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1.
Nucleic Acids Res ; 52(8): 4659-4675, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38554102

RESUMO

RexA and RexB function as an exclusion system that prevents bacteriophage T4rII mutants from growing on Escherichia coli λ phage lysogens. Recent data established that RexA is a non-specific DNA binding protein that can act independently of RexB to bias the λ bistable switch toward the lytic state, preventing conversion back to lysogeny. The molecular interactions underlying these activities are unknown, owing in part to a dearth of structural information. Here, we present the 2.05-Å crystal structure of the λ RexA dimer, which reveals a two-domain architecture with unexpected structural homology to the recombination-associated protein RdgC. Modelling suggests that our structure adopts a closed conformation and would require significant domain rearrangements to facilitate DNA binding. Mutagenesis coupled with electromobility shift assays, limited proteolysis, and double electron-electron spin resonance spectroscopy support a DNA-dependent conformational change. In vivo phenotypes of RexA mutants suggest that DNA binding is not a strict requirement for phage exclusion but may directly contribute to modulation of the bistable switch. We further demonstrate that RexA homologs from other temperate phages also dimerize and bind DNA in vitro. Collectively, these findings advance our mechanistic understanding of Rex functions and provide new evolutionary insights into different aspects of phage biology.


Assuntos
Bacteriófago lambda , Proteínas de Ligação a DNA , Modelos Moleculares , Proteínas Virais , Bacteriófago lambda/genética , Cristalografia por Raios X , Proteínas Virais/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Ligação Proteica , Multimerização Proteica , DNA Viral/genética , DNA Viral/metabolismo , Mutação , Lisogenia , Escherichia coli/virologia , Escherichia coli/genética , Escherichia coli/metabolismo , DNA/metabolismo , DNA/química
2.
J Phys Chem A ; 127(48): 10233-10242, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38011037

RESUMO

Despite several investigations on the atmospheric fate of cyclic volatile methyl siloxanes (VMS), the oxidation chemistry of these purely anthropogenic, high production volume compounds is poorly understood. This led to uncertainties in the environmental impact and fate of the oxidation products. According to laboratory measurements, the main VMS oxidation product is the siloxanol (a -CH3 replaced with an -OH); however, none of the mechanisms proposed to date satisfactorily explain its formation. Motivated by our previous experimental observations of VMS oxidation products, we use theoretical quantum chemical calculations to (1) explore a previously unconsidered reaction pathway to form the siloxanol from a reaction of a siloxy radical with gas-phase water, (2) investigate differences in reaction rates of radical intermediates in hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4) oxidation, and (3) attempt to explain the experimentally observed products. Our results suggest that while the proposed reaction of the siloxy radical with water to form the siloxanol can occur, it is too slow to compete with other unimolecular reactions and thus cannot explain the observed siloxanol formation. We also find that the reaction between the initial D3 peroxy radical (RO2•) with HO2• is slower than previously anticipated (calculated as 3 × 10-13 cm3 molecule-1 s-1 for D3 and 2 × 10-11 cm3 molecule-1 s-1 for D4 compared to the general rate of ∼1 × 10-11 cm3 molecule-1 s-1). Finally, we compare the anticipated fates of the RO2• under a variety of conditions and find that a reaction with NO (assuming a general RO2• + NO bimolecular rate constant of 9 × 10-12 cm3 molecule-1 s-1) will likely be the dominant fate in urban conditions, while isomerization can be important in cleaner environments.

3.
Photosynth Res ; 152(3): 297-304, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34985637

RESUMO

Photosystem II (PSII), the enzyme responsible for oxidizing water into molecular oxygen, undergoes a complex lifecycle during which multiple assembly proteins transiently bind to and depart from PSII assembly intermediate complexes. Psb27 is one such protein. It associates with the CP43 chlorophyll-binding subunit of PSII to form a Psb27-PSII sub-complex that constitutes 7-10% of the total PSII pool. Psb27 remains bound to PSII assembly intermediates and dissociates prior to the formation of fully functional PSII. In this study, we compared a series of Psb27 mutant strains in the cyanobacterium Synechocystis sp. PCC 6803 with varied expression levels of Psb27: wild type (WT); psb27 genetic deletion (Del27), genetically complemented psb27 (Com27); and over-expressed Psb27 (OE27). The Del27 strain demonstrated decreased non-photochemical fluorescence quenching, while the OE27 strain showed increased non-photochemical quenching and tolerance to fluctuating light conditions. Multiple flashes and fluorescence decay analysis indicated that OE27 has the least affected maximum PSII quantum yield of the mutants. OE27 also displayed a minimal impact on the half-life of the fast component of QA- reoxidation over multiple flashes, indicating robust PSII function. We propose that the close association between Psb27 and CP43, and the absence of a fully functional manganese cluster in the Psb27-PSII complex create a PSII sub-population that dissipates excitation energy prior to its recruitment into the functional PSII pool. Efficient energy dissipation prevents damage to this pre-PSII pool and allows for efficient PSII repair and maturation. Participation of Psb27 in the PSII life cycle ensures high-quality PSII assembly.


Assuntos
Complexo de Proteína do Fotossistema II , Synechocystis , Animais , Proteínas de Bactérias/metabolismo , Estágios do Ciclo de Vida , Luz , Fotossíntese , Complexo de Proteína do Fotossistema II/metabolismo , Synechocystis/metabolismo
4.
Proc Natl Acad Sci U S A ; 116(43): 21907-21913, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31594847

RESUMO

In oxygenic photosynthetic organisms, photosystem II (PSII) is a unique membrane protein complex that catalyzes light-driven oxidation of water. PSII undergoes frequent damage due to its demanding photochemistry. It must undergo a repair and reassembly process following photodamage, many facets of which remain unknown. We have discovered a PSII subcomplex that lacks 5 key PSII core reaction center polypeptides: D1, D2, PsbE, PsbF, and PsbI. This pigment-protein complex does contain the PSII core antenna proteins CP47 and CP43, as well as most of their associated low molecular mass subunits, and the assembly factor Psb27. Immunoblotting, mass spectrometry, and ultrafast spectroscopic results support the absence of a functional reaction center in this complex, which we call the "no reaction center" complex (NRC). Analytical ultracentrifugation and clear native PAGE analysis show that NRC is a stable pigment-protein complex and not a mixture of free CP47 and CP43 proteins. NRC appears in higher abundance in cells exposed to high light and impaired protein synthesis, and genetic deletion of PsbO on the PSII luminal side results in an increased NRC population, indicative that NRC forms in response to photodamage as part of the PSII repair process. Our finding challenges the current model of the PSII repair cycle and implies an alternative PSII repair strategy. Formation of this complex may maximize PSII repair economy by preserving intact PSII core antennas in a single complex available for PSII reassembly, minimizing the risk of randomly diluting multiple recycling components in the thylakoid membrane following a photodamage event.


Assuntos
Complexo de Proteína do Fotossistema II/fisiologia , Células Cultivadas , Clorofila/fisiologia , Fotoquímica , Fotossíntese , Complexo de Proteína do Fotossistema II/isolamento & purificação , Tilacoides/fisiologia
5.
Int J Neuropsychopharmacol ; 23(5): 311-318, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32060512

RESUMO

BACKGROUND: Glutamate is an excitatory neurotransmitter binding to 3 classes of receptors, including the N-methyl, D-aspartate (NMDA) receptor. NMDA receptor binding is lower in major depression disorder and suicide. NMDA receptor blocking with ketamine can have antidepressant and anti-suicide effects. Early-life adversity (ELA) may cause glutamate-mediated excitotoxicity and is more common with major depression disorder and in suicide decedents. We sought to determine whether NMDA-receptor binding is altered with suicide and ELA. METHODS: A total 52 postmortem cases were organized as 13 quadruplets of suicide and non-suicide decedents matched for age, sex, and postmortem interval, with or without reported ELA (≤16 years). Tissue blocks containing dorsal prefrontal (BA8), dorsolateral prefrontal (BA9), or anterior cingulate (BA24) cortex were collected at autopsy. Psychiatrically healthy controls and suicide decedents underwent psychological autopsy to determine psychiatric diagnoses and details of childhood adversity. NMDA receptor binding was determined by quantitative autoradiography of [3H]MK-801 binding (displaced by unlabeled MK-801) in 20-µm-thick sections. RESULTS: [3H]MK-801 binding was not associated with suicide in BA8, BA9, or BA24. However, [3H]MK-801 binding with ELA was less in BA8, BA9, and BA24 independent of suicide (P < .05). [3H]MK-801 binding was not associated with age or postmortem interval in any brain region or group. CONCLUSIONS: Less NMDA receptor binding with ELA is consistent with the hypothesis that stress can cause excitotoxicity via excessive glutamate, causing either NMDA receptor downregulation or less receptor binding due to neuron loss consequent to the excitotoxicity.


Assuntos
Experiências Adversas da Infância/psicologia , Giro do Cíngulo/química , Córtex Pré-Frontal/química , Receptores de N-Metil-D-Aspartato/análise , Suicídio/psicologia , Adolescente , Adulto , Autopsia , Autorradiografia , Estudos de Casos e Controles , Maleato de Dizocilpina/química , Regulação para Baixo , Antagonistas de Aminoácidos Excitatórios/química , Feminino , Giro do Cíngulo/fisiopatologia , Humanos , Masculino , Ensaio Radioligante
6.
J Chem Phys ; 153(12): 124701, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-33003721

RESUMO

Intercalation offers a promising way to alter the physical properties of two-dimensional (2D) layered materials. Here, we investigate the electronic and vibrational properties of 2D layered MoSe2 intercalated with atomic manganese at ambient and high pressure up to 7 GPa by Raman scattering and electronic structure calculations. The behavior of optical phonons is studied experimentally with a diamond anvil cell and computationally through density functional theory calculations. Experiment and theory show excellent agreement in optical phonon behavior. The previously Raman inactive A2u mode is activated and enhanced with intercalation and pressure, and a new Raman mode appears upon decompression, indicating a possible onset of a localized structural transition, involving the bonding or trapping of the intercalant in 2D layered materials. Density functional theory calculations reveal a shift of the Fermi level into the conduction band and spin polarization in MnxMoSe2 that increases at low Mn concentrations and low pressure. Our results suggest that intercalation and pressurization of van der Waals materials may allow one to obtain dilute magnetic semiconductors with controllable properties, providing a viable route for the development of new materials for spintronic applications.

7.
Exp Cell Res ; 347(1): 241-249, 2016 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-27539660

RESUMO

The stroma, the middle layer of the cornea, is a connective tissue making up most of the corneal thickness. The stromal extracellular matrix (ECM) consists of highly organised lamellae which are made up of tightly packed fibrils primarily composed of collagens type I and V. This layer is interspersed with keratocytes, mesenchymal cells of neural crest origin. We have previously shown that adult corneal keratocytes exhibit phenotypic plasticity and can be induced into a neuronal phenotype. In the current study we evaluated the potential of keratocytes to produce collagen type II via phenotypic reprogramming with exogenous chondrogenic factors. The cornea presents a challenge to tissue engineers owing to its high level of organisation and the phenotypic instability of keratocytes. Traditional approaches based on a scar model do not support the engineering of functional stromal tissue. Type II collagen is not found in the adult cornea but is reported to be expressed during corneal development, raising the possibility of using such an approach to regenerate the corneal ECM. Keratocytes in culture and within intact normal and diseased tissue were induced to produce collagen type II upon treatment with transforming growth factor Beta3 (TGFß3) and dexamethasone. In vivo treatment of rat corneas also resulted in collagen type II deposition and a threefold increase in corneal hardness and elasticity. Furthermore, the treatment of corneas and subsequent deposition of collagen type II did not cause opacity, fibrosis or scarring. The induction of keratocytes with specific exogenous factors and resulting deposition of type II collagen in the stroma can potentially be controlled by withdrawal of the factors. This might be a promising new approach for in vivo corneal regeneration strategies aimed at increasing corneal integrity in diseases associated with weakened ectatic corneal tissue such as keratoconus.


Assuntos
Ceratócitos da Córnea/metabolismo , Matriz Extracelular/metabolismo , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Cartilagem/metabolismo , Células Cultivadas , Condrogênese , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Ceratócitos da Córnea/efeitos dos fármacos , Opacidade da Córnea , Dexametasona/farmacologia , Módulo de Elasticidade , Matriz Extracelular/efeitos dos fármacos , Dureza , Humanos , Masculino , Especificidade de Órgãos/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Fator de Crescimento Transformador beta3/metabolismo , Fator de Crescimento Transformador beta3/farmacologia
8.
Antimicrob Agents Chemother ; 58(7): 3618-25, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24733473

RESUMO

Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Timely administration of antibiotics approved for the treatment of anthrax disease may prevent associated morbidity and mortality. However, any delay in initiating antimicrobial therapy may result in increased mortality, as inhalational anthrax progresses rapidly to the toxemic phase of disease. An anthrax antitoxin, AVP-21D9, also known as Thravixa (fully human anthrax monoclonal antibody), is being developed as a therapeutic agent against anthrax toxemia. The efficacy of AVP-21D9 in B. anthracis-infected New Zealand White rabbits and in cynomolgus macaques was evaluated, and its safety and pharmacokinetics were assessed in healthy human volunteers. The estimated mean elimination half-life values of AVP-21D9 in surviving anthrax-challenged rabbits and nonhuman primates (NHPs) ranged from approximately 2 to 4 days and 6 to 11 days, respectively. In healthy humans, the mean elimination half-life was in the range of 20 to 27 days. Dose proportionality was observed for the maximum serum concentration (Cmax) of AVP-21D9 and the area under the concentration-time curve (AUC). In therapeutic efficacy animal models, treatment with AVP-21D9 resulted in survival of up to 92% of the rabbits and up to 67% of the macaques. Single infusions of AVP-21D9 were well tolerated in healthy adult volunteers across all doses evaluated, and no serious adverse events were reported. (This study has been registered at ClinicalTrials.gov under registration no. NCT01202695.).


Assuntos
Antraz/tratamento farmacológico , Antraz/imunologia , Antibacterianos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Adolescente , Adulto , Animais , Antibacterianos/efeitos adversos , Antibacterianos/farmacologia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Anticorpos Neutralizantes/efeitos adversos , Anticorpos Neutralizantes/farmacologia , Antígenos de Bactérias/sangue , Bacteriemia/sangue , Bacteriemia/tratamento farmacológico , Anticorpos Amplamente Neutralizantes , Células CHO , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Feminino , Humanos , Macaca fascicularis , Masculino , Pessoa de Meia-Idade , Coelhos , Adulto Jovem
9.
Microorganisms ; 10(5)2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35630282

RESUMO

Photosystem II is a light-driven water-plastoquinone oxidoreductase present in cyanobacteria, algae and plants. It produces molecular oxygen and protons to drive ATP synthesis, fueling life on Earth. As a multi-subunit membrane-protein-pigment complex, Photosystem II undergoes a dynamic cycle of synthesis, damage, and repair known as the Photosystem II lifecycle, to maintain a high level of photosynthetic activity at the cellular level. Cyanobacteria, oxygenic photosynthetic bacteria, are frequently used as model organisms to study oxygenic photosynthetic processes due to their ease of growth and genetic manipulation. The cyanobacterial PSII structure and function have been well-characterized, but its lifecycle is under active investigation. In this review, advances in studying the lifecycle of Photosystem II in cyanobacteria will be discussed, with a particular emphasis on new structural findings enabled by cryo-electron microscopy. These structural findings complement a rich and growing body of biochemical and molecular biology research into Photosystem II assembly and repair.

10.
ACS Synth Biol ; 9(6): 1441-1449, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32379958

RESUMO

The cyanobacterium Synechocystis sp. PCC 6803 is used as a model organism to study photosynthesis, as it can utilize glucose as the sole carbon source to support its growth under heterotrophic conditions. CRISPR interference (CRISPRi) has been widely applied to repress the transcription of genes in a targeted manner in cyanobacteria. However, a robust and reversible induced CRISPRi system has not been explored in Synechocystis 6803 to knock down and recover the expression of a targeted gene. In this study, we built a tightly controlled chimeric promoter, PrhaBAD-RSW, in which a theophylline responsive riboswitch was integrated into a rhamnose-inducible promoter system. We applied this promoter to drive the expression of ddCpf1 (DNase-dead Cpf1 nuclease) in a CRISPRi system and chose the PSII reaction center gene psbD (D2 protein) to target for repression. psbD was specifically knocked down by over 95% of its native expression, leading to severely inhibited photosystem II activity and growth of Synechocystis 6803 under photoautotrophic conditions. Significantly, removal of the inducers rhamnose and theophylline reversed repression by CRISPRi. Expression of PsbD recovered following release of repression, coupled with increased photosystem II content and activity. This reversibly induced CRISPRi system in Synechocystis 6803 represents a new strategy for study of the biogenesis of photosynthetic complexes in cyanobacteria.


Assuntos
Proteínas de Bactérias/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Edição de Genes/métodos , Complexo de Proteína do Fotossistema II/genética , Synechocystis/metabolismo , Proteínas de Bactérias/metabolismo , Expressão Gênica/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Regiões Promotoras Genéticas , RNA Guia de Cinetoplastídeos/metabolismo , Ramnose/farmacologia , Riboswitch
11.
Infect Immun ; 77(7): 2795-801, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19398544

RESUMO

The botulinum neurotoxins (BoNTs) are a large family of extremely potent, neuroparalytic, dichain proteins which act at the peripheral nervous system. The wide genetic diversity observed with this neurotoxin family poses a significant challenge for the development of an effective botulinum vaccine. The present study describes a vaccine development platform based on protein fragments representing the N-terminal two-thirds of each toxin molecule. These fragments, designated LH(N), comprise the light chain and translocation domains of each neurotoxin and are devoid of any neuron-binding activity. Using codon-optimized genes, LH(N) fragments derived from BoNT serotypes A and B were expressed in Escherichia coli in high yield with >1 g of purified, soluble fragment recoverable from 4.5 liter-scale fermentations. The protective efficacy of LH(N)/A was significantly enhanced by treatment with formaldehyde, which induced intramolecular cross-linking but virtually no aggregation of the fragment. A single immunization of the modified fragment protected mice from challenge with a 10(3) 50% lethal dose (LD(50)) of BoNT/A(1) with an 50% effective dose (ED(50)) of 50 ng of the vaccine. In similar experiments, the LH(N)/A vaccine was shown to protect mice against challenge with BoNT/A subtypes A(1), A(2), and A(3), which is the first demonstration of single-dose protection by a vaccine against the principal toxin subtypes of BoNT/A. The LH(N)/B vaccine was also highly efficacious, giving an ED(50) of approximately 140 ng to a challenge of 10(3) LD(50) of BoNT/B(1). In addition, LH(N)/B provided single-dose protection in mice against BoNT/B(4) (nonproteolytic toxin subtype).


Assuntos
Vacinas Bacterianas/imunologia , Toxinas Botulínicas Tipo A/imunologia , Toxinas Botulínicas/imunologia , Botulismo/prevenção & controle , Animais , Vacinas Bacterianas/genética , Toxinas Botulínicas/genética , Toxinas Botulínicas Tipo A/genética , Escherichia coli/genética , Expressão Gênica , Camundongos , Modelos Moleculares , Análise de Sobrevida , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
12.
Environ Monit Assess ; 159(1-4): 475-91, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19067207

RESUMO

Water quality data at 12 sites within an urban, a suburban, and a rural stream were collected contemporaneously during four wet and eight dry periods. The urban stream yielded the highest biochemical oxygen demand (BOD), orthophosphate, total suspended sediment (TSS), and surfactant concentrations, while the most rural stream yielded the highest total organic carbon concentrations. Percent watershed development and percent impervious surface coverage were strongly correlated with BOD (biochemical oxygen demand), orthophosphate, and surfactant concentrations but negatively with total organic carbon. Excessive fecal coliform abundance most frequently occurred in the most urbanized catchments. Fecal coliform bacteria, TSS, turbidity, orthophosphate, total phosphorus, and BOD were significantly higher during rain events compared to nonrain periods. Total rainfall preceding sampling was positively correlated with turbidity, TSS, BOD, total phosphorus, and fecal coliform bacteria concentrations. Turbidity and TSS were positively correlated with phosphorus, fecal coliform bacteria, BOD, and chlorophyll a, which argues for better sedimentation controls under all landscape types.


Assuntos
Monitoramento Ambiental , Rios , Movimentos da Água , Cidades , Chuva , População Rural , Microbiologia da Água , Poluentes da Água/análise
13.
Acad Med ; 81(3): 275-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16501276

RESUMO

Mentoring, long recognized as a catalyst for successful careers, is particularly important to the career development of underrepresented minority (URM) faculty. In academic medicine, mentor-protégé relationships are seriously threatened by increased clinical, research, and administrative demands and an emphasis on scholarship over citizenship. New mentoring models are needed, and they should be adaptable to a medical school's unique structure and mission. The Peer-Onsite-Distance (POD) model, developed in 2002 by the authors and introduced at the College of Medicine at the University of Arkansas for Medical Sciences, is a targeted, multilevel mentoring prototype that is built on a solid research foundation and tailored to the unique needs of URM medical school faculty. The mentee's individual needs for guidance related to career goals, resources, and the content and interaction skills that are known to be critical to successful academic careers are targeted for development. The multilevel approach provides a unique network of peer and faculty mentors who provide site-specific career guidance. Also in the network are leaders in their fields who can provide access to accurate information, cautions, predictions, and announcements of future resources or potential restrictions in academic medicine. Mentor commitments are clearly defined and time contributions are maximized. The POD model aims to promote retention and advance the careers of URM faculty by wrapping them in a protective cushion of interpersonal and intrapersonal support. The flexibility of the design allows for adaptation to any institution's unique structure and mission.


Assuntos
Docentes de Medicina , Mentores , Grupos Minoritários , Faculdades de Medicina , Mobilidade Ocupacional , Educação Médica/organização & administração , Humanos , Relações Interprofissionais , Modelos Teóricos , Recursos Humanos
14.
J Am Geriatr Soc ; 53(2): 331-5, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15673361

RESUMO

This article describes a longitudinal study developed to assess perceived usefulness of a mandatory geriatric clerkship from the perspective of junior students completing the newly initiated program in 1998-1999 and 1999-2000 and these same students as second- or third-year residents. End-of-clerkship student evaluations were compared with follow-up resident surveys of those same students to identify the utility of information provided and strengths and weaknesses of the initial course experience. Students participated in hospice, outpatient clinics, nursing homes, and transitional care venues during their clerkship experience at the Donald W. Reynolds Department of Geriatrics, College of Medicine, University of Arkansas for Medical Sciences. Two hundred eighty-five student evaluations were collected, and 143 resident surveys were returned. Quantitative and qualitative data from students and residents corroborated each other in identifying strengths and weaknesses of the clerkship. Hospice information was successfully incorporated into residency practice. In contrast, outpatient clinic, nursing home, and transitional care segments of the clerkship were perceived as inadequate. Survey responses validated faculty changes that were initiated in the following years. These changes use settings and patients that more accurately mirror those seen in typical resident encounters.


Assuntos
Estágio Clínico , Geriatria/educação , Satisfação Pessoal , Estudantes de Medicina/psicologia , Adulto , Feminino , Humanos , Internato e Residência , Estudos Longitudinais , Masculino , Avaliação de Programas e Projetos de Saúde , Fatores de Tempo
15.
Prog Community Health Partnersh ; 8(2): 187-95, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25152100

RESUMO

BACKGROUND: Children involved in child welfare services are at high risk for emotional and behavioral problems that are not adequately identified and treated. As part of a federal review, Youth and Family Services (YFS), child protective services in Charlotte, North Carolina, was informed that they must improve their response to youth needs, particularly regarding mental health, or face losing millions of dollars in federal funding. OBJECTIVES: We have described herein an effort to build agency capacity for identifying mental health needs through a community-university partnership and share lessons learned about implementing the new process. METHODS: Community and university partners came together to develop a mental health screening pilot for one Youth and Family Services (YFS) district. LESSONS LEARNED: Community-university partners across all levels of a hierarchically structured agency must work together to align implementation of partner activities with system-level goals. Recommendations for collaboration, from a stakeholder perspective, are also described.


Assuntos
Fortalecimento Institucional/organização & administração , Transtornos do Comportamento Infantil/diagnóstico , Proteção da Criança , Saúde Mental , Transtornos do Humor/diagnóstico , Adolescente , Criança , Participação da Comunidade , Pesquisa Participativa Baseada na Comunidade , Relações Comunidade-Instituição , Feminino , Humanos , Masculino , Programas de Rastreamento , North Carolina/epidemiologia , Encaminhamento e Consulta/organização & administração , Universidades/organização & administração
16.
Clin Vaccine Immunol ; 20(7): 1016-26, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23658392

RESUMO

Antimicrobials administered postexposure can reduce the incidence or progression of anthrax disease, but they do not protect against the disease resulting from the germination of spores that may remain in the body after cessation of the antimicrobial regimen. Such additional protection may be achieved by postexposure vaccination; however, no anthrax vaccine is licensed for postexposure prophylaxis (PEP). In a rabbit PEP study, animals were subjected to lethal challenge with aerosolized Bacillus anthracis spores and then were treated with levofloxacin with or without concomitant intramuscular (i.m.) vaccination with anthrax vaccine adsorbed (AVA) (BioThrax; Emergent BioDefense Operations Lansing LLC, Lansing, MI), administered twice, 1 week apart. A significant increase in survival rates was observed among vaccinated animals compared to those treated with antibiotic alone. In preexposure prophylaxis studies in rabbits and nonhuman primates (NHPs), animals received two i.m. vaccinations 1 month apart and were challenged with aerosolized anthrax spores at day 70. Prechallenge toxin-neutralizing antibody (TNA) titers correlated with animal survival postchallenge and provided the means for deriving an antibody titer associated with a specific probability of survival in animals. In a clinical immunogenicity study, 82% of the subjects met or exceeded the prechallenge TNA value that was associated with a 70% probability of survival in rabbits and 88% probability of survival in NHPs, which was estimated based on the results of animal preexposure prophylaxis studies. The animal data provide initial information on protective antibody levels for anthrax, as well as support previous findings regarding the ability of AVA to provide added protection to B. anthracis-infected animals compared to antimicrobial treatment alone.


Assuntos
Vacinas contra Antraz/administração & dosagem , Vacinas contra Antraz/imunologia , Antraz/prevenção & controle , Profilaxia Pós-Exposição/métodos , Vacinação/métodos , Adolescente , Adulto , Idoso , Animais , Vacinas contra Antraz/efeitos adversos , Anticorpos Antibacterianos/sangue , Anticorpos Neutralizantes/sangue , Antitoxinas/sangue , Modelos Animais de Doenças , Feminino , Humanos , Macaca fascicularis , Masculino , Pessoa de Meia-Idade , Coelhos , Análise de Sobrevida , Vacinação/efeitos adversos , Adulto Jovem
17.
Cancer ; 109(2 Suppl): 368-77, 2007 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17173279

RESUMO

As similar cancer health disparities have been documented for African American (AA) women and Latinas, it would be important to determine whether comparable interventions could be used to increase screening among these 2 culturally different populations. This paper reports research findings comparing cultural dimensions of breast and cervical cancer as they impact Latino and AA social networks and explore the feasibility of creating outreach models that may serve both groups. An existing intervention that integrates the social roles and relationships of AA women, The Witness Project(R), is used as a framework for tailoring an intervention for Latino communities. Findings and data from focus groups and key informant interviews were collected from more than 120 Latinos in Arkansas and New York City. These findings are analyzed using the Pen-3 Model, categorized, and compared with previous social role and network information from AA women as reflected in the Witness Project(R) intervention model. The findings from this study demonstrated variations between AA women and Latinas with regard to roles and gender relationships while demonstrating similarities with regard to spiritual beliefs and attitudes toward cancer. We applied our results to culturally tailor and develop a breast and cervical cancer intervention, Esperanza y Vidatrade mark (Hope and Life), that incorporates Latino values and social relationships. This study demonstrates that a proven education and outreach model for AA women may provide a framework for creating a culturally appropriate intervention for Latinas. Further research is needed to study the efficacy of the new model. Cancer 2007. (c) 2006 American Cancer Society.


Assuntos
Negro ou Afro-Americano/educação , Neoplasias da Mama/prevenção & controle , Características Culturais , Hispânico ou Latino/educação , Educação de Pacientes como Assunto , Apoio Social , Neoplasias do Colo do Útero/prevenção & controle , Arkansas , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Programas de Rastreamento , Pessoa de Meia-Idade , Cidade de Nova Iorque
18.
J Cancer Educ ; 20(1): 39-44, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15876181

RESUMO

BACKGROUND: Latino immigrants are at higher risk of death from breast and cervical cancer, necessitating effective cancer education interventions. METHODS: Qualitative and quantitative information was obtained from Latinos from Arkansas and New York City through focus groups and questionnaires. Findings were analyzed using the PEN-3 model. RESULTS: The results demonstrate a mechanism for creating a culturally competent program, Esperanza y Vida, through progressively analyzing the findings to define the key perceptions, enablers, and nurturers, then applying this information to construct program components to address appropriate health behavior and cultural components that address the specific needs of a diverse Latino population. CONCLUSION: Finding a systematic approach to incorporating and embracing sociocultural perspectives and constructs may effectively appeal to diverse Latino immigrants in the development of a cancer education intervention.


Assuntos
Neoplasias da Mama/prevenção & controle , Características Culturais , Educação em Saúde/métodos , Hispânico ou Latino/educação , Neoplasias do Colo do Útero/prevenção & controle , Aculturação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Emigração e Imigração , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pessoa de Meia-Idade
19.
S D J Med ; 55(2): 59-62, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11865707

RESUMO

This case series reports results of single photon emission computed tomography (SPECT) studies in three patients with fetal alcohol syndrome (FAS), who had previously undergone structural magnetic resonance imaging (MR). The MR studies revealed several brain anomalies, including microcephaly, agenesis or hypoplasia of corpus callosum and agenesis of hippocampal commissure. The SPECT data revealed that the CBF was reduced by at least 25% in the temporal region relative to the cerebellum in all three patients. By contrast, the temporal-cerebellar differences were between 4% and 7% in two controls. The functional abnormalities in FAS, like neuroanatomical abnormalities, are likely to be multiple and varied because of heterogeneity of this syndrome. Our findings suggest the need for a larger study to test the hypothesis that temporal lobe abnormalities are a notable occurrence in FAS. Discovery of specific regional brain dysfunctions (such as temporal lobe dysfunction) that are particularly vulnerable to alcohol's teratogenic effect may allow clinicians and researchers to look for markers useful in FAS screening and may have implications for prevention and treatment of FAS.


Assuntos
Encéfalo/diagnóstico por imagem , Transtornos do Espectro Alcoólico Fetal/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Encéfalo/anormalidades , Encéfalo/irrigação sanguínea , Criança , Feminino , Transtornos do Espectro Alcoólico Fetal/patologia , Humanos , Masculino , Gravidez
20.
J Lab Clin Med ; 142(6): 385-90, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14713890

RESUMO

We have treated 9 patients who presented with hepatic decompensation resulting from Wilson's disease with a combination of trientine and zinc, generally for at least 4 months, followed by transition to zinc maintenance therapy. All of these patients had hypoalbuminemia, all but 1 had hyperbilirubinemia, and 7 had ascites. All of these patients would have been candidates for liver transplantation on the basis of their initial Child-Turcotte-Pugh (CTP) scores. The minimal listing criteria for transplant candidates is a score greater than 7. Eight of the 9 patients had demonstrated a CTP score of 10 or higher. The other scoring system that has been used in Wilson's disease to determine need for transplantation is the prognostic index of Nazer, in which a score over 6 indicates that the patient is unlikely to survive without a transplant if treated with penicillamine. Two of our patients had Nazer scores higher than 6. With our medical therapy, all 9 of these patients have recovered normal liver function as reflected by normalization of their CTP scores to 5. Because of coexisting neurologic disease, 1 of our 9 patients was initiated on a neurologic protocol and by chance randomized to receive tetrathiomolybdate (TM) and zinc after 2 weeks of trientine/zinc treatment. This patient's liver function recovered much more rapidly than did that of the other 8 patients, all of whom were treated with trientine/zinc, suggesting that TM therapy offers a further advantage. In summary, we were able to take 9 patients who presented with liver failure -8 of whom had CTP scores indicating a potential need for liver transplantation and 2 of whom had Nazer prognostic scores indicating that they were not likely to survive if treated only with penicillamine - and treat them medically, with recovery in all 9. We believe the trientine/zinc combination therapy should be the standard for initial treatment of liver failure in Wilson's disease because its efficacy is equal or slightly superior to that of penicillamine and because it has a much lower incidence of side effects. Moreover, TM warrants study to determine whether therapy for hepatic Wilson's disease can be further improved.


Assuntos
Degeneração Hepatolenticular/tratamento farmacológico , Falência Hepática/tratamento farmacológico , Trientina/administração & dosagem , Zinco/administração & dosagem , Adulto , Quimioterapia Combinada , Feminino , Degeneração Hepatolenticular/complicações , Humanos , Masculino
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