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1.
J Environ Manage ; 299: 113622, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34479152

RESUMEN

Environmental compensation (EC) aims at addressing environmental losses due to development projects and involves a need to compare development losses with compensation gains using relevant metrics. A conceptual procedure for computing no net loss is formulated and used as a point of departure for a comparative analysis of metrics used by five Swedish municipalities as a part of their EC implementation in the spatial planning context of detailed development plans. While Swedish law does not require EC in this context, these municipalities have still decided to introduce EC requirements for development projects that occur on municipality-owned land and to promote voluntary EC among private actors in development projects on private land. There is substantial variation across the municipalities studied with respect to both metrics and attributes subject to measurement, but there are also similarities: The attributes considered when assessing the need for EC in conjunction with development are not only about nature per se, but also about recreational opportunities and other types ecosystem services; semi-quantitative metrics such as scores are common while quantitative or monetary metrics are rare; and metrics are rarely applied to assess compensatory gains, focusing instead on losses from development. Streamlining across municipalities might be warranted for increasing predictability and transparency for developers and citizens, but it also introduces considerable challenges such as a need for developing consistent guidelines for semi-quantitative metrics, and to handle substitutability issues if metrics are not only applied on individual attributes but also on groups of attributes. The broad scope of attributes used by the municipalities is in line with an international tendency to broaden EC to include not only biodiversity aspects but also ecosystem services. Moreover, the EC systems applied by the municipalities are of particular importance for highlighting the crucial role of environmental management for maintaining and enhancing biodiversity and ecosystem services not only in areas having formal protection status but also in the everyday landscape. The municipalities' experience and strengths and weaknesses associated with their EC systems are therefore relevant also in an international perspective.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Benchmarking , Biodiversidad , Ciudades , Suecia
2.
J Environ Manage ; 240: 47-56, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-30928794

RESUMEN

This study focuses on drivers for changing urban flood risk. We suggest a framework for guiding climate change adaptation action concerning flood risk and manageability in cities. The identified key drivers of changing flood hazard and vulnerability are used to provide an overview of each driver's impact on flood risk and manageability at the city level. We find that identified drivers for urban flood risk can be grouped in three different priority areas with different time horizon. The first group has high impact but is manageable at city level. Typical drivers in this group are related to the physical environment such as decreasing permeability and unresponsive engineering. The second group of drivers is represented by public awareness and individual willingness to participate and urbanization and urban sprawl. These drivers may be important and are manageable for the cities and they involve both short-term and long-term measures. The third group of drivers is related to policy and long-term changes. This group is represented by economic growth and increasing values at risk, climate change, and increasing complexity of society. They have all high impact but low manageability. Managing these drivers needs to be done in a longer time perspective, e.g., by developing long-term policies and exchange of ideas.


Asunto(s)
Cambio Climático , Inundaciones , Ciudades , Ambiente , Urbanización
3.
Water Sci Technol ; 73(6): 1253-60, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27003064

RESUMEN

A new principle for mainstream nitrogen removal through nitritation followed by anammox was studied in a two-stage moving bed biofilm reactor (MBBR) configuration. The first stage was optimized for nitritation by using thin biofilms and a feed alternating between synthetic mainstream wastewater at 15°C and, for shorter periods, synthetic reject water at 30 °C. The exposure of the biofilm to reject water conditions aimed to improve the growth conditions for ammonia oxidizing bacteria, while inhibiting nitrite oxidizing bacteria. The biofilm thickness was maintained below 200 µm to ensure high exposure of the total biomass to the bulk reactor conditions. Nitritation was successfully achieved in the configuration, with a nitrite accumulation ratio above 75% during the majority of the study, and ammonia removal rates between 0.25 and 0.50 g NH4-N/L,d. The anoxic second stage, optimized for anammox, was fed with the effluent from the nitritation reactor, reaching nitrogen removal rates above 0.20 g TN/L,d.


Asunto(s)
Amoníaco/metabolismo , Biopelículas , Reactores Biológicos/microbiología , Nitrificación , Nitritos/metabolismo , Eliminación de Residuos Líquidos/métodos , Amoníaco/química , Bacterias/crecimiento & desarrollo , Biomasa , Nitritos/química , Nitrógeno/análisis , Aguas Residuales/química
4.
Zootaxa ; 3981(4): 491-507, 2015 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-26250009

RESUMEN

Tardigrades occur worldwide and in a variety of ecosystems and habitats representing an important component of the micrometazoan biodiversity. Several studies documenting the occurrence of tardigrades in Sweden have been published since the first reports in early 1900, but no comprehensive summary of these studies have been published. We compiled the available information on recorded tardigrades from Sweden, using material from published studies and museum and university collections. In total, our review document 101 species of tardigrades that have been recorded from Sweden (an updated checklist of tardigrades from Sweden will be available online), of which 14 species are new records for the country. The highest number of species was recorded in the northernmost province of Lappland and the more southern provinces of Uppland and Skåne, while much lower species numbers are reported from the middle part of Sweden. This pattern probably represents biased sampling activities of biologists rather than real differences in biodiversity of tardigrades. In view of the few studies that have been made on tardigrade biodiversity in Sweden, the relatively high number of tardigrade species recorded, representing almost a tenth of the species recorded worldwide, indicates that many more species remain to be found. In this respect, more studies of the marine ecosystems along the Swedish west coast and the long Baltic Sea coastline would be of particular interest.


Asunto(s)
Tardigrada/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Lista de Verificación , Ecosistema , Femenino , Masculino , Tamaño de los Órganos , Suecia , Tardigrada/anatomía & histología , Tardigrada/crecimiento & desarrollo
5.
Mol Ecol ; 23(9): 2275-86, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24655072

RESUMEN

Sexual selection and the ornaments that inform such choices have been extensively studied, particularly from a phenotypic perspective. Although more is being revealed about the genetic architecture of sexual ornaments, much still remains to be discovered. The comb of the chicken is one of the most widely recognized sexual ornaments, which has been shown to be correlated with both fecundity and bone allocation. In this study, we use a combination of multiple intercrosses between White Leghorn populations and wild-derived Red Junglefowl to, first, map quantitative trait loci (QTL) for bone allocation and, second, to identify expression QTL that correlate and colocalize with comb mass. These candidate quantitative genes were then assessed for potential pleiotropic effects on bone tissue and fecundity traits. We identify genes that correlate with both relative comb mass and bone traits suggesting a combination of both pleiotropy and linkage mediates gene regulatory variation in these traits.


Asunto(s)
Huesos/anatomía & histología , Pollos/anatomía & histología , Pollos/genética , Cresta y Barbas/anatomía & histología , Ligamiento Genético , Pleiotropía Genética , Sitios de Carácter Cuantitativo , Animales , Mapeo Cromosómico , Cruzamientos Genéticos , Femenino , Fertilidad/genética , Masculino , Fenotipo
6.
Ambio ; 42(2): 254-65, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23475660

RESUMEN

Translating policies about sustainable development as a social process and sustainability outcomes into the real world of social-ecological systems involves several challenges. Hence, research policies advocate improved innovative problem-solving capacity. One approach is transdisciplinary research that integrates research disciplines, as well as researchers and practitioners. Drawing upon 14 experiences of problem-solving, we used group modeling to map perceived barriers and bridges for researchers' and practitioners' joint knowledge production and learning towards transdisciplinary research. The analysis indicated that the transdisciplinary research process is influenced by (1) the amount of traditional disciplinary formal and informal control, (2) adaptation of project applications to fill the transdisciplinary research agenda, (3) stakeholder participation, and (4) functional team building/development based on self-reflection and experienced leadership. Focusing on implementation of green infrastructure policy as a common denominator for the delivery of ecosystem services and human well-being, we discuss how to diagnose social-ecological systems, and use knowledge production and collaborative learning as treatments.


Asunto(s)
Conservación de los Recursos Naturales , Comunicación Interdisciplinaria , Solución de Problemas , Conducta Cooperativa , Humanos , Aprendizaje
7.
Front Physiol ; 14: 1249773, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37731547

RESUMEN

Introduction: Tardigrades are small aquatic invertebrates with well documented tolerance to several environmental stresses, including desiccation, low temperature, and radiation, and an ability to survive long periods in a cryptobiotic state under arrested metabolism. Many tardigrade populations live in habitats where temporary exposure to hypoxia is expected, e.g., benthic layers or substrates that regularly undergo desiccation, but tolerance to hypoxia has so far not been thoroughly investigated in tardigrades. Method: We studied the response to exposure for hypoxia (<1 ppm) during 1-24 h in two tardigrade species, Richtersius cf. coronifer and Hypsibius exemplaris. The animals were exposed to hypoxia in their hydrated active state. Results: Survival was high in both species after the shortest exposures to hypoxia but tended to decline with longer exposures, with almost complete failure to recover after 24 h in hypoxia. R. cf. coronifer tended to be more tolerant than H. exemplaris. When oxygen level was gradually reduced from 8 to 1 ppm, behavioral responses in terms of irregular body movements were first observed at 3-4 ppm. Discussion: The study shows that both limno-terrestrial and freshwater tardigrades are able to recover after exposure to severe hypoxia, but only exposure for relatively short periods of time. It also indicates that tardigrade species have different sensitivity and response patterns to exposure to hypoxia. These results will hopefully encourage more studies on how tardigrades are affected by and respond to hypoxic conditions.

8.
Sci Rep ; 13(1): 19776, 2023 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-37957290

RESUMEN

Rock pools are eroded depressions in bedrock providing temporary aquatic habitats with varying morphometric and chemical conditions. Tardigrades have adapted to many habitats with varying and extreme abiotic conditions, including desiccation, but their occurrence in rock pools have rarely been investigated. This study investigated the occurrence of tardigrades and the morphometric and chemical conditions in rock pools by the Baltic Sea in southeast Sweden. Samples of benthic material were collected from rock pools at three sites near the town Karlshamn together with measurements of pool size, pH, temperature, salinity, and dissolved oxygen of the water. Tardigrades occurred in about one fifth of the rock pools and included five eutardigrade genera. Also rotifers and nematodes were observed in the samples. The morphometric and chemical variables varied both within and among the three sites but with few differences between rock pools with or without tardigrades. However, rock pools with tardigrades tended to be overall shallower than pools without tardigrades, indicating that more desiccating-prone rock pools may be more favourable habitats for tardigrades. The study shows that tardigrades are part of the micro-invertebrate fauna in rock pools and this habitat deserves more investigations into the occurrence of this animal group.


