Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 206
Filtrar
1.
Matern Child Health J ; 24(10): 1308-1317, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32557133

RESUMO

OBJECTIVES: Despite health risks for themselves and their children, urban underserved women smoke at high rates postpartum. The postpartum period is a stressful transition time that presents unique barriers to sustained cessation. There is limited extant evidence of efficacious psychosocial programs to maintain postpartum smoking cessation. METHODS: Guided by the Cognitive-Social Health Information Processing model, we explored the feasibility of TxT2Commit, a text-messaging intervention designed to prevent postpartum smoking relapse. Participants (n = 43) received supportive cessation-focused text messages for one month postpartum. Using a convergent mixed method design, surveys and interviews assessed changes in psychosocial factors and smoking status through a three month follow-up. RESULTS: Participants reported satisfaction with TxT2Commit, rating text messages as helpful, understandable, supportive, and not bothersome. However, a majority of women (n = 28, 65.1%) relapsed by three months. Participants who stayed smoke free (i.e., non-relapsers) reported significantly less temptation to smoke at one and three months postpartum compared to relapsers (ps < .01). While relapsers had significantly less temptation at one month compared to baseline, temptation increased by three months (p < .01). Consistent with the quantitative results, qualitative interviews identified informational and coping needs, with continued temptation throughout the three months. Non-relapsers were able to manage temptation and reported greater support. CONCLUSIONS FOR PRACTICE: TxT2Commit demonstrates preliminary feasibility and acceptability among urban, underserved postpartum women. However, most participants relapsed by three months postpartum. Additional research is needed to identify targeted messaging to best help women avoid temptation and bolster support to stay smoke free in this uniquely stressful period.


Assuntos
Disparidades em Assistência à Saúde/estatística & dados numéricos , Gestantes/psicologia , Fumantes/psicologia , Abandono do Hábito de Fumar/psicologia , Prevenção do Hábito de Fumar/métodos , Envio de Mensagens de Texto/estatística & dados numéricos , Adulto , Estudos de Viabilidade , Feminino , Promoção da Saúde/métodos , Humanos , Entrevistas como Assunto , Pennsylvania , Período Pós-Parto , Pesquisa Qualitativa , Abandono do Hábito de Fumar/métodos , População Urbana , Populações Vulneráveis
2.
Eur J Cancer Care (Engl) ; 24(1): 28-38, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24467411

RESUMO

Patient participation in cancer clinical trials is low. Little is known about attitudinal barriers to participation, particularly among patients who may be offered a trial during an imminent initial oncology consult. The aims of the present study were to confirm the presence of proposed subscales of a recently developed cancer clinical trial attitudinal barriers measure, describe the most common cancer clinical trials attitudinal barriers, and evaluate socio-demographic, medical and financial factors associated with attitudinal barriers. A total of 1256 patients completed a survey assessing demographic factors, perceived financial burden, prior trial participation and attitudinal barriers to clinical trials participation. Results of a factor analysis did not confirm the presence of the proposed four attitudinal barriers subscale/factors. Rather, a single factor represented the best fit to the data. The most highly-rated barriers were fear of side-effects, worry about health insurance and efficacy concerns. Results suggested that less educated patients, patients with non-metastatic disease, patients with no previous oncology clinical trial participation, and patients reporting greater perceived financial burden from cancer care were associated with higher barriers. These patients may need extra attention in terms of decisional support. Overall, patients with fewer personal resources (education, financial issues) report more attitudinal barriers and should be targeted for additional decisional support.


Assuntos
Tomada de Decisões , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias/psicologia , Participação do Paciente/psicologia , Idoso , Ensaios Clínicos como Assunto , Estudos Transversais , Análise Fatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/terapia , Participação do Paciente/economia , Participação do Paciente/estatística & dados numéricos , Encaminhamento e Consulta , Inquéritos e Questionários
3.
Ecol Lett ; 16(5): 635-41, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23461543

RESUMO

Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km(-2) , unfenced populations require budgets in excess of $2000 km(-2) to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density-independent factors. Nearly half the unfenced lion populations may decline to near extinction over the next 20-40 years.


