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1.
Data Brief ; 31: 106017, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32760765

RESUMEN

This data article provides useful information often required for numerical modeling of the so-called microbond tests. It includes the experimental and simulation data of the microbond testing using Fibre Bragg Grating (FBG) fibres for optical strains. Microbond testing was performed on five different droplets of varying embedded length and diameter to collect the data. Finite element simulation was carried out and modelling was validated, by using two variables force and strain, to collect the data. The output data of the fitted models is given and is also visualized via graphs of force-strain derivative curves. The data of the simulations is provided for different finite element mesh densities. Here, to clarify the type and form of the data for the use by readers, the energy distribution curves describing various functionalities of the droplet, fibre and interface are presented. For further reading, the interpretation and analysis of this data can be found in a research article titled "3D interfacial debonding during microbond testing: Advantages of local strain recording" (R. Dsouza et al., 2020) [1].

2.
Scand J Surg ; 107(4): 350-355, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29633655

RESUMEN

BACKGROUND:: Kick scooters are popular among children in both transportation and recreational activities. The aim of this retrospective study was to assess the incidence of and injury patterns associated with kick scooter accidents in school-aged children and adolescents. METHODS:: All 171 patients at the age of 7-15 years who were treated for kick scooter-related injuries in the metropolitan Helsinki area, Southern Finland from January 2008 to December 2013 were included. Electronic medical records were reviewed and Pediatric Trauma Scores and Injury Severity Scores were utilized to assess the injuries. RESULTS:: The annual number of patients increased from 7 in 2008 to 55 in 2013. Almost all patients (94%, n = 161) were injured after a fall from their own height. Most patients (n = 118; 69%) were diagnosed with a fracture but only 26 patients (15%) required surgical procedures under general anesthesia. Pediatric Trauma Scores were low and only one patient had an Injury Severity Score > 15 which can be considered major trauma. CONCLUSION:: Most injuries acquired from kick scooter injuries were easily treatable fractures and bruises. Considering the background population of 105,000 in the respective age group and the 6-year period of data collection from tertiary care, scooting seems a safe means of increasing the physical activity levels of school-aged children and adolescents.


Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Contusiones/epidemiología , Fracturas Óseas/epidemiología , Juego e Implementos de Juego/lesiones , Adolescente , Niño , Contusiones/diagnóstico , Contusiones/terapia , Femenino , Finlandia , Fracturas Óseas/diagnóstico , Fracturas Óseas/terapia , Hospitalización , Humanos , Incidencia , Masculino , Estudios Retrospectivos , Índices de Gravedad del Trauma
3.
J Microsc ; 263(1): 20-33, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26695385

RESUMEN

Automated handling of a natural fibrous object requires a method for acquiring the three-dimensional geometry of the object, because its dimensions cannot be known beforehand. This paper presents a method for calculating the three-dimensional reconstruction of a paper fibre on a microrobotic platform that contains two microscope cameras. The method is based on detecting curvature changes in the fibre centreline, and using them as the corresponding points between the different views of the images. We test the developed method with four fibre samples and compare the results with the references measured with an X-ray microtomography device. We rotate the samples through 16 different orientations on the platform and calculate the three-dimensional reconstruction to test the repeatability of the algorithm and its sensitivity to the orientation of the sample. We also test the noise sensitivity of the algorithm, and record the mismatch rate of the correspondences provided. We use the iterative closest point algorithm to align the measured three-dimensional reconstructions with the references. The average point-to-point distances between the reconstructed fibre centrelines and the references are 20-30 µm, and the mismatch rate is low. Given the manipulation tolerance, this shows that the method is well suited to automated fibre grasping. This has also been demonstrated with actual grasping experiments.

