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1.
Rev Calid Asist ; 30(6): 289-96, 2015.
Artículo en Español | MEDLINE | ID: mdl-26546169

RESUMEN

INTRODUCTION: The application of the Lean methodology in health institutions is an effective tool to improve the capacity and workflow, as well as to increase the level of satisfaction of patients and employees. OBJECTIVE: To optimise the time of outpatient care in a clinical laboratory, by implementing a methodology based on the organisation of operational procedures to improve user satisfaction and reduce the number of complaints for delays in care. MATERIAL AND METHODS: A quasi-experimental before and after study was conducted between October 2011 to September 2012. XBar and S charts were used to observe the mean service times and standard deviation. The user satisfaction was assessed using service questionnaires. RESULTS: A reduction of 17 minutes was observed in the time of patient care from arrival to leaving the laboratory, and a decrease of 60% in complaints of delay in care. Despite the high staff turnover and 38% increase in the number of patients seen, a culture of empowerment and continuous improvement was acquired, as well as greater efficiency and productivity in the care process, which was reflected by maintaining standards 12 months after implementation. CONCLUSION: Lean is a viable methodology for clinical laboratory procedures, improving their efficiency and effectiveness.


Asunto(s)
Servicios de Laboratorio Clínico , Laboratorios/organización & administración , Satisfacción del Paciente , Gestión de la Calidad Total , Atención Ambulatoria , Colombia , Eficiencia , Eficiencia Organizacional , Humanos , Laboratorios/normas , Mejoramiento de la Calidad , Diseño de Software , Factores de Tiempo
2.
Klin Monbl Augenheilkd ; 231(11): 1073-83, 2014 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-25285570

RESUMEN

Optic neuritis is a frequent neuro-ophthalmological disease in which the diagnosis can be based on just a few symptoms and findings. It is not only important to differentiate from other optic nerve disorders but also to recognise special types of optic neuritis, which is mostly only possible during the course of the disease. This article presents a review of the current state in diagnosis and therapy from the authors' personal point of view.


Asunto(s)
Antiinflamatorios/uso terapéutico , Dolor Ocular/diagnóstico , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/terapia , Neuritis Óptica/diagnóstico , Neuritis Óptica/terapia , Trastornos de la Visión/diagnóstico , Diagnóstico Diferencial , Dolor Ocular/etiología , Dolor Ocular/prevención & control , Humanos , Esclerosis Múltiple/complicaciones , Neuritis Óptica/complicaciones , Trastornos de la Visión/etiología , Trastornos de la Visión/prevención & control
3.
Transplant Proc ; 45(10): 3728-30, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24315010

RESUMEN

INTRODUCTION: Orthotopic liver transplantation is the treatment of choice for most terminal liver diseases in children. Currently, the improved survival of these patients is well documented, but their quality of life post-transplant is not described. In Chile, Hospital Luis Calvo Mackenna (HLCM) has performed pediatric liver transplantation in children from around the country since 1994. The aim of this study is to evaluate our patients' and parents' current quality of life. METHODS: A cross-sectional study was conducted between July 2010 and June 2011. All liver transplant patients currently in control at HLCM were invited to complete the PedsQL 4.0 report (Pediatric Quality of Life Inventory). For each group, average score was calculated and comparisons were done using Student t and χ(2) tests. RESULTS: Forty-nine patients were enrolled. One-third of the patients were between 2 and 4 years, one-third between 5 and 12, and the rest were 13 to 18 years old. Half of the patients had their transplants for more than 3 years, 53% were female, 53% lived in cities far from the transplant center, 72.5% had chronic liver disease, 53% had received a liver from cadaveric donor, and 21% had received more than 1 liver transplant. Patients under 4 years referred good health-related quality of life (HRQOL) in all categories. All school-age patients had poor or very poor psychosocial HRQOL. DISCUSSION: Our good results obtained in transplant patients under 4 years may be because the questionnaire was completed by caregivers. The school-age patients were affected in terms of school functioning, as they were not able to participate in all the activities. These findings need to be compared with HRQOL perception in other groups, such as children with other chronic conditions, and evaluated with other broader factors, as reported in international HRQOL publications.


