point mutation. These findings indicate that the anxiolytic effect of benzodiazepine drugs is mediated by alpha2 GABAA receptors, which are largely expressed in the limbic system, but not by alpha3 GABAA receptors, which predominate in the reticular activating system.


Assuntos
Ansiolíticos/farmacologia , Diazepam/farmacologia , Receptores de GABA-A/metabolismo , Animais , Ansiolíticos/metabolismo , Comportamento Animal/efeitos dos fármacos , Sítios de Ligação , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Células Cultivadas , Diazepam/metabolismo , Relação Dose-Resposta a Droga , Feminino , Marcação de Genes , Hipocampo/citologia , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Técnicas de Patch-Clamp , Fenobarbital/farmacologia , Mutação Puntual , Células Piramidais/efeitos dos fármacos , Células Piramidais/fisiologia , Receptores de GABA-A/química , Receptores de GABA-A/genética , Transmissão Sináptica , Ácido gama-Aminobutírico/farmacologia
11.
Eat Behav ; 9(1): 91-101, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18167327

RESUMO

OBJECTIVE: The current study explored family and individual variables associated with dieting and binge eating. METHOD: 581 college females completed questionnaires exploring the amount of criticism and preoccupation with weight and food they experienced in their families, their current levels of depression, external attributions, and body esteem, and their degree of focus on dieting and binge eating. RESULTS: A structural equation model incorporating previous research and theoretical considerations was evaluated. The data were consistent with a model in which family variables were mediated by individual variables of depression, external attributions, and negative body esteem to predict dieting and bingeing. Dieting was influenced by all three individual variables, and in turn, dieting and depression were associated with binge eating. DISCUSSION: These results are consistent with an internalization model of family issues. Family dysfunction and values lead to depressive symptoms, external attributions, and negative body esteem. Dieting may be a "solution" that leads to additional eating problems such as binge eating when depression is present.


Assuntos
Bulimia Nervosa/genética , Comportamento Alimentar , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Universidades , Adolescente , Adulto , Afeto , Atitude , Bulimia Nervosa/epidemiologia , Bulimia Nervosa/psicologia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/epidemiologia , Transtorno Depressivo/psicologia , Família , Feminino , Preferências Alimentares , Humanos , Estudos Prospectivos , Autoimagem , Inquéritos e Questionários
12.
Med J Malaysia ; 63 Suppl A: 30-1, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19024968

RESUMO

A major factor limiting survival following extensive thermal injury is insufficient availability of donor sites to provide enough skin for the required grafting procedures. Limitation of autologous grafting promotes the usage of allograft skin substitutes to promote wound healing. Here, we investigated the wound healing potential of allograft single layered tissue engineered skin which comprises of either keratinocytes (SLTES-K) or fibroblast (SLTES-F) with fibrin as the delivery system. Results from gross and microscopic evaluation showed our single layered tissue engineered skin constructed with keratinocytes or fibroblast after gamma radiation with the dosage of 2Gy could serve as allograft for the treatment of skin loss.


Assuntos
Queimaduras/cirurgia , Fibrina/fisiologia , Fibroblastos/fisiologia , Queratinócitos/fisiologia , Transplante de Pele/instrumentação , Engenharia Tecidual/instrumentação , Transplante Homólogo/instrumentação , Cicatrização/fisiologia , Animais , Biópsia , Modelos Animais , Projetos Piloto , Carneiro Doméstico , Transplante de Pele/métodos , Engenharia Tecidual/métodos , Transplante Homólogo/métodos
13.
Eur J Hum Genet ; 26(6): 796-807, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511323

