RESUMO
OBJECTIVES: To perform a comprehensive population genetic study of PARK2. PARK2 mutations are associated with juvenile parkinsonism, Alzheimer disease, cancer, leprosy, and diabetes mellitus, yet ironically, there has been no comprehensive study of PARK2 in control subjects; and to resolve controversial association of PARK2 heterozygous mutations with Parkinson disease (PD) in a well-powered study. METHODS: We studied 1,686 control subjects (mean age 66.1 ± 13.1 years) and 2,091 patients with PD (mean onset age 58.3 ± 12.1 years). We tested for PARK2 deletions/multiplications/copy number variations (CNV) using semiquantitative PCR and multiplex ligation-dependent probe amplification, and validated the mutations by real-time quantitative PCR. Subjects were tested for point mutations previously. Association with PD was tested as PARK2 main effect, and in combination with known PD risk factors: SNCA, MAPT, APOE, smoking, and coffee intake. RESULTS: A total of 0.95% of control subjects and 0.86% of patients carried a heterozygous CNV mutation. CNV mutations found in 16 control subjects were all in exons 1-4, sparing exons that encode functionally critical protein domains. Thirteen patients had 2 CNV mutations, 5 had 1 CNV and 1 point mutation, and 18 had 1 CNV mutation. Mutations found in patients spanned exons 2-9. In whites, having 1 CNV was not associated with increased risk (odds ratio 1.05, p = 0.89) or earlier onset of PD (64.7 ± 8.6 heterozygous vs 58.5 ± 11.8 normal). CONCLUSIONS: This comprehensive population genetic study in control subjects fills the void for a PARK2 reference dataset. There is no compelling evidence for association of heterozygous PARK2 mutations, by themselves or in combination with known risk factors, with PD.
Assuntos
Variações do Número de Cópias de DNA/genética , Predisposição Genética para Doença , Doença de Parkinson/genética , Deleção de Sequência/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Fatores Etários , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Feminino , Frequência do Gene , Testes Genéticos/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/etiologia , Valores de Referência , Estatísticas não ParamétricasRESUMO
Human paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated serum enzyme that exhibits a broad substrate specificity. In addition to protecting against exposure to some organophosphorus (OP) pesticides by hydrolyzing their toxic oxon metabolites, PON1 is important in protecting against vascular disease by metabolizing oxidized lipids. Recently, PON1 has also been shown to play a role in inactivating the quorum sensing factor N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL) of Pseudomonas aeruginosa. Native, untagged engineered recombinant human PON1 (rHuPON1) expressed in Escherichia coli and purified by conventional column chromatographic purification is stable, active, and capable of protecting PON1 knockout mice (PON1(-/-)) from exposure to high levels of the OP compound diazoxon. The bacterially derived rHuPON1 can be produced in large quantities and lacks the glycosylation of eukaryotic systems that can produce immunogenic complications when inappropriately glycosylated recombinant proteins are used as therapeutics. Previous studies have shown that the determination of PON1 status, which reveals both PON1(192) functional genotype and serum enzyme activity level, is required for a meaningful evaluation of PON1's role in risk of disease or exposure. We have developed a new two-substrate assay/analysis protocol that provides PON1 status without use of toxic OP substrates, allowing for use of this protocol in non-specialized laboratories. Factors were also determined for inter-converting rates of hydrolysis of different substrates. PON1 status also plays an important role in revealing changes in HDL-associated PON1 activities in male patients with Parkinson disease (PD). Immunolocalization studies of PONs 1, 2 and 3 in nearly all mouse tissues suggest that the functions of PONs 1 and 3 extend beyond the plasma and the HDL particle.
Assuntos
Arildialquilfosfatase/metabolismo , Doença , Exposição Ambiental/efeitos adversos , Intoxicação por Organofosfatos , Animais , Arildialquilfosfatase/genética , Arildialquilfosfatase/uso terapêutico , Biomarcadores/metabolismo , Humanos , RiscoRESUMO
LRRK2 G2019S is the most common known cause of Parkinson disease (PD) in patients of European origin, but little is known about its distribution in other populations. The authors identified two of 586 Japanese patients with PD heterozygous for the mutation who shared a haplotype distinct from that observed in Europeans. This suggests that G2019S originated from separate founders in Europe and Japan and is more widely dispersed than previously recognized.