Asunto(s)
Calidad de Vida , Adolescente , Factores de Edad , Distribución de Chi-Cuadrado , Niño , Preescolar , Chile , Estudios Transversales , Femenino , Humanos , Trasplante de Hígado/efectos adversos , Masculino , Factores de Riesgo , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento
4.
Transplant Proc ; 45(10): 3724-5, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24315008

RESUMEN

INTRODUCTION: In 1994 our group began its experience with pediatric liver transplantation. The experience gained during this period is the largest in the country, positioning the Hospital Luis Calvo Mackenna and Clinica Las Condes as major referral centers in the public and private sectors. The aim of this study was to report our experience of our pediatric liver transplantation program during this period. METHODS: The liver transplantation database of Hospital Luis Calvo Mackenna and Clinica Las Condes between January 1994 and July 2011 was reviewed recording age, gender, indications for transplantation, surgical technique, complications, and survival. Survival rates were calculated using Kaplan-Meier analysis. RESULTS: During the period described 230 transplantations were performed in 189 pediatric patients. Fifty-five percent were male patients. The average age was 5 years. The main causes of transplantation were biliary atresia (50%), fulminant hepatic failure (25%), and other cholestatic diseases by 10%. Vascular and biliary complications were the leading cause of graft loss and retransplantation. The overall rate of retransplantation at 5 years was 20%. The technique of living donor was used in 28% of the cases. The 1-year patient actuarial survival rate was 80%, 73% at 5 years, and 68% at 10 years. In the last 3 years the survival rate at 1 year exceeds 90%. DISCUSSION: Our program includes more than 90% of the national liver experience. The incorporation of living donor is a milestone that has enabled us to save many patients who previously died while waiting for an organ. Its use in cases of full acute liver failure has allowed us to dramatically reduce mortality on the waiting list. Our results in the last 3 years reflect the experience that results in a significant decrease in mortality, comparing favorably to other series published in the international literature.


Asunto(s)
Trasplante de Hígado , Factores de Edad , Preescolar , Chile , Femenino , Supervivencia de Injerto , Humanos , Estimación de Kaplan-Meier , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/mortalidad , Donadores Vivos/provisión & distribución , Masculino , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/cirugía , Evaluación de Programas y Proyectos de Salud , Reoperación , Factores de Riesgo , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Listas de Espera
5.
Transplant Proc ; 45(10): 3726-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24315009

RESUMEN

INTRODUCTION: Pediatric liver transplantation is limited by donation. In the last 5 years, urgent conditions have forced transplant teams to accept donors with minor suboptimal conditions, termed "extended donor criteria." Among those, the risk of using severe hypernatremic donors (SHD) for liver transplant is not yet well established. The aim of this study is to report the outcome of pediatric patients receiving grafts from SHD. METHODS: Clinical records of patients transplanted in the last 3 years at Hospital Luis Calvo Mackenna, Santiago, Chile, were reviewed. Outcome was evaluated in terms of patient and graft survival and complications potentially associated to the donor condition. RESULTS: Five of 33 deceased donor transplants presented with SHD. All recipients were waiting transplant in an acute condition, one of them in acute liver failure (ALF). No living related donor was available. Donors' serum sodium was 169 to 193 mEq/L before medical management and between 157 and 172 mEq/L at procurement. One patient died from sepsis related to biliary complications, and the patient suffering ALF developed primary graft nonfunction, received a second transplant 2 weeks later, and recovered to stable medical condition. No other complication was registered in these patients. DISCUSSION: Our findings allow us to postulate that hypernatremic deceased donors may be used for pediatric liver transplant under special circumstances.


Asunto(s)
Selección de Donante , Hipernatremia/complicaciones , Trasplante de Hígado , Donantes de Tejidos/provisión & distribución , Factores de Edad , Biomarcadores/sangre , Cadáver , Niño , Chile , Femenino , Humanos , Hipernatremia/sangre , Hipernatremia/diagnóstico , Hipernatremia/mortalidad , Lactante , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/mortalidad , Masculino , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/cirugía , Reoperación , Factores de Riesgo , Índice de Severidad de la Enfermedad , Sodio/sangre , Factores de Tiempo , Resultado del Tratamiento , Listas de Espera
6.
Transplant Proc ; 45(10): 3731-3, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24315011