RESUMO

CHN is genetically heterogeneous and its genetic basis is difficult to determine on features alone. CNTNAP1 encodes CASPR, integral in the paranodal junction high molecular mass complex. Nineteen individuals with biallelic variants have been described in association with severe congenital hypomyelinating neuropathy, respiratory compromise, profound intellectual disability and death within the first year. We report 7 additional patients ascertained through exome sequencing. We identified 9 novel CNTNAP1 variants in 6 families: three missense variants, four nonsense variants, one frameshift variant and one splice site variant. Significant polyhydramnios occurred in 6/7 pregnancies. Severe respiratory compromise was seen in 6/7 (tracheostomy in 5). A complex neurological phenotype was seen in all patients who had marked brain hypomyelination/demyelination and profound developmental delay. Additional neurological findings included cranial nerve compromise: orobulbar dysfunction in 5/7, facial nerve weakness in 4/7 and vocal cord paresis in 5/7. Dystonia occurred in 2/7 patients and limb contractures in 5/7. All had severe gastroesophageal reflux, and a gastrostomy was required in 5/7. In contrast to most previous reports, only one patient died in the first year of life. Protein modelling was performed for all detected CNTNAP1 variants. We propose a genotype-phenotype correlation, whereby hypomorphic missense variants partially ameliorate the phenotype, prolonging survival. This study suggests that biallelic variants in CNTNAP1 cause a distinct recognisable syndrome, which is not caused by other genes associated with CHN. Neonates presenting with this phenotype will benefit from early genetic definition to inform clinical management and enable essential genetic counselling for their families.


Assuntos
Moléculas de Adesão Celular Neuronais/genética , Doença de Charcot-Marie-Tooth/genética , Deficiência Intelectual/genética , Adolescente , Doença de Charcot-Marie-Tooth/epidemiologia , Doença de Charcot-Marie-Tooth/fisiopatologia , Criança , Pré-Escolar , Exoma/genética , Feminino , Mutação da Fase de Leitura , Estudos de Associação Genética , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/fisiopatologia , Masculino , Fenótipo , Sobrevida
14.
Mol Cell Biol ; 14(11): 7546-56, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7935470

RESUMO

Growth factors and cyclic AMP (cAMP) are known to activate distinct intracellular signaling pathways. Fibroblast growth factor (FGF) activates ras-dependent kinase cascades, resulting in the activation of MAP kinases, whereas cAMP activates protein kinase A. In this study, we report that growth factors and cAMP act synergistically to stimulate proenkephalin gene expression. Positive synergy between growth factor- and cAMP-activated signaling pathways on gene expression has not been previously reported, and we suggest that these synergistic interactions represent a useful model for analyzing interactions between these pathways. Transfection and mutational studies indicate that both FGF-dependent gene activation and cAMP-dependent gene activation require cAMP response element 2 (CRE-2), a previously characterized cAMP-dependent regulatory element. Furthermore, multiple copies of this element are sufficient to confer FGF regulation upon a minimal promoter, indicating that FGF and cAMP signaling converge upon transcription factors acting at CRE-2. Among many different ATF/AP-1 factors tested, two factors, ATF-3 and c-Jun, stimulate proenkephalin transcription in an FGF- or Ras-dependent fashion. Finally, we show that ATF-3 and c-Jun form heterodimeric complexes in SK-N-MC cells and that the levels of both proteins are increased in response to FGF but not cAMP. Together, these results indicate that growth factor- and cAMP-dependent signaling pathways converge at CRE-2 to synergistically stimulate gene expression and that ATF-3 and c-Jun regulate proenkephalin transcription in response to both growth factor- and cAMP-dependent intracellular signaling pathways.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , AMP Cíclico/farmacologia , Fatores de Crescimento de Fibroblastos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fator 2 Ativador da Transcrição , Fator 3 Ativador da Transcrição , Sequência de Bases , Linhagem Celular , AMP Cíclico/administração & dosagem , AMP Cíclico/metabolismo , Primers do DNA/genética , Sinergismo Farmacológico , Encefalinas/genética , Fatores de Crescimento de Fibroblastos/administração & dosagem , Genes ras , Humanos , Dados de Sequência Molecular , Precursores de Proteínas/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ativação Transcricional , Transfecção
15.
Mol Cell Biol ; 14(7): 4958-74, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8007991

