Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 163
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-31406963

RESUMO

Background: 1.1.Neulasta Onpro kit eliminates need for additional clinic visit after chemotherapy. Given the racially diverse population in our institution, we investigated acceptance of Onpro kit among patients on chemotherapy. Research Design and Methods: 1.2.Single-institution, retrospective review conducted in patients with GI tumors who received Onpro kit within 1 hour of completion of systemic chemotherapy from Jan 2014 through Jan 2018. Clinic/nursing notes and pharmacy records were reviewed to identify patients who refused Onpro kit and to discern reasons for refusal, including racial reason. Results: 1.3.Total 238 orders for kit were voided amongst 68 patients (Caucasian 41; African American 7; Spanish 3; Asian 17). Overall, 15/68 patients refused kit (22%) of these 87% were Asian. The reasons for refusal included dislike of bulky attachment to skin, request to place kit on stomach instead of arm, trepidation over unwitnessed administration of drug, fear of reaction, disposal at home, fear of pain, lack of confirmation of proper dose administration, and need for MRI. Conclusions: 1.4.While Onpro kit is an attractive alternative, 22% of patients with voided orders, mainly of Asian race, declined its application. We believe the current study represents the first look at important racial differences in accepting Onpro kit. Consideration of patients' cultural heritage, race, ethnicity and education may facilitate communication between physicians and patients to achieve optimal cancer care.

2.
Philos Trans A Math Phys Eng Sci ; 365(1860): 2659-74, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17666381

RESUMO

Aerosols are known to influence significantly the radiative budget of the Earth. Although the direct effect (whereby aerosols scatter and absorb solar and thermal infrared radiation) has a large perturbing influence on the radiation budget, the indirect effect (whereby aerosols modify the microphysical and hence the radiative properties and amounts of clouds) poses a greater challenge to climate modellers. This is because aerosols undergo chemical and physical changes while in the atmosphere, notably within clouds, and are removed largely by precipitation. The way in which aerosols are processed by clouds depends on the type, abundance and the mixing state of the aerosols concerned. A parametrization with sulphate and sea-salt aerosol has been successfully integrated within the Hadley Centre general circulation model (GCM). The results of this combined parametrization indicate a significantly reduced role, compared with previous estimates, for sulphate aerosol in cloud droplet nucleation and, consequently, in indirect radiative forcing. However, in this bicomponent system, the cloud droplet number concentration, N(d) (a crucial parameter that is used in GCMs for radiative transfer calculations), is a smoothly varying function of the sulphate aerosol loading. Apart from sea-salt and sulphate aerosol particles, biomass aerosol particles are also present widely in the troposphere. We find that biomass smoke can significantly perturb the activation and growth of both sulphate and sea-salt particles. For a fixed salt loading, N(d) increases linearly with modest increases in sulphate and smoke masses, but significant nonlinearities are observed at higher non-sea-salt mass loadings. This non-intuitive N(d) variation poses a fresh challenge to climate modellers.

3.
Int J Med Robot ; 3(3): 207-16, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17631675

RESUMO

INTRODUCTION: Tissue engineering provides an alternative modality allowing for decreased morbidity of donor site grafting and decreased rejection of less compatible alloplastic tissues. METHODS: Using image-based design and computer software, a precisely sized and shaped scaffold for osseous tissue regeneration can be created via selective laser sintering. Polycaprolactone has been used to create a condylar ramus unit (CRU) scaffold for application in temporomandibular joint reconstruction in a Yucatan minipig animal model. Following sacrifice, micro-computed tomography and histology was used to demonstrate the efficacy of this particular scaffold design. RESULTS: A proof-of-concept surgery has demonstrated cartilaginous tissue regeneration along the articulating surface with exuberant osseous tissue formation. Bone volumes and tissue mineral density at both the 1 and 3 month time points demonstrated significant new bone growth interior and exterior to the scaffold. CONCLUSION: Computationally designed scaffolds can support masticatory function in a large animal model as well as both osseous and cartilage regeneration. Our group is continuing to evaluate multiple implant designs in both young and mature Yucatan minipig animals.