Assuntos
Carnívoros , Conservação dos Recursos Naturais/métodos , Leões , Densidade Demográfica , Animais , Conservação dos Recursos Naturais/economia , Gana , Humanos , Namíbia , Dinâmica Populacional , Setor Privado , África do Sul
4.
Psychooncology ; 22(3): 481-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22331643

RESUMO

BACKGROUND: Cancer clinical trials (CCTs) are important tools in the development of improved cancer therapies; yet, participation is low. Key psychosocial barriers exist that appear to impact a patient's decision to participate. Little is known about the relationship among knowledge, self-efficacy, preparation, decisional conflict, and patient decisions to take part in CCTs. OBJECTIVE: The purpose of this study was to determine if preparation for consideration of a CCT as a treatment option mediates the relationship between knowledge, self-efficacy, and decisional conflict. We also explored whether lower levels of decisional conflict are associated with greater likelihood of CCT enrollment. METHOD: In a pre-post test intervention study, cancer patients (N = 105) were recruited before their initial consultation with a medical oncologist. A brief educational intervention was provided for all patients. Patient self-report survey responses assessed knowledge, self-efficacy, preparation for clinical trial participation, decisional conflict, and clinical trial participation. RESULTS: Preparation was found to mediate the relationship between self-efficacy and decisional conflict (p = 0.003 for a test of the indirect mediational pathway for the decisional conflict total score). Preparation had a more limited role in mediating the effect of knowledge on decisional conflict. Further, preliminary evidence indicated that reduced decisional conflict was associated with increased clinical trial enrollment (p = 0.049). CONCLUSIONS: When patients feel greater CCT self-efficacy and have more knowledge, they feel more prepared to make a CCT decision. Reduced decisional conflict, in turn, is associated with the decision to enroll in a clinical trial. Our results suggest that preparation for decision-making should be a target of future interventions to improve participation in CCTs.


Assuntos
Ensaios Clínicos como Assunto/psicologia , Conflito Psicológico , Tomada de Decisões , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias/terapia , Autoeficácia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/psicologia , Educação de Pacientes como Assunto/métodos , Seleção de Pacientes
5.
bioRxiv ; 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38106192

RESUMO

Chromothripsis, the process of catastrophic shattering and haphazard repair of chromosomes, is a common event in cancer. Whether chromothripsis might constitute an actionable molecular event amenable to therapeutic targeting remains an open question. We describe recurrent chromothripsis of chromosome 21 in a subset of patients in blast phase of a myeloproliferative neoplasm (BP-MPN), which alongside other structural variants leads to amplification of a region of chromosome 21 in ∼25% of patients ('chr21amp'). We report that chr21amp BP-MPN has a particularly aggressive and treatment-resistant phenotype. The chr21amp event is highly clonal and present throughout the hematopoietic hierarchy. DYRK1A , a serine threonine kinase and transcription factor, is the only gene in the 2.7Mb minimally amplified region which showed both increased expression and chromatin accessibility compared to non-chr21amp BP-MPN controls. We demonstrate that DYRK1A is a central node at the nexus of multiple cellular functions critical for BP-MPN development, including DNA repair, STAT signalling and BCL2 overexpression. DYRK1A is essential for BP-MPN cell proliferation in vitro and in vivo , and DYRK1A inhibition synergises with BCL2 targeting to induce BP-MPN cell apoptosis. Collectively, these findings define the chr21amp event as a prognostic biomarker in BP-MPN and link chromothripsis to a druggable target.