RESUMO

Human proenkephalin gene transcription is transactivated by human T-cell leukemia virus type I (HTLV-I) Tax in human Jurkat T lymphocytes. This transactivation was further enhanced in Jurkat cells treated with concanavalin A, cyclic AMP, or 12-O-tetradecanoylphorbol-13-acetate. Deletion and cis-element transfer analyses of the human proenkephalin promoter identified a cyclic AMP-responsive AP-1 element (-92 to -86) as both necessary and sufficient to confer Tax-dependent transactivation. Different AP-1 or cyclic AMP-responsive element-binding protein (CREB)/activating transcription factor (ATF) proteins which bind this element were expressed in murine teratocarcinoma F9 cells to identify those capable of mediating Tax-dependent transactivation of human proenkephalin gene transcription. Although CREB, c-Fos, c-Jun, and JunD did not have significant effects, JunB inhibited the Tax-dependent transactivation. In contrast, ATF3 dramatically induced Tax-dependent transactivation, which was further enhanced by protein kinase A. Electrophoretic mobility shift assays with recombinant fusion proteins expressed and purified from bacteria indicate that the DNA-binding activity of ATF3 is also dramatically enhanced by Tax. Chimeric fusion proteins consisting of the DNA-binding domain of the yeast transcription factor Gal4 and the amino-terminal domain (residues 1 to 66) of ATF3 were able to mediate Tax-dependent transactivation of a Gal4-responsive promoter, which suggests a direct involvement of this region of ATF3. Recombinant fusion proteins of glutathione S-transferase with either the amino- or carboxy-terminal (residues 139 to 181) domain of ATF3 were able to specifically interact with Tax. Furthermore, specific antisera directed against Tax coimmunoprecipitated ATF3 only in the presence of Tax.


Assuntos
AMP Cíclico/farmacologia , Encefalinas/biossíntese , Expressão Gênica , Produtos do Gene tax/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/genética , Regiões Promotoras Genéticas , Precursores de Proteínas/biossíntese , Fatores de Transcrição/metabolismo , Transcrição Gênica , Ativação Transcricional , Fator 3 Ativador da Transcrição , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Concanavalina A/farmacologia , Primers do DNA , Elementos Facilitadores Genéticos , Encefalinas/genética , Escherichia coli , Humanos , Dados de Sequência Molecular , Plasmídeos , Reação em Cadeia da Polimerase , Biossíntese de Proteínas , Precursores de Proteínas/genética , Proteínas Recombinantes de Fusão/biossíntese , Deleção de Sequência , Acetato de Tetradecanoilforbol , Fatores de Transcrição/biossíntese , Células Tumorais Cultivadas
16.
Mol Cell Biol ; 18(6): 3620-32, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9584203

RESUMO

Human T-cell leukemia virus type 1 is etiologically linked to the development of adult T-cell leukemia and various human neuropathies. The Tax protein of human T-cell leukemia virus type I has been implicated in cellular transformation. Like other oncoproteins, such as Myc, Jun, and Fos, Tax is a transcriptional activator. How it mechanistically dysregulates the cell cycle is unclear. Previously, it was suggested that Tax affects cell-phase transition by forming a direct protein-protein complex with p16(INK4a), thereby inactivating an inhibitor of G1-to-S-phase progression. Here we show that, in T cells deleted for p16(INK4a), Tax can compel an egress of cells from G0/G1 into S despite the absence of serum. We also show that in undifferentiated myocytes, expression of Tax represses cellular differentiation. In both settings, Tax expression was found to increase cyclin D-cdk activity and to enhance pRb phosphorylation. In T cells, a Tax-associated increase in steady-state E2F2 protein was also documented. In searching for a molecular explanation for these observations, we found that Tax forms a protein-protein complex with cyclin D3, whereas a point-mutated and transcriptionally inert Tax mutant failed to form such a complex. Interestingly, expression of wild-type Tax protein in cells was also correlated with the induction of a novel hyperphosphorylated cyclin D3 protein. Taken together, these findings suggest that Tax might directly influence cyclin D-cdk activity and function, perhaps by a route independent of cdk inhibitors such as p16(INK4a).