Assuntos
Cartilagem/transplante , Procedimentos de Cirurgia Plástica/métodos , Crânio/diagnóstico por imagem , Crânio/cirurgia , Cirurgia Assistida por Computador/métodos , Engenharia Tecidual/métodos , Tomografia Computadorizada por Raios X/métodos , Animais , Cartilagem/diagnóstico por imagem , Cartilagem/crescimento & desenvolvimento , Suínos , Porco Miniatura
4.
J Evol Biol ; 20(3): 892-900, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17465900

RESUMO

The temperature-size rule is a common pattern of phenotypic plasticity in which higher temperature during development results in a smaller adult body size (i.e. a thermal reaction norm with negative slope). Examples and exceptions to the rule are known in multiple groups of organisms, but rapid population differentiation in the temperature-size rule has not been explored. Here we examine the genetic and parental contributions to population differentiation in thermal reaction norms for size, development time and survival in the Cabbage White Butterfly Pieris rapae, for two geographical populations that have likely diverged within the past 150 years. We used split-sibship experiments with two temperature treatments (warm and cool) for P. rapae from Chapel Hill, NC, and from Seattle, WA. Mixed-effect model analyses demonstrate significant genetic differences between NC and WA populations for adult size and for thermal reaction norms for size. Mean adult mass was 12-24% greater in NC than in WA populations for both temperature treatments; mean size was unaffected or decreased with temperature (the temperature-size rule) for the WA population, but size increased with temperature for the NC population. Our study shows that the temperature-size rule and related thermal reaction norms can evolve rapidly within species in natural field conditions. Rapid evolutionary divergence argues against the existence of a simple, general mechanistic constraint as the underlying cause of the temperature-size rule.


Assuntos
Tamanho Corporal , Borboletas/crescimento & desenvolvimento , Temperatura , Animais , Evolução Biológica , Borboletas/anatomia & histologia , Borboletas/genética , Clima , Feminino , Masculino , Dinâmica Populacional , Especificidade da Espécie
5.
Risk Anal ; 21(3): 545-59, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11572432

RESUMO

This study examined radiocesium (137Cs) levels in fish from the vicinity of the Department of Energy's Savannah River Site (SRS), a former nuclear weapons production facility in South Carolina. Fish from the Savannah River were sampled above (upstream), along, and below (downstream) the SRS, and from Steel Creek, a tributary that runs through the SRS. There was some off-site contamination of 137Cs in the Savannah River watershed due to low-level releases from past nuclear production on the SRS. The null hypotheses tested were that there would be no differences in 137Cs levels as a function of location along the river, and between species collected from the river and from Steel Creek on the SRS. For six of eight species of fish collected from the Savannah River, there were no differences in 137Cs levels in muscle from fish collected above, along, or below the SRS; exceptions were bowfin and shellcracker. Fish collected from Steel Creek had significantly higher levels (by about an order of magnitude) of 137Cs in muscle tissue than fish collected in the Savannah River. However, no fish from either Steel Creek or the Savannah River had 137Cs levels above the European Economic Community limit for fresh meat of 0.6 Bq/g. Lifetime cancer risk was calculated using the cancer slope factor of 3.2 x 10(-11)/pCi, and various fish consumption scenarios reflecting actual data from Savannah River fishermen. Using mean 137Cs concentrations and median fish consumption for 70 years for Black males-the group with the highest consumption-the excess lifetime risk associated with the eight species of fish in the Savannah River ranged from 9.0 x 10(-7) to 1.0 x 10(-5). The same calculation for fish from Steel Creek gave risk estimates from 1.4 to 8.0 x 10(-5). The 95% level for consumption by Blacks, however, was about 70 kg/year. Black fishermen consuming that amount of bass from Steel Creek would sustain a lifetime risk of 3.1 x 10(-4), whereas the same consumption of Savannah River bass would yield a risk estimate of 1.5 x 10(-5).