4.
J Microsc ; 248(2): 163-71, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23078116

RESUMEN

One of the most challenging issues faced in handling specimens for microscopy, is avoiding artefacts and structural changes in the samples caused by human errors. In addition, specimen handling is a laborious and time-consuming task and requires skilful and experienced personnel. This paper introduces a flexible microrobotic platform for the handling of microscale specimens of fibrous materials for various microscopic studies such as scanning electron microscopy and nanotomography. The platform is capable of handling various fibres with diameters ranging from 10 to 1000 µm and lengths of 100 µm-15 mm, and mounting them on different types of specimen holders without damaging them. This tele-operated microrobotic platform minimizes human interaction with the samples, which is one of the main sources contributory to introducing artefacts into the specimens. The platform also grants a higher throughput and an improved success rate of specimen handling, when compared to the manual processes. The operator does not need extensive experience of microscale manipulation and only a short training period is sufficient to operate the platform. The requirement of easy configurability for various samples and sample holders is typical in the research and development of materials in this field. Therefore, one of the main criteria for the design of the microrobotic platform was the ability to adapt the platform to different specimen handling methods required for microscopic studies. To demonstrate this, three experiments are carried out using the microrobotic platform. In the first experiment, individual paper fibres are mounted successfully on scanning electron microscopy specimen holders for the in situ scanning electron microscopy diagonal compression test of paper fibres. The performance of the microrobotic platform is compared with a skilled laboratory worker performing the same experiment. In the second experiment, a strand of human hair and an individual paper fibre bond are mounted on a specimen holder for nanotomography studies. In the third experiment, individual paper fibre bonds with controlled crossing and vertical angles are made using the microrobotic platform. If an industrial application requires less flexibility but a higher speed when handling one type of sample to a specific holder, then the platform can be automated in the future.

5.
Clin Microbiol Infect ; 18(6): 582-9, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22011265

RESUMEN

No sufficiently powered trial has examined two antimicrobials in acute osteoarticular infections of childhood. We conducted a prospective, multicentre, quasi-randomized trial in Finland, comparing clindamycin with first-generation cephalosporins. The age of patients ranged between 3 months and 15 years, and all cases were culture-positive. We assigned antibiotic treatment intravenously for the first 2-4 days, and continued oral treatment with clindamycin 40 mg/kg/24 h or first-generation cephalosporin 150 mg/kg/24 h in four doses. Surgery was kept to a minimum. Subsiding symptoms and signs and normalization of C-reactive protein (CRP) level were preconditions for the discontinuation of antimicrobials. The main outcome was full recovery without further antimicrobials because of an osteoarticular indication during 12 months after therapy. The intention-to-treat analysis comprised 252 children, 169 of whom were analysed per-protocol: 82 cases of osteomyelitis, 80 of septic arthritis, and seven of osteomyelitis-arthritis. Staphylococcus aureus strains (all methicillin-sensitive) caused 84% of the cases. Except for one non-serious sequela during convalescence in both groups, and two late infections caused by dissimilar agents in one child, all patients recovered. The entire courses (medians) of clindamycin and cephalosporin lasted for 23 and 24 days, respectively. CRP normalized in both groups in 9 days. The patients were discharged, on average, on day 10. Loose stools were reported less often (1%) in the clindamycin group than in the cephalosporin group (7%), but two clindamycin recipients developed rash. Clindamycin or a first-generation cephalosporin, administered mostly orally, perform equally well in childhood osteoarticular infections, provided that high doses and administration four times daily are used. As most methicillin-resistant staphylococci remain clindamycin-sensitive, clindamycin remains an option instead of costly alternatives.


Asunto(s)
Antibacterianos/administración & dosificación , Infecciones Bacterianas/tratamiento farmacológico , Cefalosporinas/administración & dosificación , Clindamicina/administración & dosificación , Osteoartritis/tratamiento farmacológico , Administración Oral , Adolescente , Bacteriemia/tratamiento farmacológico , Niño , Preescolar , Femenino , Finlandia , Humanos , Lactante , Infusiones Intravenosas , Masculino , Osteomielitis/tratamiento farmacológico , Estudios Prospectivos , Staphylococcus aureus/aislamiento & purificación , Resultado del Tratamiento
6.
Acta Paediatr ; 100(10): 1350-3, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21592224

RESUMEN

AIM: To evaluate the prevalence of parent-reported food allergies requiring avoidance diet at early school age. METHODS: The school health nurses interviewed, by using a structured questionnaire on the required diet at school, the parents of all the 1542 children starting elementary school in a Finnish town with 210,000 inhabitants. RESULTS: An allergy to basic foods was found in 41 (2.7%) children: 1.5% to milk, 1.1% to eggs and 1.0% to grains. An allergy to nuts was present in 3.1% and to fruits and vegetables in 5.8%, both with known cross-sensitization to pollens. In all, 9.2% of the children reported some allergy. Milk, egg and grain allergies were associated with soy, nut and spice allergies. CONCLUSION: Over 2% of the 1542 Finnish first-graders reported allergies to basic foods (milk, eggs or grains) requiring special avoidance diets at school. The figure suggests that avoidance diets started in the first years of life still unnecessarily continued.


Asunto(s)
Hipersensibilidad a los Alimentos/epidemiología , Niño , Estudios Transversales , Femenino , Finlandia/epidemiología , Hipersensibilidad a los Alimentos/dietoterapia , Humanos , Masculino , Padres , Instituciones Académicas , Encuestas y Cuestionarios
7.
Nutr Metab Cardiovasc Dis ; 20(4): 249-57, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19553094

RESUMEN

BACKGROUND AND AIMS: Whole-grain cereals and diets with a low glycemic index may protect against the development of type 2 diabetes and heart disease, but the mechanisms are poorly understood. We studied the effect of carbohydrate modification on serum metabolic profiles, including lipids and branched chain amino acids, and dependencies between these and specific gene expression pathways in adipose tissue. METHODS AND RESULTS: Twenty subjects with metabolic syndrome were selected from the larger FUNGENUT study population, randomized either to a diet high in oat and wheat bread and potato (OWP) or rye bread and pasta (RP). Serum metabolomics analyses were performed using ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry (UPLC/MS), gas chromatography (GC) and UPLC. In the OWP group multiple proinflammatory lysophosphatidylcholines increased, while in the RP group docosahexaenoic acid (DHA 22:6n-3) increased and isoleucine decreased. mRNA expression of stress reactions- and adipose tissue differentiation-related genes were up-regulated in adipose tissue in the OWP group. In the RP group, however, pathways related to stress reactions and insulin signaling and energy metabolism were down-regulated. The lipid profiles had the strongest association with the changes in the adipose tissue differentiation pathway when using the elastic net regression model of the lipidomic profiles on selected pathways. CONCLUSION: Our results suggest that the dietary carbohydrate modification alters the serum metabolic profile, especially in lysoPC species, and may, thus, contribute to proinflammatory processes which in turn promote adverse changes in insulin and glucose metabolism.


Asunto(s)
Carbohidratos de la Dieta/farmacología , Síndrome Metabólico/sangre , Síndrome Metabólico/dietoterapia , Tejido Adiposo/metabolismo , Tejido Adiposo/fisiología , Aminoácidos de Cadena Ramificada/sangre , Vías Biosintéticas , Cromatografía Líquida de Alta Presión , Dieta , Ingestión de Alimentos , Ácidos Grasos/sangre , Expresión Génica/efectos de los fármacos , Expresión Génica/genética , Índice Glucémico , Humanos , Lípidos/sangre , Síndrome Metabólico/genética , Metabolómica , Grosor de los Pliegues Cutáneos , Espectrometría de Masa por Ionización de Electrospray , Resultado del Tratamiento
8.
Int J Obes (Lond) ; 33(1): 80-8, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18957933

RESUMEN

BACKGROUND: Insulin-like growth factor binding protein 5 (IGFBP5) binds to IGF and thus modulates IGF signaling pathway. We have shown earlier that the IGFBP5 gene was downregulated in the adipose tissue after 12-week carbohydrate diet with low insulinemic response. OBJECTIVE: The aim was to examine the putative contribution of genetic variation of the IGFBP5 gene to the characteristics of metabolic syndrome and incidence of type 2 diabetes (T2DM) in the Finnish Diabetes Prevention Study (DPS). METHODS: DPS is a longitudinal study where 522 subjects with impaired glucose tolerance were randomized to either lifestyle intervention group or control group. DNA was available from 507 subjects (mean body mass index (BMI) 31.2+/-4.5 kg/m(2), age 55+/-7 years). The eight single-nucleotide polymorphisms (SNPs) were selected from HapMap database and genotyped by Taqman allelic discrimination protocol. The main results were confirmed in a larger cross-sectional study population (METSIM). In addition, the gene expression of IGFBP5 was studied in two previously published study populations (FUNGENUT and GENOBIN) of 124 subjects with insulin resistance (BMI 32.2+/-3.5 kg/m(2), age 57.7+/-7.4 years). RESULTS: Three out of eight IGFBP5 markers (rs9341234, rs3276 and rs11575134) were significantly associated with circulating adiponectin concentrations in men. Furthermore, mRNA expression studies of subcutaneous adipose tissue showed that mRNA concentrations of IGFBP5 correlated with adiponectin concentrations in all subjects and in women. None of the IGFBP5 SNPs were associated with T2DM. CONCLUSIONS: Our findings show that IGFBP5 has a gender-specific association with adiponectin, which may modulate the development of metabolic syndrome.