RESUMEN

BACKGROUND: Orthotopic liver transplantation is the treatment of choice for most terminal liver diseases in children. In small children (≤ 10 kg), this procedure is challenging and has special considerations. The aim of this study is to describe the experience of a Chilean liver transplantation program in this subgroup of patients. METHODS: The liver transplant database of Hospital Luis Calvo Mackenna and Clinica Las Condes was reviewed. All children less than 10 kg undergoing liver transplantation between January 1994 and July 2011 were included. Patient and graft outcomes and main complications were analyzed. RESULTS: We have performed 230 pediatric liver transplantations, 49 of them in 41 patients weighing less than 10 kg. The first indication for transplantation was biliary atresia in 25 patients (61%). A living related donor was used in 23 cases (51%). Actuarial survival was 75.7% at 1 year and 67.1% at 5 years. The main cause of death was infection, and the leading cause of graft loss was vascular complication. DISCUSSION: Our transplant program includes 2 centers that perform more than 90% of pediatric liver transplantations in Chile, including public health pediatric patients from all around the country. Patients weighing less than 10 kg represent the most challenging group in pediatric liver transplantation due to higher rates of vascular and biliary complications and postoperative infections.


Asunto(s)
Peso Corporal , Trasplante de Hígado , Factores de Edad , Chile , Enfermedades Transmisibles/etiología , Enfermedades Transmisibles/mortalidad , Estudios Transversales , Femenino , Rechazo de Injerto/etiología , Rechazo de Injerto/mortalidad , Supervivencia de Injerto , Humanos , Lactante , Estimación de Kaplan-Meier , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/mortalidad , Donadores Vivos , Masculino , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
7.
Klin Monbl Augenheilkd ; 230(11): 1114-8, 2013 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-24243473

RESUMEN

AIM OF THE STUDY: For the construction of true accommodating intraocular lenses and for refractive surgery a knowledge about pupil diameter in daily life is important. Sufficient data are available only in darkness. MATERIAL AND METHODS: 206 volunteers aged between 18 and 72 years without disorders influencing the pupil have been examined by means of pupillography at two luminance conditions (3 and 30 cd/m2) and 3 fixation distances (5 m, 1 m, 0.33 m). RESULTS: Pupil size decreases by 0.42 mm per decade with the darker condition and 0.25 mm per decade with brighter light. Fixation change from 5 to 1 m has hardly any influence on pupil size, changing to 0.33 m constricts the pupil by 0.43 mm at dark condition and 0.33 mm at the lighter condition. CONCLUSION: Luminance has the strongest influence on pupil size, near fixation has hardly any influence down to 1 m. The well-known age relation of pupil size in darkness is also valid for mesopic and photopic conditions. At 3 cd/m2 it was the same as reported in darkness, at 30 cd/m2 it was less in absolute numbers, but relative as compared to young adults it was approximately the same.


Asunto(s)
Biometría/métodos , Iris/anatomía & histología , Iris/efectos de la radiación , Iluminación/métodos , Pupila , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
8.
Naturwissenschaften ; 100(3): 263-8, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23354758

RESUMEN

The biogenetic law posits that the ontogeny of an organism recapitulates the pattern of evolutionary changes. Morphological evidence has offered some support for, but also considerable evidence against, the hypothesis. However, biogenetic law in behavior remains underexplored. As physical manifestation of behavior, spider webs offer an interesting model for the study of ontogenetic behavioral changes. In orb-weaving spiders, web symmetry often gets distorted through ontogeny, and these changes have been interpreted to reflect the biogenetic law. Here, we test the biogenetic law hypothesis against the alternative, the optimal foraging hypothesis, by studying the allometry in Leucauge venusta orb webs. These webs range in inclination from vertical through tilted to horizontal; biogenetic law predicts that allometry relates to ontogenetic stage, whereas optimal foraging predicts that allometry relates to gravity. Specifically, pronounced asymmetry should only be seen in vertical webs under optimal foraging theory. We show that, through ontogeny, vertical webs in L. venusta become more asymmetrical in contrast to tilted and horizontal webs. Biogenetic law thus cannot explain L. venusta web allometry, but our results instead support optimization of foraging area in response to spider size.


Asunto(s)
Conducta Alimentaria/fisiología , Animales , Evolución Biológica , Tamaño Corporal , Arañas/fisiología
9.
Clin Genet ; 83(4): 365-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22775437

RESUMEN

Peutz-Jeghers syndrome (PJS) is an autosomal dominant disorder characterized by mucocutaneous melanocytic macules, gastrointestinal hamartomatous polyposis and an increased risk of various neoplasms. Germline mutations in the serine/threonine kinase 11 (STK11) gene have been identified as a cause for PJS. The aim of this study was to characterize the genotype of Chilean PJS patients. Mutation screening of 13 patients from eight PJS families was performed using a single strand conformation polymorphism analysis, DNA sequencing and multiplex ligation-dependent probe amplification assay. The breakpoints of the genomic rearrangements were assessed by a long-range polymerase chain reaction and sequencing. The results revealed the existence of seven different pathogenic mutations in STK11 gene in seven unrelated families, including three point mutations and four large genomic deletions. Three of these point mutations (43%, 3/7) may be considered as novel. Our results showed that a germline mutation is present in STK11 in 88% of probands fulfilling the diagnostic criteria of PJS. In this study, the combination of two different experimental approaches in the screening of the STK11 in PJS, led to a higher percentage of mutation detection.


Asunto(s)
Mutación de Línea Germinal , Síndrome de Peutz-Jeghers/genética , Mutación Puntual , Proteínas Serina-Treonina Quinasas/genética , Empalme del ARN/genética , Quinasas de la Proteína-Quinasa Activada por el AMP , Adolescente , Adulto , Niño , Preescolar , Femenino , Genotipo , Humanos , Lactante , Masculino , Reacción en Cadena de la Polimerasa Multiplex/métodos
10.
Neurosignals ; 21(3-4): 197-212, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22947663

RESUMEN

The development of appropriate models assessing the potential of substances for regeneration of neuronal circuits is of great importance. Here, we present procedures to analyze effects of substances on fiber outgrowth based on organotypic slice co-cultures of the nigrostriatal dopaminergic system in combination with biocytin tracing and tyrosine hydroxylase labeling and subsequent automated image quantification. Selected phosphodiesterase inhibitors (PDE-Is) were studied to identify their potential growth-promoting capacities. Immunohistochemical methods were used to visualize developing fibers in the border region between ventral tegmental area/substantia nigra co-cultivated with the striatum as well as the cellular expression of PDE2A and PDE10. The quantification shows a significant increase of fiber density in the border region induced by PDE2-Is (BAY60-7550; ND7001), comparable with the potential of the nerve growth factor and in contrast to PDE10-I (MP-10). Analysis of tyrosine hydroxylase-positive fibers indicated a significant increase after treatment with BAY60-7550 and nerve growth factor in relation to dimethyl sulfoxide. Additionally, a dose-dependent increase of intracellular cGMP levels in response to the applied PDE2-Is in PDE2-transfected HEK293 cells was found. In summary, our findings show that PDE2-Is are able to significantly promote axonal outgrowth in organotypic slice co-cultures, which are a suitable model to assess growth-related effects in neuro(re)generation.


Asunto(s)
Axones/efectos de los fármacos , Neuronas/efectos de los fármacos , Inhibidores de Fosfodiesterasa/farmacología , Sustancia Negra/efectos de los fármacos , Área Tegmental Ventral/efectos de los fármacos , Animales , Axones/fisiología , Neuronas/citología , Neuronas/fisiología , Técnicas de Cultivo de Órganos , Ratas , Ratas Wistar , Sustancia Negra/citología , Sustancia Negra/crecimiento & desarrollo , Área Tegmental Ventral/citología , Área Tegmental Ventral/crecimiento & desarrollo
11.
IEEE Trans Vis Comput Graph ; 17(11): 1547-59, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21282859

RESUMEN

We present a novel method to visualize multidimensional point clouds. While conventional visualization techniques, like scatterplot matrices or parallel coordinates, have issues with either overplotting of entities or handling many dimensions, we abstract the data using topological methods before presenting it. We assume the input points to be samples of a random variable with a high-dimensional probability distribution which we approximate using kernel density estimates on a suitably reconstructed mesh. From the resulting scalar field we extract the join tree and present it as a topological landscape, a visualization metaphor that utilizes the human capability of understanding natural terrains. In this landscape, dense clusters of points show up as hills. The nesting of hills indicates the nesting of clusters. We augment the landscape with the data points to allow selection and inspection of single points and point sets. We also present optimizations to make our algorithm applicable to large data sets and to allow interactive adaption of our visualization to the kernel window width used in the density estimation.

12.
IEEE Trans Vis Comput Graph ; 17(11): 1599-611, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21173451

RESUMEN

The contour tree compactly describes scalar field topology. From the viewpoint of graph drawing, it is a tree with attributes at vertices and optionally on edges. Standard tree drawing algorithms emphasize structural properties of the tree and neglect the attributes. Applying known techniques to convey this information proves hard and sometimes even impossible. We present several adaptions of popular graph drawing approaches to the problem of contour tree drawing and evaluate them. We identify five esthetic criteria for drawing contour trees and present a novel algorithm for drawing contour trees in the plane that satisfies four of these criteria. Our implementation is fast and effective for contour tree sizes usually used in interactive systems (around 100 branches) and also produces readable pictures for larger trees, as is shown for an 800 branch example.

13.
Eur J Clin Invest ; 39(3): 174-82, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19260946

RESUMEN

BACKGROUND: The optimal duration of clopidogrel treatment following percutaneous coronary intervention (PCI) and the patient population that would benefit most are still unknown. In a porcine coronary injury model, we tested two different durations of clopidogrel treatment on severely or moderately injured arteries and examined the arterial response to injury. To understand the molecular mechanism, we also investigated the effects on transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein 1 (AP-1). MATERIALS AND METHODS: In 24 cross-bred pigs, one coronary artery was only moderately injured by percutaneous transluminal coronary angioplasty (PTCA) and one coronary artery was severely injured by PTCA and subsequent beta-irradiation (Brachy group). Animals received 325 mg aspirin daily for 3 months and 75 mg clopidogrel daily for either 28 days [short-term (ST) clopidogrel group] or 3 months [long-term (LT) clopidogrel group]. RESULTS: After 3 months, the number of proliferating cells per cross-section differed significantly between ST and LT in both injury groups (PTCA(ST) 90.2 +/- 10.3 vs. PTCA(LT )19.2 +/- 4.7, P < 0.05; Brachy(ST) 35.8 +/- 8.4 vs. Brachy(LT) 7.5 +/- 2.0, P < 0.05). Similar results were seen for inflammatory cells (CD3(+) cells): PTCA(ST) 23.5 +/- 3.55 vs. PTCA(LT )4.67 +/- 0.92, P < 0.05; Brachy(ST) 83.17 +/- 11.17 vs. Brachy(LT) 20 +/- 4.82, P < 0.05). Long-term administration also reduced the activity of NF-kappaB and AP-1 by 62-64% and 42-58%, respectively. However, the effects of different durations of clopidogrel administration on artery dimensions were not statistically significant. CONCLUSIONS: Regarding inflammation and transcription factor activity at the PCI site, long-term clopidogrel administration is superior to short-term administration, especially in severely injured arteries. Transferring our results to the human situation, patients with more severely diseased arteries may benefit from a prolonged clopidogrel medication after PCI.


Asunto(s)
Aspirina/administración & dosificación , Reestenosis Coronaria/tratamiento farmacológico , FN-kappa B/metabolismo , Inhibidores de Agregación Plaquetaria/administración & dosificación , Ticlopidina/análogos & derivados , Factor de Transcripción AP-1/metabolismo , Animales , Clopidogrel , Reestenosis Coronaria/patología , Modelos Animales de Enfermedad , Quimioterapia Combinada , Estadística como Asunto , Sus scrofa/lesiones , Ticlopidina/administración & dosificación , Factores de Tiempo
15.
Neuroscience ; 149(1): 165-81, 2007 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-17869006

RESUMEN

Extracellular ATP facilitates the release of dopamine via P2 receptor activation in parts of the mesolimbic system. To characterize P2X/Y receptor subtypes in the developing dopaminergic system, their expression in organotypic slice co-cultures including the ventral tegmental area/substantia nigra (VTA/SN) complex and the prefrontal cortex (PFC) was studied in comparison to the receptor expression in 3-5 day-old and adult rats. Reverse transcriptase-polymerase chain reaction (RT-PCR) with specific primers for the P2X(1,2,3,4,6,7) and P2Y(1) receptors in the tissue extracts of organotypic co-cultures revealed the presence of the P2X and P2Y receptor mRNAs investigated. Multiple immunofluorescence labeling of the P2X/Y receptor protein indicated differences in the regional expression in the organotypic co-cultures after 10 days of cultivation (VTA/SN, P2X(1,2,3,4,6,7), P2Y(1,6,12); PFC, P2X(1,3,4,6,7), P2Y(1,2,4,6,12)). At postnatal days 3-5, an immunofluorescence mostly comparable to that of adult rats was observed (VTA/SN and PFC: P2X(1,2,3,4,6,7), P2Y(1,2,4,6,12)). There was one important exception: the P2X(7) receptor immunocytochemistry was not found in adult tissue, suggesting a potential role of this receptor in the development. Only few P2 receptors (e.g. P2X(1), P2Y(1)) were expressed at fibers interconnecting the dopaminergic VTA/SN with the PFC in the organotypic co-cultures. The treatment of the cultures with the ATP analogues 2-methylthio-ATP and alpha,beta-methylene-ATP induced an increase in axonal outgrowth and fiber density, which could be inhibited by pre-treatment with the P2X/Y receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid. The co-localization of the dopamine-(D1) receptor with the P2X(1) receptor in organotypic slice cultures was evident. In the PFC of the co-cultures, and that of young but not adult rats, a number of tyrosine hydroxylase (TH)-positive cells also possessed P2Y(1)-immunoreactivity (IR). Additionally, a strong P2Y(1)-IR was observed on astrocytes. The present results show a time-, region- and cell type-dependent in vitro and in vivo expression pattern of different P2 receptor subtypes in the dopaminergic system indicating the involvement of ATP and its receptors in neuronal development and growth.


Asunto(s)
Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Dopamina/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Receptores Purinérgicos P2/metabolismo , Animales , Animales Recién Nacidos , Técnicas de Cocultivo/métodos , Regulación del Desarrollo de la Expresión Génica/genética , Proteína Ácida Fibrilar de la Glía/metabolismo , Lisina/análogos & derivados , Lisina/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Técnicas de Cultivo de Órganos , Corteza Prefrontal/crecimiento & desarrollo , Corteza Prefrontal/metabolismo , ARN Mensajero/biosíntesis , Ratas , Ratas Wistar , Receptores Purinérgicos P2/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Sustancia Negra/crecimiento & desarrollo , Sustancia Negra/metabolismo , Tirosina 3-Monooxigenasa/metabolismo , Área Tegmental Ventral/crecimiento & desarrollo , Área Tegmental Ventral/metabolismo
16.
Am Nat ; 169(4): 534-42, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17262697

RESUMEN

In natural communities, species are embedded in networks of direct and indirect interactions. Most studies on indirect interactions have focused on how they affect predator-prey or competitive relationships. However, it is equally likely that indirect interactions play an important structuring role in mutualistic relationships in a natural community. We demonstrate experimentally that on a small spatial scale, dense thickets of endemic Pandanus plants have a strong positive trait-mediated indirect effect on the reproduction of the declining endemic Mauritian plant Trochetia blackburniana. This effect is mediated by the endemic gecko Phelsuma cepediana moving between Pandanus thickets, a preferred microhabitat, and nearby T. blackburniana plants, where it feeds on nectar and pollinates the plants. Our findings emphasize the importance of considering plant-animal interactions such as pollination at relatively small spatial scales in both basic ecological studies and applied conservation management.


Asunto(s)
Ecosistema , Lagartos/fisiología , Malvaceae/fisiología , Pandanaceae/fisiología , Simbiosis , Análisis de Varianza , Animales , Conducta Alimentaria/fisiología , Mauricio , Observación , Polen , Dinámica Poblacional , Reproducción/fisiología
17.
Neuroscience ; 138(1): 303-11, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16431028

RESUMEN

Extracellular ATP might act as a trophic factor on growing axons during development of the CNS via P2 receptors. In the present study the postnatal presence of selected P2 receptor subtypes was analyzed and their putative trophic capacity in entorhino-hippocampal slice co-cultures of mouse brain was tested. The effect of the P2 receptor ligands 2-methylthioadenosine-5'-triphosphate (P2X/Y receptor agonist) and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (P2X/Y receptor antagonist) on axonal growth and fiber density of biocytin-labeled hippocampal projections was compared both with untreated cultures and with cultures treated with artificial cerebrospinal fluid. After 10 days in vitro, double immunofluorescence labeling revealed the expression of P2X(1), P2X(2), P2X(4) as well as P2Y(1) and P2Y(2) receptors in the examined regions of entorhinal fiber termination. Further, quantitative analysis of identified biocytin-traced entorhinal fibers showed a significant increase in fiber density in the dentate gyrus after incubation of the slices with the P2 receptor agonist 2-methylthioadenosine-5'-triphosphate. This neurite outgrowth promoting effect was completely abolished by the P2 receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid. Our in vitro data indicate that ATP via its P2X and P2Y receptors can shape hippocampal connectivity during development.


Asunto(s)
Axones/fisiología , Hipocampo/crecimiento & desarrollo , Agonistas del Receptor Purinérgico P2 , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/farmacología , Animales , Axones/efectos de los fármacos , Recuento de Células , Técnicas de Cocultivo , Giro Dentado/citología , Giro Dentado/efectos de los fármacos , Corteza Entorrinal/fisiología , Técnica del Anticuerpo Fluorescente Indirecta , Hipocampo/citología , Hipocampo/efectos de los fármacos , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Fibras Nerviosas/efectos de los fármacos , Técnicas de Cultivo de Órganos , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/farmacología , Estimulación Química , Tionucleótidos/farmacología
18.
Neuroscience ; 127(2): 431-41, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15262333

RESUMEN

The expression of purinoceptor (P2)Y-subtypes on astrocytes in vivo under physiological conditions and after stab wound injury was investigated. Reverse transcriptase-polymerase chain reaction with specific primers for the receptor-subtypes P2Y1,2,4,6,12 in tissue extracts of the nucleus accumbens of untreated rats revealed the presence of all P2Y receptor mRNAs investigated. Double immunofluorescence visualized with laser scanning microscopy indicated the expression of the P2Y1,4 receptors on glial fibrillary acidic protein (GFAP)-labeled astrocytes under physiological conditions. After stab wound injury the additional expression of the P2Y2 and P2Y6 receptors, and an up-regulation of the P2Y1,4 receptor-labeling on astrocytic cell bodies and/or processes was observed. Astrocytes of cortical, in contrast to accumbal areas exhibited P2Y1,2,4,6 receptor-immunoreactivity (IR) under control conditions, which was up-regulated after stab would injury. Labeling for the P2Y12 receptor was not observed on GFAP-positive cortical and accumbal astrocytes under any of the conditions used. For the first time, the co-localization of different P2 receptor-subtypes (e.g. P2Y1 and P2X3) on the same astrocyte was shown immunocytochemically. The up-regulation of P2Y1 receptor-IR on astrocytes and non-glial cells after mechanical injury could be facilitated by microinfusion of the P2Y1,12,13 receptor agonist adenosine 5'-O-(2-thiodiphosphate) (ADPbetaS). Proliferative changes after ADPbetaS-microinjection were characterized by means of double-staining with antibodies against GFAP and 5-bromo-2'-deoxyuridine. The non-selective P2 receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid, the P2Y1 receptor antagonist N6-methyl-2'-deoxyadenosine 3',5'-bisphosphate and the P2Y1 receptor-antibody itself inhibited the agonist-induced effects. The data indicate the region-specific presence of P2Y receptors on astrocytes in vivo and their up-regulation after injury as well as the co-localization of P2X and P2Y receptor-subtypes on the same astrocyte. The dominant role of P2Y1 receptors in proliferation and the additional stimulation of non-P2Y1 receptors has been demonstrated in vivo suggesting the involvement of this receptor-type in the gliotic response under physiological and pathological conditions.


Asunto(s)
Adenosina Difosfato/análogos & derivados , Astrocitos/metabolismo , Lesiones Encefálicas/metabolismo , Gliosis/metabolismo , Núcleo Accumbens/metabolismo , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2/metabolismo , Adenosina Difosfato/farmacología , Animales , Astrocitos/citología , Astrocitos/efectos de los fármacos , Lesiones Encefálicas/fisiopatología , Bromodesoxiuridina , División Celular/efectos de los fármacos , División Celular/fisiología , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Corteza Cerebral/fisiopatología , Técnica del Anticuerpo Fluorescente , Proteína Ácida Fibrilar de la Glía/metabolismo , Gliosis/etiología , Gliosis/fisiopatología , Masculino , Núcleo Accumbens/patología , Núcleo Accumbens/fisiopatología , Subunidades de Proteína/efectos de los fármacos , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Agonistas del Receptor Purinérgico P2 , Antagonistas del Receptor Purinérgico P2 , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptores Purinérgicos P2/efectos de los fármacos , Receptores Purinérgicos P2Y1 , Tionucleótidos/farmacología , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
19.
Disabil Rehabil ; 24(15): 763-73, 2002 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-12437862

RESUMEN

With increasing longevity among populations, age-related vision and hearing impairments are becoming prevalent conditions in the older adult populations. In combination dual sensory loss occurs. Dual sensory loss is becoming a more common condition seen by clinicians and previous research has shown that 6% of non-institutionalized older adults had a dual sensory impairment, whilst 70% of severely vision-impaired older adults also demonstrated a significant hearing loss. Decreased vision and/or hearing acuity interferes with reception of the spoken message and hence people with sensory loss frequently experience communication breakdown. Many personal, situational and environmental triggers are also responsible for communication breakdown. Limited ability to improve communication performance frequently results in poor psychosocial functioning. Older adults with sensory loss often experience difficulty adjusting to their sensory loss. Depression, anxiety, lethargy and social dissatisfaction are often reported. Sensory loss, decreased communication performance and psychosocial functioning impacts on one's quality of life and feelings of well-being. Rehabilitation services for older adults with age-related sensory loss need to accommodate these difficulties. Improved staff education and rehabilitation programmes providing clients and carers with strategies to overcome communication breakdown is required. A multidisciplinary perspective to the assessment and remediation of older adults is recommended.


Asunto(s)
Envejecimiento/psicología , Comunicación , Pérdida Auditiva/psicología , Baja Visión/psicología , Actividades Cotidianas , Anciano , Pérdida Auditiva/epidemiología , Pérdida Auditiva/rehabilitación , Humanos , Persona de Mediana Edad , Prevalencia , Carencia Psicosocial , Calidad de Vida , Conducta Social , Baja Visión/epidemiología , Baja Visión/rehabilitación
20.
Acta Radiol ; 43(3): 242-8, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12100319

RESUMEN

PURPOSE: A post-processing protocol for 3D visualization of the cranial nerves V-VIII along their intracisternal course is presented. MATERIAL AND METHODS: Six healthy volunteers underwent MR imaging (1.5 T) to obtain high-resolution heavily T2-weighted data sets (3DFT CISS) with isotropic voxels (0.5 mm3). The data sets were post-processed by using volume rendering software in order to visualize the intracisternal courses of the cranial nerves V-VIII as well as their root entry zones. The data acquisition and post-processing protocol was then applied in 14 patients with a suspected neural compression syndrome according to the clinical findings as well as cross-sectional images and evaluated with respect to image quality and diagnostic value by two neuroradiologists, using a five-point scale. RESULTS: Virtual cisternoscopy allowed a comprehensive intracisternal 3D visualization of the affected cranial nerves in 12/14 patients. The mean post-processing time amounted to 13.1/5.6/13.7 min for the cranial nerves V/VI/VII and VIII. The mean score for image quality was 4.2, that for diagnostic value 4.1. 2D and/or 3D reference images were indispensable for appreciating the spatial information provided by virtual cisternoscopy. CONCLUSION: The data acquisition and post-processing protocol presented here allows comprehensive and standardized intracisternal 3D visualization of the cranial nerves V-VIII in a routine setting as a complementary imaging procedure.


Asunto(s)
Nervio Abducens/anatomía & histología , Cisterna Magna , Endoscopía/métodos , Nervio Facial/anatomía & histología , Imagen por Resonancia Magnética/métodos , Nervio Trigémino/anatomía & histología , Nervio Vestibulococlear/anatomía & histología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndromes de Compresión Nerviosa/diagnóstico
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