Assuntos
Haplótipos/genética , Doença de Parkinson/epidemiologia , Doença de Parkinson/genética , Proteínas Serina-Treonina Quinases/genética , Medição de Risco/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , Feminino , Marcadores Genéticos/genética , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Humanos , Japão/epidemiologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Masculino , Pessoa de Meia-Idade , Mutação , Prevalência , Fatores de Risco , Washington/epidemiologiaRESUMO
Referral-based studies indicate that a mutation (G2019S) in exon 41 of the LRRK2 gene might be a common cause of Parkinson disease (PD). The authors sequenced leucine-rich repeat kinase 2 (LRRK2) exons 31, 35, and 41 in 371 consecutively recruited patients with PD and found mutations in six (1.6%) subjects, including two heterozygous for new putative pathogenic variants (R1441H, IVS31 + 3A-->G). These data confirm the important contribution of LRRK2 to PD susceptibility in a clinic-based population.
Assuntos
Predisposição Genética para Doença/genética , Mutação/genética , Doença de Parkinson/genética , Proteínas Serina-Treonina Quinases/genética , Idoso , Análise Mutacional de DNA , Éxons/genética , Saúde da Família , Feminino , Frequência do Gene/genética , Testes Genéticos , Genótipo , Heterozigoto , Homozigoto , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/metabolismo , LinhagemRESUMO
This pilot study measured and examined the relationship between surface dust, deep dust, lead (Pb), and the 3-spot test during vacuuming of carpets. The 3-spot test measures the total time in seconds for the indicator light on a Hoover vacuum with dirt detector (HVDD) to turn from red to green on three spots 3 feet apart at least 4 feet from an entrance door. Ten older carpets were sampled in the Seattle area by using the following: (1) a 3-spot test to estimate the deep dust; (2) measuring the surface dust in g/m(2) with the High-Volume Small Simplified Surface Sampler; (3) vacuuming with an HVDD to extract a portion of the deep dust in g/m(2); and (4) repeating this cycle of a 3-spot test, surface dust sample, and deep dust sample until the clean-carpet criteria was reached. Dust particles <150 mum were analyzed for Pb. The surface dust, deep dust, and dust collection rate (g/min) decreased rapidly at first and then much more slowly as vacuuming continued. The initial 3-spot test ranged from 12 to 110 seconds (median 40). The starting surface dust loading was 0.7 to 21.1 g/m(2) (median 2.9 g/m(2)), and it decreased by 84% to 99% when the deep dust was removed. Total dust-the sum of the surface dust and deep dust-ranged from 8.3 to 465 g/m(2) (median 63.2 g/m(2)). It took from 2.3 to 92 min/m(2) (median of 7.5 min/m(2)) to remove the total dust. The starting dust collection rate of 3.8 to 37 g/min decreased to final rates of 0.5 to 4.3 g/min. The 3-spot test (seconds) correlated with total dust (g/m(2)) (r = 0.63, p = 0.037) and cleaning time (min/m(2)) (r = 0.50, p = 0.12) when the data were log transformed. This study supports the utility of the 3-spot test. It tends to provide families and professional carpet cleaners with a quick and low-cost estimate of the deep dust present and the time required to clean carpets as well as indicating when the carpet is clean. Deep dust tends to accumulate in older carpets and becomes surface and airborne dust after activity on a carpet. Monitoring and removing the deep dust in old carpets may decrease the exposure of infants and sensitive adults to Pb, allergen, and other pollutants in house dust.