Assuntos
Radioisótopos de Césio/toxicidade , Peixes/metabolismo , Poluentes Radioativos da Água/toxicidade , Animais , Animais Selvagens , Radioisótopos de Césio/análise , Exposição Ambiental , Cadeia Alimentar , Água Doce/análise , Humanos , Guerra Nuclear , Medição de Risco , South Carolina , Especificidade da Espécie , Poluentes Radioativos da Água/análise
6.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(5 Pt 1): 051705, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11414919

RESUMO

Deuterium NMR spectroscopy of 2H2O has been used to monitor the magnetic-field-induced order on approaching a transition to a nematic phase in isotropic solutions of disklike micelles of cesium pentadecafluorooctanoate. Highly accurate data on the phase boundaries and spinodals have been obtained for solutions with volume fraction concentration straight phi between 0.078 and 0.201. The quantity TIN-T*, where T* is the spinodal limit of the isotropic phase and TIN is the temperature at which the nematic phase first appears on cooling, decreases linearly with decreasing concentration, extrapolating to zero only at zero concentration. Thus, there is no evidence to support the presence of a Landau point along the transition line as has previously been conjectured. The values for (TIN-T*)/TIN are in the range 10(-5)-10(-4), up to two orders of magnitude smaller than corresponding values reported for calamitic thermotropic nematics. The transition gap (phiNI-phiIN)/phiIN approximately 0.33% for phi<0.20 is also very small, although finite as required for a first-order phase transition. These data, when combined with previously measured properties, present an intriguing picture of the isotropic-to-nematic phase transition in a paradigmatic system of self-assembled diskotic particles. However, it is not completely clear, within the context of current theoretical understanding, whether the behavior of this system is explicable by hard-particle models, or if the self-assembly plays a crucial role in weakening the phase transition.

7.
J Infect Dis ; 184(2): 196-200, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11424018

RESUMO

Resiquimod (R-848), a topically active immune response modifier, induced production of interferon-alpha and interleukin-12 in cultured blood mononuclear cells and decreased genital herpes recurrences in an animal model. In this study, 52 patients with frequently recurrent genital herpes applied topical resiquimod gel 0.01% (twice or thrice weekly) or 0.05% (once or twice weekly) or vehicle gel to herpes lesions for 3 weeks. During the 6-month observation period after treatment, median days to first recurrence in the pooled resiquimod group was 169 days, compared with 57 days for the vehicle group (P=.0058). In all, 32% of resiquimod-treated patients completed the observation period without a recurrence, compared with 6% of vehicle-treated patients (P=.039). Resiquimod 0.05% twice weekly produced dose-limiting inflammation at the lesion sites, but the other regimens were well tolerated. Application of resiquimod to genital herpes lesions appeared to reduce the frequency of recurrences.


Assuntos
Herpes Genital/tratamento farmacológico , Herpes Genital/prevenção & controle , Imidazóis/administração & dosagem , Fatores Imunológicos/administração & dosagem , Adulto , Método Duplo-Cego , Feminino , Géis , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Modelos de Riscos Proporcionais , Prevenção Secundária , Resultado do Tratamento
8.
Appl Environ Microbiol ; 67(5): 2298-303, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11319115