6.
Carbon Balance Manag ; 15(1): 22, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33052488

RESUMO

BACKGROUND: Cities contribute more than 70% of global anthropogenic carbon dioxide (CO2) emissions and are leading the effort to reduce greenhouse gas (GHG) emissions through sustainable planning and development. However, urban greenhouse gas mitigation often relies on self-reported emissions estimates that may be incomplete and unverifiable via atmospheric monitoring of GHGs. We present the Hestia Scope 1 fossil fuel CO2 (FFCO2) emissions for the city of Baltimore, Maryland-a gridded annual and hourly emissions data product for 2010 through 2015 (Hestia-Baltimore v1.6). We also compare the Hestia-Baltimore emissions to overlapping Scope 1 FFCO2 emissions in Baltimore's self-reported inventory for 2014. RESULTS: The Hestia-Baltimore emissions in 2014 totaled 1487.3 kt C (95% confidence interval of 1158.9-1944.9 kt C), with the largest emissions coming from onroad (34.2% of total city emissions), commercial (19.9%), residential (19.0%), and industrial (11.8%) sectors. Scope 1 electricity production and marine shipping were each generally less than 10% of the city's total emissions. Baltimore's self-reported Scope 1 FFCO2 emissions included onroad, natural gas consumption in buildings, and some electricity generating facilities within city limits. The self-reported Scope 1 FFCO2 total of 1182.6 kt C was similar to the sum of matching emission sectors and fuels in Hestia-Baltimore v1.6. However, 20.5% of Hestia-Baltimore's emissions were in sectors and fuels that were not included in the self-reported inventory. Petroleum use in buildings were omitted and all Scope 1 emissions from industrial point sources, marine shipping, nonroad vehicles, rail, and aircraft were categorically excluded. CONCLUSIONS: The omission of petroleum combustion in buildings and categorical exclusions of several sectors resulted in an underestimate of total Scope 1 FFCO2 emissions in Baltimore's self-reported inventory. Accurate Scope 1 FFCO2 emissions, along with Scope 2 and 3 emissions, are needed to inform effective urban policymaking for system-wide GHG mitigation. We emphasize the need for comprehensive Scope 1 emissions estimates for emissions verification and measuring progress towards Scope 1 GHG mitigation goals using atmospheric monitoring.

7.
Rev Sci Instrum ; 91(6): 063507, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611066

RESUMO

Magnetized Liner Inertial Fusion (MagLIF) at Sandia National Laboratories involves a laser preheating stage where a few-ns laser pulse passes through a few-micron-thick plastic window to preheat gaseous fusion fuel contained within the MagLIF target. Interactions with this window reduce heating efficiency and mix window and target materials into the fuel. A recently proposed idea called "Laser Gate" involves removing the window well before the preheating laser is applied. In this article, we present experimental proof-of-principle results for a pulsed-power implementation of Laser Gate, where a thin current-carrying wire weakens the perimeter of the window, allowing the fuel pressure to push the window open and away from the preheating laser path. For this effort, transparent targets were fabricated and a test facility capable of studying this version of Laser Gate was developed. A 12-frame bright-field laser schlieren/shadowgraphy imaging system captured the window opening dynamics on microsecond timescales. The images reveal that the window remains largely intact as it opens and detaches from the target. A column of escaping pressurized gas appears to prevent the detached window from inadvertently moving into the preheating laser path.

8.
Science ; 152(3721): 529-30, 1966 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-17815082

RESUMO

Typical elongate, beaded chromosomes have been observed in squash preparations of testicular tissue of the butterfly Speyeria aphrodite (Fabricius), the first demonstration of relatively uncondensed chromosomes in the Lepidoptera.