Asunto(s)
Adiponectina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Síndrome Metabólico/genética , Polimorfismo de Nucleótido Simple , Índice de Masa Corporal , Distribución de Chi-Cuadrado , Estudios Transversales , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Finlandia/epidemiología , Frecuencia de los Genes , Humanos , Incidencia , Resistencia a la Insulina/genética , Desequilibrio de Ligamiento , Masculino , Síndrome Metabólico/metabolismo , Persona de Mediana Edad , Grasa Subcutánea/metabolismo
9.
Int J Obes (Lond) ; 32(2): 292-303, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17848939

RESUMEN

OBJECTIVE: Lifestyle and genetic factors interact in the development of obesity and the metabolic syndrome. The molecular mechanisms underlying the beneficial dietary modifications are, however, unclear. We aimed to examine the effect of the long-term moderate weight reduction on gene expression in adipose tissue (AT) and to identify genes and gene clusters responsive to treatment and thereby likely contributing to the development of the metabolic syndrome. DESIGN: Randomized controlled and individualized weight reduction intervention. SUBJECTS: Forty-six subjects with impaired fasting glycemia or impaired glucose tolerance and features of metabolic syndrome, aged 60+/-7 years were randomized either to a weight reduction (WR) (n=28) or a control (n=18) group lasting for 33 weeks. MEASUREMENTS: Oral and intravenous glucose tolerance tests and subcutaneous AT biopsies were performed before and after the intervention. Gene expression of AT was studied using microarray technology in subgroups of WR (with weight reduction > or =5%, n=9) and control group (n=10). The results were confirmed using quantitative PCR. RESULTS: In the WR group, glucose metabolism improved. Moreover, an inverse correlation between the change in S (I) and the change in body weight was found (r=-0.44, P=0.026). Downregulation of gene expression (P<0.01) involving gene ontology groups of extracellular matrix and cell death was seen. Such changes did not occur in the control group. The tenomodulin-gene was one of the most downregulated genes (-39+/-16%, P<0.0001). Moreover, its expression correlated with insulin sensitivity (r=-0.34, P=0.005) before the intervention and with body adiposity both before (r=0.42, P=0.007) and after (r=0.30, P=0.056) the intervention. CONCLUSION: Genes regulating the extracellular matrix and cell death showed a strong downregulation after long-term weight reduction. This likely reflects a new stable state at the molecular level in AT. Further studies are warranted to elucidate the mechanisms of these genetic factors.


Asunto(s)
Glucemia/metabolismo , Matriz Extracelular/genética , Insulina/metabolismo , Síndrome Metabólico/genética , Obesidad/genética , Pérdida de Peso/genética , Adulto , Anciano , Estudios de Casos y Controles , Muerte Celular/genética , Femenino , Regulación de la Expresión Génica , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Persona de Mediana Edad , Obesidad/dietoterapia
10.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 2557-60, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-17270795

RESUMEN

This work presents the basic design and tests of a device designed for detecting the contact between a microinjection pipette and cell membrane. The device facilitates the automation of the microinjection procedure of living adherent cells. The measurement of the contact is based on measuring the resistance of the pipette. Breakage and clogging of the pipette can be detected with the same measurement.

11.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 4998-5001, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-17271437

RESUMEN

Capillary pressure microinjection is a popular method for the delivery of samples into cells. Needs for automatic reliable microinjection systems are growing, but the current systems do not possess ideal characteristics and many researchers do not even recognize the limits of the current systems. In many cases for example, the experiments are influenced by so called influx or efflux. This paper discusses the limits and challenges related to the automatic microinjection of single adherent cells. The discussion focuses on the reasons for the variability of the injected volume and shows the complexity of the problem. Solutions are outlined and future steps sketched. Future developments in the field of microinjection are proposed.

12.
Skeletal Radiol ; 30(9): 504-11, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11587518

RESUMEN

OBJECTIVE: To evaluate the diagnosis of acute physeal ankle fractures on plain radiographs using MRI as the gold standard. METHODS: Sixty consecutive children, 29 with a clinical diagnosis of lateral ligament injury and 31 with physeal ankle fractures, were examined using both radiographs and MRI in the acute period. The imaging data were reviewed by three "masked" radiologists. The fracture diagnosis and Slater-Harris classification of radiographs were compared with findings on MRI. RESULTS: Plain radiography produced five of 28 (18%) false negative and 12 of 92 (13%) false positive fracture diagnoses compared with MRI. Six of the 12 false positive fractures were due to a misclassification of lateral ligament disruption as SH1 fractures, Altogether a difference was found in 21% of cases in either the diagnosis or the classification of the fractures according to Salter-Harris. All bone bruises in the distal tibia and fibula and 64% of bone bruises in the talus were seen in association with lateral ligament injuries. Talar bone bruises in association with fractures occurred on the same side as the malleolar fracture; talar bone bruises in association with lateral ligament disruption were seen in different locations. The errors identified on radiographs by MRI did not affect the management of the injury. CONCLUSIONS: The incidence of false negative ankle fractures in plain radiographs was small and no complex ankle fractures were missed on radiographs. The total extent of complex fractures was, however, not always obvious on radiographs. In an unselected series of relatively mild ankle injuries, we were unable to show a single case where the treatment or prognosis based on plain radiography should have been significantly altered after having done a routine MRI examination. Plain radiography is still the diagnostic cornerstone of paediatric ankle injuries.


Asunto(s)
Traumatismos del Tobillo/diagnóstico por imagen , Traumatismos del Tobillo/patología , Errores Diagnósticos , Fracturas Óseas/diagnóstico por imagen , Fracturas Óseas/patología , Imagen por Resonancia Magnética , Enfermedad Aguda , Adolescente , Traumatismos del Tobillo/complicaciones , Niño , Contusiones/complicaciones , Femenino , Fracturas Óseas/clasificación , Fracturas Óseas/complicaciones , Humanos , Masculino , Radiografía , Sensibilidad y Especificidad
13.
Biotechnol Prog ; 17(5): 798-808, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11587567

RESUMEN

Limited oxygen availability is a prevalent problem in microbial biotechnology. Recombinant Escherichia coli expressing the hemoglobin from Vitreoscilla (VHb) or the flavohemoglobin from Ralstonia eutropha (formerly Alcaligenes eutrophus) (FHP) demonstrate significantly increased cell growth and productivity under microaerobic conditions. We identify novel bacterial hemoglobin-like proteins and examine if these novel bacterial hemoglobins can elicit positive effects similar to VHb and FHP and if these hemoglobins alleviate oxygen limitation under microaerobic conditions when expressed in E. coli. Several finished and unfinished bacterial genomes were screened using R. eutropha FHP as a query sequence for genes (hmp) encoding hemoglobin-like proteins. Novel hmp genes were identified in Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumoniae, Deinococcus radiodurans, and Campylobacter jejuni. Previously characterized hmp genes from E. coli and Bacillus subtilis and the novel hmp genes from P. aeruginosa, S. typhi, C. jejuni, K. pneumoniae, and D. radiodurans were PCR amplified and introduced into a plasmid for expression in E. coli. Biochemically active hemoproteins were expressed in all constructs, as judged by the ability to abduct carbon monoxide. Growth behavior and byproduct formation of E. coli K-12 MG1655 cells expressing various hemoglobins were analyzed in microaerobic fed-batch cultivations and compared to plasmid-bearing control and to E. coli cells expressing VHb. The clones expressing hemoglobins from E. coli, D. radiodurans, P.aeruginosa, and S. typhi reached approximately 10%, 27%, 23%, and 36% higher final optical density values, respectively, relative to the plasmid bearing E. coli control (A(600) 5.5). E. coli cells expressing hemoproteins from P. aeruginosa, S. typhi, and D. radiodurans grew to similar final cell densities as did the strain expressing VHb (A(600) 7.5), although none of the novel constructs was able to outgrow the VHb-expressing E. coli strain. Additionally, increased yield of biomass on glucose was measured for all recombinant strains, and an approximately 2-fold yield enhancement was obtained with D. radiodurans hemoprotein-expressing E. coli relative to the E. coli control carrying the parental plasmid without any hemoglobin gene.


Asunto(s)
Proteínas Bacterianas/farmacología , Escherichia coli/crecimiento & desarrollo , Hemoglobinas/farmacología , Secuencia de Aminoácidos , Anaerobiosis/efectos de los fármacos , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Biomasa , Reactores Biológicos , Clonación Molecular , Escherichia coli/metabolismo , Hemoglobinas/genética , Hemoglobinas/fisiología , Datos de Secuencia Molecular , Alineación de Secuencia , Transducción Genética , Hemoglobinas Truncadas
14.
Gene ; 275(1): 115-24, 2001 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-11574159

RESUMEN

A synthetic gene based on the primary sequence of the mature spruce budworm antifreeze protein (sbwAFP) was constructed by primer overlap extension. The amino acid codons were chosen to mimic those of a highly expressed tobacco nuclear gene. A DNA sequence encoding the amino-terminal leader sequence from the tobacco pathogen related protein 1b (PR), which targets the protein to the apoplastic space, was fused in frame to the synthetic sbwAFP gene. This fusion was placed downstream of the cauliflower mosaic virus 35S promoter and upstream of the nopaline synthase terminator in a T-DNA binary vector. Transgenic tobacco lines transcribing PR-sbwAFP were selected by RT-PCR. The apoplastic protein fractions of sbwAFP expressing tobacco lines exhibited enhanced antifreeze activity as demonstrated by the ability to inhibit ice re-crystallization and increased thermal hysteresis.


Asunto(s)
Proteínas Anticongelantes/genética , Congelación , Genes Sintéticos/genética , Nicotiana/genética , Adaptación Fisiológica/genética , Animales , Codón/genética , Expresión Génica , Vectores Genéticos/genética , Proteínas de Insectos/genética , Hojas de la Planta/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Nicotiana/crecimiento & desarrollo , Transcripción Genética , Transformación Genética
15.
Virology ; 286(2): 336-44, 2001 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-11485401

RESUMEN

Theiler's murine encephalomyelitis viruses (TMEV) are divided into two groups: high-neurovirulence strains, such as GDVII, cause fatal encephalitis, while low-neurovirulence strains, such as BeAn and DA, cause persistent infection and demyelination in mice. Cell surface sialic acid is bound by the low-neurovirulence DA and BeAn viruses, but not by the high-neurovirulence GDVII virus. We have identified a clone from a BHK-21 cell cDNA library that mediates TMEV entry and infection by viruses of both TMEV groups in a receptor-negative BHK-21 cell variant (R26). The sequence of this clone is 96.4% identical to the human UDP-galactose transporter (UGT), which belongs to a family of nucleotide-sugar transporter proteins involved in the biosynthesis of complex carbohydrate structures in the trans-Golgi network. UGT mRNA from R26 cells was found to have a 490-nucleotide deletion involving the C-terminal amino acids 255 to 392 and 81 nucleotides of the 3' noncoding region. These results suggest two possibilities by which UGT may mediate TMEV entry and infection. The most likely one relates to the transporter function of adding galactose to another receptor protein. This possibility suggests the requirement for a specific glycoprotein interaction for GDVII virus cell binding and entry, e.g., galactose for GDVII and sialic acid for BeAn. Alternatively, UGT might be a TMEV receptor itself, acting via UGT cycling to the cell surface.


Asunto(s)
Infecciones por Cardiovirus/virología , Proteínas de Transporte de Monosacáridos/metabolismo , Theilovirus/patogenicidad , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Cricetinae , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Proteínas de Transporte de Monosacáridos/genética , Receptores Virales/genética , Receptores Virales/metabolismo , Análisis de Secuencia de ADN , Theilovirus/fisiología , Transfección , Virulencia
17.
J Virol ; 75(16): 7420-8, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11462014

RESUMEN

The low-neurovirulence Theiler's murine encephalomyelitis viruses (TMEV), such as BeAn virus, cause a persistent infection of the central nervous system (CNS) in susceptible mouse strains that results in inflammatory demyelination. The ability of TMEV to persist in the mouse CNS has traditionally been demonstrated by recovering infectious virus from the spinal cord. Results of infectivity assays led to the notion that TMEV persists at low levels. In the present study, we analyzed the copy number of TMEV genomes, plus- to minus-strand ratios, and full-length species in the spinal cords of infected mice and infected tissue culture cells by using Northern hybridization. Considering the low levels of infectious virus in the spinal cord, a surprisingly large number of viral genomes (mean of 3.0 x 10(9)) was detected in persistently infected mice. In the transition from the acute (approximately postinfection [p.i.] day 7) to the persistent (beginning on p.i. day 28) phase of infection, viral RNA copy numbers steadily increased, indicating that TMEV persistence involves active viral RNA replication. Further, BeAn viral genomes were full-length in size; i.e., no subgenomic species were detected and the ratio of BeAn virus plus- to minus-strand RNA indicated that viral RNA replication is unperturbed in the mouse spinal cord. Analysis of cultured macrophages and oligodendrocytes suggests that either of these cell types can potentially synthesize high numbers of viral RNA copies if infected in the spinal cord and therefore account for the heavy viral load. A scheme is presented for the direct isolation of both cell types directly from infected spinal cords for further viral analyses.


Asunto(s)
Infecciones por Cardiovirus/virología , Sistema Nervioso Central/virología , ARN Viral/fisiología , Theilovirus/fisiología , Animales , Infecciones por Cardiovirus/patología , Dosificación de Gen , Genoma Viral , Ratones , Replicación Viral
18.
Biotechnol Bioeng ; 74(2): 154-63, 2001 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-11370004

RESUMEN

Novel gene regulation systems were designed for plant cells responsive to the streptogramin antibiotic pristinamycin. The pristinamycin-repressible plant gene regulation concept (PIPpOFF) is based on a transcriptional activator (PIT) which consists of the Pip protein, the repressor of the pristinamycin resistance operon of Streptomyces coelicolor, fused to the VP16 transactivation domain of the Herpes simplex virus. PIT mediates pristinamycin-repressible activation of a synthetic plant promoter (P(pPIR)) in tobacco cells consisting of a nine Pip-binding site-containing artificial operator (PIR3) placed upstream of a TATA-box derived from the cauliflower mosaic virus 35S promoter (P(CaMV35S)). Pristinamycin interferes with induction by negatively regulating the DNA-binding capacity of the Pip moiety of PIT. A second, streptogramin-inducible plant gene regulation system (PIPpON) was constructed by combining Pip expression with a plant-specific pristinamycin-inducible promoter (P(pPIRON)). P(pPIRON) consists of a PIR3 module cloned downstream of the strong constitutive plant promoter P(CaMV35S). As in the native Streptomyces configuration, Pip binds to its cognate sequence within P(pPIRON) in the absence of regulating antibiotic and silences the chimeric plant promoter. Upon addition of pristinamycin, Pip is released from the PIR3 operator and full P(CaMV35S)-driven expression of desired plant genes is induced. The PIPpOFF and PIPpON systems performed well in Nicotiana tabacum suspension cultures and promise to provide an attractive extension of existing plant gene regulation technology for basic plant research or biopharmaceutical manufacturing using plant tissue culture.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Ingeniería Genética/métodos , Nicotiana/genética , Plantas Tóxicas , Virginiamicina/farmacología , Secuencia de Aminoácidos , Secuencia de Bases , Caulimovirus/genética , Técnicas de Cultivo de Célula/métodos , Células Cultivadas , Farmacorresistencia Microbiana/genética , Proteína Vmw65 de Virus del Herpes Simple/genética , Datos de Secuencia Molecular , Operón , Proteínas Represoras/efectos de los fármacos , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Streptomyces/genética , Nicotiana/efectos de los fármacos , Nicotiana/metabolismo
19.
Skeletal Radiol ; 30(2): 61-6, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11310200

RESUMEN

OBJECTIVE: To assess MRI changes in the ankle and foot after physical exercise. DESIGN AND PATIENTS: Nineteen non-professional marathon runners and 19 age- and sex-matched controls volunteered for the study. All had ankle and foot MR images (1.5 T) taken in three perpendicular planes (STIR, T2F and T1FS sequences) within 3 h of running a full-length marathon (42.125 km). Three radiologists independently analysed the groups on a masked basis using a predefined form. RESULTS: Severe bone marrow oedema was seen in one and slight bone marrow oedema in three marathon runners. Slight bone marrow oedema was found in three control subjects. Signal alteration within the soleus muscle, consistent with a grade 1 strain, was found in one marathon runner. Small punctate hyperintensities within the Achilles tendon were seen in 26% of the marathon runners and in 63% of controls (P = 0.016). An increased amount of fluid in the retrocalcaneal bursa was found in one control and in none of the marathon runners. Small amounts of fluid in the retrocalcaneal bursa were seen in 68% of marathon runners and in 53% of controls. Grade 1 or 2 peritendinous joint fluid was found around 22% of tendons, among both marathon runners and controls, most often involving the tendon sheath of the flexor hallucis longus muscle. An increased amount of joint fluid was noted in 34% of the joints of the marathon runners, and in 18% of the controls. CONCLUSION: MRI shows several abnormalities in the ankle and foot both after marathon races and in asymptomatic physically active individuals without any preceding extraordinary strain. Recreational sports may lead to a number of positive MRI findings without correlation with clinical findings.


Asunto(s)
Articulación del Tobillo/patología , Pie/patología , Imagen por Resonancia Magnética , Adulto , Médula Ósea/patología , Bolsa Sinovial/patología , Edema/diagnóstico , Edema/patología , Femenino , Humanos , Hidrartrosis/diagnóstico , Masculino , Persona de Mediana Edad , Músculo Esquelético/patología , Carrera
20.
Appl Environ Microbiol ; 67(2): 680-7, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11157231

RESUMEN

Escherichia coli MG1655 cells expressing Vitreoscilla hemoglobin (VHb), Alcaligenes eutrophus flavohemoprotein (FHP), the N-terminal hemoglobin domain of FHP (FHPg), and a fusion protein which comprises VHb and the A. eutrophus C-terminal reductase domain (VHb-Red) were grown in a microaerobic bioreactor to study the effects of low oxygen concentrations on the central carbon metabolism, using fractional (13)C-labeling of the proteinogenic amino acids and two-dimensional [(13)C, (1)H]-correlation nuclear magnetic resonance (NMR) spectroscopy. The NMR data revealed differences in the intracellular carbon fluxes between E. coli cells expressing either VHb or VHb-Red and cells expressing A. eutrophus FHP or the truncated heme domain (FHPg). E. coli MG1655 cells expressing either VHb or VHb-Red were found to function with a branched tricarboxylic acid (TCA) cycle. Furthermore, cellular demands for ATP and reduction equivalents in VHb- and VHb-Red-expressing cells were met by an increased flux through glycolysis. In contrast, in E. coli cells expressing A. eutrophus hemeproteins, the TCA cycle is running cyclically, indicating a shift towards a more aerobic regulation. Consistently, E. coli cells displaying FHP and FHPg activity showed lower production of the typical anaerobic by-products formate, acetate, and D-lactate. The implications of these observations for biotechnological applications are discussed.


Asunto(s)
Carbono/metabolismo , Escherichia coli/crecimiento & desarrollo , Hemoglobinas/metabolismo , Anaerobiosis , Reactores Biológicos , Biotecnología/métodos , Isótopos de Carbono/metabolismo , Escherichia coli/metabolismo , Hemoglobinas/genética , Espectroscopía de Resonancia Magnética
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