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1.
Neurogastroenterol Motil ; 25(7): 567-e456, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23433238

RESUMO

BACKGROUND: Our objective is to evaluate the effect of gastric electrical stimulation (GES) on symptoms and quality of life for pediatric patients with functional dyspepsia (FD). METHODS: Twenty-four patients (16 female, median 15 years) were treated with GES for FD after a median of 24 months of symptoms (3 months-14 years). At baseline, 46% required tube feeds and 25% parenteral nutrition. Sixty percent had gastroparesis. The PedsQL GI Module (PedsQL) was completed for 18/24 both pre-/post-GES after a median of 8 months. Patients also completed the Symptom Monitor Worksheet (SMW) pre-/post-GES after a median of 6 months. Pre-/post-GES global health was also assessed. KEY RESULTS: Significant improvements were seen in multiple areas of the PedsQL, including stomach pain/upset, food/drink limits, heartburn/reflux, gas/bloating, patient worry, medication tolerance, and constipation (P < 0.05). A decrease was found in combined symptom severity/frequency based on SMW (P < 0.01). Improvements were made in all categories, including vomiting, nausea, early satiety, bloating, fullness, epigastric pain, and burning (P < 0.01). Improvements in PedsQL/SMW scores remained when analysis was limited to normal or delayed gastric emptying (P < 0.05, P < 0.05). Thirteen percent needed tube feeds and 13% parenteral nutrition after GES. Sixty-five percent reported that their health was much improved after GES vs 15% the same or worse. Five patients experienced complications, primarily mild abdominal discomfort. CONCLUSIONS & INFERENCES: In the largest series to date of pediatric patients who have undergone GES for FD, we found significant improvements in upper gastrointestinal symptoms, quality of life, and perception of global health. Patients were less dependent on tube feeding or parenteral nutrition.


Assuntos
Dispepsia/terapia , Terapia por Estimulação Elétrica/métodos , Qualidade de Vida , Adolescente , Criança , Pré-Escolar , Dispepsia/psicologia , Eletrodos Implantados , Feminino , Humanos , Masculino , Resultado do Tratamento
2.
Lupus ; 20(9): 912-20, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21562020

RESUMO

Therapeutic agents currently in use to treat systemic lupus erythematosus (SLE) are predominantly immunosuppressive agents with limited specificities. Multiple groups, including ours, have illustrated that inducing tolerance in SLE animal models ameliorates disease symptoms and increases survival. We examined if oral administration of a tolerogenic peptide could affect SLE disease progression. The pConsensus (pCons) peptide, based on protein sequences of anti-double stranded (anti-ds)DNA antibodies, induces tolerance through upregulation of regulatory T cells when administered intravenously. Six different forms of pCons, including multiple antigenic peptides (MAP) and cyclic peptides made up of L- and D-amino acids, at three different concentrations, were fed to BWF1 SLE-susceptible mice for 30 weeks. Mice fed 100 µg of L-MAP or D-MAP had less cumulative proteinuria and serum anti-dsDNA antibody levels than controls. In addition, animals in these groups also survived significantly longer than controls with a corresponding increase in serum transforming growth factor beta (TGFß, implying a protective role for pCons-induced regulatory T cells. Oral administration of a tolerogenic peptide is a safe, effective method for ameliorating SLE disease manifestations and prolonging survival in SLE-prone mice. Induction of oral tolerance using modified pCons peptides could lead to a novel targeted therapy for human SLE.


