163 research outputs found
Estimating tourism social carrying capacity
Abstract The paper proposes a novel method of measuring the social carrying capacity threshold by using measures of subjective well-being. In particular, we show that there exists an inverted u-shaped relationship between subjective well-being and tourism intensity. Consequently, social carrying capacity can be estimated as the level of tourism intensity corresponding to the area from which the subjective well-being starts to decrease. The approach proposed operationalizes the concept of social carrying capacity and allows for cross-space and time-series comparisons of the levels of carrying capacity, taking into considerations other concurring factors. Such proposal is useful for policy makers to guide their decisions on tourism policy design. The method allows for the use of panel data models being based on longitudinal data
Weltbürger in soziologischer Absicht: Peter Atteslander überwältigte in Begegnungen durch seine starke persönliche Ausstrahlung. Er war ein Weltbürger in soziologischer Absicht.
Integrin control of the transforming growth factor-β pathway in glioblastoma
Transforming growth factor-β is a central mediator of the malignant phenotype of glioblastoma, the most common and malignant form of intrinsic brain tumours. Transforming growth factor-β promotes invasiveness and angiogenesis, maintains cancer cell stemness and induces profound immunosuppression in the host. Integrins regulate cellular adhesion and transmit signals important for cell survival, proliferation, differentiation and motility, and may be involved in the activation of transforming growth factor-β. We report that αvβ3, αvβ5 and αvβ8 integrins are broadly expressed not only in glioblastoma blood vessels but also in tumour cells. Exposure to αv, β3 or β5 neutralizing antibodies, RNA interference-mediated integrin gene silencing or pharmacological integrin inhibition using the cyclic RGD peptide EMD 121974 (cilengitide) results in reduced phosphorylation of Smad2 in most glioma cell lines, including glioma-initiating cell lines and reduced transforming growth factor-β-mediated reporter gene activity, coinciding with reduced transforming growth factor-β protein levels in the supernatant. Time course experiments indicated that the loss of transforming growth factor-β bioactivity due to integrin inhibition likely results from two distinct mechanisms: an early effect on activation of preformed inactive protein, and second, major effect on transforming growth factor-β gene transcription as confirmed by decreased activity of the transforming growth factor-β gene promoter and decreased transforming growth factor-β1 and transforming growth factor-β2 messenger RNA expression levels. In vivo, EMD 121974 (cilengitide), which is currently in late clinical development as an antiangiogenic agent in newly diagnosed glioblastoma, was a weak antagonist of pSmad2 phosphorylation. These results validate integrin inhibition as a promising strategy not only to inhibit angiogenesis, but also to block transforming growth factor-β-controlled features of malignancy including invasiveness, stemness and immunosuppression in human glioblastom
Do neurooncological patients and their significant others agree on quality of life ratings?
<p>Abstract</p> <p>Introduction</p> <p>Patients suffering from brain tumours often experience a wide range of cognitive impairments that impair their ability to report on their quality of life and symptom burden. The use of proxy ratings by significant others may be a promising alternative to gain information for medical decision making or research purposes, if self-ratings are not obtainable. Our study investigated the agreement of quality of life and symptom ratings by the patient him/herself or by a significant other.</p> <p>Methods</p> <p>Patients with primary brain tumours were recruited at the neurooncological outpatient unit of Innsbruck Medical University. Quality of life self- and proxy-ratings were collected using the EORTC QLQ-C30 and its brain cancer module, the QLQ-BN20.</p> <p>Results</p> <p>Between May 2005 and August 2007, 42 pairs consisting of a patient and his/her significant other were included in the study. Most of the employed quality of life scales showed fairly good agreement between patient- and proxy-ratings (median correlation 0.46). This was especially true for Physical Functioning, Sleeping Disturbances, Appetite Loss, Constipation, Taste Alterations, Visual Disorders, Motor Dysfunction, Communication Deficits, Hair Loss, Itchy Skin, Motor Dysfunction and Hair Loss. Worse rater agreement was found for Social Functioning, Emotional Functioning, Cognitive Functioning, Fatigue, Pain, Dyspnoea and Seizures.</p> <p>Conclusion</p> <p>The assessment of quality of life in brain cancer patients through ratings from their significant others seems to be a feasible strategy to gain information about certain aspects of patient's quality of life and symptom burden, if the patient is not able to provide information himself.</p
Potential Immunocompetence of Proteolytic Fragments Produced by Proteasomes before Evolution of the Vertebrate Immune System
To generate peptides for presentation by major histocompatibility complex (MHC) class I molecules to T lymphocytes, the immune system of vertebrates has recruited the proteasomes, phylogenetically ancient multicatalytic high molecular weight endoproteases. We have previously shown that many of the proteolytic fragments generated by vertebrate proteasomes have structural features in common with peptides eluted from MHC class I molecules, suggesting that many MHC class I ligands are direct products of proteasomal proteolysis. Here, we report that the processing of polypeptides by proteasomes is conserved in evolution, not only among vertebrate species, but including invertebrate eukaryotes such as insects and yeast. Unexpectedly, we found that several high copy ligands of MHC class I molecules, in particular, self-ligands, are major products in digests of source polypeptides by invertebrate proteasomes. Moreover, many major dual cleavage peptides produced by invertebrate proteasomes have the length and the NH2 and COOH termini preferred by MHC class I. Thus, the ability of proteasomes to generate potentially immunocompetent peptides evolved well before the vertebrate immune system. We demonstrate with polypeptide substrates that interferon γ induction in vivo or addition of recombinant proteasome activator 28α in vitro alters proteasomal proteolysis in such a way that the generation of peptides with the structural features of MHC class I ligands is optimized. However, these changes are quantitative and do not confer qualitatively novel characteristics to proteasomal proteolysis. The data suggest that proteasomes may have influenced the evolution of MHC class I molecules
TUMORES RELACIONADOS AO HPV: ESTUDO RETROSPECTIVO DE QUATRO CASOS SOBRE MULHERES PÓS-MENOPAUSA
Papilomavírus humano (HPV) é um vírus transmitido sexualmente que pode ficar no organismo por anos e não desenvolver sintomas; porém os tipos de alto risco, como 16 e 18, estão associados à maior incidência de câncer de colo de útero (INCA, 2016). No presente estudo teve-se como objetivo analisar casos em que mulheres no período pós-menopausa não detectaram a presença do vírus HPV antes de o tumor se desenvolver. Trata-se de uma análise de relatos de caso encontrados no PubMed de quatro mulheres com quadros parecidos de não diagnóstico da patologia citada. Os quatro casos estudados são de mulheres no período pós-menopausa, entre 63 e 79 anos, que desenvolveram câncer de colo de útero em razão da presença do HPV. Em um dos casos, o exame citopatológico não foi capaz de detectar a existência do vírus, e nos outros três, o diagnóstico tardio veio apenas para confirmar a suspeita da relação entre o desenvolvimento do câncer com o HPV (SHI et al., 2015; ZAPPACOSTA, 2015). A importância de efetuar o preventivo é evidente em qualquer faixa etária. Em mulheres de meia idade, inclusive as pós-menopáusicas, o exame deve ser indispensável e anual, visto que muitas o negligenciam por acreditarem não estar mais suscetíveis a determinadas patologias depois de certa idade. Por possuir algumas limitações como alta taxa de falsos negativos, outras formas de diagnóstico para infecção decorrente de HPV devem ser utilizadas. A partir da análise dos casos, evidencia-se a necessidade de um acompanhamento bem feito da saúde da mulher idosa, seja por Papanicolau ou exames complementares, como testes biomoleculares para HPV, pois esta é a melhor maneira de identificá-lo e prevenir o câncer de colo de útero (SHI et al., 2015; ZAPPACOSTA, 2015).Palavras-chave: HPV pós-menopausa. Papanicolau. Câncer de colo de útero.
Functional antigen matching in corneal transplantation: matching for the HLA-A, -B and -DRB1 antigens (FANCY) – study protocol
Selective intra-carotid blood cooling in acute ischemic stroke : a safety and feasibility study in an ovine stroke model
Selective therapeutic hypothermia (TH) showed promising preclinical results as a neuroprotective strategy in acute ischemic stroke. We aimed to assess safety and feasibility of an intracarotid cooling catheter conceived for fast and selective brain cooling during endovascular thrombectomy in an ovine stroke model.
Transient middle cerebral artery occlusion (MCAO, 3 h) was performed in 20 sheep. In the hypothermia group (n = 10), selective TH was initiated 20 minutes before recanalization, and was maintained for another 3 h. In the normothermia control group (n = 10), a standard 8 French catheter was used instead. Primary endpoints were intranasal cooling performance (feasibility) plus vessel patency assessed by digital subtraction angiography and carotid artery wall integrity (histopathology, both safety). Secondary endpoints were neurological outcome and infarct volumes.
Computed tomography perfusion demonstrated MCA territory hypoperfusion during MCAO in both groups. Intranasal temperature decreased by 1.1 °C/3.1 °C after 10/60 minutes in the TH group and 0.3 °C/0.4 °C in the normothermia group (p < 0.001). Carotid artery and branching vessel patency as well as carotid wall integrity was indifferent between groups. Infarct volumes (p = 0.74) and neurological outcome (p = 0.82) were similar in both groups.
Selective TH was feasible and safe. However, a larger number of subjects might be required to demonstrate efficacy
Differential utilization of ketone bodies by neurons and glioma cell lines: a rationale for ketogenic diet as experimental glioma therapy
Background: Even in the presence of oxygen, malignant cells often highly depend on glycolysis for energy generation, a phenomenon known as the Warburg effect. One strategy targeting this metabolic phenotype is glucose restriction by administration of a high-fat, low-carbohydrate (ketogenic) diet. Under these conditions, ketone bodies are generated serving as an important energy source at least for non-transformed cells. Methods: To investigate whether a ketogenic diet might selectively impair energy metabolism in tumor cells, we characterized in vitro effects of the principle ketone body 3-hydroxybutyrate in rat hippocampal neurons and five glioma cell lines. In vivo, a non-calorie-restricted ketogenic diet was examined in an orthotopic xenograft glioma mouse model. Results: The ketone body metabolizing enzymes 3-hydroxybutyrate dehydrogenase 1 and 2 (BDH1 and 2), 3-oxoacid-CoA transferase 1 (OXCT1) and acetyl-CoA acetyltransferase 1 (ACAT1) were expressed at the mRNA and protein level in all glioma cell lines. However, no activation of the hypoxia-inducible factor-1alpha (HIF-1alpha) pathway was observed in glioma cells, consistent with the absence of substantial 3-hydroxybutyrate metabolism and subsequent accumulation of succinate. Further, 3-hydroxybutyrate rescued hippocampal neurons from glucose withdrawal-induced cell death but did not protect glioma cell lines. In hypoxia, mRNA expression of OXCT1, ACAT1, BDH1 and 2 was downregulated. In vivo, the ketogenic diet led to a robust increase of blood 3-hydroxybutyrate, but did not alter blood glucose levels or improve survival. Conclusion: In summary, glioma cells are incapable of compensating for glucose restriction by metabolizing ketone bodies in vitro, suggesting a potential disadvantage of tumor cells compared to normal cells under a carbohydrate-restricted ketogenic diet. Further investigations are necessary to identify co-treatment modalities, e.g. glycolysis inhibitors or antiangiogenic agents that efficiently target non-oxidative pathways
EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe
AbstractIntroductionThe aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe.MethodsThis was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries.ResultsData on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge.ConclusionThe results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe.EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events
- …