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1.
Benef Microbes ; : 1-10, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39244201

RESUMEN

Treatment with probiotics can help manage chronic constipation by softening the stools and possibly acting synergistically with front-line treatments. We assessed the efficacy of Bifidobacterium animalis subsp. lactis BLa80 in maltodextrin as a food supplement in regulating the intestinal habit of subjects with chronic constipation with type 1 or 2 stools on the Bristol scale index and/or less than three stools per week. A multicentre, randomised, double-blind, placebo-controlled clinical trial was carried out in subjects aged 18 and over with chronic constipation. The study enrolled forty-six subjects who were randomised one-to-one to receive the potential probiotic in maltodextrin (n = 23) or a placebo (n = 23). Investigators assessed changes in intestinal habits by analysing the mean number of weekly stools and the stool types according to the Bristol Scale. Patients reported constipation symptoms with PAC-SYM (patient assessment of constipation - symptoms), and the impact on quality of life with PAC-QoL (patient assessment of constipation - quality of life) and GI-QLI (gastrointestinal quality of life index). Patients on the intervention group showed a greater tendency to normalise the type of stools than those in the placebo group. This difference towards regular stool types (type 3 and 4) was statistically significant at weeks 8 and 12 relative to week 4 (P-values = 0.006 and 0.027, respectively). The proportion of constipated patients in the experimental group dropped over time, while the rate slightly increased in the placebo group in a statistically significant manner at week 12 relative to week 4 ( P = 0.037). Overall, the present study shows oral intake of B. animalis subsp. lactis BLa80 in maltodextrin for 12 weeks improves intestinal habits in subjects with chronic constipation. Our study provides evidence to the efficacy and safety use of this formulation as an effective tool for improving stool consistency in constipated patients. The trial was registered at ClinicalTrials.gov: NCT05980988.

2.
Cereb Cortex ; 28(2): 549-560, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-27999122

RESUMEN

The fronto-parietal attention networks have been extensively studied with functional magnetic resonance imaging (fMRI), but spatiotemporal dynamics of these networks are not well understood. We measured event-related potentials (ERPs) with electroencephalography (EEG) and collected fMRI data from identical experiments where participants performed visual and auditory discrimination tasks separately or simultaneously and with or without distractors. To overcome the low temporal resolution of fMRI, we used a novel ERP-based application of multivariate representational similarity analysis (RSA) to parse time-averaged fMRI pattern activity into distinct spatial maps that each corresponded, in representational structure, to a short temporal ERP segment. Discriminant analysis of ERP-fMRI correlations revealed 8 cortical networks-2 sensory, 3 attention, and 3 other-segregated by 4 orthogonal, temporally multifaceted and spatially distributed functions. We interpret these functions as 4 spatiotemporal components of attention: modality-dependent and stimulus-driven orienting, top-down control, mode transition, and response preparation, selection and execution.


Asunto(s)
Atención/fisiología , Corteza Auditiva/fisiología , Electroencefalografía/métodos , Imagen por Resonancia Magnética/métodos , Red Nerviosa/fisiología , Corteza Visual/fisiología , Estimulación Acústica/métodos , Adulto , Corteza Auditiva/diagnóstico por imagen , Percepción Auditiva/fisiología , Femenino , Humanos , Masculino , Red Nerviosa/diagnóstico por imagen , Estimulación Luminosa/métodos , Factores de Tiempo , Corteza Visual/diagnóstico por imagen , Percepción Visual/fisiología
3.
Osteoarthritis Cartilage ; 24(9): 1656-64, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27143363