Assuntos
Anticorpos Antinucleares/biossíntese , Tolerância Imunológica/imunologia , Imunossupressores , Lúpus Eritematoso Sistêmico , Nefrite/tratamento farmacológico , Peptídeos , Administração Oral , Animais , Anticorpos Antinucleares/sangue , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/imunologia , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/patologia , Camundongos , Nefrite/patologia , Nefrite/fisiopatologia , Compostos Orgânicos , Peptídeos/administração & dosagem , Peptídeos/imunologia , Peptídeos/uso terapêutico , Taxa de Sobrevida , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/sangue , Fator de Crescimento Transformador beta/imunologia
3.
Lupus ; 19(8): 913-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20410156

RESUMO

Atherosclerosis is accelerated in people with systemic lupus erythematosus, and the presence of dysfunctional, pro-inflammatory high-density lipoproteins is a marker of increased risk. We developed a mouse model of multigenic lupus exposed to environmental factors known to accelerate atherosclerosis in humans - high-fat diet with or without injections of the adipokine leptin. BWF1 mice were the lupus-prone model; BALB/c were non-autoimmune controls. High-fat diet increased total serum cholesterol in both strains. In BALB/c mice, non-high-density lipoprotein cholesterol levels increased; they did not develop atherosclerosis. In contrast, BWF1 mice on high-fat diets developed increased quantities of high-density lipoproteins as well as elevated high-density lipoprotein scores, indicating pro-inflammatory high-density lipoproteins; they also developed atherosclerosis. In the lupus-prone strain, addition of leptin increased pro-inflammatory high-density lipoprotein scores and atherosclerosis, and accelerated proteinuria. These data suggest that environmental factors associated with obesity and metabolic syndrome can accelerate atherosclerosis and disease in a lupus-prone background.


Assuntos
Aterosclerose/imunologia , Gorduras na Dieta/imunologia , Leptina/imunologia , Lipoproteínas HDL/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Animais , Aterosclerose/sangue , Aterosclerose/etiologia , Aterosclerose/patologia , Dieta , Modelos Animais de Doenças , Feminino , Humanos , Lipoproteínas HDL/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/etiologia , Lúpus Eritematoso Sistêmico/patologia , Síndrome Metabólica/complicações , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NZB , Obesidade/complicações , Fatores de Risco
4.
Proc Natl Acad Sci U S A ; 107(13): 6112-7, 2010 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20224037

RESUMO

Point mutations in the phosphorylation domain of the Bcr-Abl fusion oncogene give rise to drug resistance in chronic myelogenous leukemia patients. These mutations alter kinase-mediated signaling function and phenotypic outcome. An information theoretic analysis of the correlation of phosphoproteomic profiling and transformation potency of the oncogene in different mutants is presented. The theory seeks to predict the leukemic transformation potency from the observed signaling by constructing a distribution of maximal entropy of site-specific phosphorylation events. The theory is developed with special reference to systems biology where high throughput measurements are typical. We seek sets of phosphorylation events most contributory to predicting the phenotype by determining the constraints on the signaling system. The relevance of a constraint is measured by how much it reduces the value of the entropy from its global maximum, where all events are equally likely. Application to experimental phospho-proteomics data for kinase inhibitor-resistant mutants shows that there is one dominant constraint and that other constraints are not relevant to a similar extent. This single constraint accounts for much of the correlation of phosphorylation events with the oncogenic potency and thereby usefully predicts the trends in the phenotypic output. An additional constraint possibly accounts for biological fine structure.


Assuntos
Oncogenes , Biologia de Sistemas , Sequência de Aminoácidos , Entropia , Proteínas de Fusão bcr-abl/química , Proteínas de Fusão bcr-abl/genética , Genes abl , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Fenótipo , Fosforilação , Mutação Puntual , Estrutura Terciária de Proteína , Proteínas Tirosina Quinases/química , Proteínas Tirosina Quinases/genética , Proteômica , Transdução de Sinais
5.
J Clin Microbiol ; 45(6): 1811-20, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17428932