Assuntos
Ciclo Celular , Inibidor p16 de Quinase Dependente de Ciclina/antagonistas & inibidores , Quinases Ciclina-Dependentes/metabolismo , Produtos do Gene tax/metabolismo , Vírus Linfotrópico T Tipo 1 Humano , Proteínas Proto-Oncogênicas , Proteína do Retinoblastoma/metabolismo , Ciclina D3 , Quinase 4 Dependente de Ciclina , Ciclinas/metabolismo , Fator de Transcrição E2F2 , Ativação Enzimática , Sequências Hélice-Alça-Hélice , Humanos , Células Jurkat , Leucemia de Células T/metabolismo , Leucemia de Células T/virologia , Fatores de Transcrição/metabolismo
17.
Nat Biotechnol ; 17(1): 37-41, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9920266

RESUMO

Systemically administered tumor-targeted Salmonella has been developed as an anticancer agent, although its use could be limited by the potential induction of tumor necrosis factor alpha (TNFalpha)-mediated septic shock stimulated by lipid A. Genetic modifications of tumor-targeting Salmonella that alter lipid A and increase safety must, however, retain the useful properties of this bacteria. We report here that disruption of the Salmonella msbB gene reduces TNFalpha induction and increases the LD50 of this pathogenic bacteria by 10,000-fold. Notwithstanding this enormous difference, Salmonella retains its tumor-targeting properties, exhibiting tumor accumulation ratios in excess of 1000:1 compared with normal tissues. Administration of this bacteria to mice bearing melanoma results in tumors that are less than 6% the size of tumors in untreated controls at day 18. Thus, the antitumor activity previously demonstrated using tumor-targeting Salmonella with normal lipid A is retained. Lipid modification of tumor-specific bacterial vectors provides a means for reducing septic shock and further suggests that the antitumor activity of these bacteria may be independent of TNFalpha.


Assuntos
Aciltransferases , Proteínas de Escherichia coli , Lipídeo A/genética , Melanoma Experimental/terapia , Salmonella/fisiologia , Salmonella/patogenicidade , Neoplasias Cutâneas/terapia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Proteínas de Bactérias/genética , Sobrevivência Celular , Humanos , Lipídeo A/análogos & derivados , Fígado/microbiologia , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos , Transplante de Neoplasias , Respiração , Salmonella/genética , Salmonelose Animal/etiologia , Salmonelose Animal/prevenção & controle , Deleção de Sequência , Choque Séptico/microbiologia , Choque Séptico/prevenção & controle , Suínos , Virulência/genética
18.
Chemosphere ; 62(6): 961-7, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16081131

RESUMO

This study describes an investigation using tropical water lilies (Nymphaea spontanea) to remove hexavalent chromium from aqueous solutions and electroplating waste. The results show that water lilies are capable of accumulating substantial amount of Cr(VI), up to 2.119 mg g(-1) from a 10 mg l(-1) solution. The roots of the plant accumulated the highest amount of Cr(VI) followed by leaves and petioles, indicating that roots play an important role in the bioremediation process. The maturity of the plant exerts a great effect on the removal and accumulation of Cr(VI). Plants of 9 weeks old accumulated the most Cr(VI) followed by those of 6 and 3 weeks old. The results also show that removal of Cr(VI) by water lilies is more efficient when the metal is present singly than in the presence of Cu(II) or in waste solution. This may be largely associated with more pronounced phytotoxicity effect on the biochemical changes in the plants and saturation of binding sites. Significant toxicity effect on the plant was evident as shown in the reduction of chlorophyll, protein and sugar contents in plants exposed to Cr(VI) in this investigation.


Assuntos
Cromo/metabolismo , Nymphaea/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Metabolismo dos Carboidratos , Clorofila/metabolismo , Cromo/isolamento & purificação , Cromo/toxicidade , Cobre , Galvanoplastia , Resíduos Industriais , Nymphaea/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Proteínas/metabolismo , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/toxicidade
19.
Cancer Res ; 57(20): 4537-44, 1997 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-9377566

RESUMO

There has been little investigation of bacteria as gene delivery vectors. Here, we demonstrate that genetically engineered Salmonella have many of the desirable properties of a delivery vector, including targeting of multiple tumors from a distant inoculation site, selective replication within tumors, tumor retardation, and the ability to express effector genes, such as the herpes simplex virus thymidine kinase (HSV TK). When wild-type Salmonella were introduced into melanoma-bearing mice, the bacteria were found within the tumor at levels exceeding 10(9) per g, although as pathogens, they caused the death of the mice. However, when attenuated, hyperinvasive auxotrophic mutants were used, the tumor-targeting and amplification phenomena were retained, whereas their pathogenicity was limited. With such attenuated strains, the tumor:liver ratios ranged between 250:1 and 9000:1. When these auxotrophs were inoculated i.p. into C57B6 mice bearing B16F10 melanomas, they suppressed tumor growth and prolonged average survival to as much as twice that of untreated mice. A plasmid containing the HSV TK gene with a beta-lactamase secretion signal was constructed that, when expressed, resulted in translocation to the periplasm and phosphorylation of the prodrug ganciclovir. Melanoma-bearing animals inoculated with HSV TK-expressing Salmonella showed ganciclovir-mediated, dose-dependent suppression of tumor growth and prolonged survival in addition to that seen with bacteria alone. The results demonstrate that attenuated Salmonella would be useful both for inherent antitumor activity and delivery of therapeutic proteins to cancer cells in vivo.


Assuntos
Neoplasias da Mama/terapia , Neoplasias do Colo/terapia , Vetores Genéticos , Melanoma Experimental/terapia , Salmonella typhimurium/genética , Simplexvirus/genética , Timidina Quinase/biossíntese , Animais , Neoplasias da Mama/microbiologia , Neoplasias da Mama/patologia , Neoplasias do Colo/microbiologia , Neoplasias do Colo/patologia , Feminino , Engenharia Genética , Humanos , Melanoma Experimental/microbiologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Nus , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/biossíntese , Salmonella typhimurium/classificação , Salmonella typhimurium/ultraestrutura , Taxa de Sobrevida , Timidina Quinase/genética , Células Tumorais Cultivadas , beta-Lactamases/biossíntese
20.
Methods Mol Biol ; 1409: 95-123, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26846806

RESUMO

Tumor-targeted Salmonella offers a promising approach to the delivery of therapeutics for the treatment of cancer. The Salmonella strains used, however, must be stably attenuated in order to provide sufficient safety for administration. Approaches to the generation of attenuated Salmonella strains have included deletion of the msbB gene that is responsible for addition of the terminal myristol group to lipid A. In the absence of myristoylation, lipid A is no longer capable of inducing septic shock, resulting in a significant enhancement in safety. However, msbB Salmonella strains also exhibit an unusual set of additional physiological characteristics, including sensitivities to NaCl, EGTA, deoxycholate, polymyxin, and CO2. Suppressor mutations that compensate for these sensitivities include somA, Suwwan, pmrA (C), and zwf. We describe here methods for isolation of strains with compensatory mutations that suppress these types of sensitivities and techniques for determining their underlying genetic changes and analysis of their effects in murine tumor models.


Assuntos
Proteínas de Bactérias/genética , Mutação , Salmonella typhimurium/genética , Animais , Dióxido de Carbono/metabolismo , Mapeamento Cromossômico , Clonagem Molecular , Elementos de DNA Transponíveis , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Humanos , Camundongos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/terapia , Salmonella typhimurium/metabolismo , Carga Tumoral
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