RESUMEN

OBJECTIVE: To investigate the sensitivity of quantitative magnetic resonance imaging (MRI) parameters to increase of collagen cross-linking in articular cartilage, a factor possibly contributing to the aging-related development of osteoarthritis (OA). The issue has not been widely studied although collagen cross-links may significantly affect the evaluation of cartilage imaging outcome. DESIGN: Osteochondral samples (n = 14) were prepared from seven bovine patellae. To induce cross-linking, seven samples were incubated in threose while the other seven served as non-treated controls. The specimens were scanned at 9.4 T for T1, T1Gd (dGEMRIC), T2, adiabatic and continuous wave (CW) T1ρ, adiabatic T2ρ and T1sat relaxation times. Specimens from adjacent tissue were identically treated and used for reference to determine biomechanical properties, collagen, proteoglycan and cross-link contents, fixed charge density (FCD), collagen fibril anisotropy and water concentration of cartilage. RESULTS: In the threose-treated sample group, cross-links (pentosidine, lysyl pyridinoline (LP)), FCD and equilibrium modulus were significantly (P < 0.05) higher as compared to the non-treated group. Threose treatment resulted in significantly greater T1Gd relaxation time constant (+26%, P < 0.05), although proteoglycan content was not altered. Adiabatic and CW-T1ρ were also significantly increased (+16%, +28%, P < 0.05) while pre-contrast T1 was significantly decreased (-10%, P < 0.05) in the threose group. T2, T2ρ and T1sat did not change significantly. CONCLUSION: Threose treatment induced collagen cross-linking and changes in the properties of articular cartilage, which were detected by T1, T1Gd and T1ρ relaxation time constants. Cross-linking should be considered especially when interpreting the outcome of contrast-enhanced MRI in aging populations.


Asunto(s)
Cartílago Articular , Animales , Bovinos , Colágeno , Imagen por Resonancia Magnética , Osteoartritis , Rótula
4.
Neuroimage ; 134: 113-121, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27063068

RESUMEN

The current generation of young people indulges in more media multitasking behavior (e.g., instant messaging while watching videos) in their everyday lives than older generations. Concerns have been raised about how this might affect their attentional functioning, as previous studies have indicated that extensive media multitasking in everyday life may be associated with decreased attentional control. In the current study, 149 adolescents and young adults (aged 13-24years) performed speech-listening and reading tasks that required maintaining attention in the presence of distractor stimuli in the other modality or dividing attention between two concurrent tasks. Brain activity during task performance was measured using functional magnetic resonance imaging (fMRI). We studied the relationship between self-reported daily media multitasking (MMT), task performance and brain activity during task performance. The results showed that in the presence of distractor stimuli, a higher MMT score was associated with worse performance and increased brain activity in right prefrontal regions. The level of performance during divided attention did not depend on MMT. This suggests that daily media multitasking is associated with behavioral distractibility and increased recruitment of brain areas involved in attentional and inhibitory control, and that media multitasking in everyday life does not translate to performance benefits in multitasking in laboratory settings.


Asunto(s)
Atención/fisiología , Percepción Auditiva/fisiología , Comportamiento Multifuncional/fisiología , Corteza Prefrontal/fisiología , Lectura , Análisis y Desempeño de Tareas , Adolescente , Mapeo Encefálico/métodos , Femenino , Humanos , Masculino , Multimedia , Red Nerviosa/fisiología , Adulto Joven
5.
Epidemiol Infect ; 142(2): 335-9, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23688392

RESUMEN

In Finland in April 2010, a 3-month old baby was diagnosed with type A infant botulism. He excreted botulinum neurotoxin and/or Clostridium botulinum in his faeces until November 2010. Five months of excretion was after clinical recovery and discharge from hospital. C. botulinum isolates recovered from the household dust in the patient's home were genetically identical to those found in the infant's stool samples. Long-term faecal excretion of C. botulinum may pose a possible health risk for the parents and others in close contact with the infant.


Asunto(s)
Derrame de Bacterias , Botulismo/microbiología , Heces/microbiología , Toxinas Botulínicas Tipo A/análisis , Toxinas Botulínicas Tipo A/fisiología , Botulismo/transmisión , Clostridium botulinum tipo A/fisiología , Polvo/análisis , Heces/química , Finlandia , Humanos , Lactante , Masculino , Factores de Tiempo
6.
Nutr Hosp ; 27(2): 469-76, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22732970

