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1.
J Intellect Disabil Res ; 57(6): 489-99, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22471408

RESUMO

BACKGROUND: Concepts such as support, quality of life and quality of services are customary in services for people with intellectual disabilities. The identification of the different ways of conceiving, prioritising and implementing these concepts by service providers can help to drive changes to achieve better personal outcomes for this population. The current study aims to identify service providers' perceptions regarding the quality of life of their clients and the quality of services they provide. It also aims to identify similarities and differences of appraisals among professionals, and to identify associations between supports, quality of life and quality of services. METHOD: Data were collected from 22 service providers who attended three focus groups (professionals, direct support staff, and managers) from whom 424 comments were analysed. Service providers were asked about the required support for users, the meaning of quality of life for those users, and about features that should characterise quality services. Thematic analysis was employed and transcripts of the sessions were coded according to the dimensions of models on supports, quality of life and quality of services. Chi-squared tests were utilised to test for potential differences among groups. RESULTS: Each professional group has its own priorities concerning required supports. Among the organisation different and potentially conflicting perceptions regarding the meaning of experiencing quality of life coexist. Concerning quality of services, only managers mentioned personal outcomes. Finally, institutionalisation has a negative impact on supports, quality of life and quality of services. CONCLUSIONS: It is necessary to move beyond a shared awareness of the negative impact of institutionalisation towards the transformation of services in search of personal quality outcomes.


Assuntos
Atitude do Pessoal de Saúde , Institucionalização/normas , Deficiência Intelectual/psicologia , Deficiência Intelectual/terapia , Garantia da Qualidade dos Cuidados de Saúde , Qualidade de Vida , Feminino , Grupos Focais , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Instituições Residenciais/normas , Apoio Social
2.
Clin Transl Radiat Oncol ; 41: 100649, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37346275

RESUMO

Background and purpose: MAPKs are among the most relevant signalling pathways involved in coordinating cell responses to different stimuli. This group includes p38MAPKs, constituted by 4 different proteins with a high sequence homology: MAPK14 (p38α), MAPK11 (p38ß), MAPK12 (p38γ) and MAPK13 (p38δ). Despite their high similarity, each member shows unique expression patterns and even exclusive functions. Thus, analysing protein-specific functions of MAPK members is necessary to unequivocally uncover the roles of this signalling pathway. Here, we investigate the possible role of MAPK11 in the cell response to ionizing radiation (IR). Materials and methods: We developed MAPK11/14 knockdown through shRNA and CRISPR interference gene perturbation approaches and analysed the downstream effects on cell responses to ionizing radiation in A549, HCT-116 and MCF-7 cancer cell lines. Specifically, we assessed IR toxicity by clonogenic assays; DNA damage response activity by immunocytochemistry; apoptosis and cell cycle by flow cytometry (Annexin V and propidium iodide, respectively); DNA repair by comet assay; and senescence induction by both X-Gal staining and gene expression of senescence-associated genes by RT-qPCR. Results: Our findings demonstrate a critical role of MAPK11 in the cellular response to IR by controlling the associated senescent phenotype, and without observable effects on DNA damage response, apoptosis, cell cycle or DNA damage repair. Conclusion: Our results highlight MAPK11 as a novel mediator of the cellular response to ionizing radiation through the control exerted onto IR-associated senescence.

3.
Artigo em Inglês | MEDLINE | ID: mdl-21869902

RESUMO

To evaluate the effectiveness of Uncaria tomentosa in minimizing the side effects of chemotherapy and improving the antioxidant status of colorectal cancer (CRC) patients, a randomized clinical trial was conducted. Patients (43) undergoing adjuvant/palliative chemotherapy with 5-Fluorouracil/leucovorin + oxaliplatin (FOLFOX4) were split into two groups: the UT group received chemotherapy plus 300 mg of Uncaria tomentosa daily and the C group received only FOLFOX4 and served as a control. Blood samples were collected before each of the 6 cycles of chemotherapy, and hemograms, oxidative stress, enzymes antioxidants, immunologic parameters, and adverse events were analyzed. The use of 300 mg of Uncaria tomentosa daily during 6 cycles of FOLFOX4 did not change the analyzed parameters, and no toxic effects were observed.

4.
Water Sci Technol ; 66(2): 247-53, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22699327

RESUMO

The adsorption of the three chlorophenol isomers, ortho, meta and para, by silicalite-1 has been studied at 30 °C, below the solubility (at the same temperature) in water. Large differences, up to 30 times, have been observed between the adsorption of the para- vs. the ortho-isomer. The difference of behavior observed between the isomers is assigned to the tendency to self-organization of the para-isomer. It seems probable that the adsorption sites are at the intersection channels. From a technical point of view, silicalite-1 seems a competitive adsorbent for p-chlorophenol.


Assuntos
Clorofenóis/química , Silicatos/química , Adsorção
5.
Am J Transplant ; 11(9): 1810-4, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21831153

RESUMO

Kidney donor exchanges enable recipients with immunologically incompatible donors to receive compatible living donor grafts; however, the financial management of these exchanges, especially when an organ is shipped, is complex and thus has the potential to impede the broader implementation of donor exchange programs. Representatives from transplant centers that utilize the National Kidney Registry database to facilitate donor exchange transplants developed a financial model applicable to paired donor exchanges and donor chain transplants. The first tenet of the model is to eliminate financial liability to the donor. Thereafter, it accounts for the donor evaluation, donor nephrectomy hospital costs, donor nephrectomy physician fees, organ transport, donor complications and recipient inpatient services. Billing between hospitals is based on Medicare cost report defined costs rather than charges. We believe that this model complies with current federal regulations and effectively captures costs of the donor and recipient services. It could be considered as a financial paradigm for the United Network for Organ Sharing managed donor exchange program.


Assuntos
Custos e Análise de Custo , Transplante de Rim , Doadores Vivos , Meios de Transporte/economia , Humanos , Modelos Econômicos
6.
Water Environ Res ; 83(2): 162-72, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21449478

RESUMO

For activated sludge modeling purposes, the methods used to evaluate the readily biodegradable chemical oxygen demand (RBCOD) in the influents are by biological or via physicochemical assays. However, there has not been sufficient wide comparison between these methods. The main goal of this study was to investigate the performance of the main chemical oxygen demand (COD) fractionation protocols, considering a representative wastewater in the context of tropical and developing countries. Different physicochemical characterization procedures, respirometric tests, and chemical analyses were performed. The fate of the soluble COD in the aeration tanks was studied. The results of the study showed that a marked difference may exist, in municipal wastewaters, between the estimates of the RBCOD fractions measured by respirometry and by any of the physicochemical methods. The evaluated influent showed a rather large fraction of COD that was passing the filters without being rapidly biodegradable, but which was removed quickly by enmeshment in the bioflocs. The consequences of such divergences and behavior are discussed.


Assuntos
Biodegradação Ambiental , Reatores Biológicos , Consumo de Oxigênio/fisiologia , Eliminação de Resíduos Líquidos , Monitoramento Ambiental , Poluentes Químicos da Água
7.
Ann Rheum Dis ; 68(2): 257-63, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18653628

RESUMO

OBJECTIVES: The I kappaB kinase (IKK)-related kinase IKKepsilon regulates type I interferon expression and responses as well as proinflammatory mediator production. We examined the role of IKKepsilon in arthritis and its ability to enhance the therapeutic response to systemic interferon (IFN) beta therapy in passive murine K/BxN arthritis. METHODS: IKKepsilon(-/-), IFN alpha(approximately)beta R(-/-) and wild type mice were given K/BxN serum and treated with polyinosinic polycytidylic acid (poly(I:C)), IFN beta, or normal saline. Clinical response and histological scores were assessed. Gene expression in the paws was measured by quantitative PCR. Serum interleukin 1a receptor agonist (IL1Ra) and IL10 were measured by ELISA and multiplex bead array. RESULTS: Arthritis was almost completely blocked in wild type mice if arthritogenic K/BxN serum and the Toll-like receptor (TLR)3 ligand, poly(I:C), were coadministered at the onset of the model, but not in established disease. Mice deficient in IFN alpha(approximately)beta R had an accelerated course of arthritis, and did not respond to poly(I:C). IKKepsilon null mice had a modest decrease in clinical arthritis compared with heterozygous mice. Low doses of IFN beta that were ineffective in wild type mice significantly decreased clinical arthritis in IKKepsilon null mice. Articular chemokine gene expression was reduced in the IKKepsilon(-/-) mice with arthritis and secreted IL1Ra (sIL1Ra) mRNA was significantly increased. Serum levels of IL1Ra were increased in low dose IFN beta-treated IKKepsilon(-/-) mice. CONCLUSIONS: Subtherapeutic doses of IFN beta enhance the anti-inflammatory effects of IKKepsilon deficiency, possibly by increasing production of IL1Ra and unmasking the antichemokine effects. Combination therapy with low dose IFN beta and an IKKepsilon inhibitor might improve efficacy of either agent alone and offers a novel approach to RA.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Experimental/tratamento farmacológico , Quinase I-kappa B/fisiologia , Interferon beta/uso terapêutico , Animais , Artrite Experimental/enzimologia , Artrite Experimental/patologia , Modelos Animais de Doenças , Progressão da Doença , Avaliação Pré-Clínica de Medicamentos/métodos , Quinase I-kappa B/deficiência , Indutores de Interferon/uso terapêutico , Proteína Antagonista do Receptor de Interleucina 1/biossíntese , Proteína Antagonista do Receptor de Interleucina 1/genética , Proteína Antagonista do Receptor de Interleucina 1/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Poli I-C/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Índice de Gravidade de Doença , Resultado do Tratamento
8.
J Evol Biol ; 22(10): 1975-83, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19678864

RESUMO

Cyclical parthenogens, which combine asexual and sexual reproduction, are good models for research into the ecological and population processes affecting the evolutionary maintenance of sex. Sex in cyclically parthenogenetic rotifers is necessary for diapausing egg production, which is essential to survive adverse conditions between planktonic growing seasons. However, within a planktonic season sexual reproduction prevents clonal proliferation. Hence, clones with a low propensity for sex should be selected, becoming dominant in the population as the growing season progresses. In this context, we studied the dynamics of the heritable variation in propensity for sexual reproduction among clones of a Brachionus plicatilis rotifer population in a temporary Mediterranean pond during the period the species occurred in plankton. Clonal isolates displayed high heritable variation in their propensity for sex. Moreover, the frequency of clones with low propensity for sex increased during the growing season, which supports the hypothesized short-term selection for low investment in sex within a growing season. These results demonstrate (1) the inherent instability of the cyclical parthenogenetic life cycle, (2) the cost of sexual reproduction in cyclical parthenogens where sex produces diapausing eggs and (3) the role of the association between sexual reproduction and diapause in maintaining sex in these cyclical parthenogens.


Assuntos
Partenogênese , Rotíferos/genética , Animais , Bioensaio , Reprodução , Rotíferos/fisiologia
11.
Arch Soc Esp Oftalmol (Engl Ed) ; 94(10): 514-517, 2019 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31171387

RESUMO

We report the case of a 68-year-old man with a left lower eyelid basal cell carcinoma with squamous differentiation. Resection was performed under frozen section technique and the defect (inner canthus, two thirds of the lower eyelid and 2.5cm of the cheek) reconstructed 2 days after surgery in a single surgical operation: posterior lamella with pericranial graft and anterior lamella with Mustarde flap. After one year of follow-up, the patient has an adequate appearance, good eyelid support and position, vascularized tissue like the native eyelid and no tumor recurrence.


Assuntos
Blefaroplastia/métodos , Carcinoma Basocelular/cirurgia , Neoplasias Palpebrais/cirurgia , Periósteo/transplante , Retalhos Cirúrgicos , Idoso , Humanos , Masculino , Crânio
12.
Appl Environ Microbiol ; 74(3): 907-11, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18083865

RESUMO

Outer membrane proteins (OMPs) expressed by Vibrio tubiashii under different environmental growth conditions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and PCR analyses. Results showed the presence of a 38- to 40-kDa OmpU-like protein and ompU gene, a maltoporin-like protein, several novel OMPs, and a regulatory toxR homolog.


Assuntos
Proteínas da Membrana Bacteriana Externa , Proteínas de Bactérias , Proteínas de Ligação a DNA , Fatores de Transcrição , Vibrio/crescimento & desenvolvimento , Adesinas Bacterianas/química , Adesinas Bacterianas/genética , Adesinas Bacterianas/metabolismo , Sequência de Aminoácidos , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Porinas/química , Porinas/genética , Porinas/metabolismo , Receptores Virais/química , Receptores Virais/genética , Receptores Virais/metabolismo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Vibrio/classificação , Vibrio/genética , Vibrio/metabolismo
13.
Arch Soc Esp Oftalmol (Engl Ed) ; 93(12): 606-609, 2018 Dec.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30055902

RESUMO

CASE REPORT: We report a case of 70-year-old male from Sicily, who presented with a bilateral eyelid mass involving the tarsal conjunctiva, found to be Kaposi's sarcoma on histologic examination. Cutaneous and pulmonary Kaposi's sarcoma involvement was documented. The patient had no prior diagnosis of human immunodeficiency virus infection. This case was managed successfully after the completion of five cycles of chemotherapy with liposomal doxorubicin, and his eyelid, skin and pulmonary lesions disappeared. CONCLUSIONS: Location in the eyelid is a possible, though rare, initial solitary manifestation of Kaposi's sarcoma in elderly HIV-negative patients. Liposomal doxorubicin is a safe and effective treatment.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Doxorrubicina/análogos & derivados , Neoplasias Palpebrais/tratamento farmacológico , Neoplasias Primárias Múltiplas/tratamento farmacológico , Sarcoma de Kaposi/tratamento farmacológico , Idoso , Doxorrubicina/uso terapêutico , Neoplasias Palpebrais/diagnóstico por imagem , Soronegatividade para HIV , Humanos , Masculino , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Polietilenoglicóis/uso terapêutico , Indução de Remissão , Sarcoma de Kaposi/diagnóstico por imagem , Tomografia Computadorizada por Raios X
14.
Mult Scler Relat Disord ; 25: 212-215, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30107335

RESUMO

INTRODUCTION: Multiple Sclerosis (MS) is one of the leading causes of disability in young adults. Its prevalence varies according to different countries. In Argentina there is a wide heterogeneity regarding data published in different areas of the country. Prevalence established in most studies is 17 cases per 100,000 inhabitants; however, most of the available data comes from studies that took place in Buenos Aires. There is little or no information from other provinces, especially from Northwest of Argentina (NOA), where there are no studies of the disease prevalence. The aim of this study is to investigate MS prevalence, phenotypes and epidemiological characteristics in Salta, Argentina, in order to contribute to the current knowledge of MS epidemiology and distribution in our country. METHODS: A descriptive, observational, transversal study was carried out in the capital city of Salta. Researchers from all public and private hospitals with a Neurology Department have participated. Private researchers who are well known leaders in demyelinating diseases in the city provided valuable information. Patients who did not have medical control for the past two years as well as patients whose last address was not registered in Salta were excluded. RESULTS: 120 registries were obtained from the four hospitals that participated and from the 12 private researchers. Ten patients were excluded due to overlapping data. The population of the area based on 2010 census was 535,310, so we estimated an MS prevalence 23.8 cases per 100,000 inhabitants (95% CI 20.1-27.4), 24.1 cases per 100,000 inhabitants in female population (95% CI 21.2-28.6) and 18.2 cases per 100,000 inhabitants (95% CI 15.2-21.1) in male population. In our analysis, 64 (58.2%) were female and the average age was 42.1 years. 81.8% are recurrent remitting forms, 16.4% secondary progressive and 1.8% primary progressive. CONCLUSION: This is the first study that provides epidemiological data on the prevalence and clinical forms of MS in Salta City as well as in the entire Northwest Region of Argentina(NOA). We estimate a prevalence of 23.8 cases per 100,000 inhabitants, which establishes a moderate risk area for MS.


Assuntos
Esclerose Múltipla/epidemiologia , Adolescente , Adulto , Argentina/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Sistema de Registros , População Urbana/estatística & dados numéricos , Adulto Jovem
15.
Acta Ortop Mex ; 32(6): 342-346, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-31184005

RESUMO

INTRODUCTION: Cervical spine involvement is common in patients with RA, risk factors such as disease activity may be related to asymptomatic cervical instability. OBJECTIVE: To determine the associated factors for asymptomatic cervical spine instability in patients with rheumatoid arthritis. MATERIAL AND METHODS: Case and control study from the external spine and rheumatology consultation of a level II trauma center to identify all patients diagnosed with rheumatoid arthritis (RA) and asymptomatic cervical instability. With simple X-rays of the cervical spine, carrying out radiographic measurements, the diagnosis of cervical instability was performed, risk factors such as the presence of rheumatoid factor (FR), previous articular surgeries, elevations of the C-reactive protein (PCR) values were evaluated. The severity and activity of the disease measured in the activity index of 28 articulations (DAS 28) in addition to the index of activity of the simplified disease (SDAI). RESULTS: We assessed 32 patients, nine patients (28.1%) met the criteria for instability of the anterior cervical spine atlantoaxial subluxation (SAAa) (100%), also one patient with SAAa presented vertical subluxation (SV), risk factors more relevant: DAS 28 with an OR = 3.54, SDA with an OR = 2.34 and finally the PCR 1.0 its OR = 2.88. CONCLUSION: The risk factors associated opportunely in our population are the severity of the activity of the disease that we can see in the DAS and SDAI when applied in patients and PCR 1.0.


INTRODUCCIÓN: La afectación de la columna cervical es común en pacientes con artritis reumatoide (AR), factores de riesgo como la actividad de la enfermedad puede estar relacionada con inestabilidad cervical asintomática. OBJETIVO: Determinar los factores asociados a la inestabilidad de la columna cervical asintomáticos en pacientes con artritis reumatoide. MATERIAL Y MÉTODOS: Estudio de casos y controles provenientes de la consulta externa de reumatología y columna de un centro de trauma de nivel II para identificar a todos los pacientes diagnosticados con AR e inestabilidad cervical asintomáticos. Con radiografías simples de la columna cervical que hacen mediciones radiográficas, se realizó el diagnóstico de inestabilidad cervical, se evaluaron los factores de riesgo como la presencia de factor reumatoide (FR), cirugías articulares previas, las elevaciones de los valores de proteína C reactiva (PCR), la severidad y actividad de la enfermedad medida en el índice de actividad de la enfermedad de 28 articulaciones (DAS 28), además del índice de actividad de la enfermedad simplificada (SDAI). RESULTADOS: Se evaluaron 32 pacientes, nueve (28.1%) cumplieron con los criterios para inestabilidad de la columna cervical con subluxación atlantoaxial anterior (SAAa) (100%), también un paciente con SAAa presentaba subluxación vertical (SV), los factores de riesgo más relevantes: el DAS 28 con un OR = 3.54, SDA con un OR = 2.34 y por último el PCR 1.0 su OR = 2.88. CONCLUSIÓN: Los factores de riesgo asociados oportunamente en nuestra población son la severidad de la actividad de la enfermedad que podemos observar en el DAS y SDAI al aplicarlos en los pacientes y PCR 1.0.


Assuntos
Artrite Reumatoide , Vértebras Cervicais , Luxações Articulares , Instabilidade Articular , Artrite Reumatoide/complicações , Articulação Atlantoaxial , Vértebras Cervicais/patologia , Humanos
16.
Nat Biotechnol ; 14(5): 620-3, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-9630954

RESUMO

Glucose is the preferred substrate for certain fermentation processes. During its internalization and concomitant formation of glucose-6-phosphate through the glucose phosphotransferase system (PTS), one molecule of phosphoenolpyruvate (PEP) is consumed. Together with erythrose 4-phosphate (E4P), PEP is condensed to form 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP), the first intermediate of the common segment of the aromatic pathway. From this metabolic route, several commercially important aromatic compounds can be obtained. We have selected Escherichia coli mutants that can transport glucose efficiently by a non-PTS uptake system. In theory, this process should increase the availability of PEP for other biosynthetic reactions. Using these mutants, in a background where the DAHP synthase (the enzyme that catalyzes the condensation of PEP and E4P into DAHP) was amplified, we were able to show that at least some of the PEP saved during glucose transport, can be redirected into the aromatic pathway. This increased carbon commitment to the aromatic pathway was enhanced still further upon amplification of the E. coli tktA gene that encodes for a transketolase involved in the biosynthesis of E4P.


Assuntos
Escherichia coli/genética , Escherichia coli/metabolismo , Engenharia Genética , Hidrocarbonetos Aromáticos/metabolismo , 3-Desoxi-7-Fosfo-Heptulonato Sintase/genética , 3-Desoxi-7-Fosfo-Heptulonato Sintase/metabolismo , Transporte Biológico Ativo , Biotecnologia , Genes Bacterianos , Glucose/metabolismo , Mutação , Fenótipo , Fosfoenolpiruvato/metabolismo , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/genética , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/metabolismo , Plasmídeos/genética , Fosfatos Açúcares/metabolismo , Transcetolase/genética , Transcetolase/metabolismo
17.
Pharmacol Ther ; 72(2): 83-108, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8981572

RESUMO

Experimental and clinical observations of the involvement of platelets in the pathophysiology of myocardial ischaemia indicate the importance of interactions between these formed elements and the heart. The aim of this review is to outline evidence linking platelet activation, myocardial ischaemia and infarction, and to present evidence for a link between platelet activation, arrhythmogenesis and sudden death. A brief review of platelet physiology and pharmacology is provided, with a review of the cardiac electrophysiological effects of ischaemia and the electrophysiological effects of platelet-derived substances. The concept that platelet activation during myocardial ischaemia is a contributory arrhythmogenic mechanism is discussed.


Assuntos
Arritmias Cardíacas/sangue , Isquemia Miocárdica/sangue , Ativação Plaquetária/fisiologia , Animais , Antiarrítmicos/farmacologia , Arritmias Cardíacas/etiologia , Morte Súbita Cardíaca/etiologia , Humanos , Infarto do Miocárdio/sangue , Infarto do Miocárdio/complicações , Isquemia Miocárdica/complicações , Ativação Plaquetária/efeitos dos fármacos
18.
J Phys Chem B ; 109(45): 21305-12, 2005 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-16853763

RESUMO

We study the complex between a colloidal particle and a semiflexible polymer chain that "wraps" around it. Via molecular dynamics simulation we investigate statistical and dynamical properties of this system. First we establish the dependence of wrapped chain length on absorption energy and chain persistence length and obtain the distribution of wrapped-sphere positions. Then we study the length and position distributions of thermally excited loop defects. Finally we consider the repositioning dynamics of the colloid, focusing on the case where the chain stays wrapped onto the complex. Specifically we determine the mean square displacement of the central monomer of the wrapped chain and the resulting diffusion coefficient of the chain as a function of its persistence length, absorption energy, chain length, and size of the sphere. We argue that both statics and dynamics of these complexes can be mainly understood by energetic arguments, whereas entropic contributions from the chain configurations play only a minor role.

19.
J Food Prot ; 68(3): 534-7, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15771178

RESUMO

The effect of 15 consumable products, including juices, wines, and vinegar, used as rinsing agents on microbial loads of retail skinless, boneless chicken breasts was evaluated in two studies. Ten breasts were rinsed for 1 min with each solution. Samples were swabbed before and after rinsing with a cellulose sponge and evaluated for total aerobic (APC), total coliform (TCC), and generic Escherichia coli counts by Petrifilm methods. No differences were found in initial APC or TCC in either study, with initial mean APC ranging from 5.30 to 7.05 log CFU/cm2 and initial mean TCC ranging from 2.21 to 3.36 log CFU/cm2. In study 1, the APC for breasts rinsed with distilled white vinegar (3.22 log CFU/cm2) was lower than for those rinsed with all other solutions except cranberry juice cocktail (3.86 log CFU/cm2). The TCC for breasts rinsed with distilled white vinegar (0.00 log CFU/cm2) and cranberry juice cocktail (0.20 log CFU/cm2) were lower than those for all other solutions except 10% NaCl (0.43 log CFU/cm2) and 10% NaHCO3 (0.48 log CFU/cm2). In study 2, APC values for breasts rinsed with red wine (5.29 log CFU/cm2) and white wine (5.32 log CFU/cm2) were lower than for breasts rinsed with the other three solutions. The TCC after rinsing with chicken broth (4.48 log CFU/cm2) was higher than for all other solutions except Italian dressing. Although distilled white vinegar was the most effective rinsing agent, all solutions produced lower counts after rinsing, indicating that consumers could use rinsing to remove microorganisms from chicken breast surfaces prior to cooking.


Assuntos
Desinfetantes/farmacologia , Manipulação de Alimentos/métodos , Carne/microbiologia , Animais , Galinhas , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Microbiologia de Alimentos , Humanos
20.
Cardiovasc Res ; 42(1): 15-26, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10434992

RESUMO

Diadenosine polyphosphates are members of a group of dinucleoside polyphosphates that are ubiquitous, naturally occurring molecules. They form a recently identified class of compounds derived from ATP and consist of two adenosine molecules bridged by up to six phosphate groups. These compounds are stored in high concentrations in platelet dense granules and are released when platelets become activated. Some of the compounds promote platelet aggregation, while others are inhibitory. Possible roles as neurotransmitters, extracellular signalling molecules or 'alarmones' secreted by cells in response to physiologically stressful stimuli have been postulated. Recent studies suggest a role for these compounds in atrial and synaptic neurotransmission. Studies using isolated mesenteric arteries indicate an important role of phosphate chain length in determining whether diadenosine polyphosphates produce vasodilation or vasoconstriction, but in the coronary circulation, diadenosine polyphosphates generally produce vasodilation via mechanisms thought to involve release of NO or prostacyclin (PGI2). They produce cardiac electrophysiological effects by altering ventricular refractoriness at submicromolar concentrations and reduce heart rate. Mechanisms involving KATP channels have been proposed in addition to the involvement of P1- and P2-purinergic receptors and the specific diadenosine polyphosphate receptor identified on isolated cardiac myocytes. Clinical evidence suggests a role for diadenosine polyphosphates in hypertensive patients and those with the Chédiak-Higashi syndrome. This review outlines the effects of these compounds on the cardiovascular system and considers their potential involvement in mediating the pathophysiological effects associated with platelet activation during myocardial ischaemia.


Assuntos
Sistema Cardiovascular/fisiopatologia , Fosfatos de Dinucleosídeos/fisiologia , Inibidores da Agregação Plaquetária/farmacologia , Sistemas do Segundo Mensageiro/fisiologia , Vasodilatação/fisiologia , Potenciais de Ação , Animais , Sistema Cardiovascular/metabolismo , Fosfatos de Dinucleosídeos/química , Endotélio Vascular/metabolismo , Humanos , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/fisiopatologia , Canais de Potássio , Receptores Purinérgicos/metabolismo , Resistência Vascular
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