RESUMO

The purpose of this study was to correlate inhibition zone diameters, in millimeters (agar diffusion disk method), with the broth dilution MICs or minimum effective concentrations (MECs) (CLSI M38-A method) of five antifungal agents to identify optimal testing guidelines for disk mold testing. The following disk diffusion testing parameters were evaluated for 555 isolates of the molds Absidia corymbifera, Aspergillus sp. (five species), Alternaria sp., Bipolaris spicifera, Fusarium sp. (three species), Mucor sp. (two species), Paecilomyces lilacinus, Rhizopus sp. (two species), and Scedosporium sp. (two species): (i) two media (supplemented Mueller-Hinton agar [2% dextrose and 0.5 microg/ml methylene blue] and plain Mueller-Hinton [MH] agar), (ii) three incubation times (16 to 24, 48, and 72 h), and (iii) seven disks (amphotericin B and itraconazole 10-microg disks, voriconazole 1- and 10-microg disks, two sources of caspofungin 5-microg disks [BBL and Oxoid], and posaconazole 5-microg disks). MH agar supported better growth of all of the species tested (24 to 48 h). The reproducibility of zone diameters and their correlation with either MICs or MECs (caspofungin) were superior on MH agar (91 to 100% versus 82 to 100%; R, 0.71 to 0.93 versus 0.53 to 0.96 for four of the five agents). Based on these results, the optimal testing conditions for mold disk diffusion testing were (i) plain MH agar; (ii) incubation times of 16 to 24 h (zygomycetes), 24 h (Aspergillus fumigatus, A. flavus, and A. niger), and 48 h (other species); and (iii) the posaconazole 5-microg disk, voriconazole 1-microg disk, itraconazole 10-microg disk (for all except zygomycetes), BBL caspofungin 5-microg disk, and amphotericin B 10-microg (zygomycetes only).


Assuntos
Antifúngicos/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/normas , Fungos/efeitos dos fármacos , Anfotericina B/farmacologia , Caspofungina , Meios de Cultura , Equinocandinas , Fungos/classificação , Fungos/crescimento & desenvolvimento , Itraconazol/farmacologia , Lipopeptídeos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Peptídeos Cíclicos/farmacologia , Pirimidinas/farmacologia , Reprodutibilidade dos Testes , Triazóis/farmacologia , Voriconazol
6.
J Clin Microbiol ; 44(12): 4353-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17050812

RESUMO

The Clinical and Laboratory Standards Institute (CLSI; formerly National Committee for Clinical Laboratory Standards, or NCCLS) M38-A standard for the susceptibility testing of filamentous fungi does not specifically address the testing of dermatophytes. In 2003, a multicenter study investigated the reproducibility of the microdilution method developed at the Center for Medical Mycology, Cleveland, Ohio, for testing the susceptibility of dermatophytes. Data from that study supported the introduction of this method for testing dermatophytes in the future version of the CLSI M38-A standard. In order for the method to be accepted by CLSI, appropriate quality control isolates needed to be identified. To that end, an interlaboratory study, involving the original six laboratories plus two additional sites, was conducted to evaluate potential candidates for quality control isolates. These candidate strains included five Trichophyton rubrum strains known to have elevated MICs to terbinafine and five Trichophyton mentagrophytes strains. Antifungal agents tested included ciclopirox, fluconazole, griseofulvin, itraconazole, posaconazole, terbinafine, and voriconazole. Based on the data generated, two quality control isolates, one T. rubrum isolate and one T. mentagrophytes isolate, were identified and submitted to the American Type Culture Collection (ATCC) for inclusion as reference strains. Ranges encompassing 95.2 to 97.9% of all data points for all seven drugs were established.


Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Testes de Sensibilidade Microbiana/normas , Controle de Qualidade , Padrões de Referência
7.
Antimicrob Agents Chemother ; 46(4): 947-57, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11897574