Assuntos
Poeira/análise , Pisos e Cobertura de Pisos , Utensílios Domésticos , Chumbo/análise , Monitoramento Ambiental , Humanos , Projetos Piloto , Fatores de TempoRESUMO
OBJECTIVE: To assess cognitive and affective functioning in patients with essential tremor (ET). BACKGROUND: ET is traditionally thought to occur in isolation, without other neurologic abnormalities or cognitive changes. Recent evidence of gait disturbance and bradykinesia in these patients suggests that the neurologic abnormalities in ET may be more widespread than was once thought. Cognitive function in these patients has not been the subject of in-depth study. METHODS: Cognitive performance and mood were assessed in 18 consecutive patients with ET and 18 consecutive patients with PD who visited the neurosurgical clinic for surgical treatment of their symptoms. RESULTS: The patients with ET were found to have deficits on tests of verbal fluency, naming, mental set-shifting, verbal memory, and working memory, as well as higher levels of depression. In contrast to these areas of deficit, their performance was better than that of the normative sample on several tests of verbal and nonverbal conceptualization and reasoning. Tremor severity was not correlated with cognitive deficits. Patients with PD had deficits on the same tests that were impaired in the ET group and on tests of visuospatial processes. Direct comparison of the ET and PD groups showed greater impairment in facial perception in the PD group and greater impairment in verbal fluency and working memory in the ET group. CONCLUSION: Patients with ET have deficits in specific aspects of neuropsychological functioning, particularly those thought to rely on the integrity of the prefrontal cortex, which suggests involvement of frontocerebellar circuits in this disease.
Assuntos
Transtornos Cognitivos/psicologia , Tremor Essencial/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos/estatística & dados numéricos , Doença de Parkinson/psicologia , Análise de RegressãoRESUMO
The structure of an intermediate in the initiation to elongation transition of Escherichia coli RNA polymerase has been visualized through region-specific DNA cleavage by the hydroxyl radical reagent FeBABE. FeBABE was tethered to specific sites of the final sigma(70) subunit and incorporated into two specialized paused elongation complexes that obligatorily retain the final sigma(70) initiation subunit and are targets for modification by lambdoid phage late gene antiterminators. The FeBABE cleavage pattern reveals structures similar to open complex, except for notable changes to region 3 of final sigma(70) that might reflect the presence of stably bound transcript. Binding of the antiterminator protein Q displaces the reactivity of FeBABE conjugated to region 4 of final sigma(70), suggesting that final sigma(70) subunit rearrangement is a step in conversion of RNAP to the antiterminating form.
Assuntos
Bacteriófago lambda/metabolismo , RNA Polimerases Dirigidas por DNA/genética , Fatores de Alongamento de Peptídeos/metabolismo , Proteínas Virais/metabolismo , Bacteriófago lambda/genética , Sequência de Bases , DNA Viral , Dados de Sequência Molecular , Regiões Promotoras GenéticasRESUMO
Using the SCID-human model, we recently found that human circulating prostate cancer cells formed tumors in human bone but not mouse bone (Nemeth et al. Cancer Res 1999; 59: 1987-93). It is possible that this tissue preference was mediated by interaction between human tumor cells and human endothelial cells within the implanted bone tissue. We sought to determine the relative amounts of human and mouse vasculature within human bone implants and resulting prostate cancer bone tumors in the SCID-human model. Paraffin sections of plain bone implants or PC3 or LNCaP human bone tumors were double stained for factor VIII (all vessels) and human CD31 (human vessels) followed by fluorescent secondary reagents. At 4 weeks post implantation (when cancer cells are typically introduced), the vasculature within human bone fragments remained primarily human (84.5%), and this pattern persisted to at least 10 weeks (91.6% human). Injection of PC3 cells into the bone resulted in an increase in mouse-derived vessels, however the majority (58%) of the vessels remained human even after the formation of large bone tumors. LNCaP bone tumors were highly angiogenic, and there was a sharp decline in the proportion of vessels which were antigenically human (36.8%), suggesting recruitment of mouse endothelial cells during the angiogenic process. Nonetheless, the persistence of human vasculature suggests the SCID-human model can be used to study the interaction between bone-seeking tumor cells, such as prostate cancer, and human bone endothelium in vivo, and to test potential therapeutic strategies which may depend on the presence of human vessels.
