931 resultados para Life-limiting conditions


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Hunter syndrome (mucopolysaccharidosis type II) is a rare and life-limiting multisystemic disorder with an X-linked recessive pattern of inheritance. Short stature is a prominent feature of this condition. This analysis aimed to investigate the effects of enzyme replacement therapy with idursulfase on growth in patients enrolled in HOS - the Hunter Outcome Survey which is a multinational observational database. As of Jan 2012, height data before treatment were available for 567 of 740 males followed prospectively after HOS entry. Cross-sectional analysis showed that short stature became apparent after approximately 8 years of age; before this, height remained within the normal range. Age-corrected standardized height scores (z-scores) before and after treatment were assessed using piecewise regression model analysis in 133 patients (8-15 years of age at treatment start; data available on ≥ 1 occasion within +/-24 months of treatment start; growth hormone-treated patients excluded). Results showed that the slope after treatment (slope=-0.005) was significantly improved compared with before treatment (slope=-0.043) (difference=0.038, p=0.004). Analysis of covariates (age at treatment start, cognitive involvement, presence of puberty at the start of ERT, mutation type, functional classification), showed a significant influence on growth of mutation type (height deficit in terms of z-scores most pronounced in patients with deletions/large rearrangements/nonsense mutations, p<0.0001) and age (most pronounced in the 12-15-year group, p<0.0001). Cognitive involvement, pubertal status at the start of ERT and functional classification were not related to the growth deficit or response to treatment. In conclusion, the data showed an improvement in growth rate in patients with Hunter syndrome following idursulfase treatment.

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Blisters in the newborn period can be a sign of potentially life-threatening conditions. An accurate and rapid diagnostic is therefore crucial to distinguish among the numerous conditions which can present with blisters in the neonate. A diagnosis based on the clinical picture alone, however, is not sufficient nor possible in the most cases. A diagnostic algorithm will be presented.

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Liver transplantation recipients, like other solid organ transplantation recipients, have an increased risk of dermatologic problems due to their long-term immunosuppression and benefit from pre-and post-transplantation screenings, and management by a dermatologist and dermatologic care should be integrated into the comprehensive, multidisciplinary care of liver transplantation recipients [1,2]. Cutaneous findings include aesthetic alterations, infections, precancerous lesions, and malignancies. The severity of skin alterations ranges from benign, unpleasant changes to life-threatening conditions [3-5]. In addition to skin cancer diagnosis and management, visits with a dermatologist serve to educate and improve the patient's sun-protection behavior. Among all solid organ transplantations, liver transplantation requires the least amount of immunosuppression, sometimes even permitting its complete cessation [6]. As a result, patients who have undergone liver transplantation tend to have fewer dermatologic complications compared with other solid organ transplantation recipients [7]. However, due to the large volume of the liver, patients undergoing liver transplantation receive more donor lymphocytes than kidney, heart, or lung transplantation recipients. Because of the immunosuppression, the transplanted lymphocytes proliferate and rarely trigger graft-versus-host-disease [8,9]. This topic will provide an overview of dermatologic disorders that may be seen following liver transplantation. A detailed discussion of skin cancer following solid organ transplantation and the general management of patients following liver transplantation are discussed separately. (See "Development of malignancy following solid organ transplantation" and "Management of skin cancer in solid organ transplant recipients" and "Long-term management of adult liver transplant recipients".)