RESUMO

The incidence of fungal infections has increased dramatically, which has necessitated additional and prolonged use of the available antifungal agents. Increased resistance to the commonly used antifungal agents, primarily the azoles, has been reported, thus necessitating the discovery and development of compounds that would be effective against the major human fungal pathogens. The sterol biosynthetic pathway has proved to be a fertile area for antifungal development, and steps which might provide good targets for novel antifungal development remain. The sterol C-14 reductase, encoded by the ERG24 gene, could be an effective target for drug development since the morpholine antifungals, inhibitors of Erg24p, have been successful in agricultural applications. The ERG24 gene of Candida albicans has been isolated by complementation of a Saccharomyces cerevisiae erg24 mutant. Both copies of the C. albicans ERG24 gene have been disrupted by using short homologous regions of the ERG24 gene flanking a selectable marker. Unlike S. cerevisiae, the C. albicans ERG24 gene was not required for growth, but erg24 mutants showed several altered phenotypes. They were demonstrated to be slowly growing, with doubling times at least twice that of the wild type. They were also shown to be significantly more sensitive to an allylamine antifungal and to selected cellular inhibitors including cycloheximide, cerulenin, fluphenazine, and brefeldin A. The erg24 mutants were also slightly resistant to the azoles. Most importantly, erg24 mutants were shown to be significantly less pathogenic in a mouse model system and failed to produce germ tubes upon incubation in human serum. On the basis of these characteristics, inhibitors of Erg24p would be effective against C. albicans.


Assuntos
Antifúngicos/farmacologia , Candida albicans/enzimologia , Oxirredutases/efeitos dos fármacos , Oxirredutases/genética , Sequência de Aminoácidos , Animais , Antifúngicos/uso terapêutico , Cálcio/metabolismo , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Meios de Cultura , Sondas de DNA , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Escherichia coli/metabolismo , Feminino , Biblioteca Gênica , Genes Fúngicos/genética , Camundongos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Fenótipo , Plasmídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Esteróis/biossíntese , Transformação Bacteriana/genética
8.
Antimicrob Agents Chemother ; 44(8): 2081-5, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10898679

RESUMO

MIC end point determination for the most commonly prescribed azole antifungal drug, fluconazole, can be complicated by "trailing" growth of the organism during susceptibility testing by the National Committee for Clinical Laboratory Standards approved M27-A broth macrodilution method and its modified broth microdilution format. To address this problem, we previously developed the sterol quantitation method (SQM) for in vitro determination of fluconazole susceptibility, which measures cellular ergosterol content rather than growth inhibition after exposure to fluconazole. To determine if SQM MICs of fluconazole correlated better with in vivo outcome than M27-A MICs, we used a murine model of invasive candidiasis and analyzed the capacity of fluconazole to treat infections caused by C. albicans isolates which were trailers (M27-A MICs at 24 and 48 h, /=64 microg/ml, respectively; SQM MIC, /=64 microg/ml; SQM MIC, 54 microg/ml). Compared with the untreated controls, fluconazole therapy increased the survival of mice infected with a sensitive isolate and both trailing isolates but did not increase the survival of mice infected with a resistant isolate. These results indicate that the SQM is more predictive of in vivo outcome than the M27-A method for isolates that give unclear MIC end points due to trailing growth in fluconazole.


Assuntos
Antifúngicos/uso terapêutico , Candida albicans/metabolismo , Candidíase/tratamento farmacológico , Ergosterol/análise , Fluconazol/uso terapêutico , Animais , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candidíase/mortalidade , Modelos Animais de Doenças , Feminino , Fluconazol/farmacologia , Rim/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Estatística como Assunto , Resultado do Tratamento
9.
J Clin Microbiol ; 38(6): 2254-60, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10834985