9.
J Child Orthop ; 13(4): 431-437, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31489051

RESUMO

PURPOSE: The purpose of the study was to evaluate the reliability, review differences and assess patient satisfaction of electronic patient-reported outcome measures (PROMs) compared with paper PROMs. METHODS: Participants between 12 and 19 years of age with a knee-related primary complaint were randomized into two groups. Group 1 completed paper PROMs followed by electronic, while Group 2 received the electronic followed by paper. PROMs included the Pediatric International Knee Documentation Committee (Pedi-IKDC), Hospital for Special Surgery (HSS) Pediatric Functional Activity Brief Scale (HSS Pedi-FABS), Tegner Activity Level Scale, Visual Analogue Scale (VAS), PedsQL Teen and a satisfaction survey. RESULTS: In all, 87 participants were enrolled with one excluded due to incomplete PROMs. Of the 86 participants, 54 were female and 32 were male with an average age of 14.3 years (12 to 18). A high degree of reliability was found when comparing the paper and electronic versions of the Pedi-IKDC (0.946; p < 0.001), HSS Pedi-FABS (0.923; p < 0.001), PedsQL Teen (0.894; p < 0.001), Tegner Activity Level Scale before injury (0.848; p < 0.001) and the Tegner Activity Level Scale after (0.930; p < 0.001). Differences were noted between the VAS scores, with paper scores being significantly higher than electronic (5.3 versus 4.6; p < 0.001). While not significant, a trend was noted in which electronic PROMs took, overall, less time than paper (10.0 mins versus 11.2 mins; p = 0.096).Of all participants, 69.8% preferred the electronic PROMs, 67.4% felt they were faster, 93.0% stated they would complete forms at home prior to appointments and 91.8% were not concerned about the safety/privacy of electronic forms. CONCLUSION: PROMs captured electronically were reliable when compared with paper. Electronic PROMs may be quicker, will not require manual scoring and are preferred by patients. LEVEL OF EVIDENCE: II.

10.
Rev Sci Instrum ; 90(12): 124707, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31893831

RESUMO

The MAIZE Linear Transformer Driver consists of 40 capacitor-switch-capacitor "bricks" connected in parallel. When these 40 bricks are charged to ±100-kV and then discharged synchronously, the MAIZE facility generates a 1-MA current pulse with a 100-ns rise time into a matched load impedance. Discharging each of the capacitors in a brick is carried out by the breakdown of a spark-gap switch, a process that results in the emission of light. Monitoring this output light with a fiber optic coupled to a photomultiplier tube (PMT) and an oscilloscope channel provides information on switch performance and timing jitter-whether a switch fired early, late, or in phase with the other switches. However, monitoring each switch with a dedicated detector-oscilloscope channel can be problematic for facilities where the number of switches to be monitored (e.g., 40 on MAIZE) greatly exceeds the number of detector-oscilloscope channels available. The technique of using fibers to monitor light emission from switches can be optimized by treating a PMT as a binary digit or bit and using a combinatorial encoding scheme, where each switch is monitored by a unique combination of fiber-PMT-oscilloscope channels simultaneously. By observing the unique combination of fiber-PMT-oscilloscope channels that are turned on, the prefiring or late-firing of a single switch on MAIZE can be identified by as few as six PMT-oscilloscope channels. The number of PMT-oscilloscope channels, N, required to monitor X switches can be calculated by 2N = X + 1, where the number "2" is selected because the PMT-oscilloscope acts as a bit. In this paper, we demonstrate the use of this diagnostic technique on MAIZE. We also present an analysis of how this technique could be scaled to monitor the tens of thousands of switches proposed for various next generation pulsed power facilities.

11.
J Intellect Disabil Res ; 52(12): 1039-47, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18671809

RESUMO

BACKGROUND: The purpose of this study was to examine factors that predict life satisfaction in individuals with intellectual disabilities (ID). Two groups of variables were studied: life skills (interpersonal, instrumental and leisure) and higher-order predictors (social support, self-determination and productivity). METHOD: Fifty-six participants with ID were recruited from two community agencies in Wisconsin. Data were collected using both a self-report inventory, which was administered to each individual in an interview format, and a behaviour rating scale, which was completed by a knowledgeable staff member. Hierarchical regression was used to analyse the data. RESULTS: Both sets of variables were found to explain a significant amount of the variance in life satisfaction. Within the sets, social support and interpersonal skills were individually significantly associated with life satisfaction. CONCLUSION: It is hoped that the results of this study will help support providers organise services in such a way that maximises the life satisfaction of the consumers that they serve.