RESUMEN

BACKGROUND: Malnutrition among inpatients is highly prevalent, and has a negative impact on their clinical outcome. The Working Group for the Study of Malnutrition in Hospitals in Catalonia was created to generate consensus guidelines for the prevention and/or treatment of malnutrition in hospitals in Catalonia, Spain. AIMS: The objectives of the study were to determine the prevalence of malnutrition on admission to hospital in Catalonia and to assess relationships between malnutrition, social and demographic data, overall costs, and mortality. METHODS: Prospective and multicenter study conducted with 796 patients from 11 hospitals representative of the hospitalized population in Catalonia. Nutritional status was evaluated using the Nutritional Risk Screening 2002 method. RESULTS: Overall, 28.9% of the patients are malnourished or at nutritional risk. Elderly patients, non-manual workers, those admitted to hospital as emergencies and with higher co-morbidities had higher risk of malnutrition. The type of hospital (second level vs. tertiary or University referral) to which they were admitted was also a factor predisposing to malnutrition. Length of hospital stay was longer in malnourished patients (10.5 vs. 7.7 days, p < 0.0001). The need for a convalescent home on leaving hospital was higher as well as the risk of mortality (8.6% malnourished vs. 1.3% nonmalnourished, p < 0.0001). CONCLUSIONS: The prevalence of malnutrition is high in patients on admission to hospital in our community, resulting in elevated overall costs and higher risk of mortality. Age, social class and characteristics of the Unit and the Hospital are the main factors involved in hospital malnutrition.


Asunto(s)
Desnutrición/epidemiología , Desnutrición/etiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Antropometría , Femenino , Tamaño de las Instituciones de Salud , Recursos en Salud , Mortalidad Hospitalaria , Hospitalización , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Evaluación Nutricional , Estudios Prospectivos , Tamaño de la Muestra , Factores Sexuales , Factores Socioeconómicos , España/epidemiología , Resultado del Tratamiento , Adulto Joven
7.
Nutr. hosp ; 27(2): 469-476, mar.-abr. 2012. tab
Artículo en Inglés | IBECS | ID: ibc-103427

RESUMEN

Background: Malnutrition among inpatients is highly prevalent, and has a negative impact on their clinical outcome. The Working Group for the Study of Malnutrition in Hospitals in Catalonia was created to generate consensus guidelines for the prevention and/or treatment of malnutrition in hospitals in Catalonia, Spain. Aims: The objectives of the study were to determine the prevalence of malnutrition on admission to hospital in Catalonia and to assess relationships between malnutrition, social and demographic data, overall costs, and mortality. Methods: Prospective and multicenter study conducted with 796 patients from 11 hospitals representative of the hospitalized population in Catalonia. Nutritional status was evaluated using the Nutritional Risk Screening 2002 method. Results: Overall, 28.9% of the patients are malnourished or at nutritional risk. Elderly patients, non-manual workers, those admitted to hospital as emergencies and with higher co-morbidities had higher risk of malnutrition. The type of hospital (second level vs. tertiary or University referral) to which they were admitted was also a factor predisposing to malnutrition. Length of hospital stay was longer in malnourished patients (10.5 vs. 7.7 days, p < 0.0001). The need for a convalescent home on leaving hospital was higher as well as the risk of mortality (8.6% malnourished vs. 1.3% nonmalnourished, p < 0.0001). Conclusions: The prevalence of malnutrition is high in patients on admission to hospital in our community, resulting in elevated overall costs and higher risk of mortality. Age, social class and characteristics of the Unit and the Hospital are the main factors involved in hospital malnutrition (AU)


Introducción: La desnutrición en los pacientes ingresados en el hospital es altamente prevalente, e impacta negativamente en su evolución clínica. El Grupo de Trabajo para el Estudio de la Desnutrición Hospitalaria en Cataluña se creó para general Guías de consenso para prevenir y/o tratar la desnutrición en los hospitales de Cataluña, España. Objetivos: Los objetivos del estudio fueron determinar la prevalencia de desnutrición al ingreso en los hospitales de Cataluña, y evaluar la relación entre desnutrición, datos sociales y demográficos, coste relacionado con la enfermedad y mortalidad. Métodos: Estudio prospectivo y multicéntrico realizado en 796 pacientes ingresados en 11 hospitales representativos de la población hospitalizada en Cataluña. El estado nutricional se evaluó utilizando la herramienta Nutritional Risk Screening 2002. Resultados: De forma global, 28,9% de los pacientes estaban desnutridos en el momento del ingreso. Los pacientes más ancianos, trabajadores no manuales, ingresados en el hospital procedentes de Urgencias y con más comorbilidades son los que presentaron mayor prevalencia de desnutrición. El tipo de hospital (Segundo nivel versus Tercer Nivel) también fue un factor predisponerte a la desnutrición. La estancia hospitalaria fue mayor en los pacientes desnutridos (10,5 vs 7,7 días, p < 0,0001). La necesidad de centro de convalecencia al alta hospitalaria fue mayor en los pacientes desnutridos, así como la mortalidad (8,6% desnutridos vs 1,3% normonutridos, p < 0,0001). Conclusiones: La prevalencia de desnutrición es elevada en los pacientes ingresados en el hospital en nuestra comunidad, lo que resulta en mayores costes sanitarios y mayor mortalidad. La edad, clase social y características del Servicio y del Hospital son los principales factores involucrados en la presencia de desnutrición hospitalaria (AU)


Asunto(s)
Humanos , Desnutrición/epidemiología , Hospitalización/estadística & datos numéricos , Tamizaje Masivo , Factores de Riesgo , Evaluación Nutricional , Estado Nutricional
8.
Osteoarthritis Cartilage ; 20(2): 117-26, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22179030

RESUMEN

OBJECTIVES: The delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) technique is a method proposed for non-invasive measurement of cartilage glycosaminoglycan (GAG) content. In this method, gadopentetate (Gd-DTPA²â») is assumed to distribute in cartilage in inverse relation to the GAG distribution, thus allowing quantification of the GAG content. For accurate GAG quantification, the kinetics of Gd-DTPA²â» in articular cartilage is of critical importance. However, the diffusion of Gd-DTPA²â» has not been systematically studied over long time periods using MRI-feasible gadopentetate concentrations. Thus, the present study aims to investigate the diffusion of gadopentetate into cartilage in vitro in intact and enzymatically degraded cartilage. METHODS: The diffusion of gadopentetate into bovine articular cartilage was investigated at 9.4 T over 18-h time period using repeated T(1) measurements in two models, (1) comparing intact and trypsin-treated tissue and (2) assessing the effect of penetration direction. The diffusion process was further assessed by determining the gadopentetate flux and diffusivity. The results were compared with histological and biochemical reference methods. RESULTS AND CONCLUSIONS: The results revealed that passive diffusion of Gd-DTPA²â» was significantly slower than previously assumed, leading to overestimation of the GAG content at equilibrating times of few hours. Moreover, Gd-DTPA²â» distribution was found to depend not only on GAG content, but also on collagen content and diffusion direction. Interestingly, the dGEMRIC technique was found to be most sensitive to cartilage degradation in the early stages of diffusion process, suggesting that full equilibrium between gadopentetate and cartilage may not be required in order to detect cartilage degeneration.


Asunto(s)
Cartílago Articular/metabolismo , Medios de Contraste/farmacocinética , Gadolinio DTPA/farmacocinética , Animales , Cartílago Articular/química , Bovinos , Colágeno/análisis , Imagen de Difusión por Resonancia Magnética/métodos , Glicosaminoglicanos/análisis
9.
J Pediatr ; 151(3): 289-92, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17719940

RESUMEN

OBJECTIVE: We carried out a prospective, randomized, controlled trial to clarify the effect of tonsillectomy on the clinical course of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. STUDY DESIGN: Twenty-six consecutive children (mean age 4.1 years) with at least 5 PFAPA attacks were recruited from 3 tertiary care pediatric hospitals during 1999-2003 and randomly allocated to tonsillectomy or follow-up alone. They were all followed up with symptom diaries for 12 months. Tonsillectomy was allowed after 6 months in the control group if the attacks recurred. RESULTS: Six months after randomization all 14 children in the tonsillectomy group and 6/12 children in the control group (50%) were free of symptoms (difference 50%, 95% confidence interval 23% to 75%, P < .001). Tonsillectomy was performed on 5/6 of the patients in the control group who still had symptoms after 6 months. The remaining unoperated child in the control group had recurrences of the fever episodes throughout the follow-up, but the symptoms became less severe, and the parents did not choose tonsillectomy. CONCLUSION: Tonsillectomy appeared to be effective for treating PFAPA syndrome. The fever episodes ceased without any intervention in half of the control subjects. We conclude that although the mechanisms behind this syndrome are unknown, tonsillectomy can be offered as an effective intervention for children with PFAPA.


Asunto(s)
Fiebre Mediterránea Familiar/cirugía , Linfadenitis/cirugía , Faringitis/cirugía , Estomatitis Aftosa/cirugía , Tonsilectomía , Preescolar , Fiebre Mediterránea Familiar/complicaciones , Femenino , Humanos , Linfadenitis/complicaciones , Masculino , Faringitis/complicaciones , Estudios Prospectivos , Recurrencia , Estomatitis Aftosa/complicaciones , Síndrome
10.
Euro Surveill ; 11(3): 18-20, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16567879

RESUMEN

In Finland, all newborns are currently offered BCG vaccination, and the national coverage is over 98%. The annual incidence of tuberculosis is low, at 6.6/100,000 in 2004 and has been steadily declining in recent years. Finland differs from the other Nordic countries in that the majority of cases are detected in people aged 65 and over in the indigenous population, and only a smaller proportion (12%) detected in immigrants. The high incidence of TB and MDR TB in neighbouring countries has raised concern, but no increase in TB detected in Finnish-born citizens has been seen. A decision has been made to change from mass BCG vaccination to targeting risk groups.


Asunto(s)
Vacuna BCG , Programas de Inmunización , Tuberculosis/prevención & control , Vacunación , Adolescente , Adulto , Factores de Edad , Anciano , Vacuna BCG/administración & dosificación , Niño , Preescolar , Emigración e Inmigración , Finlandia/epidemiología , Humanos , Programas de Inmunización/métodos , Lactante , Recién Nacido , Inyecciones Intradérmicas , Persona de Mediana Edad , Muslo , Tuberculosis/epidemiología
11.
Proc Natl Acad Sci U S A ; 100(24): 14046-51, 2003 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-14615580

RESUMEN

To generate transgenic planarians we used a set of versatile vectors for animal transgenesis based on the promiscuous transposons, mariner, Hermes and piggyBac, and a universal enhanced GFP (EGFP) marker system with three Pax6 dimeric binding sites, the 3xP3-EGFP developed by Berghammer et al. [Berghammer, A. J., Klinger, M. & Wimmer, E. A. (1999) Nature 402, 370-371]. This marker is expressed specifically in the eyes of various arthropod taxa. Upon microinjection into the parenchyma of adult planarians and subsequent electroporation, these vectors transpose efficiently into the planarian genome. One of the cell types transformed are the totipotent "neoblast" stem cells present in the adults, representing 30% of total cells. The neoblast represents a unique cell type with the capacity to proliferate and to differentiate into all somatic cell types as well as into germ cells. All three transposon vectors have high transformation efficiency, but only Hermes and piggyBac show stable integration. The mariner vector is frequently lost presumably because of the presence of active mariner-type transposons in the genome of the Girardia tigrina. Transformed animals are mosaics containing both transformed and untransformed neoblasts. These differentiate to form EGFP-positive and -negative photoreceptor cells. Such mosaicism is maintained through several cycles of regeneration induced by decapitation or asexual reproduction. Transformed neoblasts also contribute to the germ line, and can give rise to pure transgenic planarian lines in which EGFP is expressed in all photoreceptor cells after sexual reproduction. The presence of the transgenes was confirmed by PCR, plasmid rescue assay, inverse PCR, and Southern blotting. Our results with the 3xP3-EGFP marker confirm the presence of Pax6 activity in the differentiated photoreceptor cells of planarian eyes. Transgenesis will be an important tool to dissect developmental molecular mechanisms in planarian regeneration, development and stem cell biology, and may also be an entry point to analyze the biology of parasitic Platyhelminthes.


Asunto(s)
Planarias/genética , Animales , Animales Modificados Genéticamente , Secuencia de Bases , Elementos Transponibles de ADN/genética , ADN Recombinante/genética , Electroporación , Ojo/metabolismo , Proteínas del Ojo , Vectores Genéticos , Genoma , Proteínas Fluorescentes Verdes , Proteínas de Homeodominio/genética , Proteínas Luminiscentes/genética , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Planarias/anatomía & histología , Proteínas Recombinantes/genética , Proteínas Represoras , Transformación Genética
12.
J Infect Dis ; 185(3): 375-9, 2002 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-11807720

RESUMEN

Seventeen infants with an index episode of pyelonephritis caused by Escherichia coli were monitored for 18 months for recurrent urinary tract infections (UTIs). All the infants had at least 1 recurrent UTI caused by the same pathogen. Twenty-six recurrent UTI episodes were recorded. The 40 E. coli strains available were analyzed by multiplex polymerase chain reaction for 3 alleles (classes I-III) of the papG gene and by pulsed-field gel electrophoresis (PFGE) after genomial digestion by XbaI. Of the 17 index strains, 12 (71%) carried the papG gene; 67% of these strains had class II alleles. In recurrent UTI isolates, the papG-positive E. coli appeared in 16 (70%) of 23 isolates. The proportion of all recurrent isolates available that represented a strain previously encountered (indistinguishable or highly similar in PFGE) in the same infant was 65%. Our results suggest that most recurrent UTIs in infants are endogenous relapses rather than reinfections caused by new organisms.


Asunto(s)
Proteínas Fimbrias , Infecciones Urinarias/etiología , Adhesinas de Escherichia coli/genética , Preescolar , Electroforesis en Gel de Campo Pulsado , Escherichia coli/genética , Femenino , Humanos , Lactante , Masculino , Recurrencia , Infecciones Urinarias/tratamiento farmacológico
13.
Scand J Infect Dis ; 33(8): 625-7, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11525360

RESUMEN

A previously healthy 6-y-old girl presented with a disease very similar to pneumococcal pneumonia. However, Moraxella osloensis was isolated by lung tap. The patient responded well to a course of parenteral penicillin. This is probably the first documented case of community-acquired pneumonia associated with this agent. Clinical isolates of M. osloensis are rare and its pathogenesis has not been delineated; however, a literature review suggests that the organism is more common than is generally recognized.


Asunto(s)
Moraxella/aislamiento & purificación , Infecciones por Neisseriaceae/diagnóstico , Neumonía Bacteriana/diagnóstico , Niño , Diagnóstico Diferencial , Femenino , Humanos , Infecciones por Neisseriaceae/microbiología , Neumonía Bacteriana/microbiología , Neumonía Neumocócica/diagnóstico , Resultado del Tratamiento
15.
J Infect Dis ; 181(5): 1822-4, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10823793

RESUMEN

P-fimbrial genotypes of Escherichia coli strains and their possible association with urinary tract abnormalities were studied in infants with pyelonephritis. A total of 153 urinary E. coli strains were analyzed by polymerase chain reaction for class I, II, and III alleles of the pyelonephritis-associated adhesin gene papG. Strains with any class II papG alleles were found significantly more often in infants with normal anatomy and function or in infants with clinically insignificant abnormalities than they were in infants with significant abnormalities (90 of 119 vs. 14 of 34 infants; P<. 001). On the other hand, strains without any papG alleles were found significantly more often in infants with major urinary tract abnormalities (11 of 34 vs. 17 of 119 infants; P=.016). Our genotypic findings indicate that, especially in infants with a normal urinary tract, infection is caused by more-virulent E. coli than is present in infants without a normal urinary tract. This virulence could be due to expression of pyelonephritogenic P fimbriae by an infecting E. coli strain.


Asunto(s)
Adhesinas de Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Escherichia coli/genética , Proteínas Fimbrias , Pielonefritis/microbiología , Sistema Urinario/anatomía & histología , Alelos , Femenino , Fimbrias Bacterianas/genética , Humanos , Lactante , Masculino , Reacción en Cadena de la Polimerasa , Valores de Referencia
16.
Proc Natl Acad Sci U S A ; 97(9): 4525-9, 2000 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-10781056

RESUMEN

We have identified a sine oculis gene in the planarian Girardia tigrina (Platyhelminthes; Turbellaria; Tricladida). The planarian sine oculis gene (Gtso) encodes a protein with a sine oculis (Six) domain and a homeodomain that shares significant sequence similarity with so proteins assigned to the Six-2 gene family. Gtso is expressed as a single transcript in both regenerating and fully developed eyes. Whole-mount in situ hybridization studies show exclusive expression in photoreceptor cells. Loss of function of Gtso by RNA interference during planarian regeneration inhibits eye regeneration completely. Gtso is also essential for maintenance of the differentiated state of photoreceptor cells. These results, combined with the previously demonstrated expression of Pax-6 in planarian eyes, suggest that the same basic gene regulatory circuit required for eye development in Drosophila and mouse is used in the prototypic eye spots of platyhelminthes and, therefore, is truly conserved during evolution.


