| 1. |
- Bjarnegård, Mattias, 1970, et al.
(författare)
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Endothelium-specific ablation of PDGFB leads to pericyte loss and glomerular, cardiac and placental abnormalities
- 2004
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Ingår i: DEVELOPMENT. - : The Company of Biologists. - 0950-1991 .- 1477-9129. ; 131:8, s. 1847-1857
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor-B (PDGFB) is necessary for normal cardiovascular development, but the relative importance of different cellular sources of PDGFB has not been established. Using Cre-lox techniques, we show here that genetic ablation of Pdgfb in endothelial cells leads to impaired recruitment of pericytes to blood vessels. The endothelium-restricted Pdgfb knockout mutants also developed organ defects including cardiac, placental and renal abnormalities. These defects were similar to those observed in Pdgfb null mice. However, in marked contrast to the embryonic lethality of Pdgfb null mutants, the endothelium-specific mutants survived into adulthood with persistent pathological changes, including brain microhemorrhages, focal astrogliosis, and kidney glomerulus abnormalities. This spectrum of pathological changes is reminiscent of diabetic microangiopathy, suggesting that the endothelium-restricted Pdgfb knockouts may serve as models for some of the pathogenic events of vascular complications to diabetes. Key words: PDGFB, Endothelium, Cre, loxP, Pericytes, Microaneurysm
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| 2. |
- Borg, Michael A., et al.
(författare)
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Maltese Antibiotic Stewardship Programme in the Community (MASPIC): Protocol of a prospective quasiexperimental social marketing intervention
- 2017
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Ingår i: BMJ Open. - : BMJ Publishing Group: Open Access / BMJ Publishing Group. - 2044-6055. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Antibiotic misuse is a key driver of antibiotic resistance. In 2015/2016, Maltese respondents reported the highest proportions of antibiotic consumption in Europe. Since antibiotics are prescription-only medicines in Malta, research on effective strategies targeting general practitioners' (GPs) knowledge and behaviour is needed. Multifaceted behaviour change (BC) interventions are likely to be effective. Social marketing (SM) can provide the tools to promote sustained BC; however, its utilisation in Europe is limited. This paper aims to describe the design and methods of a multifaceted SM intervention aimed at changing Maltese GPs' antibiotic prescribing behaviour for patients with acute respiratory tract infections (aRTIs). Methods and analysis This 4-year quasiexperimental intervention study will be carried out in Malta and includes three phases: preintervention, intervention and postintervention. The preintervention phase intends to gain insight into the practices and attitudes of GPs, pharmacists and parents through interviews, focus group discussions and antibiotic prescribing surveillance. A 6-month intervention targeting GPs will be implemented following assessment of their prescribing intention and readiness for BC. The intervention will likely comprise: prescribing guidelines, patient educational materials, delayed antibiotic prescriptions and GP education. Outcomes will be evaluated in the postintervention phase through questionnaires based on the theory of planned behaviour and stages-of-change theory, as well as postintervention surveillance. The primary outcome will be the antibiotic prescribing rate for all patients with aRTIs. Secondary outcomes will include the proportion of diagnosis-specific antibiotic prescription and symptomatic relief medication prescribed, and the change in GPs stage-of-change and their intention to prescribe antibiotics. Ethics and dissemination The project received ethical approval from the University of Malta's Research Ethics Committee. Should this intervention successfully decrease antibiotic prescribing, it may be scaled up locally and transferred to similar settings.
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| 3. |
- Choquet, Remi, et al.
(författare)
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Estimating demographic parameters from capturerecapture data with dependence among individuals within clusters
- 2013
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Ingår i: Methods in Ecology and Evolution. - 2041-210X. ; 4:5, s. 474-482
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Tidskriftsartikel (refereegranskat)abstract
- Two-level data, in which level-1 units or individuals are nested within level-2 units or clusters, are very common in natural populations. However, very few multilevel analyses are conducted for data with imperfect detection of individuals. Multilevel analyses are important to quantify the variability at each level of the data. In this study, we present two-level analyses for estimating demographic parameters from data with imperfect detection of individuals and with a source of individual variability that is nested within a source of cluster variability. This method allows separating and quantifying the phenotypic plasticity or facultative behavioural responses from the evolutionary responses. We illustrate our approach using data from studies of a long-lived perennially monogamous seabird, the Cory's shearwater (Calonectris diomedea) and a patchy population of collared flycatchers (Ficedula albicollis). We demonstrate the existence of dependence in recapture probability between paired individuals in the Cory's shearwater. In addition, we show that family structure has no influence on parentoffspring resemblance in collared flycatchers dispersal. The new method is implemented in program e-surge which is freely available from the internet.
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| 4. |
- Comasco, Erika, et al.
(författare)
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Psychiatric symptoms in adolescents: FKBP5 genotype-early life adversity interaction effects
- 2015
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Ingår i: European Child and Adolescent Psychiatry. - : Springer. - 1018-8827 .- 1435-165X. ; 24:12, s. 1473-1483
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Tidskriftsartikel (refereegranskat)abstract
- Psychiatric disorders are multi-factorial and their symptoms overlap. Constitutional and environmental factors influence each other, and this contributes to risk and resilience in mental ill-health. We investigated functional genetic variation of stress responsiveness, assessed as FKBP5 genotype, in relation to early life adversity and mental health in two samples of adolescents. One population-based sample of 909 12-year-old adolescents was assessed using the Life Incidence of Traumatic Events scale and the Strengths and Difficulties Questionnaire. One sample of 398 17-year-old adolescents, enriched for poly-victimized individuals (USSS), was assessed using the Juvenile Victimization Questionnaire and the Trauma Symptom Checklist for Children (TSCC). The FKBP5 rs1360780 and rs3800373 polymorphisms were genotyped using a fluorescence-based competitive allele-specific PCR. Most prominently among poly-victimized older male adolescents, the least common alleles of the polymorphisms, in interaction with adverse life events, were associated with psychiatric symptoms, after controlling for ethno-socio-economic factors. The interaction effect between rs3800373 and adverse life events on the TSCC sub-scales-anxiety, depression, anger, and dissociation-and with the rs1360780 on dissociation in the USSS cohort remained significant after Bonferroni correction. This pattern of association is in line with the findings of clinical and neuroimaging studies, and implies interactive effects of FKBP5 polymorphisms and early life environment on several psychiatric symptoms. These correlates add up to provide constructs that are relevant to several psychiatric symptoms, and to identify early predictors of mental ill-health.
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| 5. |
- Costell, M, et al.
(författare)
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Hyperplastic conotruncal endocardial cushions and transposition of great arteries in perlecan-null mice
- 2002
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Ingår i: Circulation Research. - 0009-7330. ; 91:2, s. 158-164
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Tidskriftsartikel (refereegranskat)abstract
- Perlecan is a heparan-sulfate proteoglycan abundantly expressed in pericellular matrices and basement membranes during development. Inactivation of the perlecan gene in mice is lethal at two developmental stages: around E10 and around birth. We report a high incidence of malformations of the cardiac outflow tract in perlecan-deficient embryos. Complete transposition of great arteries was diagnosed in 11 out of 15 late embryos studied (73%). Three of these 11 embryos also showed. malformations of semilunar valves. Mesenchymal cells in the outflow tract were abnormally abundant in mutant embryos by E9.5, when the endocardial-mesenchymal transformation starts in wild-type embryos. At E10.5, mutant embryos lacked well-defined spiral endocardial ridges, and the excess of mesenchymal cells obstructed sometimes the outflow tract lumen. Most of this anomalous mesenchyme expressed the smooth muscle cell-specific a-actin isoform, a marker of the neural crest in the outflow tract of the mouse. In wild-type embryos, perlecan is present in the basal surface of myocardium and endocardium, as well as surrounding presumptive neural crest cells. We suggest that the excess of mesenchyme at the earlier stages of conotruncal development precludes the formation of the spiral ridges and the rotation of the septation complex in order to achieve a concordant ventriculoarterial connection. The observed mesenchymal overpopulation might be due to an uncontrolled migration of neural crest cells, which would arrive prematurely to the heart. Thus, perlecan is involved in the control of the outflow tract mesenchymal population size, underscoring the importance of the extracellular matrix in cardiac morphogenesis.
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| 6. |
- Costell, Mercedes, et al.
(författare)
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Perlecan maintains the integrity of cartilage and some basement membranes
- 1999
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Ingår i: Journal of Cell Biology. - 0021-9525. ; 147:5, s. 1109-1122
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Tidskriftsartikel (refereegranskat)abstract
- Perlecan is a heparan sulfate proteoglycan that is expressed in all basement membranes (BMs), in cartilage, and several other mesenchymal tissues during development. Perlecan binds growth factors and interacts with various extracellular matrix proteins and cell adhesion molecules. Homozygous mice with a null mutation in the perlecan gene exhibit normal formation of BMs. However, BMs deteriorate in regions with increased mechanical stress such as the contracting myocardium and the expanding brain vesicles showing that perlecan is crucial for maintaining BM integrity. As a consequence, small clefts are formed in the cardiac muscle leading to blood leakage into the pericardial cavity and an arrest of heart function. The defects in the BM separating the brain from the adjacent mesenchyme caused invasion of brain tissue into the overlaying ectoderm leading to abnormal expansion of neuroepithelium, neuronal ectopias, and exencephaly. Finally, homozygotes developed a severe defect in cartilage, a tissue that lacks BMs. The chondrodysplasia is characterized by a reduction of the fibrillar collagen network, shortened collagen fibers, and elevated expression of cartilage extracellular matrix genes, suggesting that perlecan protects cartilage extracellular matrix from degradation.
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| 7. |
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| 8. |
- Enge, Maria, 1970, et al.
(författare)
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Endothelium-specific platelet-derived growth factor-B ablation mimics diabetic retinopathy.
- 2002
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Ingår i: The EMBO journal. - : Wiley. - 0261-4189 .- 1460-2075. ; 21:16, s. 4307-16
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Tidskriftsartikel (refereegranskat)abstract
- Loss of pericytes from the capillary wall is a hallmark of diabetic retinopathy, however, the pathogenic significance of this phenomenon is unclear. In previous mouse gene knockout models leading to pericyte deficiency, prenatal lethality has so far precluded analysis of postnatal consequences in the retina. We now report that endothelium-restricted ablation of platelet-derived growth factor-B generates viable mice with extensive inter- and intra-individual variation in the density of pericytes throughout the CNS. We found a strong inverse correlation between pericyte density and the formation of a range of retinal microvascular abnormalities strongly reminiscent of those seen in diabetic humans. Proliferative retinopathy invariably developed when pericyte density was <50% of normal. Our data suggest that a reduction of the pericyte density is sufficient to cause retinopathy in mice, implying that pericyte loss may also be a causal pathogenic event in human diabetic retinopathy.
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| 9. |
- Ewerlöf, Sofia, et al.
(författare)
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DN Debatt. ”Låt gräsklipparen stå – för naturens skull”
- 2023
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Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In an era of species extinction and climate change, we should abandon the well-trimmed lawn and let gardens grow wilder, writes Anna Persson and other researchers and landscape architects on DN Debatt.
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| 10. |
- Fletcher, Kevin, et al.
(författare)
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Glucocorticoid response to both predictable and unpredictable challenges detected as corticosterone metabolites in collared flycatcher droppings
- 2018
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- In most vertebrate animals, glucocorticoid hormones are the chief mediators of homeostasis in response to ecological conditions and as they progress through their lifecycle. In addition, glucocorticoids are a major part of the stress response and stress induced elevations of the hormone can make it difficult to assess glucocorticoid secretion in response to changes in life-stage and current environmental conditions in wild animals. Particularly when quantifying circulating levels of glucocorticoids in the blood which fluctuate rapidly in response to stress. An alternative method of quantifying glucocorticoids is as hormone metabolites in faeces or urine giving a historical sample related to the gut passage time and urinary tract that is less sensitive to stressful events which cause spikes in the circulating hormone level. Although the concentration of glucocorticoid metabolites are influenced by faecal mass thereby potentially affecting any differences in hormone metabolites detected amongst samples. In the present study, we aimed to detect changes in levels of corticosterone, the primary bird glucocorticoid, in relation to the phase of reproduction, in a breeding population of collared flycatchers by sampling corticosterone metabolites in droppings. We also tested how corticosterone metabolite concentrations were affected by ambient temperature and related to body condition in adult birds. Our results indicate that the upregulation of corticosterone between incubation and nestling feeding in female birds is crucial for successful reproduction in this species. Also, females appear to downregulate corticosterone during incubation in response to lower ambient temperature and poorer body condition. Our results did not indicate a relationship between dropping mass and corticosterone metabolite concentrations, which suggests that our findings were linked to the regulation of corticosterone in response to predictable and unpredictable challenges.
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