Assuntos
Deficiência Intelectual/psicologia , Qualidade de Vida/psicologia , Atividades Cotidianas/classificação , Atividades Cotidianas/psicologia , Adulto , Eficiência , Feminino , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/reabilitação , Relações Interpessoais , Atividades de Lazer , Masculino , Pessoa de Meia-Idade , Autonomia Pessoal , Reabilitação Vocacional , Apoio Social , Socialização
12.
Curr Biol ; 10(7): 383-92, 2000 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-10753744

RESUMO

BACKGROUND: Binocular rivalry refers to the alternating perceptual states that occur when the images seen by the two eyes are too different to be fused into a single percept. Logothetis and colleagues have challenged suggestions that this phenomenon occurs early in the visual pathway. They have shown that, in alert monkeys, neurons in the primary visual cortex continue to respond to their preferred stimulus despite the monkey reporting its absence. Moreover, they found that neural activity higher in the visual pathway is highly correlated with the monkey's reported percept. These and other findings suggest that the neural substrate of binocular rivalry must involve high levels, perhaps the same levels involved in reversible figure alternations. RESULTS: We present evidence that activation or disruption of a single hemisphere in human subjects affects the perceptual alternations of binocular rivalry. Unilateral caloric vestibular stimulation changed the ratio of time spent in each competing perceptual state. Transcranial magnetic stimulation applied to one hemisphere disrupted normal perceptual alternations when the stimulation was timed to occur at one phase of the perceptual switch, but not at the other. Furthermore, activation of a single hemisphere by caloric stimulation affected the perceptual alternations of a reversible figure, the Necker cube. CONCLUSIONS: Our findings suggest that interhemispheric switching mediates perceptual rivalry. Thus, competition for awareness in both binocular rivalry and reversible figures occurs between, rather than within, each hemisphere. This interhemispheric switch hypothesis has implications for understanding the neural mechanisms of conscious experience and also has clinical relevance as the rate of both types of perceptual rivalry is slow in bipolar disorder (manic depression).


Assuntos
Dominância Cerebral/fisiologia , Visão Binocular/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Tronco Encefálico/fisiologia , Temperatura Baixa , Corpo Caloso/fisiologia , Feminino , Lateralidade Funcional , Humanos , Magnetismo , Masculino , Pessoa de Meia-Idade , Modelos Neurológicos , Estimulação Física , Vestíbulo do Labirinto/fisiologia , Vias Visuais
13.
Neurogastroenterol Motil ; 19(7): 585-95, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17593140

RESUMO

The factors underlying the survival and maintenance of interstitial cells of Cajal (ICC) are not well understood. Loss of ICC is often associated with loss of neuronal nitric oxide synthase (nNOS) in humans, suggesting a possible link. The aim of this study was to determine the effect of neuronal NO on ICC in the mouse gastric body. The volumes of ICC were determined in nNOS(-/-) and control mice in the gastric body and in organotypic cultures using immunohistochemistry, laser scanning confocal microscopy and three-dimensional reconstruction. ICC numbers were determined in primary cell cultures after treatment with an NO donor or an NOS inhibitor. The volumes of myenteric c-Kit-immunoreactive networks of ICC from nNOS(-/-) mice were significantly reduced compared with control mice. No significant differences in the volumes of c-Kit-positive ICC were observed in the longitudinal muscle layers. ICC volumes were either decreased or unaltered in the circular muscle layer after normalization for the volume of circular smooth muscle. The number of ICC was increased after incubation with S-nitroso-N-acetylpenicillamine and decreased by N(G)-nitro-l-arginine. Neuronally derived NO modulates ICC numbers and network volume in the mouse gastric body. NO appears to be a survival factor for ICC.