RESUMO

Mannases have industrial uses in food and pulp industries, and their regulation may influence development of the mushrooms of commercially important basidiomycetes. We expressed an Agaricus bisporus cel4 cDNA, which encodes a mannanase, in Saccharomyces cerevisiae and Pichia pastoris. CEL4 had no detectable activity on cellulose or xylan. This gene is the first isolated from this economically important fungus to encode a mannanase. P. pastoris secreted about three times more CEL4 than S. cerevisiae. The removal of the cellulose-binding domain of CEL4 lowered the secreted specific activity by P. pastoris by approximately 97%. The genomic sequence of cel4 was isolated by screening a cosmid library of A. bisporus C54-carb8. The open reading frame was interrupted by 12 introns. The level of extracellular CEL4 increases dramatically at the postharvest stage in compost extracts of A. bisporus fruiting cultures. In laboratory liquid cultures of A. bisporus, the activity of CEL4 detected in the culture filtrate reached a maximum after 21 days. The levels of CEL4 broadly mirrored the levels of enzyme activity. In the Solka floc-bound mycelium, CEL4 protein showed a maximum after 2 to 3 weeks of culture and then declined. Changes in CEL4 activity during fruiting-body development suggest that hemicellulose utilization plays an important role in sporophore formation. The availability of the cloned gene will further studies of compost decomposition and the extracellular enzymes that fungi deploy in this process.


Assuntos
Agaricus/genética , Proteínas Fúngicas , Glicosídeo Hidrolases/genética , Manosidases/genética , Agaricus/enzimologia , Agaricus/crescimento & desenvolvimento , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Glicosídeo Hidrolases/metabolismo , Manosidases/metabolismo , Dados de Sequência Molecular , Pichia/enzimologia , Pichia/genética , Recombinação Genética , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Análise de Sequência de DNA , beta-Manosidase
9.
Nurse Educ ; 26(1): 33-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-16372453

RESUMO

Clinical faculty have a legal, ethical, and professional obligation to evaluate students' clinical performance to ensure safe practitioners. However, many clinical faculty members fear litigation and hesitate to give an unsatisfactory grade to students who do not meet established standards. If the decision to assign a failing clinical grade was "careful and deliberate" and the student was afforded due process, the principle of judicial deference emerges to protect the clinical instructor and the educational institution.


Assuntos
Direitos Civis/legislação & jurisprudência , Competência Clínica , Educação em Enfermagem/legislação & jurisprudência , Avaliação Educacional , Humanos , Decisões da Suprema Corte , Estados Unidos
10.
Cell Immunol ; 214(2): 139-44, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-12088412

RESUMO

CD8+ T-lymphocytes recognize peptides in the context of major histocompatibility complex (MHC) class I antigens. Upon activation, these cells differentiate into effector cytotoxic T lymphocytes (CTL) and no longer require formal antigen presentation by professional antigen presenting cells (APC). Subsequently, any cell expressing MHC class I/cognate peptide can stimulate CTL. Using TIL specific for a melanoma antigen-derived peptide, IMDQVPFSV (g209 2M), we sought to determine whether these CTL could present peptide to each other. Our findings demonstrate that peptide presentation of the g209 2M peptide epitope by TIL is comparable to conventional methods of using T2 cells as APC. We report here that CTL are capable of self-presentation of antigenic peptide to neighboring CTL resulting in IFN-gamma secretion, proliferation, and lysis of peptide-loaded CTL. These results demonstrate that human TIL possess both APC functions as well as cytotoxic functions and that this phenomenon could influence CTL activity elicited by immunotherapy.


Assuntos
Apresentação de Antígeno , Antígenos de Neoplasias/imunologia , Linfócitos do Interstício Tumoral/imunologia , Melanoma/imunologia , Proteínas de Neoplasias/imunologia , Fragmentos de Peptídeos/imunologia , Antígenos de Neoplasias/metabolismo , Células Cultivadas , Antígeno HLA-A2/imunologia , Humanos , Imunização , Interferon gama/metabolismo , Ativação Linfocitária , Linfócitos do Interstício Tumoral/metabolismo , Antígenos Específicos de Melanoma , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Proteínas da Matriz Viral/imunologia
11.
Appl Opt ; 40(22): 3659-67, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18360396

RESUMO

The complex refractive index of materials at infrared wavelengths is often determined when absorption measurements are made at selected wavelengths, and then the Kramers-Kronig relationship is used to calculate the real part of the index. Because many organic materials are highly absorbing in the infrared, absorption measurements require a short path length. We report on the use of an attenuated total internal reflection (TIR) method in combination with an infrared Mueller matrix spectropolarimeter to measure the Mueller matrix spectrum of samples from 3 to 14 mum. From the elements of the Mueller matrix the complex refractive index is determined for materials whose TIR interfaces are eigenstates of s and p polarization. The calculated index for water compares well with data found in the literature.

12.
Health Educ Behav ; 27(6): 708-24, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11104371

RESUMO

Diversification, like tobacco use prevention and cessation, is an important public health concern. The multilevel patterns of tobacco dependency suggest the need for public health approaches to the "tobacco problem." To understand how newspaper and wire service journalists cover issues involving diversification among tobacco farmers, the authors performed a content analysis of a subset of 100 articles on diversification and tobacco farming. Prochaska and DiClemente's stages of change model was applied to the "problem behavior" of tobacco farming. Among news accounts relating to tobacco farmers or tobacco farming, print media accounts gave relatively little attention to the issue of diversification. Farmers in the sample of news accounts were generally cognizant of pressures to diversify away from reliance on tobacco cultivation but were frustrated due to obstacles to diversification such as limited diversification options and relative absence of infrastructure supports. Community leaders and policy-relevant sources generally supported diversification.


Assuntos
Agricultura/organização & administração , Atitude Frente a Saúde , Meios de Comunicação de Massa/estatística & dados numéricos , Motivação , Jornais como Assunto/estatística & dados numéricos , Nicotiana , Plantas Tóxicas , Opinião Pública , Conhecimentos, Atitudes e Prática em Saúde , Política de Saúde/tendências , Humanos , Modelos Psicológicos , Inovação Organizacional , Prática de Saúde Pública , Mudança Social , Apoio Social , Estados Unidos
13.
J Biomed Opt ; 5(4): 371-4, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11092424

RESUMO

Several optical techniques that investigate blood contained within the retinal vessels are available or under development. We present a mechanical model that simulates the optical properties of the eye, the retinal vessels, and the ocular fundus. A micropipette is chosen as the retinal vessel model, and a mechanical housing is constructed to simulate the eyeball. Spectralon is used to simulate the retinal layers. Filling the eye with fluid index matched to the glass pipette eliminates reflection and refraction effects from the pipette. An apparatus is constructed and used to set the oxygen, nitrogen, and carbon dioxide concentrations in whole human blood. These whole blood samples are pumped through the pipette at 34 microL/min. Measurements made in the model eye closely resemble measurements made in the human eye. This apparatus is useful for developing the science and testing the systems that optically investigate blood and blood flow in the large retinal vessels.


Assuntos
Óptica e Fotônica , Oximetria/métodos , Oxigênio/sangue , Imagens de Fantasmas , Vasos Retinianos/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Hemoglobinas/metabolismo , Humanos , Consumo de Oxigênio
14.
Cell Immunol ; 204(1): 64-74, 2000 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-11006019

RESUMO

R-848 and imiquimod belong to a class of immune response modifiers that are potent inducers of cytokines, including IFN-alpha, TNF-alpha, IL-12, and IFN-gamma. Many of these cytokines can affect the acquired immune response. This study examines the effects of R-848 on aspects of acquired immunity, including immunoglobulin secretion, in vivo cytokine production, and Ag-specific T cell cytokine production. Results are compared with those of Th1 CpG ODN. R-848 and CpG ODN are effective at skewing immunity in the presence of Alum toward a Th1 Ab response (IgG2a) and away from a Th2 Ab response (IgE). R-848 and CpG ODN are also capable of initiating an immune response in the absence of additional adjuvant by specifically enhancing IgG2a levels. Both R-848 and imiquimod showed activity when given subcutaneously or orally, indicating that the compound mechanism was not through generation of a depot effect. Although CpG ODN behaves similarly to R-848, CpG ODN has a distinct cytokine profile, is more effective than R-848 when given with Alum in the priming dose, and is active only when given by the same route as the Ag. The mechanism of R-848's adjuvant activity is linked to cytokine production, where increases in IgG2a levels are associated with IFN-alpha, TNF-alpha, IL-12, and IFN-gamma induction, and decreases in IgE levels are associated with IFN-alpha and TNF-alpha. Imiquimod also enhances IgG2a production when given with Ag. The above results suggest that the imidazoquinolines R-848 and imiquimod may be attractive compounds for use as vaccine adjuvants and in inhibiting pathological responses mediated by Th2 cytokines.