RESUMO

The PASCO antifungal susceptibility test system, developed in collaboration with a commercial company, is a broth microdilution assay which is faster and easier to use than the reference broth microdilution test performed according to the National Committee for Clinical Laboratory Standards (NCCLS) document M27-A guidelines. Advantages of the PASCO system include the system's inclusion of quality-controlled, premade antifungal panels containing 10, twofold serial dilutions of drugs and a one-step inoculation system whereby all wells are simultaneously inoculated in a single step. For the prototype panel, we chose eight antifungal agents for in vitro testing (amphotericin B, flucytosine, fluconazole, ketoconazole, itraconazole, clotrimazole, miconazole, and terconazole) and compared the results with those of the NCCLS method for testing 74 yeast isolates (14 Candida albicans, 10 Candida glabrata, 10 Candida tropicalis, 10 Candida krusei, 10 Candida dubliniensis, 10 Candida parapsilosis, and 10 Cryptococcus neoformans isolates). The overall agreements between the methods were 91% for fluconazole, 89% for amphotericin B and ketoconazole, 85% for itraconazole, 80% for flucytosine, 77% for terconazole, 66% for miconazole, and 53% for clotrimazole. In contrast to the M27-A reference method, the PASCO method classified as resistant seven itraconazole-susceptible isolates (9%), two fluconazole-susceptible isolates (3%), and three flucytosine-susceptible isolates (4%), representing 12 major errors. In addition, it classified two fluconazole-resistant isolates (3%) and one flucytosine-resistant isolate (1%) as susceptible, representing three very major errors. Overall, the agreement between the methods was greater than or equal to 80% for four of the seven species tested (C. dubliniensis, C. glabrata, C. krusei, and C. neoformans). The lowest agreement between methods was observed for miconazole and clotrimazole and for C. krusei isolates tested against terconazole. When the data for miconazole and clotrimazole were removed from the analysis, agreement was >/=80% for all seven species tested. Therefore, the PASCO method is a suitable alternative procedure for the testing of the antifungal susceptibilities of the medically important Candida spp. and C. neoformans against a range of antifungal agents with the exceptions only of miconazole and clotrimazole and of terconazole against C. krusei isolates.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Meios de Cultura , Estudos de Avaliação como Assunto , Testes de Sensibilidade Microbiana/normas , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes
10.
Med Mycol ; 38 Suppl 1: 293-304, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11204157

RESUMO

As new antifungal agents are introduced for the treatment of infections caused by yeasts and filamentous fungi (moulds), it is important that reliable methods are available for the in vitro testing of both new and established agents. The ultimate goal of in vitro testing is the prediction of the clinical outcome of therapy. The use of the M27-A procedures that were developed by the US National Committee for Clinical Laboratory Standards (NCCLS) has led to increased interlaboratory agreement of minimum inhibitory concentrations (MICs) for yeasts and has facilitated the establishment of interpretive breakpoints for fluconazole and itraconazole. The clinical relevance and limitations of these breakpoints are discussed elsewhere. The focus of this paper is to review the advantages and disadvantages of the available methods for antifungal susceptibility testing of yeasts and moulds as well as the clinical implications of in vitro antifungal resistance.


Assuntos
Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Micoses/microbiologia , Resistência Microbiana a Medicamentos , Humanos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas
11.
Heart Lung ; 28(6): 409-17, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10580215

RESUMO

OBJECTIVE: To examine the differences in realization of expected benefits, complications, and quality of life (QOL) 3 months after percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG) surgery. DESIGN: Nonexperimental, prospective, and comparative. Before discharge, participants listed benefits expected from the procedure, as well as comorbid health problems (Charlson Comorbidity Index) and complications. At 3 months, they quantified their realization of expected benefits, reported postdischarge complications, and completed Ferrans and Powers' Quality of Life Index-Cardiac Version III. SAMPLE: 36 patients who had PTCA; 38 patients who had CABG. RESULTS: There were no differences between groups in realization of expected benefits or QOL. Patients who had CABG reported a greater number of complications after discharge, and a greater proportion of patients who had PTCA reported angina. Patients who had PTCA and then recurrent angina had significantly lower health QOL and psychologic and spiritual QOL. CONCLUSIONS: Patients who undergo CABG need guidance regarding what complications to expect, and patients who undergo PTCA need to know that recurrent angina is possible and how to manage it.


Assuntos
Angioplastia Coronária com Balão/psicologia , Ponte de Artéria Coronária/psicologia , Qualidade de Vida , Doença das Coronárias/psicologia , Doença das Coronárias/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Recidiva , Fatores de Tempo
12.
J Clin Microbiol ; 37(10): 3332-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10488201

RESUMO

MIC end points for the most commonly prescribed azole antifungal drug, fluconazole, can be difficult to determine because its fungistatic nature can lead to excessive "trailing" of growth during susceptibility testing by National Committee for Clinical Laboratory Standards broth macrodilution and microdilution methods. To overcome this ambiguity, and because fluconazole acts by inhibiting ergosterol biosynthesis, we developed a novel method to differentiate fluconazole-susceptible from fluconazole-resistant isolates by quantitating ergosterol production in cells grown in 0, 1, 4, 16, or 64 microg of fluconazole per ml. Ergosterol was isolated from whole yeast cells by saponification, followed by extraction of nonsaponifiable lipids with heptane. Ergosterol was identified by its unique spectrophotometric absorbance profile between 240 and 300 nm. We used this sterol quantitation method (SQM) to test 38 isolates with broth microdilution end points of /=64 microg/ml (resistant) and 10 isolates with trailing end points by the broth microdilution method. No significant differences in mean ergosterol content were observed between any of the isolates grown in the absence of fluconazole. However, 18 susceptible isolates showed a mean reduction in ergosterol content of 72% after exposure to 1 microg of fluconazole/ml, an 84% reduction after exposure to 4 microg/ml, and 95 and 100% reductions after exposure to 16 and 64 microg of fluconazole/ml, respectively. Ten SDD isolates showed mean ergosterol reductions of 38, 57, 73, and 99% after exposure to 1, 4, 16, and 64 microg of fluconazole/ml, respectively. In contrast, 10 resistant isolates showed mean reductions in ergosterol content of only 25, 38, 53, and 84% after exposure to the same concentrations of fluconazole. The MIC of fluconazole, by using the SQM, was defined as the lowest concentration of the drug which resulted in 80% or greater inhibition of overall mean ergosterol biosynthesis compared to that in the drug-free control. Of 38 isolates which gave clear end points by the broth microdilution method, the SQM MIC was within 2 dilutions of the broth microdilution MIC for 33 (87%). The SQM also discriminated between resistant and highly resistant isolates and was particularly useful for discerning the fluconazole susceptibilities of 10 additional isolates which gave equivocal end points by the broth microdilution method due to trailing growth. In contrast to the broth microdilution method, the SQM determined trailing isolates to be susceptible rather than resistant, indicating that the SQM may predict clinical outcome more accurately. The SQM may provide a means to enhance current methods of fluconazole susceptibility testing and may provide a better correlation of in vitro with in vivo results, particularly for isolates with trailing end points.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Ergosterol/análise , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana/métodos , Resistência Microbiana a Medicamentos , Reprodutibilidade dos Testes
13.
FEBS Lett ; 392(2): 161-5, 1996 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-8772195

RESUMO

Regulation of sterol biosynthesis in the terminal portion of the pathway represents an efficient mechanism by which the cell can control the production of sterol without disturbing the production of other essential mevalonate pathway products. We demonstrate that mutations affecting early and late steps in sterol homeostasis modulate the expression of the ERG3 gene: a late step in sterol biosynthesis in yeast. Expression of ERG3 is increased in response to a mutation in the major isoform of HMG CoA reductase which catalyzes the rate-limiting step of sterol biosynthesis. Likewise, mutations in non-auxotrophic ergosterol biosynthetic genes downstream of squalene production (erg2, erg3, erg4, erg5, and erg6) result in an up-regulation of ERG3 expression. Deletion analysis of the ERG3 promoter identified two upstream activation sequences: UAS1 which when deleted reduces ERG3 gene expression 3-4-fold but maintains sterol regulation and UAS2, which when deleted further reduces ERG3 expression and abolishes sterol regulation. The recent isolation of two yeast genes responsible for the esterification of intracellular sterol (ARE1 and ARE2) has enabled us to directly analyze the relationship between sterol esterification and de novo biosynthesis. Our results demonstrate that the absence of sterol esterification leads to a decrease in total intracellular sterol and ERG3 is a target of this negative regulation.