Assuntos
Sistema Nervoso Entérico/citologia , Sistema Nervoso Entérico/enzimologia , Intestino Delgado/inervação , Óxido Nítrico Sintase Tipo I/metabolismo , Estômago/inervação , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Feminino , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos , Camundongos Mutantes , Músculo Liso/citologia , Músculo Liso/inervação , Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase Tipo I/antagonistas & inibidores , Óxido Nítrico Sintase Tipo I/genética , Nitroarginina/farmacologia , Técnicas de Cultura de Órgãos , Proteínas Proto-Oncogênicas c-kit/metabolismo , S-Nitroso-N-Acetilpenicilamina/farmacologia
14.
Mol Cell Biol ; 11(12): 6229-47, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1682801

RESUMO

We analyzed the upstream region of the GDH2 gene, which encodes the NAD-linked glutamate dehydrogenase in Saccharomyces cerevisiae, for elements important for the regulation of the gene by the nitrogen source. The levels of this enzyme are high in cells grown with glutamate as the sole source of nitrogen and low in cells grown with glutamine or ammonium. We found that this regulation occurs at the level of transcription and that a total of six sites are required to cause a CYC1-lacZ fusion to the GDH2 gene to be regulated in the same manner as the NAD-linked glutamate dehydrogenase. Two sites behaved as upstream activation sites (UASs). The remaining four sites were found to block the effects of the two UASs in such a way that the GDH2-CYC1-lacZ fusion was not expressed unless the cells containing it were grown under conditions favorable for the activity of both UASs. This complex regulatory system appears to account for the fact that GDH2 expression is exquisitely sensitive to glutamine, whereas the expression of GLN1, coding for glutamine synthetase, is not nearly as sensitive.


Assuntos
Regulação Fúngica da Expressão Gênica , Glutamato Desidrogenase/genética , Nitrogênio/metabolismo , Sequências Reguladoras de Ácido Nucleico , Saccharomyces cerevisiae/genética , Sequência de Aminoácidos , Amônia/metabolismo , Sequência de Bases , Clonagem Molecular , DNA Fúngico , Glutamato Desidrogenase/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico , Dados de Sequência Molecular , Biossíntese de Proteínas , RNA Fúngico/metabolismo , RNA Mensageiro/metabolismo , Mapeamento por Restrição , Saccharomyces cerevisiae/enzimologia , Transcrição Gênica
15.
Mol Cell Biol ; 11(9): 4455-65, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1652057

RESUMO

We found that cells of Saccharomyces cerevisiae have an elevated level of the NAD-dependent glutamate dehydrogenase (NAD-GDH; encoded by the GDH2 gene) when grown with a nonfermentable carbon source or with limiting amounts of glucose, even in the presence of the repressing nitrogen source glutamine. This regulation was found to be transcriptional, and an upstream activation site (GDH2 UASc) sufficient for activation of transcription during respiratory growth conditions was identified. This UAS was found to be separable from a neighboring element which is necessary for the nitrogen source regulation of the gene, and strains deficient for the GLN3 gene product, required for expression of NAD-GDH during growth with the activating nitrogen source glutamate, were unaffected for the expression of NAD-GDH during growth with activating carbon sources. Two classes of mutations which prevented the normal activation of NAD-GDH in response to growth with nonfermentable carbon sources, but which did not affect the nitrogen-regulated expression of NAD-GDH, were found and characterized. Carbon regulation of GDH2 was found to be normal in hxk2, hap3, and hap4 strains and to be only slightly altered in a ssn6 strain; thus, in comparison with the regulation of previously identified glucose-repressed genes, a new pathway appears to be involved in the regulation of GDH2.


Assuntos
Carbono/metabolismo , Citocromos c , Proteínas de Ligação a DNA , Glutamato Desidrogenase/genética , Proteínas Nucleares , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Northern Blotting , Clonagem Molecular , Grupo dos Citocromos c/genética , Proteínas Fúngicas/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Glucose/metabolismo , Glutamato Desidrogenase/metabolismo , Glicosídeo Hidrolases/genética , Mutação , NAD/metabolismo , Plasmídeos , Saccharomyces cerevisiae/enzimologia , beta-Frutofuranosidase
16.
Mol Cell Biol ; 7(1): 199-208, 1987 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3031459

RESUMO

A method for introducing specific mutations into the diploid Candida albicans by one-step gene disruption and subsequent UV-induced recombination was developed. The cloned C. albicans URA3 gene was disrupted with the C. albicans ADE2 gene, and the linearized DNA was used for transformation of two ade2 mutants, SGY-129 and A81-Pu. Both an insertional inactivation of the URA3 gene and a disruption which results in a 4.0-kilobase deletion were made. Southern hybridization analyses demonstrated that the URA3 gene was disrupted on one of the chromosomal homologs in 15 of the 18 transformants analyzed. These analyses also revealed restriction site dimorphism of EcoRI at the URA3 locus which provides a unique marker to distinguish between chromosomal homologs. This enabled us to show that either homolog could be disrupted and that disrupted transformants of SGY-129 contained more than two copies of the URA3 locus. The A81-Pu transformants heterozygous for the ura3 mutations were rendered homozygous and Ura- by UV-induced recombination. The homozygosity of a deletion mutant and an insertion mutant was confirmed by Southern hybridization. Both mutants were transformed to Ura+ with plasmids containing the URA3 gene and in addition, were resistant to 5-fluoro-orotic acid, a characteristic of Saccharomyces cerevisiae ura3 mutants as well as of orotidine-5'-phosphate decarboxylase mutants of other organisms.


Assuntos
Candida albicans/genética , Genes Fúngicos/efeitos da radiação , Mutação , Raios Ultravioleta , Candida albicans/efeitos da radiação , Enzimas de Restrição do DNA , DNA Fúngico/genética , DNA Fúngico/efeitos da radiação , Genótipo , Métodos , Mapeamento de Nucleotídeos
17.
Mol Cell Biol ; 7(1): 209-17, 1987 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3031460

RESUMO

A pool of Candida albicans RsaI fragments cloned onto a vector containing pBR322 sequences and the Candida ADE2 gene was used to transform a Candida ade2 mutant to adenine protrophy. A potential autonomously replicating sequence (ARS) in Candida DNA was identified by two criteria: instability of the selectable marker in the absence of selection and the presence of free plasmid in total DNA preparations. Plasmids carrying the ARS transformed C. albicans at a high frequency (200 to 1,000 ADE+ transformants per microgram of DNA), and Southern hybridization analysis of these transformants indicated that multiple copies of the plasmid sequences were present and that, although they were present in high-molecular-weight molecules, these sequences had not undergone rearrangement. Orthogonal field alternation gel electrophoresis indicated that the high-molecular-weight transforming sequences were not associated with any chromosome. The simplest interpretation to account for these data is that the transforming sequences are present as oligomers consisting of head-to-tail tandem repeats. The transformed strains occasionally yield stable segregants in which the transforming sequences are integrated into the chromosome as repeats. The Candida sequence responsible for the ARS phenotype was limited to a single 0.35-kilobase RsaI fragment which is present in one copy per haploid genome.


Assuntos
Candida albicans/genética , Replicação do DNA , Plasmídeos , Clonagem Molecular , Enzimas de Restrição do DNA , Escherichia coli/genética , Teste de Complementação Genética , Vetores Genéticos , Mutação , Hibridização de Ácido Nucleico , Tetra-Hidrofolato Desidrogenase/genética
18.
J Natl Cancer Inst ; 89(10): 703-8, 1997 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-9168185