Assuntos
Adjuvantes Imunológicos , Imidazóis/imunologia , Oligodesoxirribonucleotídeos/imunologia , Administração Oral , Animais , Separação Celular , Citocinas/análise , Feminino , Imunização Secundária , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Baço/citologia , Baço/imunologia , Células Th1/imunologia , Células Th2/imunologia , Vacinação
15.
J Cardiothorac Vasc Anesth ; 14(4): 428-32, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10972610

RESUMO

OBJECTIVE: To evaluate if increasing age is a major determinant of long-term neuropsychologic (NP) dysfunction in patients undergoing coronary artery bypass graft (CABG) surgery. DESIGN: Prospective cohort study. SETTING: A single university hospital. PARTICIPANTS: Three hundred eighty-one patients undergoing elective CABG surgery. INTERVENTIONS: Baseline preoperative and intraoperative characteristics were assessed for all patients. A comprehensive NP test battery was conducted preoperatively and at 1 month postoperatively. MEASUREMENTS AND MAIN RESULTS: Of the initial 381 patients, 319 (84%) returned for the 1-month visit. The overall incidence of an NP deficit was 21.6%. There was no significant difference seen with increasing age, although a trend was observed with highest NP deficit rate in the older than 65 age group. Other preoperative risk factors, including gender, education level, and preexisting diseases, were nonsignificant. Intraoperative variables were evaluated and revealed no significant differences across the age groups. CONCLUSIONS: This cohort study did not find an increased incidence of NP deficits in elderly patients after CABG surgery. It has addressed the limitations of other studies, however, with (1) a comprehensive NP test battery, (2) longer-term follow-up, and (3) adequate sample size.


Assuntos
Transtornos Cognitivos/etiologia , Ponte de Artéria Coronária/efeitos adversos , Transtornos Psicomotores/etiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Transtornos Cognitivos/diagnóstico , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estudos Prospectivos , Transtornos Psicomotores/diagnóstico , Desempenho Psicomotor , Fatores de Risco
16.
Antimicrob Agents Chemother ; 44(7): 1869-73, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10858346

RESUMO

Imiquimod (IQ) has been successfully used in treatment of genital warts. In clinical settings, patients responded well but wart reduction rates varied. Our aim was to find a correlation between clinical responses and pretreatment (constitutive) levels of genes that might be involved in the molecular action of IQ. Since IQ is a cytokine inducer, we analyzed levels of expression of genes of the JAK/STAT signaling pathway and their inhibitors as well as interferon response factors (IRFs) in pretreatment biopsy specimens from complete responders (99 to 100% wart reduction rate) versus incomplete responders (75 to 92% wart reduction rate) by reverse transcription-PCR. We found that mRNA levels of signal transducer and activator of transcription 1 (STAT1) and IRF1 were higher in complete responders than in incomplete responders. Incomplete responders expressed larger amounts of STAT3, IRF2, and protein inhibitor of activated STAT1 (PIAS1) mRNAs compared to complete responders before IQ treatment. We hypothesize that high-level expression of STAT1 and IRF1 is advantageous for a better IQ response. The observed differences in constitutive mRNA levels of these genes may be the consequence of alterations in cellular differentiation and/or variable expression of endogenous interferons. Previous in vitro studies showed that keratinocyte differentiation coordinates the balance between positive and negative signals along the JAK/STAT pathway by regulating the IRF1:IRF2 and STAT1:PIAS1 ratios and thus affecting induction of IQ-inducible genes. Specifically, differentiation supports constitutive expression of STAT1 and IRF1 mRNAs but not expression of IRF2 and PIAS1. Our data are in good agreement with studies that showed the importance of STAT1 in cytokine induction and activation of interferon-responsive genes by IQ.


Assuntos
Aminoquinolinas/farmacologia , Condiloma Acuminado/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Indutores de Interferon/farmacologia , Transativadores/genética , Aminoquinolinas/uso terapêutico , Biópsia , Diferenciação Celular/efeitos dos fármacos , Condiloma Acuminado/tratamento farmacológico , Condiloma Acuminado/imunologia , Condiloma Acuminado/metabolismo , Proteínas de Ligação a DNA/metabolismo , Método Duplo-Cego , Humanos , Imiquimode , Indutores de Interferon/uso terapêutico , Interferons/genética , Interferons/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/fisiologia , Proteínas Inibidoras de STAT Ativados , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Fator de Transcrição STAT1 , Fator de Transcrição STAT3 , Transativadores/metabolismo
17.
Biochemistry ; 39(13): 3565-74, 2000 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-10736155

RESUMO

We have used NMR spectroscopy to determine the three-dimensional (3D) structure, and to characterize the backbone dynamics, of a recombinant version of bovine beta-lactoglobulin (variant A) at pH 2. 6, where the protein is a monomer. The structure of this low-pH form of beta-lactoglobulin is very similar to that of a subunit within the dimer at pH 6.2. The root-mean-square deviation from the pH 6.2 (crystal) structure, calculated for backbone atoms of residues 6-160, is approximately 1.3 A. Differences arise from the orientation, with respect to the calyx, of the A-B and C-D loops, and of the flanking three-turn alpha-helix. The hydrophobic cavity within the calyx is retained at low pH. The E-F loop (residues 85-90), which moves to occlude the opening of the cavity over the pH range 7.2-6.2, is in the "closed" position at pH 2.6, and the side chain of Glu89 is buried. We also carried out measurements of (15)N T(1)s and T(2)s and (1)H-(15)N heteronuclear NOEs at pH 2.6 and 37 degrees C. Although the residues of the E-F loop (residues 86-89) have the highest crystallographic B-factors, the conformation of this loop is reasonably well defined by the NMR data, and its backbone is not especially mobile on the pico- to nanosecond time scale. Several residues (Ser21, Lys60, Ala67, Leu87, and Glu112) exhibit large ratios of T(1) to T(2), consistent with conformational exchange on a micro- to millisecond time scale. The positions of these residues in the 3D structure of beta-lactoglobulin are consistent with a role in modulating access to the hydrophobic cavity.


Assuntos
Lactoglobulinas/química , Lactoglobulinas/metabolismo , Animais , Bovinos , Cristalização , Cristalografia por Raios X , Dimerização , Concentração de Íons de Hidrogênio , Ressonância Magnética Nuclear Biomolecular/métodos , Fragmentos de Peptídeos/química , Estrutura Secundária de Proteína , Soluções , Relação Estrutura-Atividade
18.
Avian Dis ; 44(1): 23-33, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10737641

RESUMO

In this study, 294 Escherichia coli isolates from birds with colibacillosis were collected from disease outbreaks throughout the United States and were compared with 75 fecal E. coli isolates of apparently healthy chickens by their possession of several purported virulence genes, resistance to rough-lipopolysaccharide-specific bacteriophages (rLPSr), and elaboration of capsule. Traits were selected for study on the basis of their association with complement resistance. The genes targeted in this study included those encoding colicin V (cvaC) and the outer membrane proteins TraT (traT), OmpA (ompA), and Iss (iss). No significant differences were found between the two groups of isolates in the occurrence of cvaC-, traT-, or ompA-homologous sequences or in rLPSr. Only a few isolates were encapsulated, and the isolates of healthy birds were significantly more likely to be encapsulated than were the isolates of sick birds. However, iss, whether detected through hybridization or amplification, was found in more of the disease-associated isolates than in those of healthy birds. This difference was highly significant. Further, iss sequences were widely distributed among isolates of different serotypes from various avian host species and sites within these hosts. Such results suggest that possession of the iss sequence by an avian E. coli isolate may be a good indicator of that isolate's potential to cause disease. This association warrants further study because iss and the protein it encodes may be useful targets of future colibacillosis control efforts.


Assuntos
Proteínas do Sistema Complemento/imunologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/patogenicidade , Doenças das Aves Domésticas/microbiologia , Animais , Galinhas , Suscetibilidade a Doenças , Escherichia coli/classificação , Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Amplificação de Genes , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/imunologia , Sorotipagem , Perus
19.
Appl Opt ; 39(7): 1183-93, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-18338002

RESUMO

Techniques for noninvasively measuring the oxygen saturation of blood in retinal arteries and veins are reported in the literature, but none have been sufficiently accurate and reliable for clinical use. Addressing the need for increased accuracy, we present a series of oximetric equations that explicitly consider the effects of backscattering by red blood cells and lateral diffusion of light in the ocular fundus. The equations are derived for the specific geometry of a scanning-beam retinal vessel oximeter; however, the results should also be applicable to photographic oximeters. We present in vitro and in vivo data that suggest the validity of these equations.

20.
Sci Total Environ ; 263(1-3): 255-62, 2000 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-11194159

RESUMO

Radiocesium (137Cs) concentrations were determined during 1974, 1981 and 1998 for seven species of fish inhabiting a stream (Steel Creek) contaminated by effluents from a nuclear reactor to examine the decline of this radionuclide in a natural ecosystem. Median 137Cs concentrations were highest in Micropterus salmoides (largemouth bass) during each year of the investigation (1974 = 6.67 Bq g(-1) dry wt. of whole body; 1981 = 3.72 Bq g(-1); 1998 = 0.35 Bq g(-1)), but no patterns of differences were observed among Aphredoderus sayanus (pirate perch), Esox americanus (redfin pickerel), Lepomis auritus (redbreast sunfish), L. gulosus (warmouth), L. punctatus (spotted sunfish), and Notropis cummingsae (dusky shiner). Results demonstrated a rapid decline in 137Cs within fish from Steel Creek during the 24-year period. For example, 137Cs concentrations in all fish species declined significantly among years, even after accounting for radioactive decay. The observed percent declines in 137Cs concentrations of individual species were 3-4 times greater between 1974 and 1981 compared to that expected by physical decay alone, and 2-3 times greater during 1981-1998. Ecological half-lives (EHLs) of 137Cs in fish ranged from 4.43 years in A. sayanus to 6.53 years in L. gulosus. The EHL for 137Cs in all fish species combined was 5.54 years. Current levels of 137Cs in fish from Steel Creek (1.16 Bq g(-1) dry wt. of whole body to below detection limits) indicate that the consumption of fish from this ecosystem poses little risk to humans and sensitive wildlife species. These results demonstrate the importance of incorporating the concept of ecological half-life into determinations concerning the length and severity of potential risks associated with radiocontaminants.


Assuntos
Radioisótopos de Césio/farmacocinética , Monitoramento Ambiental , Peixes/fisiologia , Centrais Elétricas , Poluentes Radioativos da Água/farmacocinética , Animais , Radioisótopos de Césio/análise , Contaminação de Alimentos , Meia-Vida , Humanos , Saúde Pública , Medição de Risco , Distribuição Tecidual , Poluentes Radioativos da Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA