Evaluation of migration forces of a retrievable filter: experimental setup and finite element study.

The aim of this paper is to provide a computational study of migration forces of a retrievable filter (Günther Tulip inferior vena cava filter). Using an experimental setup and finite element simulation, the migration forces and stress at the end of the anchored hooks in the struts were estimated. After that, the estimation value of migration stress (τ(rup)) was used to analyze the effect of different mechanical factors (strut thickness, vena cava diameter) in the migration of the IVC filter. Our results show that the migration stress is τ(rup)=4.37 N/mm(2). Using this value we obtain that the filter with higher strut diameter (ϕ(strut)=0.45 mm) shows the maximal migration forces in every cava diameter. On the other hand, the value of the migration force decreases when the cava diameter increases. In addition, the finite element simulations also show that there are contact between the struts of the filter and the vein in regions close to the anchors.

Experimental study and constitutive modelling of the passive mechanical properties of the porcine carotid artery and its relation to histological analysis: Implications in animal cardiovascular device trials.

The present study focusses on the determination, comparison and constitutive modelling of the passive mechanical properties of the swine carotid artery over very long stretches in both proximal and distal regions. Special attention is paid to the histological and mechanical variations of these properties depending on the proximity to the heart. The results can have clinical relevance, especially in the research field of intravascular device design. Before the final clinical trials on humans, research in the vascular area is conducted on animal models, swine being the most common due to the similarities between the human and swine cardiovascular systems as well as the fact that the swine size is suitable for testing devices, in this case endovascular carotid systems. The design of devices usually involves numerical techniques, and an important feature is the appropriate modelling of the mechanical properties of the vessel. Fourteen carotid swine arteries were harvested just after sacrifice and cyclic uniaxial tension tests in longitudinal and circumferential directions were performed for distal and proximal samples. The stress-stretch curves obtained were fitted with a hyperelastic anisotropic model. Stress-free configuration states were also analyzed. Finally, human and swine samples were processed in a histological laboratory and images were used to quantify their microconstituents. The statistical analysis revealed significant differences between the mechanical behavior of proximal and distal locations in the circumferential but not in the longitudinal direction. Circumferential direction samples show clear differences both in residual stretches and tensile curves between the two locations, while the features of longitudinal specimens are independent of the axial position. The statistical analysis provides significant evidence of changes depending on the position of the sample, mainly in elastin and SMC quantification.

A constitutive formulation of vascular tissue mechanics including viscoelasticity and softening behaviour.

Nearly all soft tissues, among which the vascular tissue is included, present a certain degree of viscoelastic response. This behaviour may be attributed in part to fluid transport within the solid matrix, and to the friction between its fluid and solid constituents. After being preconditioned, the tissue displays highly repetitive behaviour, so that it can be considered pseudo-elastic, that is, elastic but behaving differently in loading and unloading. Because of this reason, very few constitutive laws accounting for the viscoelastic behaviour of the tissue have been developed. Nevertheless, the consideration of this inelastic effect is of crucial importance in surgeries-like vascular angioplasty-where the mentioned preconditioning cannot be considered since non-physiological deformation is applied on the vessel which, in addition, can cause damage to the tissue. A new constitutive formulation considering the particular features of the vascular tissue, such as anisotropy, together with these two inelastic phenomena is presented here and used to fit experimental stress-stretch curves from simple tension loading-unloading tests and relaxation test on porcine and ovine vascular samples.

Percutaneous treatment of intrabdominal abscess: urokinase versus saline serum in 100 cases using two surgical scoring systems in a randomized trial.

The purpose of this study was to assess whether regular instillation of urokinase during abscess drainage leads to an improved outcome compared to saline irrigation alone. One hundred patients referred for image-guided abdominal abscess drainage were randomized between thrice daily urokinase instillation or saline irrigation alone. At the end of the study, patient medical records were reviewed to determine drainage, study group, Altona (PIA II) and Mannheim (MPI) scoring, duration of drainage, procedure-related complications, hospital stay duration, and clinical outcome. The technical success rate of the percutaneous abscess drainage was 100%. The success or failure of abscess remission did not differ significantly between groups (success rate of 91.5% in the urokinase group vs. 88.8% in the saline group; failure rate was of 8.5 vs. 21.2%, respectively); however, days of drainage, main hospital stay, and overall costs were significantly reduced in patients treated with urokinase compared to the control group (P < 0.05). No adverse effects from urokinase were observed. Surgical scores were a useful homogeneity factor, and MPI showed a good correlation with prognosis, while PIA results did not have a significant correlation. For drainage of complex abscesses (loculations, hemorrhage, viscous material), fibrinolytics safely accelerate drainage and recovery, reducing the length of the hospital stay and, therefore, the total cost.

Response of intertidal macrobenthic communities to long term human induced changes in the Eo estuary (Asturias, Spain): implications for environmental management.

Long term macrobenthos data together with physical habitat parameters were analysed to investigate spatial and temporal changes at an estuary under different anthropogenic pressures, mainly increasing shellfish farming. The aim was to assess the possible impacts of these pressures on the macrobenthic communities by comparing a period before and after changes in these pressures. Benthic samples were seasonally collected in 1990 (before major anthropogenic changes), 2000 and 2005 at the same sampling stations located on three different habitats in the Eo estuary (Northern Spanish coast). Multivariate and univariate methods were used to assess spatial variability of benthic assemblages and to compare community changes over time. Data from 1990 was assumed as the reference situation to appraise the subsequent impacts. We observed a significant spatial variability of the benthic assemblages in the system as a function of habitat heterogeneity in relation to sediment composition, presence/absence and density of seagrasses, and hydrodynamic regime. Changes were detected in the community composition at all sites during this 15 year period. The extent of changes was related to initial community conditions, rather than the intensity of the pressure. The results suggest that the responses of the benthic communities to human induced perturbations occurring in the system are largely dependent on its intrinsic buffer capacity, and that these communities have been able to cope with an increasing environmental stress (organic enrichment). In conclusion, to keep shellfish farming at a sustainable level without undesirable impacts, the disturbance intensity must be kept below the system carrying capacity. This will allow natural communities to cope with pressures and thus avoid further deterioration in ecological quality.

Ecological status assessment in the lower Eo estuary (Spain). The challenge of habitat heterogeneity integration: a benthic perspective.

The implementation of the European Water Framework Directive (WFD) requires evaluation of the ecological status (ES) of benthic communities in coastal and transitional water systems, and the intercalibration of assessment methodologies therefore becomes a research challenge. Our aim was to test the suitability of applying the M-AMBI index to assess the status of the Eo estuary (northern coast of Spain). Our results showed that M-AMBI was influenced by the natural variability of benthic communities, and presented an apparent dependence on habitat characteristics. Consequently, the definition of homogeneous areas in transitional water systems should be based on the salinity gradient combined with other factors. To achieve an accurate ES assessment, habitat-specific reference conditions should then be defined prior to the application of M-AMBI; this necessitates dividing an estuary into several sections, which may be classified as different ESs. From this perspective, a novel approach to integrate habitat heterogeneity in a global ES assessment was tested.

[Follow-up of patients who seek treatment for grief]. / Seguimiento de pacientes que consultan por duelo.

INTRODUCTION: Based on several contributions and studies on evolutive aspects of grief, this study aims to focus on the two-year follow-up of patients from the Community Mental Health Service of Pa rla who came to the clinic in relationship with grief. METHODS: Based upon a previous research, the authors have performed a follow-up study at two years in a sample of 51 patients, carried out by a telephone interview that examined subjective improvement, coping strategies and grieving process, biographical continuity and later life events. RESULTS: Two years after the first visit, most of the patients considered that they had coped well with the loss and were able to resume their normal activities. They ranked their clinical situation as <>. One out of every four reported a partial or marked detention in their biographical course. CONCLUSIONS: In the long term evolution of a visit due to grief, a positive outcome might be expected in the most of the cases. Factors associated with a worst outcome are a problematic bond with the deceased, and the son/daughter loss. Positive outcome was associated with social support and psychotherapy.

Seguimiento de pacientes que consultan por duelo / Follow-up of patients who seek treatment for grief

Introducción. Partiendo de diversas aportaciones y estudios sobre aspectos evolutivos del duelo, el presente trabajo se centra en el seguimiento a los 2 años de pacientes del Servicio de Salud Mental de Parla que consultaban en relación a un duelo. Métodos. A partir de una investigación anterior se realizó un estudio de seguimiento a los 2 años a una muestra de 51 personas mediante una encuesta de aplicación telefónica que exploraba mejoría subjetiva, afrontamiento de la pérdida, continuidad del curso biográfico y circunstancias posteriores. Resultados. A los 2 años de la primera consulta la mayoría de los pacientes afirmaban una mejoría clínica, así como haber podido afrontar total o parcialmente la pérdida y continuar sus actividades con normalidad, si bien una cuarta parte refería una parcial o marcada detención del curso biográfico. Conclusiones. En la evolución a largo plazo de una consulta por duelo es mayoritaria la remisión de sintomatología asociada. Asimismo influyen negativamente en este proceso variable como la calidad del vínculo con el fallecido y el hecho de que el fallecido sea un hijo, y positivamente factores como el apoyo social y la psicoterapia (AU)

Tratamiento grupal en trastornos de la conducta alimentaria / Group treatment of eating disorders

El presente trabajo describe el tratamiento grupal de los trastornos de la conducta alimentaria desarrollado en un Centro de Salud Mental. La orientación teórica que guía la intervención fue la de grupo operativo. El grupo está formado por diecisiete pacientes (media de la edad =18,88; desviación típica =2,12) que acuden con una periodicidad semanal a lo largo de veintiuna sesiones. Para la recogida de información se ha empleado un protocolo que recoge datos acerca de la clínica previa al tratamiento, la situación actual y la valoración subjetiva de su participación, así como el Inventario de Trastornos de la Conducta Alimentaria (EDl). El perfil de puntuaciones en el EDl después de la intervención se aproxima al de los sujetos sin trastornos de la conducta alimentaria. Podemos concluir que la intervención grupal facilita un clima de confianza que puede permitir una mayor individualización y un lugar para la expresión del deseo (AU)

This work describes the group treatment of eating disorders developed in a Mental Health Center. The theoretical orientation that guides was the one of the operative group in which a place of listening was provided and the recognition of their individuality, the appearance of desire, the place occupied within the family dynamic and their relationship with others. The group is formed by seventeen patients (mean age =18,88; standard desviation =2,12) who attend on a weekly basis throughout twenty one sesions. A protocol that gathers data about the symptoms previous to treatment their current situation and their subjective value about their level of participation was used. We also used the Ealing Disorders Inventary (EDl). The scores obtained of the EDl after the intervention is similar lo the subjects without eating disorders. We can conclude that group intervention provides of a trust atmosphere where a better autonomy and express ion of their desire is favoured (AU)

Desestructuración social y demanda en psiquiatría / Social desestructuration and demand in Psiquiatria

El presente trabajo relaciona diversos factores de desestructuración socio-familiar con los modelos de demanda en Salud Mental. Se trata de un análisis descriptivo transversal, cuya conclusión fundamental es el hallazgo de dos patrones diferentes de demanda, en función de la existencia o ausencia de desestructuración socio-familiar. (AU)

[Biochemical control after external radiotherapy in localized prostatic cancer: results of a modern cohort]. / Control bioquímico tras radioterapia externa en el cáncer de próstata localizado: resultados de una cohorte moderna.

PURPOSE: The present study reports biochemical outcomes of a modern series of patients with localised prostate cancer treated with external beam radiation therapy, and analyses the implications of the nadir PSA levels in monitoring outcome after treatment. METHODS: From March 1993 to March 1997, eighty three patients with clinical stages T1-T3 NxM0 prostate cancer received definitive external radiation therapy, median dose 66 Gy (range 60 to 68 Gy). Adjuvant androgen deprivation was associated in 53 high risk patients. Initial response to treatment was defined as a decrease of serum PSA to levels of < or = 1.5 ng/ml, and biochemical failure as three consecutive PSA rises over post-treatment nadir PSA value. RESULTS: The 3-year actuarial BDFS was 78% +/- 7 for the whole series, 74% +/- 12 for patients treated with radiotherapy alone, and 71% +/- 10 for high risk patients treated with combination therapy (p = 0.27). Only nPSA emerged as a potential indicator of biochemical control. The probability of BDFS at 3 years was 82%, 83% and 40% for nPSA of < or = 1 ng/ml, 1-2 ng/ml and > 2 ng/ml respectively (p = 0.0409). In multivariate analysis, this correlation was independent on the effect of other variables and persisted after adjusting for the effect of hormonal therapy (p = 0.0540). CONCLUSION: Radiation therapy is a potentially curative treatment for prostate carcinoma. Our data indicate that the nadir PSA value after radiation can be an excellent early determinant of outcome.

Control bioquímico tras radioterapia externa en el cáncer de próstata localizado: resultados de una cohorte moderna / Biochemical control after external radiotherapy in localised prostate cancer: results from a modern cohort

FUNDAMENTO: En este trabajo presentamos los resultados de control bioquímico de una cohorte moderna de pacientes con cáncer de próstata localizado tratados con radioterapia, y las implicaciones del valor de nadir de PSA (nPSA) en la monitorización del tratamiento. MATERIAL Y MÉTODOS: Entre Marzo de 1993 y Marzo de 1997, 83 varones con adenocarcinoma de próstata T1-3 Nx M0, fueron tratados con radioterapia externa con intención radical (dosis total media de 66 Gy, rango 60-68 Gy). Se asoció deprivación androgénica en 53 pacientes de alto riesgo. Se ha definido la respuesta al tratamiento como un descenso del PSA a niveles ?1,5 ng/ml, y la recaída bioquímica como la presencia de tres elevaciones consecutivas de PSA sobre el valor de nPSA. RESULTADOS: La supervivencia libre de fracaso bioquímico (SLFB) actuarial a 3 años fue del 78 por ciento ñ 7 para toda la serie, 74 por ciento ñ 16 para los pacientes tratados con radioterapia exclusiva y 71 por ciento ñ 10 para los pacientes tratados con radioterapia y hormonoterapia adyuvante (p = 0,27). De los factores analizados, sólo el nivel de nPSA se correlacionó de forma significativa con la probabilidad de control bioquímico: la SLFB fue del 82 por ciento, 83 por ciento y 40 por ciento para valores de nPSA de ?1 ng/ml, 1-2 ng/ml y > 2 ng/ml respectivamente (p = 0,0409). En análisis multivariante, el valor pronóstico del nPSA se mantuvo independiente del resto de las variables y del efecto del tratamiento hormonal (p = 0,0540). CONCLUSIONES: La radioterapia externa es un tratamiento eficaz en los pacientes con cáncer de próstata localizado.El valor nadir de PSA tras radioterapia es un excelente predictor de los resultados del tratamiento (AU)

Venation pattern formation in Arabidopsis thaliana vegetative leaves.

Branching net-like structures are a trait common to most multicellular organisms. However, our knowledge is still poor when it comes to the genetic operations at work in pattern formation of complex network structures such as the vasculature of plants and animals. In order to initiate a causal analysis of venation pattern formation in dicotyledonous plant leaves, we have first studied its developmental profile in vegetative leaves of a wild-type strain of the model organism Arabidopsis thaliana. As landmarks of the complexity of the venation pattern, we have defined three main developmental parameters, which have been quantitatively followed in time: the ratios of (a) the length and (b) the number of branchpoints of the vein network with the surface of the lamina, which decrease in parallel as the leaf grows, only small differences existing between successive leaves, and (c) the number of hydathodes per leaf, which increases both during leaf expansion and from juvenile to adult rosette leaves. We next searched for natural variations in the first vegetative leaves of 266 ecotypes, finding only 2 which showed a venation pattern unequivocally different from that of the rest, Ba-1 and Ei-5, the latter displaying an extremely simple pattern that we have called Hemivenata. This phenotype, which is inherited as a monogenic recessive trait, is visible both in leaves and in cotyledons and seems to arise from a perturbation in an early acting patterning mechanism. Finally, we have screened for mutants with abnormal venation pattern but normally shaped leaves, concluding that such a phenotype is rare, since only one recessive mutation was obtained, extrahydathodes, characterized by the presence of an increased number of hydathodes per leaf.

[Radiotherapy of localized cancer of the prostate: current status and new strategies]. / Tratamiento radioterápico del cáncer de próstata localizado: estado actual y nuevas estrategias.

Radiation therapy is a well established modality for the management of prostate cancer and the reported results are comparable to those obtained with radical prostatectomy. After the introduction of prostate specific antigen (PSA) determination, when results are analyzed on the basis of strict biochemical criteria, it is clearly evident that total and permanent eradication of the localized prostate cancer is obtained less frequently than what was thought in the las few decades. Although there are currently only a few series with radical radiation therapy with long results and with complete PSA determination during follow-up, disease free survival (DFS) for T1b-T2 Nx is approximately 65% at 4-5 years, whereas for T1-2 NO DFS at 9-10 years is maintained between 67% and 83%. New therapeutic strategies leading to improvement in the locoregional control are discussed, including dose escalation programs in the setting of new technologies of three-dimensional conforma radiation therapy, and neoadjuvant androgenic blockade.

Localization of expression of KNAT3, a class 2 knotted1-like gene.

KNAT3 is a class 2 kn1-like gene in Arabidopsis thaliana. The RNA expression patterns of KNAT3 were characterized through the use of promoter-GUS fusion analysis and in situ hybridization. KNAT3 is expressed in several tissues and at several times during development. There are three main expression patterns: (1) during early organ development in young leaves, buds and pedicels; (2) at and near the junction between two organs at specific times during development, including the hypocotyl-root boundary in young seedlings, the anther-filament junction in mature flowers, and the ovule-funiculus and peduncle-silique boundaries in elongating siliques; and (3) in maturing tissues such as the style of elongating siliques, the petioles of maturing leaves, and most of the root. The varied expression patterns may indicate that KNAT3 plays several different roles in plants, depending on when and where it is expressed. Previous work on KNAT3 (Serikawa et al., 1996) indicated that expression of its RNA is regulated by light. Promoter-GUS seedlings were grown under different light conditions (continuous white, red and far-red light) to examine more closely the light regulation of the KNAT3 promoter. Continuous white light resulted in stronger overall GUS staining in the same patterns seen in seedlings grown under long-day conditions (cotyledons, upper hypocotyl and roots). Continuous red light resulted in reduced GUS expression in those same tissues. Continuous far-red light led to seedlings showing stronger staining in the hypocotyl and cotyledons than red light-grown plants but no staining in the roots. Thus, the KNAT3 promoter responds differently to red and far-red light.

Three knotted1-like homeobox genes in Arabidopsis.

Five arabidopsis kn1-like homeobox genes were cloned through low-stringency screening of Arabidopsis cDNA libraries with the kn1 homeobox from maize. These five genes were named KNAT1-5 (for kn1-like Arabidopsis thaliana). An analysis of KNAT1 and 2 has been presented previously [19]. Here we present an analysis of the genes KNAT3, 4 and 5. On the basis of sequence and expression patterns, these three genes belong to the class II subfamily of kn1-like homeobox genes [16]. Low-stringency Southern analysis suggests several additional members of the class II genes exist in the Arabidopsis genome. The predicted amino acid sequences of the three genes share extensive homology outside of the homeodomain, including 84% between KNAT3 and KNAT4. Northern analysis shows that although all three genes are expressed in all tissues examined, the level of KNAT3 RNA is highest in young siliques, inflorescences and roots, KNAT4 RNA level is strongest in leaves and young siliques, and KNAT5 RNA level is highest in roots. The specificity of these patterns was confirmed by RNA fingerprint analysis. KNAT3 and 4 are light-regulated as they show reduced expression in etiolated seedlings and also in hy3, cop1 and det1 mutant backgrounds.

A genetic analysis of bx bxd cis double mutants in the Drosophila Ultrabithorax gene.

The Ultrabithorax (Ubx) gene of Drosophila melanogaster includes two functionally distinguishable regions. One is the Ubx transcription unit, which gives rise by alternative splicing to a family of morphogenetic Ubx proteins (UBX). The other is its upstream bithoraxoid (bxd) region. On the basis of genetic and molecular studies, it is generally assumed that the Ubx transcription unit contains internal positively acting cis-regulatory elements controlling UBX expression in the T3a compartment of the body of Drosophila, while the bxd region contains positive cis-regulatory elements controlling UBX expression in the T3p and A1a compartments. We have performed a genetic analysis of bx bxd cis double mutant chromosomes containing one mutation (bx alleles) affecting the Ubx unit, and a second (bxd alleles) affecting the bxd region of the Ubx gene. Our study of different bx bxd/bx combinations shows that bxd alleles partially rescue the adult mutant phenotypes of bx alleles, which suggests that the bxd region contains a negative cis-regulatory element involved in the control of the activity of the Ubx gene in the T3a compartment.