Asunto(s)
Evolución Biológica , Proteínas de Drosophila , Proteínas del Ojo/genética , Ojo/embriología , Genes Homeobox , Proteínas de Homeodominio/genética , Planarias/fisiología , Regeneración , Secuencia de Aminoácidos , Animales , Secuencia Conservada , Drosophila , Evolución Molecular , Humanos , Ratones , Datos de Secuencia Molecular , Familia de Multigenes , Filogenia , Planarias/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido
19.
Proc Natl Acad Sci U S A ; 96(2): 558-63, 1999 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-9892672

RESUMEN

The Pax-6 gene encodes a transcription factor containing both a paired and a homeodomain and is highly conserved among Metazoa. In both vertebrates and invertebrates, Pax-6 is required for eye morphogenesis, development of parts of the central nervous system, and, in some phyla, for the development of olfactory sense organs. Ectopic expression of Pax-6 from insects, mammals, cephalopods, and ascidians induces ectopic eyes in Drosophila, suggesting that Pax-6 may be a universal master control gene for eye morphogenesis. Platyhelminthes are an ancient phylum, originating from the base of spiralian protostomes, that bear primitive eyes, consisting of a group of rhabdomeric photoreceptor cells enclosed in a cup of pigment cells. The analysis of Pax-6 and its expression pattern should provide insights into the ancestral function of Pax-6 in eye morphogenesis. We have identified the Pax-6 gene of the planarian Dugesia(G)tigrina (Platyhelminthes; Turbellaria; Tricladida). This gene shares significant sequence identity and conserved genomic organization with Pax-6 proteins from other phyla. Phylogenetic analysis indicates that it clusters with the other Pax-6 genes, but in the most basal position. DtPax-6 is expressed as a single transcript in both regenerating and fully grown eyes, and electron microscopy studies show strong expression in the perykarion of both photoreceptor and pigment cells. Very low levels of expression also are detectable in other body regions. Because a bona fide Pax-6 homolog so far has not been detected in diploblastic animals, we speculate that Pax-6 may be typical for triploblasts and that the appearance of additional Pax genes may have coincided with increasingly complex body plans.


Asunto(s)
Proteínas de Unión al ADN/genética , Regulación del Desarrollo de la Expresión Génica/genética , Proteínas de Homeodominio , Planarias/genética , Regeneración/genética , Secuencia de Aminoácidos , Animales , Ojo/crecimiento & desarrollo , Proteínas del Ojo , Hibridación in Situ , Datos de Secuencia Molecular , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Filogenia , ARN Mensajero/genética , Proteínas Represoras , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Factores de Transcripción/genética
20.
Dev Genes Evol ; 208(8): 467-73, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9799427

RESUMEN

In recent years the characterization of Hox genes in different phyla has led to the suggestion of a universal role for these genes in animal axis determination. Some phyla, such as Platyhelminthes, have not yielded easily to such analysis, although a range of Hox genes have been shown to be present. In this report we present data concerning the relatively large number of Hox genes with a close similarity to representatives of annelids, supporting a phylogenetic clustering of Platyhelminthes within the spiralian protostomes. We also point out the permanent presence of Hox transcripts in adult planarians, with two classes distinguishable by their different patterns of axial expression: some are expressed uniformly, whilst a second group shows a nested expression with graded anterior expression boundaries. During posterior regeneration the nested Hox genes increase differentially depending on the level of sectioning, and then turn on gradually to recover the differential axial pattern of intact adults. These molecular results and others at the cellular level support the previous hypothesis that Platyhelminthes may have become simplified by progenesis.


Asunto(s)
Genes Homeobox , Platelmintos/fisiología , Regeneración/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cartilla de ADN , Regulación del Desarrollo de la Expresión Génica , Filogenia , Platelmintos/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido
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