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Trophism as a "clonal dominance" support mechanism for tumor cells is an unexplored area of tumor progression. This report presents evidence that the human melanoma low-affinity neurotrophin receptor (p75) can signal independently of its high-affinity tyrosine kinase counterparts, the TRK family of kinases. Signaling may be accomplished by a p75-associated purine-analog-sensitive kinase and results in enhanced invasion into a reconstituted basement membrane with a corresponding stimulation of matrix metalloproteinase-2 expression. Additionally, a "stress culture" survival assay was developed to mimic the growth limiting conditions encountered by melanoma cells in a rapidly growing primary tumor or metastatic deposit prior to neoangiogenesis. Under these conditions, p75, promotes the survival of high p75 expressing brain-colonizing melanoma cells. Extensive 70W melanoma cell-cell contact, which downregulates p75, immediately precedes the induction of cell death associated with diminished production of two key cell survival factors, bcl-2 and the p85 subunit of phosphoinositol-3-kinase, and an elevation in apoptosis promoting intracellular reactive oxygen species (ROSs). Since one function of bcl-2 may be to control the generation of ROSs via the antioxidant pathway, these cells may receive a apoptosis-prompting "double hit". 70W melanoma cell death occurred by an apoptotic mechanism displaying classical morphological changes including plasma membrane blebbing, loss of microvilli and redistribution of ribosomes. 70W apoptosis could be pharmacologically triggered following anti-p75 monoclonal antibody-mediated clustering of p75 receptors. 70W cells fluorescently sorted for high-p75 expression (p75$\sp{\rm H}$ cells) exhibited an augmented survival potential and a predilection to sort with the S + G2/M growth phase, relative to their low p75 expressing, p75$\sp{\rm L}$ counterparts. Apoptosis is significantly delayed by p75$\sp{\rm H}$ cells, whereas p75$\sp{\rm L}$ cells are exquisitely prone to initiate apoptosis. Importantly, the p75$\sp{\rm L}$ cells that survive apoptosis, highly re-expressed p75 and were remarkably responsive to exogenous NGF.^ These are the first data to implicate p75-mediated neurotrophism as an invasion and survival support mechanism employed by brain-metastatic cells. In particular, these results may have implications in little understood phenomena of tumor progression, such as the emergence of "clonal dominance" and tumor dormancy. ^

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Phosphorus and nitrogen are essential nutrient elements that are needed by plants in large amounts. The arbuscular mycorrhizal symbiosis between plants and soil fungi improves phosphorus and nitrogen acquisition under limiting conditions. On the other hand, these nutrients influence root colonization by mycorrhizal fungi and symbiotic functioning. This represents a feedback mechanism that allows plants to control the fungal symbiont depending on nutrient requirements and supply. Elevated phosphorus supply has previously been shown to exert strong inhibition of arbuscular mycorrhizal development. Here, we address to what extent inhibition by phosphorus is influenced by other nutritional pathways in the interaction between Petunia hybrida and R. irregularis. We show that phosphorus and nitrogen are the major nutritional determinants of the interaction. Interestingly, the symbiosis-promoting effect of nitrogen starvation dominantly overruled the suppressive effect of high phosphorus nutrition onto arbuscular mycorrhiza, suggesting that plants promote the symbiosis as long as they are limited by one of the two major nutrients. Our results also show that in a given pair of symbiotic partners (Petunia hybrida and R. irregularis), the entire range from mutually symbiotic to parasitic can be observed depending on the nutritional conditions. Taken together, these results reveal complex nutritional feedback mechanisms in the control of root colonization by arbuscular mycorrhizal fungi.

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OBJECTIVES Despite new treatment modalities, cyclophosphamide (CYC) remains a cornerstone in the treatment of organ or life-threatening vasculitides and connective tissue disorders. We aimed at analysing the short- and long-term side-effects of CYC treatment in patients with systemic autoimmune diseases. METHODS Chart review and phone interviews regarding side effects of CYC in patients with systemic autoimmune diseases treated between 1984 and 2011 in a single university centre. Adverse events were stratified according to the "Common Terminology Criteria for Adverse Events" version 4. RESULTS A total of 168 patients were included. Cumulative CYC dose was 7.45 g (range 0.5-205 g). Gastro-intestinal side effects were seen in 68 events, hair loss occurred in 38 events. A total of 58 infections were diagnosed in 44/168 patients (26.2%) with 9/44 suffering multiple infections. Severity grading of infections was low in 37/58 cases (63.8%). One CYC-related infection-induced death (0.6%) was registered. Amenorrhoea occurred in 7/92 females (7.6%) with 5/7 remaining irreversible. In females with reversible amenorrhoea, prophylaxis with nafarelin had been administered. Malignancy was registered in 19 patients after 4.7 years (median, range 0.25-22.25) presenting as 4 premalignancies and 18 malignancies, 3 patients suffered 2 premalignancies/malignancies each. Patients with malignancies were older with a higher cumulative CYC dose. Death was registered in 28 patients (16.6%) with 2/28 probably related to CYC. CONCLUSIONS Considering the organ or life-threatening conditions which indicate the use of CYC, severe drug-induced health problems were rare. Our data confirm the necessity to follow-up patients long-term for timely diagnosis of malignancies. CYC side-effects do not per se justify prescription of newer drugs or biologic agents in the treatment of autoimmune diseases.

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PURPOSES Geriatric problems frequently go undetected in older patients in emergency departments (EDs), thus increasing their risk of adverse outcomes. We evaluated a novel emergency geriatric screening (EGS) tool designed to detect geriatric problems. BASIC PROCEDURES The EGS tool consisted of short validated instruments used to screen 4 domains (cognition, falls, mobility, and activities of daily living). Emergency geriatric screening was introduced for ED patients 75 years or older throughout a 4-month period. We analyzed the prevalence of abnormal EGS and whether EGS increased the number of EGS-related diagnoses in the ED during the screening, as compared with a preceding control period. MAIN FINDINGS Emergency geriatric screening was performed on 338 (42.5%) of 795 patients presenting during screening. Emergency geriatric screening was unfeasible in 175 patients (22.0%) because of life-threatening conditions and was not performed in 282 (35.5%) for logistical reasons. Emergency geriatric screening took less than 5 minutes to perform in most (85.8%) cases. Among screened patients, 285 (84.3%) had at least 1 abnormal EGS finding. In 270 of these patients, at least 1 abnormal EGS finding did not result in a diagnosis in the ED and was reported for further workup to subsequent care. During screening, 142 patients (42.0%) had at least 1 diagnosis listed within the 4 EGS domains, significantly more than the 29.3% in the control period (odds ratio 1.75; 95% confidence interval, 1.34-2.29; P<.001). Emergency geriatric screening predicted nursing home admission after the in-hospital stay (odds ratio for ≥3 vs <3 abnormal domains 12.13; 95% confidence interval, 2.79-52.72; P=.001). PRINCIPAL CONCLUSIONS The novel EGS is feasible, identifies previously undetected geriatric problems, and predicts determinants of subsequent care.

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Purpose – A growing body of literature provides evidence for the efficacy of workplace health promotion (WHP). However, little is known about effective dissemination strategies for WHP interventions. The purpose of this paper is to describe how a WHP agency in Zurich, Switzerland, used bulk mailings, information events, telephone marketing and free initial consultations for the large-scale geographic marketing of WHP services, with a focus on tobacco prevention (TP). Design/methodology/approach – To analyze the number of companies responding positively to solicitation, examine the predictors of positive responses and explore the reasons for negative responses, the authors used both quantitative (e.g. a standardized questionnaire) and qualitative (telephone interviews) methods. Findings – The results show that except for telephone marketing (69 percent), the success rates of dissemination activities were very low (3-9 percent). Predictors for a positive response were institutionalization of WHP, the representative’s personal concern about TP, and problems with environmental tobacco smoke within the company. The most prominent reason for a negative Response was that the companies had already implemented TP measures by themselves and needed no further external support. Practical implications – It is suggested that TP was the wrong emphasis for a WHP program to be disseminated at that particular time, because a law on protection from passive smoking was introduced in Switzerland shortly afterwards. Originality/value – The study examines dissemination strategies under real-life Consulting conditions. It builds on on a large sample of companies and uses both quantitative and qualitative research methods. It reports specific numbers and success rates of marketing activities and thereby contributes to the knowledge about an important issue for intervention planning in the field of WHP.

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Resistance to current chemo- and radiation therapy is the principal problem in anticancer treatment. Although intensively investigated, the therapeutic outcome is still far from satisfactory. Among the multiple factors which contribute to the drug resistance in cancer cells, the involvement of autophagy is becoming more and more evident. Autophagy describes a cellular self-digestion process, in which cytoplasmic elements can be selectively engulfed and finally degraded in autophagolysosomes to supply nutrients and building blocks for the cells. Autophagy controls cellular homeostasis and can be induced in response to stresses, like hypoxia and growth factor withdrawal. Since the essential physiological function of autophagy is to maintain cellular metabolic balance, dysregulated autophagy has been found associated with multiple diseases, including cancer. Interestingly, the role of autophagy in cancer is two-sided; it can be pro- or antitumor. Autophagy can suppress tumor formation, for example, by controlling cell proliferation and the production of reactive oxygen species. On the other hand, autophagy can provide nutrients to the tumor cells to support tumor growth under nutrition-limiting conditions, thereby promoting tumor development. This ambivalent behavior is also evident in anticancer therapy: By inducing autophagic cell death, autophagy has been shown to potentiate the cytotoxicity of chemotherapeutic drugs, but autophagy has also been linked to drug resistance, since inhibiting autophagy has been found to sensitize tumor cells toward anticancer drug-induced cell death. In this chapter, we will focus on the dual role of autophagy in tumorigenesis and chemotherapy, will classify autophagy inducers and inhibitors used in anticancer treatment, and will discuss topics related to future drug development which have arisen.

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La fijación de N por los cultivos de leguminosas puede ser un buen componente dentro de un plan general de mejora de la eficiencia del sistema agrícola. Para lograrlo, se debe establecer la adecuación de los cultivos a los ambientes específicos. El objetivo de este trabajo es evaluar el crecimiento del haba Alameda en el agroclima de Azul. Para alcanzar dicho objetivo se realizaron ensayos de campo en condiciones no limitantes utilizando el haba cv. Alameda desde el invierno de 2008 en la chacra experimental de la Facultad de Agronomía de Azul (Universidad del Centro de la Provincia de Buenos Aires), con cinco fechas de siembra desde mediados de julio a mediados de noviembre; también se realizó un seguimiento de algunos índices agrometeorológicos. La fecha de siembra tuvo una fuerte influencia sobre la producción de biomasa, rendimiento en grano y sus componentes. Ese efecto fue asociado con los cambios en la captura de radiación fotosintéticamente activa. Las fechas de siembra tempranas interceptaron más radiación a lo largo de la estación de crecimiento que las fechas de siembra de primavera. La primera y la segunda fechas de siembras (mediados de julio y mediados de agosto, respectivamente) tuvieron los valores más altos en producción. Las siembras de primavera (cuarta fecha: mediados de octubre; quinta fecha: mediados de noviembre) presentaron los rendimientos más bajos en granos, los que decrecieron a medida que se atrasó la fecha de siembra, con menor número de vainas por m2 y más bajo peso de mil semillas.

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Las teorías sobre el desarrollo son en realidad un dinámico debate acerca de la relación población/recursos, de las condiciones de inequidad a escala planetaria y al interior de las naciones, y de las formas de superarlas. Para avanzar hacia el desarrollo humano, es prioritario enfocar las acciones en la superación de las carencias que afectan la situación personal de los ciudadanos y eliminar los obstáculos que impiden su bienestar en relación con las condiciones medioambientales en las que transcurre su vida. La educación es comprendida como el eje fundamental para alcanzar niveles de desarrollo aceptables, asegurando superar situaciones de exclusión social. Sobre la base de encuestas en cuatro establecimientos educativos del Gran Mendoza, se analizan las relaciones existentes entre las representaciones, de los adolescentes y sus familias sobre la importancia de la educación como medio optimizador de las situaciones socioeconómicas y los proyectos de capacitación futura, tanto a nivel terciario como universitario.

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Based on combined microsensor measurements of irradiance, temperature and O2, we compared light energy budgets in photosynthetic microbial mats, with a special focus on the efficiency of light energy conservation by photosynthesis. The euphotic zones in the three studied mats differed in their phototrophic community structure, pigment concentrations and thickness. In all mats, < 1% of the absorbed light energy was conserved via photosynthesis at high incident irradiance, while the rest was dissipated as heat. Under light-limiting conditions, the photosynthetic efficiency reached a maximum, which varied among the studied mats between 4.5% and 16.2% and was significantly lower than the theoretical maximum of 27.7%. The maximum efficiency correlated linearly with the light attenuation coefficient and photopigment concentration in the euphotic zone. Higher photosynthetic efficiency was found in mats with a thinner and more densely populated euphotic zone. Microbial mats exhibit a lower photosynthetic efficiency compared with ecosystems with a more open canopy-like organization of photosynthetic elements, where light propagation is not hindered to the same extent by photosynthetically inactive components; such components contributed about 40-80% to light absorption in the investigated microbial mats, which is in a similar range as in oceanic planktonic systems.

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The formation of calcareous skeletons by marine planktonic organisms and their subsequent sinking to depth generates a continuous rain of calcium carbonate to the deep ocean and underlying sediments. This is important in regulating marine carbon cycling and ocean-atmosphere CO2 exchange. The present rise in atmospheric CO2 levels causes significant changes in surface ocean pH and carbonate chemistry. Such changes have been shown to slow down calcification in corals and coralline macroalgae, but the majority of marine calcification occurs in planktonic organisms. Here we report reduced calcite production at increased CO2 concentrations in monospecific cultures of two dominant marine calcifying phytoplankton species, the coccolithophorids Emiliania huxleyi and Gephyrocapsa oceanica . This was accompanied by an increased proportion of malformed coccoliths and incomplete coccospheres. Diminished calcification led to a reduction in the ratio of calcite precipitation to organic matter production. Similar results were obtained in incubations of natural plankton assemblages from the north Pacific ocean when exposed to experimentally elevated CO2 levels. We suggest that the progressive increase in atmospheric CO2 concentrations may therefore slow down the production of calcium carbonate in the surface ocean. As the process of calcification releases CO2 to the atmosphere, the response observed here could potentially act as a negative feedback on atmospheric CO2 levels.

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Precipitation of calcium carbonate by phytoplankton in the photic oceanic layer is an important process regulating the carbon cycling and the exchange of CO2 at the ocean-atmosphere interface. Previous experiments have demonstrated that, under nutrient-sufficient conditions, doubling the partial pressure of CO2 (pCO2) in seawater-a likely scenario for the end of the century-can significantly decrease both the rate of calcification by coccolithophorids and the ratio of inorganic to organic carbon production. The present work investigates the effects of high pCO2 on calcification by the coccolithophore Emiliania huxleyi (Strain TW1) grown under nitrogen-limiting conditions, a situation that can also prevail in the ocean. Nitrogen limitation was achieved in NO3-limited continuous cultures renewed at the rate of 0.5 d-1 and exposed to a saturating light level. pCO2 was increased from 400 to 700 ppm and controlled by bubbling CO2-rich or CO2-free air into the cultures. The pCO2 shift has a rapid effect on cell physiology that occurs within 2 cell divisions subsequent to the perturbation. Net calcification rate (C) decreased by 25% and, in contrast to previous studies with N-replete cultures, gross community production (GCP) and dark community respiration (DCR) also decreased. These results suggest that increasing pCO2 has no noticeable effect on the calcification/photosynthesis ratio (C/P) when cells of E. huxleyi are NO3-limited.

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Esta tesis doctoral pretende profundizar en el conocimiento de la ecología de Ulmus laevis Pallas, especie autóctona en peligro de extinción en la Península Ibérica, con el fin de proponer medidas adecuadas para su conservación. Se ha estudiado la distribución natural de la especie atendiendo a aspectos edáficos. Los resultados muestran que U. laevis presenta menor capacidad de acidificación de la rizosfera, menor actividad de la reductasa férrica y menor homeostasis que U. minor Mill. cuando crecen en sustratos con una disponibilidad de hierro limitada. Estas diferencias ayudan a comprender la distribución de ambas especies en la Península Ibérica: U. laevis se ve restringido a suelos ácidos o moderadamente ácidos, mientras que U. minor es capaz de habitar tanto suelos ácidos como básicos. Se han analizado las propiedades hidráulicas y anatómicas de U. laevis, constatando que sus características son favorables en ambientes con gran disponibilidad hídrica y que se trata del olmo ibérico más vulnerable a la cavitación por estrés hídrico, por lo que la aridificación del clima y la pérdida de los freáticos supone un riesgo para sus poblaciones. Para evaluar la capacidad de recuperación de la especie se han estudiado la diversidad y estructura genética espacial de las dos mayores poblaciones españolas. Los resultados evidencian que estas poblaciones mantienen niveles de diversidad equiparables o ligeramente superiores a los europeos, pese a haber sufrido un cuello de botella prolongado durante las glaciaciones y a las reducciones poblacionales recientes. En la actualidad la endogamia no representa un riesgo para estas poblaciones. También se ha analizado la producción, dispersión y predación de semillas en Valdelatas (Madrid). Los resultados han mostrado que el viento dispersa las sámaras a corta distancia (<30 m) y que los años no veceros las probabilidades de establecimiento de regenerado son bajas. Además, la producción de sámaras vanas puede tratarse de un carácter adaptativo que aumenta la eficiencia biológica de la especie, ya que favorece la supervivencia de las semillas embrionadas disminuyendo sus tasas de predación pre- y post-dispersión. La modificación del hábitat de esta especie como consecuencia de las actividades humanas afecta de manera negativa al establecimiento del regenerado. La conservación de esta especie a largo plazo requiere la recuperación de los niveles freáticos y de regímenes hidrológicos que permitan avenidas, ya que estas crean las condiciones adecuadas para el establecimiento de regenerado al eliminar la vegetación preexistente y depositar barro. ABSTRACT Ulmus laevis Pallas is an endangered species in the Iberian Peninsula. Therefore, in order to be able to propose adequate management guidelines for its conservation, this PhD Thesis intends to advance the knowledge on the species ecology in the region. Firstly, the species natural distribution was studied in relation to soil nature. Results show that U. minor Mill. had a higher root ferric reductase activity and proton extrusion capability than U. laevis, and maintained a better nutrient homeostasis when grown under iron limiting conditions. These differences in root Fe acquisition efficiencies proved helpful to understand the distribution of these species in the Iberian Peninsula, where U. laevis is restricted to acid or moderately acid soils, whereas U. minor can grow both in acid and basic soils. Secondly, we studied Ulmus laevis’ xylem anatomy and hydraulic traits. These proved favourable for growing under high water availability, but highly susceptible to drought-stress cavitation. Therefore, this species is vulnerable to the Iberian Peninsula’s aridification. Spatial genetic structure and diversity were evaluated in two of the biggest U. laevis populations in Spain in order to evaluate their recovery capabilities. These populations maintain similar or slightly higher diversity levels than European populations, despite having undergone an ancestral genetic bottleneck and having suffered recent population size reductions. No inbreeding problems have been detected in these populations. Seed production, dispersal and predation were assessed in Valdelatas’ elm grove (Madrid). Despite U. laevis samaras being winged nuts, wind dispersed them short distances from the mother tree (<30 m). The seed shadow models show that non-mast years provide very few chances for the stand to regenerate due to their low full seed flux. Empty samaras deceive pre- and post-dispersal predators increasing full seed survival probabilities. Therefore, empty fruit production might be an adaptive trait that increases plant fitness. Finally, human-induced changes in water-table levels and river regulation may affect U. laevis seed dispersal and regeneration establishment negatively. The long-term conservation and expansion of this species in the Iberian Peninsula requires the recovery of water-tables and of natural hydrological regimes, as flooding eliminates vegetation, creating open microhabitats and deposits mud, creating the ideal conditions for seedling establishment.