Assuntos
Neoplasias Ósseas/secundário , Endotélio Vascular/patologia , Neoplasias da Próstata/patologia , Animais , Neoplasias Ósseas/irrigação sanguínea , Fator VIII/imunologia , Humanos , Masculino , Camundongos , Camundongos SCID , Transplante de Neoplasias , Células Neoplásicas Circulantes , Molécula-1 de Adesão Celular Endotelial a Plaquetas/imunologiaRESUMO
Gre proteins of prokaryotes, and SII proteins of eukaryotes and archaea, are transcription elongation factors that promote an endogenous transcript cleavage activity of RNA polymerases; this process promotes elongation through obstructive regions of DNA, including transcription pauses that act as sites of genetic regulation. We show that a regulatory pause in the early part of the late gene operon of bacteriophage lambda is subject to such cleavage and resynthesis. In cells lacking the cleavage factors GreA and GreB, the pause is prolonged, and RNA polymerase occupies a variant position at the pause site. Furthermore, GreA and GreB are required to mediate efficient function of the lambda gene Q antiterminator at this site. Thus, cleavage factors are necessary for the natural progression of RNA polymerase in vivo.
Assuntos
Proteínas de Bactérias/metabolismo , Bacteriófago lambda/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas de Escherichia coli , Regulação Viral da Expressão Gênica , Fatores de Transcrição/metabolismo , Transcrição Gênica/genética , Proteínas de Bactérias/genética , Sequência de Bases , Pegada de DNA , RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/virologia , Genes Virais/genética , Cinética , Modelos Genéticos , Dados de Sequência Molecular , Mutação/genética , Nucleotídeos/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Fatores de Transcrição/genética , Fatores de Elongação da Transcrição , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
The sigma subunit of eubacterial RNA polymerase is required throughout initiation, but how it communicates with core polymerase (alpha(2)betabeta') is poorly understood. The present work addresses the location and function of the interface of sigma with core. Our studies suggest that this interface is extensive as mutations in six conserved regions of sigma(70) hinder the ability of sigma to bind core. Direct binding of one of these regions to core can be demonstrated using a peptide-based approach. The same regions, and even equivalent residues, in sigma(32) and sigma(70) alter core interaction, suggesting that sigma(70) family members use homologous residues, at least in part, to interact with core. Finally, the regions of sigma that we identify perform specialized functions, suggesting that different portions of the interface perform discrete roles during transcription initiation.
Assuntos
Proteínas de Bactérias/química , RNA Polimerases Dirigidas por DNA/química , Proteínas de Choque Térmico/química , RNA Polimerase I/química , Fator sigma/química , Fatores de Transcrição/química , Transcrição Gênica , Sequência de Aminoácidos , Substituição de Aminoácidos , Proteínas de Bactérias/metabolismo , Sítios de Ligação , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Proteínas de Choque Térmico/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , RNA Polimerase I/metabolismo , Proteínas Recombinantes de Fusão/química , Fator sigma/genética , Fator sigma/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Gene expression is modulated by regulatory elements that influence transcription elongation by RNA polymerase: terminators that disrupt the elongation complex and release RNA, and regulators that overcome termination signals. RNA release from Escherichia coli RNA polymerase can be induced by a complementary oligonucleotide that replaces the upstream half of the RNA hairpin stem of intrinsic terminator transcripts, implying that RNA hairpins act by extracting RNA from the transcription complex. A transcription antiterminator inhibits this activity of oligonucleotides and therefore protects the elongation complex from destabilizing attacks on the emerging transcript. These effects illuminate the structure of the complex and the mechanism of transcription termination.
Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/genética , RNA Mensageiro/metabolismo , Regiões Terminadoras Genéticas , Transcrição Gênica , Proteínas Virais/metabolismo , Pareamento de Bases , Sequência de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/metabolismo , Modelos Genéticos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/metabolismo , RNA Bacteriano/química , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Mensageiro/química , RNA Mensageiro/genética , Moldes GenéticosRESUMO
The sigma initiation factor sigma70 of Escherichia coli acts not only in promoter recognition and DNA strand opening, but also to mediate the transformation of RNA polymerase (RNAP) to an antiterminating form by the phage lambda gene Q protein. Q is able to bind and modify RNAP when alpha70, still present in the initially elongating enzyme, recognizes a repeat of the -10 promoter element and induces a transcription pause. We have isolated mutations in the rpoD gene for sigma70 that impair Q function because they reduce the ability of sigma70 to recognize the downstream pause site. These mutations identify a locus of sigma70 that is important for the formation and stability of open promoter complex, likely because it mediates protein interactions with RNAP core.
Assuntos
Bacteriófago lambda/genética , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/fisiologia , Terminação Traducional da Cadeia Peptídica/genética , Regiões Promotoras Genéticas , Fator sigma/genética , Fator sigma/fisiologia , Proteínas Virais/metabolismo , Substituição de Aminoácidos/genética , Asparagina/genética , Ácido Aspártico/genética , Bacteriófago lambda/crescimento & desenvolvimento , Sequência de Bases , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Leucina/genética , Substâncias Macromoleculares , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese , Fenilalanina/genética , Ligação Proteica/genética , Fator sigma/metabolismo , Transcrição GênicaRESUMO
This study tested the hypothesis that stroke patients without a cardiac source of embolism suspected by clinical examination can be risk stratified by transesophageal echocardiography. Forty ischemic stroke patients without atrial fibrillation, prosthetic valves, ejection fraction < 20%, or recent myocardial infarction underwent multiplane transesophageal echocardiography: 24 (designated high risk) had > or = 1 of the following: left heart thrombus, vegetation, mass or spontaneous echo contrast, mobile ascending aortic or arch debris, patent foramen ovale, atrial septal defect or aneurysm, mitral annular calcification, mitral valve thickening, prolapse or mitral valve strands. End points were death, recurrent stroke, transient ischemic attack, myocardial infarction or peripheral embolism. Thirty-eight patients (95%) (23 high, 15 low risk) were followed for 14 +/- 8 months: 9 (24%) died of vascular causes including 4 who had a cardiac cause of death and 5 who had fatal strokes. Eight had recurrent strokes (4 nonfatal) and 1 nonfatal myocardial infarction occurred. Cardiovascular survival was predicted by transesophageal echocardiography: survival rates were 92% (low risk) and 63% (high risk) at 24 months (p = 0.036). Left atrial enlargement was independently associated with death from stroke (fatal stroke occurred in 25% of those with atrial enlargement compared to 8% of those with normal atrial dimension, p < or = 0.03), as was left atrial spontaneous echo contrast (50% died vs 9% without contrast, p < or = 0.03). Left ventricular hypertrophy and aortic atherosclerosis were both associated with the risk of recurrent stroke (30% of patients with ventricular hypertrophy had recurrent stroke compared to 10% with normal wall thickness (p < or = 0.05); 30% with aortic atherosclerosis had a recurrent stroke compared to none with a normal aorta (p < or = 0.05). Thus, transesophageal echocardiography clearly identifies patients at a high risk for cardiovascular mortality and morbidity after stroke despite an unsuspected source of embolism by clinical examination.
Assuntos
Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/mortalidade , Ecocardiografia Transesofagiana , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Valor Preditivo dos Testes , Medição de Risco , Análise de SobrevidaAssuntos
Poluentes Atmosféricos , Benzeno , Exposição Ambiental , Habitação , Humanos , Praguicidas , População Urbana , Emissões de VeículosRESUMO
An apparatus that can characterize and visualize temporal dynamics of spatial light modulators (SLM's) and flat-panel displays is constructed and evaluated by use of a commercially available SLM. The apparatus is based on the stroboscopic video sampling method and has a temporal resolution of the order of microseconds, permitting measurement of a long event (>100ms) with a high signal-to-noise ratio. Experimental results demonstrate the visualization of the temporal image sequencing and addressing in an SLM.
Assuntos
Bacteriófago lambda/genética , Transcrição Gênica , Proteínas Virais/metabolismo , Bacteriófago lambda/metabolismo , Sequência de Bases , DNA Viral/química , DNA Viral/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/genética , Escherichia coli/virologia , Regulação Viral da Expressão Gênica , Modelos Genéticos , Modelos Moleculares , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Fator sigma/metabolismo , Proteínas Virais/químicaRESUMO
In transcription initiation, the DNA strands must be separated to expose the template to RNA polymerase. As the closed initiation complex is converted to an open one, specific protein-DNA interactions involving bases of the nontemplate strand form and stabilize the promoter complex in the region of unwinding. Specific interaction between RNA polymerase and the promoter in Escherichia coli was detected and quantified as the binding affinity of nontemplate oligonucleotide sequences. The RNA polymerase subunit sigma factor 70 contacted the bases of the nontemplate DNA strand through its conserved region 2; a mutation that affected promoter function altered the binding affinity of the oligonucleotide to the enzyme.
Assuntos
DNA Bacteriano/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/genética , Regiões Promotoras Genéticas , Fator sigma/metabolismo , Eletroforese em Gel de Poliacrilamida , Escherichia coli/metabolismo , Oligodesoxirribonucleotídeos/metabolismo , Ligação Proteica/efeitos da radiação , Moldes Genéticos , Raios UltravioletaRESUMO
Thirty-nine patients with Parkinson's disease (PD) were categorized into one of three subgroups using discriminant function analysis and three key indices from the California Verbal Learning Test (CVLT). Patients were classified as having one of three memory profiles: (a) a normal memory profile; (b) a memory profile often observed in patients with Huntington's disease (HD); or (c) a memory profile often observed in patients with Alzheimer's disease (AD). Twenty of the patients with PD were classified as having a normal profile, 10 as having an HD profile, and 9 as having an AD profile. The three subgroups did not differ on measures of global cognitive functioning, letter fluency, confrontation naming, or visuo-construction, suggesting that the patients with PD with an AD memory profile were not experiencing AD, per se. These results demonstrate that the memory deficits associated with PD can be similar to those found in patients with either HD or AD, and argues against the notion that the behavioral manifestations of PD are homogeneous.
Assuntos
Transtornos da Memória/psicologia , Doença de Parkinson/psicologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Transtornos da Memória/etiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/complicações , Fatores SocioeconômicosRESUMO
We used limited trypsin digestion to determine the domain organization of the Escherichia coli RNA polymerase sigma 70 subunit. Trypsin-resistant fragments containing sigma 70 conserved region 2 (sigma 70(2)), and carboxy-terminal fragments containing conserved regions 3 and 4 (sigma 70(3-4)) were identified by a combination of amino acid sequencing and mass spectrometry. The domains were studied for partial biochemical functions of sigma 70.sigma 70(2) bound core RNA polymerase competitively with intact sigma 70. In contrast to sigma 70(2) alone, the RNA polymerase holoenzyme formed with sigma 70(2) specifically bound a single-stranded DNA oligomer with a sequence corresponding to the non-template strand of the -10 promoter element (the Pribnow box). Sigma 70(2) also forms crystals that are suitable for X-ray analysis. Sigma 70(3-4) bound the T4 AsiA protein with high affinity. The epitope for T4 AsiA on sigma 70 was further localized to within sigma 70[551-608], comprising sigma conserved region 4.2.
Assuntos
RNA Polimerases Dirigidas por DNA/química , Escherichia coli/enzimologia , Fator sigma/química , Sequência de Aminoácidos , Bacteriófago T4/metabolismo , Ligação Competitiva , RNA Polimerases Dirigidas por DNA/metabolismo , Dados de Sequência Molecular , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Fator sigma/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Especificidade por Substrato , Moldes Genéticos , Transcrição Gênica , Tripsina/química , Proteínas Virais/metabolismoRESUMO
BACKGROUND: Stereotactic breast biopsy has been developed as a less invasive means of performing biopsy for mammographic abnormalities. METHODS: From July 1994 through June 1995, 103 women with mammographic abnormalities requiring biopsy were prospectively evaluated. RESULTS: Fifty-one women had open biopsy, and 52 women had stereotactic biopsy. The average age in both groups was 60 years. Pathology revealed malignancy in 12% of stereotactic biopsies and 13% of open biopsies. Complications occurred in 6% of the open biopsies and 4% of the stereotactic biopsies and were limited to hematomas or seromas. The average cost was $2400 for open biopsy and $650 for stereotactic biopsy (P < 0.01). One hundred and one patients returned for a follow-up mammogram within 6 months, and 1 patient in each group required a second biopsy, which revealed benign pathology. A Patient Satisfaction Survey revealed no significant differences in patient satisfaction between the two types of procedures. CONCLUSION: There were no differences between open and stereotactic biopsies in regards to diagnostic accuracy, complications, or patient satisfaction. A significant difference was noted in charges during the time frame of our study.