RESUMO

BACKGROUND: Although the incidence of precancerous conditions of the cervix has recently been increasing, prompt initial and long-term follow-up care can effectively reduce unnecessary morbidity and mortality. For example, the 4-year survival rates among those individuals at greatest risk for cervical cancer (i.e., minority women of low socioeconomic status) approach 95% with early detection. Women who present with advanced disease have a much poorer outlook (0%-39% survival). Yet, high-risk individuals are least likely to adhere to recommended diagnostic regimens. PURPOSE: We tested the effectiveness of a brief telephone counseling intervention directed to low-income, inner-city women after they had received an abnormal Pap smear result. The women were counseled on the importance of having an initial and 6-month repeat follow-up diagnostic procedure (i.e., colposcopic examination of the cervix). METHODS: A randomized trial design was used to compare the effects on these women of telephone counseling with (n = 192) or without (n = 203) a booster counseling telephone call prior to the appointment for a repeat colposcopy 6 months later, with a telephone appointment confirmation/reminder call (n = 216) and with standard care (i.e., no telephone contact) (n = 217). The telephone counseling protocol probed for and addressed three psychologic barriers to adherence (i.e., attendance at appointment for colposcopy examination): 1) encoding/expectancy (e.g., did the patient understand her risk of developing cervical cancer?); 2) affective/emotional (e.g., was the woman worried about the condition and its consequences?); and 3) self-regulatory/practical (e.g., was the woman likely to forget medical appointments?). Logistic regression was used to analyze the effects of the intervention group and the type of psychologic barriers elicited on colposcopy adherence. RESULTS: The results of logistic regression analysis (using those who received an appointment confirmation/reminder telephone call as the comparison group) revealed that telephone counseling produced significantly higher adherence rates to the initial colposcopy visit compared with telephone confirmation (300 [76%] of 395 women versus 147 [68%] of 216; odds ratio [OR] = 1.50; 95% confidence interval [CI] = 1.04-2.17). Additionally, standard care resulted in significantly lower adherence rates than did telephone confirmation (109 [50%] of 217 women versus 147 [68%] of 216; OR = 0.47; 95% CI = 0.32-0.73). Regarding attendance at the 6-month repeat colposcopy appointments, the 80 patients who had received telephone counseling prior to the initial visit (and were recommended for follow-up colposcopy) were significantly more likely to adhere than were the 47 patients who had received telephone confirmation (49 [61%] of 80 women versus 17 [36.2%] of 47; OR = 2.70; 95% CI = 1.15-6.51). The 6-month adherence rates for patients in the telephone confirmation group and the standard care group (n = 30) were low and did not differ significantly (17 [36.2%] of 47 women versus nine [30.0%] of 30; OR = 1.08; 95% CI = 0.40-2.89). Forgetting medical appointments (OR = 0.31; 95% CI = 0.19-0.51) and having scheduling conflicts (OR = 0.45; 95% CI = 0.28-0.72) were also associated with lower rates of adherence. CONCLUSION: The use of telephone counseling appears to be an effective strategy for enhancing initial and long-term adherence to a follow-up cervical diagnostic procedure in a traditionally underserved population. Patients who respond to a positive Pap test result with a particular profile of psychologic barriers may require more intensive and targeted counseling interventions.


Assuntos
Aconselhamento/métodos , Grupos Minoritários , Teste de Papanicolaou , Cooperação do Paciente , Esfregaço Vaginal , Colposcopia , Emoções , Feminino , Humanos , Pobreza , Medicina Preventiva , Análise de Regressão , Fatores Socioeconômicos , Telefone
19.
Essays Biochem ; 34: 17-30, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10730186

RESUMO

The most common bacterial mechanism for resistance to mercuric-ion species involves intracellular reduction of Hg(II) to Hg(0). Key proteins of the pathway typically include: MerR, which regulates pathway expression; MerP, which protects the external environment; MerT or MerC, which transport Hg(II) species across the inner membrane; MerA, which catalyses reduction of Hg(II); and sometimes MerB, which catalyses cleavage of C-Hg bonds in organomercurials. Cysteine residues of varying number are arranged in each of the key proteins to optimize their unique roles in sensing (high affinity), transporting (exchangeability), and reducing (redox accessibility) Hg(II). Nature's regulator of this pathway, MerR, is an exquisitely sensitive, Hg(II)-binding, DNA-binding protein that holds the system primed for immediate transcription at the slightest influx of Hg(II).


Assuntos
Bactérias/metabolismo , Mercúrio/metabolismo , Compostos Organomercúricos/metabolismo , Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Resistência Microbiana a Medicamentos , Regulação Bacteriana da Expressão Gênica , Inativação Metabólica , Modelos Moleculares , Óperon
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA