RESUMEN
Harsh weather patterns that are unpredictable owing to climate change, remoteness, dependence on food imports and limited local food production place Arctic and Subarctic food systems under serious pressure. The model of food sovereignty provides a surprisingly interesting contribution to address the food insecurity in these regions; it promotes long-term stable provision of healthy foods (sustainable) that are accessible to all (equity) and fosters local food production-consumption patterns (localisation). This study aims to deepen the understanding of food insecurity in the Subarctic regions and explores the possibilities for a food sovereignty approach at both individual and regional level. The study focuses on Whitehorse, capital of Yukon, Canada, and uses a cross-sectional online survey among residents of Whitehorse and semi-structured in-depth interviews with food-systems experts in Yukon. The findings indicated a need for affordable year-round local food production. Application of food sovereignty has provided the opportunities for local food procurement, innovation hubs, and several types of greenhouses including hydroponics and vertical farming, to work towards a more localised food system, thereby improving food security and sovereignty in Yukon. The findings constitute the scientific knowledge base for the formulation of prospective scenarios in the spirit of the food sovereignty theory.
Asunto(s)
Abastecimiento de Alimentos , Alimentos , Estudios Transversales , Seguridad Alimentaria , Humanos , Estudios Prospectivos , El YukónRESUMEN
Purpose: Recurrent pregnancy loss (RPL) is defined as three or more consecutive pregnancy losses and affects 1-3% of couples trying to conceive. Pregnancy loss is more common among RPL patients' siblings than in the general population. Our objective was to investigate whether first-degree relatives with pregnancy losses influenced the chance of live birth in the first pregnancy after referral among women with RPL.Materials and methods: This is a cohort study of 2138 women with RPL seen at the Danish RPL Unit at Copenhagen University Hospital, Rigshospitalet between January 1st 2000 and December 31st 2017 with follow-up until December 2018. Pregnancies among first-degree relatives were reported by patients at their first consultation. Chance of live birth after referral was compared by logistic regression analysis.Results: Overall, 76% of the referred women achieved a pregnancy after referral and of these, 58% delivered a live born child. Women whose mother had experienced pregnancy loss were referred at a younger age than women with no pregnancy losses among first-degree relatives (mean age 33.6 (SD 4.6) versus 34.3 (SD 4.5), p = 0.002). Pregnancy losses among first-degree relatives did not influence chance of live birth.Conclusions: Our results indicate that pregnancy losses among first-degree family members is not an important risk factor for outcome of the first pregnancy after referral among women with RPL.
Asunto(s)
Aborto Habitual/genética , Nacimiento Vivo/genética , Derivación y Consulta/estadística & datos numéricos , Historia Reproductiva , Adulto , Bases de Datos Factuales , Dinamarca , Femenino , Humanos , Linaje , Embarazo , Sistema de Registros , Factores de RiesgoRESUMEN
Three questionnaires are recommended in the management of chronic obstructive pulmonary disease by the global initiative for obstructive lung disease, of which two are the more comprehensive assessments: the chronic obstructive pulmonary disease assessment test and the clinical chronic obstructive pulmonary disease questionnaire. Both are carefully designed high-quality questionnaires, but information on the feasibility for routine use is scarce. The aim of this study was to compare the time to complete the chronic obstructive pulmonary disease assessment test and the clinical chronic obstructive pulmonary disease questionnaire and the acceptability of the questionnaires. Furthermore, the agreement between electronic and paper versions of the questionnaires was explored. The time to complete the electronic versions of the questionnaires was 99.6 [IQR 74; 157] vs. 97.5 [IQR 68; 136] seconds for clinical clinical chronic obstructive pulmonary disease questionnaire and chronic obstructive pulmonary disease assessment test, respectively. The difference in time to complete the questionnaire was not significant. The two questionnaires did not differ in "easiness to complete" or "importance of issues raised in questionnaires". Electronic vs. paper versions revealed high agreement (ICC CCQ = 0.815 [0.712; 0.883] and ICC CAT = 0.751 [0.608; 0.847]) between the administration methods. Based on this study it can be concluded that both questionnaires are equally suitable for use in routine clinical practice, because they are both quick to complete and have a good acceptability by the patient. Agreement between electronic and paper versions of the questionnaires was high, so use of electronic versions is justified.COPD: QUESTIONNAIRES EQUALLY SUITABLE FOR CLINICAL PRACTICE: Two questionnaires commonly used to manage chronic obstructive pulmonary diseases (COPD) are equally suitable for routine primary care. Researchers in The Netherlands, led by Janwillem Kocks from the University Medical Center Groningen, administered both the COPD assessment test (CAT) and the clinical COPD questionnaire (CCQ) to 95 patients with the lung disease. These two tests are the most comprehensive assessments recommended by the global initiative for obstructive lung disease for guiding treatment decisions. The researchers found that both tests took approximately 95-100 s on average. Both tests were also equally easy to complete and provided similar types of information. Most patients said they had no preference for either one, and they filled out both electronic and paper versions of the questionnaires in much the same way. The authors conclude that both tests seem fine for routine use.
Asunto(s)
Atención Primaria de Salud , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Anciano , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos , Aceptación de la Atención de Salud , Encuestas y Cuestionarios , Factores de TiempoRESUMEN
BACKGROUND: COPD is a highly complex disease to manage as patients show great variation in symptoms and limitations in daily life. In the last decade self-management support of COPD has been introduced as an effective method to improve quality and efficiency of care, and to reduce healthcare costs. Despite the urge to change the organisation of health care and the potential of eHealth to support this, large-scale implementation in daily practice remains behind, especially in the Netherlands. METHODS/DESIGN: We designed a multilevel study, called e-Vita, to investigate different organisational implementation methods of a self-management web portal to support and empower patients with COPD in three different primary care settings. Using a parallel cohort design, the clinical effects of the web portal will be assessed using an interrupted times series (ITS) study design and measured according to changes in health status with the Clinical COPD Questionnaire (CCQ). The different implementations and net benefits of self-management through eHealth on clinical outcomes will be evaluated from human, organisational, and technical perspectives. DISCUSSION: To our knowledge this is the first study to combine different study designs that enable simultaneous investigation of clinical effects, as well as effects of different organisational implementation methods whilst controlling for confounding effects of the organisational characteristics. We hypothesize that an implementation with higher levels of personal assistance, and integrated in an existing care program will result in increased use of and satisfaction with the platform, thereby increasing health status and diminishing exacerbation and hospitalisation. TRIAL REGISTRATION NUMBER: NTR4098 (31-07-2013).
RESUMEN
BACKGROUND: COPD is a highly complex disease to manage as patients show great variation in symptoms and limitations in daily life. In the last decade self-management support of COPD has been introduced as an effective method to improve quality and efficiency of care, and to reduce healthcare costs. Despite the urge to change the organisation of health care and the potential of eHealth to support this, large-scale implementation in daily practice remains behind, especially in the Netherlands. METHODS/DESIGN: We designed a multilevel study, called e-Vita, to investigate different organisational implementation methods of a self-management web portal to support and empower patients with COPD in three different primary care settings. Using a parallel cohort design, the clinical effects of the web portal will be assessed using an interrupted times series (ITS) study design and measured according to changes in health status with the Clinical COPD Questionnaire (CCQ). The different implementations and net benefits of self-management through eHealth on clinical outcomes will be evaluated from human, organisational, and technical perspectives. DISCUSSION: To our knowledge this is the first study to combine different study designs that enable simultaneous investigation of clinical effects, as well as effects of different organisational implementation methods whilst controlling for confounding effects of the organisational characteristics. We hypothesize that an implementation with higher levels of personal assistance, and integrated in an existing care program will result in increased use of and satisfaction with the platform, thereby increasing health status and diminishing exacerbation and hospitalisation. TRIAL REGISTRATION: NTR4098 (31-07-2013).
Asunto(s)
Prestación Integrada de Atención de Salud/economía , Manejo de la Enfermedad , Enfermedad Pulmonar Obstructiva Crónica/terapia , Autocuidado/métodos , Telemedicina/estadística & datos numéricos , Costos de la Atención en Salud , Estado de Salud , Humanos , Internet , Países Bajos , Evaluación de Resultado en la Atención de Salud , Atención Primaria de Salud/métodos , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/economía , Proyectos de Investigación , Encuestas y CuestionariosRESUMEN
The objective of the present study was to investigate exposure-response relationships between current endotoxin exposure and allergic and respiratory symptoms in adults, taking into account farming exposures during childhood. A cross-sectional study was conducted among 877 Dutch farmers and agricultural industry workers in 2006. Based on 249 full-shift personal airborne endotoxin samples, a job-exposure matrix was constructed to assign endotoxin exposure levels to all participants. Associations between endotoxin exposure and questionnaire data on symptoms were studied by multiple logistic regression. Adjusted odds ratios (OR) for an interquartile range increase in endotoxin level were elevated for respiratory symptoms such as wheezing (OR 1.41 (95% confidence interval 1.16-1.72)), wheezing with shortness of breath (1.50 (1.18-1.90)) and daily cough (1.29 (1.03-1.62)). In contrast, endotoxin was strongly associated with a decreased prevalence of hay fever (0.62 (0.49-0.78)). Workers who had grown up on a farm had a lower prevalence of hay fever, but no evidence was found of effect modification by farm childhood. In conclusion, occupational endotoxin exposure in adulthood is associated with an increased risk of asthma-like symptoms but a reduced prevalence of hay fever.
Asunto(s)
Enfermedades de los Trabajadores Agrícolas/etiología , Asma/etiología , Endotoxinas/efectos adversos , Exposición Profesional/efectos adversos , Trastornos Respiratorios/etiología , Adulto , Enfermedades de los Trabajadores Agrícolas/epidemiología , Enfermedades de los Trabajadores Agrícolas/inmunología , Niño , Estudios Transversales , Endotoxinas/análisis , Endotoxinas/inmunología , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Exposición Profesional/análisis , Oportunidad Relativa , Trastornos Respiratorios/epidemiología , Rinitis Alérgica Estacional/epidemiología , Rinitis Alérgica Estacional/etiologíaRESUMEN
Human parvovirus B19 is a small non-enveloped DNA virus with an icosahedral capsid consisting of proteins of only two species, the major protein VP2 and the minor protein VP1. VP2 is contained within VP1, which has an additional unique portion (VP1u) of 227 amino acids. We determined the ability of eukaryotically expressed parvovirus B19 virus-like particles consisting of VP1 and VP2 in the ratio recommended for vaccine use, or of VP2 alone, to stimulate, in an HLA class II restricted manner, peripheral blood mononuclear cells (PBMC) to proliferate and to secrete interferon gamma (IFN-gamma) and interleukin (IL)-10 cytokines among recently and remotely B19 infected subjects. PBMC reactivity with VP1u was determined specifically with a prokaryotically expressed VP1u antigen. In general, B19-specific IFN-gamma responses were stronger than IL-10 responses in both recent and remote infection; however, IL-10 responses were readily detectable among both groups, with the exception of patients with relapsed or persisting symptoms who showed strikingly low IL-10 responses. Whereas VP1u-specific IFN-gamma responses were very strong among the recently infected subjects, the VP1u-specific IFN-gamma and IL-10 responses were virtually absent among the remotely infected subjects. The disappearance of VP1u-specific IFN-gamma expression is surprising, as B-cell immunity against VP1u is well maintained.
Asunto(s)
Proteínas de la Cápside/inmunología , Interferón gamma/inmunología , Infecciones por Parvoviridae/inmunología , Parvovirus B19 Humano/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Adulto , División Celular/inmunología , Células Cultivadas , Endotoxinas/inmunología , Epítopos/inmunología , Femenino , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Inmunidad Celular/inmunología , Interleucina-10/inmunología , Leucocitos Mononucleares/inmunología , Masculino , Persona de Mediana Edad , Embarazo , Complicaciones Infecciosas del Embarazo/inmunologíaRESUMEN
Canine parvovirus (CPV) is a small non-enveloped ssDNA virus composed of the viral proteins VP1, VP2, and VP3 with a T=1 icosahedral symmetry. VP2 is nested in VP1 and the two proteins are produced by differential splicing of a primary transcript of the right ORF of the viral genome. The VP2 protein can be further proteolytically cleaved to form VP3. Previous studies have shown that VP1 and VP3 are unnecessary for capsid formation and consequently, that VP2 alone is sufficient for assembly. We have hypothesized that insertion of the enhanced green fluorescent protein (EGFP) at the N-terminus of VP2 could be carried out without altering assembly. To investigate the possibility to develop fluorescent virus-like particles (fVLPs) from such chimeric VP2 proteins, the corresponding fusion construct was abundantly expressed in insect cells. Confocal imaging indicated that the EGFP-VP2 fusion product was assembled to fluorescent capsid-like complexes. In addition, electron micrographs of purified EGFP-VP2 complexes showed that they displayed a very similar size and appearance when compared to VP2 VLPs. Further, immunolabelling of purified EGFP-VP2 VLPs showed the presence of EGFP within the structure. Fluorescence correlation spectroscopy (FCS) studies confirmed that fVLPs were very similar in size when compared to authentic CPV. Finally, feeding of mammalian cells susceptible to CPV infection with these fVLPs indicated that entry and intracellular trafficking could be observed. In summary, we have developed fluorescent virus-like nanoparticles carrying a heterologous entity that can be utilized as a visualization tool to elucidate events related to a canine parvovirus infection.
Asunto(s)
Cuerpos de Inclusión Viral/ultraestructura , Parvovirus Canino/genética , Parvovirus Canino/ultraestructura , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Proteínas de la Cápside/genética , Proteínas de la Cápside/metabolismo , Línea Celular , Quimera , Proteínas Fluorescentes Verdes , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Microscopía Confocal , Microscopía Electrónica , Parvovirus Canino/fisiología , Plásmidos/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Spodoptera , Ensamble de VirusRESUMEN
The purpose of this retrospective analysis was to evaluate the use of nuclear scintigraphy in determining the rate of secondary sites of osseous malignancy at initial presentation in dogs with osteosarcoma. Radiographs of suspicious secondary lesions were reviewed and placed into four separate categories: benign lesions; no lesion seen on radiographs; subtle radiographic changes suggestive of, but not conclusive for, metastasis; and metastatic lesions highly suspected on radiographs. Three hundred and ninety-nine dogs were evaluated by technetium nuclear scanning for suspected osteosarcoma. Three hundred and twenty-six of 399 dogs (82%) had only one apparent site on the nuclear scan, whereas 72 dogs (18%) had more than one suspicious site on the nuclear scans. Highly suspected secondary metastatic lesions were detected by nuclear scans in 7.8% of cases. Although interpretation of nuclear scans is subjective, this study showed a 7.8% chance of detecting unsuspected osseous metastasis with nuclear scans in canine osteosarcoma patients on initial presentation.
RESUMEN
AIM: To improve the quality of dietetic care, dietitians in the University Medical Center Utrecht (UMCU) are encouraged to develop and implement 'evidence-based' guidelines. The aim of this pilot study was to develop and test a questionnaire for implementation research to monitor the process of developing and implementing these guidelines. METHODS: A questionnaire was developed and distributed to 15 dietitians, who have started developing an 'evidence-based' guideline. The questionnaire measures determinants of dietitians' behaviour and the presence of conditions facilitating the development of a guideline. Cronbach's alpha with a cut-off point of 0.7 was used to analyse the internal consistence between the items related to behavioural determinants. A panel of professionals such as a member of staff from the UMCU, a communication expert and project-managers ensured the completeness of the questionnaire. RESULTS: The internal consistency was high (alpha > 0.7) between the items related to the determinants of behaviour. The questionnaire gives a structured overview of factors affecting positively or negatively the process of guideline development. Although dietitians have a positive behaviour towards guideline development, they perceived barriers related to the presence of conditions to develop a guideline. CONCLUSION: We concluded that the applied questionnaire is appropriate for implementation research and has given a structured overview of factors that influence the development of dietetic guidelines by dietitians in the UMCU.
Asunto(s)
Actitud del Personal de Salud , Dietética/normas , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios , Medicina Basada en la Evidencia , Conocimientos, Actitudes y Práctica en Salud , Humanos , Países Bajos , Proyectos PilotoRESUMEN
Phosphatidylinositol 4-kinases (PI4K) catalyze the first step in the synthesis of phosphatidylinositol 4,5-bisphosphate, an important lipid regulator of several cellular functions. Here we show that the Ca(2+)-binding protein, neuronal calcium sensor-1 (NCS-1), can physically associate with the type III PI4Kbeta with functional consequences affecting the kinase. Recombinant PI4Kbeta, but not its glutathione S-transferase-fused form, showed enhanced PI kinase activity when incubated with recombinant NCS-1, but only if the latter was myristoylated. Similarly, in vitro translated NCS-1, but not its myristoylation-defective mutant, was found associated with recombinant- or in vitro translated PI4Kbeta in PI4Kbeta-immunoprecipitates. When expressed in COS-7 cells, PI4Kbeta and NCS-1 formed a complex that could be immunoprecipitated with antibodies against either proteins, and PI 4-kinase activity was present in anti-NCS-1 immunoprecipitates. Expressed NCS-1-YFP showed co-localization with endogenous PI4Kbeta primarily in the Golgi, but it was also present in the walls of numerous large perinuclear vesicles. Co-expression of a catalytically inactive PI4Kbeta inhibited the development of this vesicular phenotype. Transfection of PI4Kbeta and NCS-1 had no effect on basal PIP synthesis in permeabilized COS-7 cells, but it increased the wortmannin-sensitive [(32)P]phosphate incorporation into phosphatidylinositol 4-phosphate during Ca(2+)-induced phospholipase C activation. These results together indicate that NCS-1 is able to interact with PI4Kbeta also in mammalian cells and may play a role in the regulation of this enzyme in specific cellular compartments affecting vesicular trafficking.
Asunto(s)
1-Fosfatidilinositol 4-Quinasa/metabolismo , Señalización del Calcio , Proteínas de Unión al Calcio/metabolismo , Neuropéptidos/metabolismo , Fosfatidilinositoles/metabolismo , Animales , Transporte Biológico , Células COS , Bovinos , Compartimento Celular , Membrana Celular/metabolismo , Permeabilidad de la Membrana Celular , Chlorocebus aethiops , Lipoproteínas/metabolismo , Ácidos Mirísticos , Proteínas Sensoras del Calcio Neuronal , Fosfatos de Fosfatidilinositol/metabolismo , Unión Proteica , Procesamiento Proteico-Postraduccional , RatasRESUMEN
BACKGROUND: the structural proteins of rubella virus, the capsid protein C and the envelope glycoproteins E1 and E2 were produced in lepidopteran insect cells using baculovirus expression vectors. The C-terminal ends of the corresponding proteins were fused to a polyhistidine tag for easy and gentle purification by metal ion affinity chromatography. OBJECTIVES: to investigate the maturation of natural and vaccinal IgG avidity against individual authentic and recombinant rubella virus (RV) structural proteins. STUDY DESIGN: the analysis was carried out using a modified immunoblotting technique where the purified baculovirus-expressed proteins were compared with authentic rubella virus proteins. Altogether, 47 well-characterised serum samples from both naturally infected patients and vaccines were studied. RESULTS: after natural RV infection, IgG antibodies specific for the E1 protein were predominant not only in terms of levels, but also in terms of rate and magnitude of avidity maturation. The avidity development of the IgG antibodies was much slower in vaccines than in patients after a natural RV infection. CONCLUSIONS: together, our results indicate that IgG avidity determination in conjunction with immunoblot analysis is useful in the diagnosis of a RV infection. The recombinant proteins showed similar reactivity patterns in the immunoblot analyses as compared with the authentic viral structural proteins, suggesting suitability for serodiagnostics.
Asunto(s)
Anticuerpos Antivirales/inmunología , Afinidad de Anticuerpos/inmunología , Inmunoglobulina G/inmunología , Rubéola (Sarampión Alemán)/inmunología , Proteínas del Núcleo Viral/inmunología , Proteínas del Envoltorio Viral/inmunología , Anticuerpos Antivirales/sangre , Humanos , Inmunoglobulina G/sangre , Rubéola (Sarampión Alemán)/sangre , Vacuna contra la Rubéola/inmunología , Virus de la Rubéola/inmunología , VacunaciónRESUMEN
Viral vectors displaying specific ligand binding moieties have raised an increasing interest in the area of targeted gene therapy. In this report, we describe baculovirus vectors displaying either a functional single chain antibody fragment (scFv) specific for the carcinoembryonic antigen (CEA) or the synthetic IgG binding domains (ZZ) derived from protein A of Staphylococcus aureus. In addition, the vectors were engineered to incorporate a reporter gene encoding the enhanced green fluorescent protein (EGFP) under the transcriptional regulation of the cytomegalovirus (CMV) IE promoter. Display of the targeting moieties on the viral surface was achieved through fusion to the N-terminus of gp64, the major envelope protein of the Autographa californica nuclear polyhedrosis virus (AcNPV). Specific binding of the gp64 fusion viruses to mammalian target cells was demonstrated by using monoclonal anti-gp64 antibodies followed by fluorescence and/or confocal microscopy. The anti-CEA scFv displaying baculovirus was shown to bind specifically to CEA expressing cells (PC-3). Similarly, the virus displaying the ZZ domains of protein A was targeted to BHK cells via binding of an appropriate IgG antibody. In all cases, the reporter gene was expressed in the transduced mammalian cells as shown by fluorescence microscopy and flow cytometric analyses.
Asunto(s)
Baculoviridae/genética , Proteínas Virales de Fusión/genética , Animales , Anticuerpos Monoclonales/inmunología , Antígeno Carcinoembrionario/inmunología , Línea Celular , Cricetinae , Genes Reporteros , Terapia Genética , Vectores Genéticos , Proteínas Fluorescentes Verdes , Región Variable de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/inmunología , Proteínas Luminiscentes/genética , Microscopía Fluorescente , Proteínas Recombinantes de Fusión/metabolismo , Spodoptera/genética , Proteína Estafilocócica A/inmunología , Transducción Genética , Transfección , Células Tumorales Cultivadas , Proteínas Virales de Fusión/inmunología , Proteínas Virales de Fusión/metabolismoRESUMEN
The ability to couple genotype to phenotype has proven to be of immense value in systems such as phage display and has allowed genes encoding novel functions to be selected directly from complex libraries. However, the complexity of many eukaryotic proteins places a severe constraint on successful display in Escherichia coli. This restriction could be resolved if a eukaryotic virus could be similarly engineered for display purposes. Preliminary data have suggested that the baculovirus Autographa californica, a multiple nuclear polyhedrosis virus (AcMNPV) is a candidate for eukaryotic virus display because the insertion of peptides into the native virus coat protein, or the expression of foreign proteins as coat protein fusions, results in incorporation of the sequence of interest onto the surface of virus particles. A variety of strategies are currently under investigation to develop further the display capabilities of AcMNPV and to improve the complexity of library that might be accommodated. Several expression vectors for different forms of surface display have been developed and, coupled with improved recombination strategies, represent progress towards a refined tool for use in functional genomics and in vitro protein evolution.
Asunto(s)
Baculoviridae/genética , Ingeniería Genética/métodos , Biblioteca de Péptidos , Animales , Clonación Molecular , Técnicas de Transferencia de Gen , Genoma Viral , Insectos/citología , Proteínas Virales de Fusión/genética , Proteínas Virales de Fusión/metabolismo , ViriónRESUMEN
Fibroblast growth factor receptor subtype 4 (FGFR4) has been shown to have special activation properties and just one splicing form, unlike the other FGFRs. FGFR4 overexpression is correlated with breast cancer and therefore FGFR4 is a target for drug design. Our aim is to overexpress high amounts of homogeneous FGFR4 extracellular domain (FGFR4(ed)) for structural studies. We show that baculovirus-insect cell-expressed FGFR4(ed) is glycosylated on three (N88, N234, and N266) of the six possible N-glycosylation sites but is not O-glycosylated. The deglycosylated triple mutant was expressed and had binding properties similar to those of glycosylated FGFR4(ed), but was still heterogeneous. Large amounts of FGFR4(ed) have been produced into inclusion bodies in Escherichia coli and refolded at least partly correctly but the refolded E. coli-produced FGFR4(ed) still aggregates.
Asunto(s)
Receptores de Factores de Crecimiento de Fibroblastos/química , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Secuencia de Aminoácidos , Animales , Baculoviridae/genética , Western Blotting , Línea Celular , Cromatografía Líquida de Alta Presión , Disulfuros/metabolismo , Escherichia coli/genética , Glicosilación , Heparina/metabolismo , Humanos , Immunoblotting , Cuerpos de Inclusión/metabolismo , Espectrometría de Masas , Datos de Secuencia Molecular , Mutación/genética , Pliegue de Proteína , Renaturación de Proteína , Receptor Tipo 4 de Factor de Crecimiento de Fibroblastos , Receptores de Factores de Crecimiento de Fibroblastos/genética , Receptores de Factores de Crecimiento de Fibroblastos/aislamiento & purificación , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Tripsina/metabolismoRESUMEN
The coleopteran firefly, Photinus pyralis, luciferase was produced in lepidopteran Trichoplusia ni insect cells using a baculovirus expression vector. The recombinant protein was equipped with a polyhistidine affinity tag at the carboxyl terminus and purified by immobilized metal-ion affinity chromatography in combination with an expanded bed adsorption system. This approach enabled an efficient, one-step purification protocol of a genetically modified luciferase with properties similar to those of the authentic counterpart. According to light emission measurements, the final yield of highly purified protein was 23 mg l(-1) of cell culture. In addition, no specific interaction of interfering substances, such as, ATP, adenylate kinase, nucleoside diphosphokinase, as well as, creatine kinase of the final preparation were identified. Together, the results presented here clearly show that the baculovirus expression system in combination with immobilized metal-ion affinity chromatography is a potential strategy for process scale-up of polyhistidine tagged insect luciferase.
Asunto(s)
Histidina/biosíntesis , Histidina/genética , Luciferasas/biosíntesis , Luciferasas/genética , Péptidos/genética , Péptidos/aislamiento & purificación , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/aislamiento & purificación , Animales , Escarabajos/enzimología , Escarabajos/genética , Histidina/aislamiento & purificación , Luciferasas/aislamiento & purificación , Mariposas Nocturnas/enzimología , Mariposas Nocturnas/genética , Péptidos/metabolismo , Ingeniería de Proteínas/métodos , Proteínas Recombinantes de Fusión/genéticaRESUMEN
Viral vectors displaying specific ligand binding moities such as scFv fragments or intact antibodies hold promise for the development of targeted gene therapy vectors. In this report we describe baculoviral vectors displaying either functional scFv fragments or the synthetic Z/ZZ IgG binding domain derived from protein A. Display on the baculovirus surface was achieved via fusion of the scFv fragment or Z/ZZ domain to the N-terminus of gp64, the major envelope protein of the Autographa californica nuclear polyhedrosis virus, AcNPV. As examples of scFv fragments we have used a murine scFv specific for the hapten 2-phenyloxazolone and a human scFv specific for carcinoembryonic antigen. In principle, the Z/ZZ IgG binding domain displaying baculoviruses could be targeted to specific cell types via the binding of an appropriate antibody. We envisage applications for scFv and Z/ZZ domain displaying baculoviral vectors in the gene therapy field.
Asunto(s)
Baculoviridae/genética , Sitios de Unión de Anticuerpos/inmunología , Fragmentos de Inmunoglobulinas/inmunología , Inmunoglobulina G/inmunología , Biblioteca de Péptidos , Animales , Especificidad de Anticuerpos , Baculoviridae/metabolismo , Sitios de Unión de Anticuerpos/genética , Western Blotting , Antígeno Carcinoembrionario/genética , Antígeno Carcinoembrionario/inmunología , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Haptenos/genética , Haptenos/inmunología , Humanos , Fragmentos de Inmunoglobulinas/genética , Inmunoglobulina G/genética , Ratones , Oxazolona/análogos & derivados , Oxazolona/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismo , Spodoptera/virología , Proteínas Virales de Fusión/genética , Proteínas Virales de Fusión/metabolismoRESUMEN
In a study on the mechanism of stimulated petiole elongation in submerged plants, oxygen concentrations in petioles of the flood-tolerant plant Rumex palustris were measured with micro-electrodes. Short-term submergence lowered petiole partial oxygen pressure to c. 19 kPa whereas prolonged submergence under continuous illumination depressed oxygen levels to c. 8-12 kPa after 24 h. Oxygen levels in petioles depended on the presence of the lamina, even in submerged conditions, and on available light. In darkness, petiole oxygen levels in submerged plants dropped quickly to values as low as 0.5-4 kPa. It is hypothesized that prolonged submergence in the light is accompanied by a decrease in carbon dioxide in the petiole. Submergence-enhanced petiolar elongation rate was compared with emergent plants. Peak daily elongation rates occurred at the end of the dark period in emergent plants, but in the middle of the light period in submerged plants. We suggest that this shift in daily elongation pattern is induced by dependence of growth on photosynthetically derived oxygen in submerged plants. Implications of reduced oxygen for ethylene production are raised. Levels of 1- aminocyclopropane-1-carboxylic acid synthase and 1-aminocyclopropane-1-carboxylic acid oxidase and ethylene sensitivity are cited as potential factors in hypoxia-induced ethylene release.