Assuntos
Quinases Ciclina-Dependentes , Ergosterol/metabolismo , Regulação Fúngica da Expressão Gênica , Oxirredutases/genética , Saccharomyces cerevisiae/genética , Aciltransferases/genética , Sequência de Bases , Quinase 8 Dependente de Ciclina , DNA Recombinante , Escherichia coli/genética , Esterificação , Proteínas Fúngicas/genética , Dados de Sequência Molecular , Mutação , Oxirredutases/metabolismo , Regiões Promotoras Genéticas , Proteínas de Saccharomyces cerevisiae , Esqualeno/metabolismo , Regulação para Cima
14.
Gene ; 169(1): 105-9, 1996 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-8635732

RESUMO

The ERG5 gene from Saccharomyces cerevisiae was cloned by complementation of an erg5-1 mutation using a negative selection protocol involving screening for nystatin-sensitive transformants. ERG5 is the putative gene encoding the C-22 sterol desaturase required in ergosterol biosynthesis. The functional gene was localized to a 2.15-kb SacI-EcoRI DNA fragment containing an open reading frame of 538 amino acids (aa). ERG5 contains a 10-aa motif consistent with its role as a cytochrome P-450 (CyP450) enzyme and is similar to a number of mammalian CyP450 enzymes. Gene disruption demonstrates that ERG5 is not essential for cell viability.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Ergosterol/biossíntese , Genes Fúngicos , Oxirredutases/genética , Saccharomyces cerevisiae/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Clonagem Molecular , Expressão Gênica , Dados de Sequência Molecular , Mapeamento por Restrição , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae , Homologia de Sequência de Aminoácidos
15.
Lipids ; 30(3): 221-6, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7791529

RESUMO

Research on the ergosterol biosynthetic pathway in fungi has focused on the identification of the specific sterol structure required for normal membrane structure and function and for completion of the cell cycle. The pathway and its end product are also the targets for a number of antifungal drugs. Identification of essential steps in ergo-sterol biosynthesis could provide new targets for the development of novel therapeutic agents. Nine of the eleven genes in the portion of the pathway committed exclusively to ergosterol biosynthesis have been cloned, and their essentiality for aerobic growth has been determined. The first three genes, ERG9 (squalene synthase), ERG1 (squalene epoxidase), and ERG7 (lanosterol synthase), have been cloned and found to be essential for aerobic viability since their absence would result in the cell being unable to synthesize a sterol molecule. The remaining eight genes encode enzymes which metabolize the first sterol, lanosterol, to ultimately form ergosterol. The two earliest genes, ERG11 (lanosterol demethylase) and ERG24 (C-14 reductase), have been cloned and found to be essential for aerobic growth but are suppressed by mutations in the C-5 desaturase (ERG3) gene and fen1 and fen2 mutations, respectively. The remaining cloned genes, ERG6 (C-24 methylase), ERG2 (D8AE7 isomerase), ERG3 (C-5 desaturase), and ERG4 (C-24(28) reductase), have been found to be nonessential. The remaining genes not yet cloned are the C-4 demethylase and the C-22 desaturase (ERG5).


Assuntos
Ergosterol/biossíntese , Genes Fúngicos/genética , Saccharomyces cerevisiae/genética , Clonagem Molecular , Lanosterol/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/metabolismo , Esqualeno/metabolismo , Fatores de Tempo
16.
J Cardiovasc Nurs ; 9(1): 1-15, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7996165

RESUMO

In light of the minimal follow-up care that cardiovascular patients typically receive and the few patients who enter cardiac rehabilitation programs, it is evident that these patients need more support resources to improve their health outcomes. A better understanding is needed of the basic support processes that occur after a cardiac event so that the different sources and types of support can be tapped for the desired outcome. This article highlights the research findings on social support for cardiovascular patients in light of various theoretical perspectives and provides implications for practice and future research.


Assuntos
Doenças Cardiovasculares/psicologia , Apoio Social , Doenças Cardiovasculares/enfermagem , Cuidadores/psicologia , Feminino , Humanos , Relações Interpessoais , Masculino , Cônjuges/psicologia
20.
NLN Publ ; (41-1985): 201-5, 1985 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3852219
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