Asunto(s)
Tardigrada , Animales , Ecosistema , Invertebrados , Agua , Temperatura
9.
Radiography (Lond) ; 29(6): 1123-1129, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37797480

RESUMEN

INTRODUCTION: The temporary trauma teams in trauma alerts consist of a diverse group of unique professionals requiring interprofessional collaboration and coordination to achieve efficient, high-quality care. The uncertain situation and complex care environment impose high demands on team dynamics such as individual attitudes and team behaviours. Within interprofessional teams, interaction and coordination reflect the collective success of collaboration and the achievement of goals. Interactions with radiographers have increased in trauma teams given computed tomography's prominent role in providing crucial knowledge for decision-making in trauma care. This study aimed to explore radiographers' experiences of interprofessional collaboration during trauma alerts. METHOD: The study was designed with focus group methodology, including 17 radiographers participating in five focus groups, analysed with an inductive focus group analysis. RESULTS: An overarching theme, "On the edge of decision-making", emerged along with three sub-themes: "Feeling included requires acknowledgement", "Exclusion precludes shared knowledge", and "Experience and mutual awareness facilitate team interaction". CONCLUSIONS: Interprofessional collaboration from the radiographer's perspective within trauma teams requires a sense of inclusion and the ability to interact with the team. Exclusion from vital decision-making obstructs radiographers' comprehension of situations and thereby the interdependence in interprofessional collaboration. IMPLICATIONS FOR PRACTICE: Common platforms are needed for knowledge sharing and team practices, including radiographers' areas of responsibility and relational coordination to foster interprofessional relationships. Through these means interdependence through awareness and shared knowledge can be facilitated on trauma teams.


Asunto(s)
Técnicos Medios en Salud , Servicios Médicos de Urgencia , Humanos , Grupos Focales , Conducta Cooperativa , Comunicación
10.
Org Biomol Chem ; 10(12): 2453-63, 2012 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-22344369

RESUMEN

Bacterial polysaccharides are comprised of a variety of monosaccharides, L-rhamnose (6-deoxy-L-mannose) being one of them. This sugar is often part of α-(1 → 2)- and/or α-(1 → 3)-linkages and we have therefore studied the disaccharide α-L-Rhap-(1 → 2)-α-L-Rhap-OMe to obtain information on conformational preferences at this glycosidic linkage. The target disaccharide was synthesized with (13)C site-specific labeling at C1' and at C2', i.e., in the terminal group. 2D (1)H,(13)C-HSQC-HECADE and (1)H,(13)C-J-HMBC NMR experiments, 1D (13)C and (1)H NMR spectra together with total line-shape analysis were used to extract conformationally dependent hetero- and homonuclear spin-spin coupling constants. This resulted in the determination of (2)J(C2',H1'), (3)J(C1',C1), (3)J(C1',C3), (3)J(C2',C2), (2)J(C1',C2), (1)J(C1',C2'), and (1)J(C1',H1'). These data together with previously determined J(CH) and (1)H,(1)H NOEs result in fourteen conformationally dependent NMR parameters that are available for analysis of glycosidic linkage flexibility and conformational preferences. A 100 ns molecular dynamics (MD) simulation of the disaccharide with explicit water molecules as solvent showed a major conformational state at φ(H)≈ 40° and ψ(H)≈-35°, consistent with experimental NMR data. In addition, MD simulations were carried out also for α-L-Rhap-(1 → 3)-α-L-Rhap-OMe and a rhamnan hexasaccharide. The gathered information on the oligosaccharides was used to address conformational preferences for a larger structure, a 2- and 3-linked nonasaccharide, with implications for the 3D structure of rhamnan polysaccharides, which should be regarded as flexible polymers.


Asunto(s)
Bacterias/química , Desoxiazúcares/química , Mananos/química , Oligosacáridos/química , Ramnosa/química , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular
11.
Oecologia ; 170(3): 641-9, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22565493

RESUMEN

Environmental variation connected with seasonality is likely to affect the evolution of life-history strategies in ectotherms, but there is no consensus as to how important life-history traits like body size are influenced by environmental variation along seasonal gradients. We compared adult body size, skeletal growth, mean age, age at first reproduction and longevity among 11 common frog (Rana temporaria) populations sampled along a 1,600-km-long latitudinal gradient across Scandinavia. Mean age, age at first reproduction and longevity increased linearly with decreasing growth season length. Lifetime activity (i.e. the estimated number of active days during life-time) was highest at mid-latitudes and females had on average more active days throughout their lives than males. Variation in body size was due to differences in lifetime activity among populations--individuals (especially females) were largest where they had the longest cumulative activity period--as well as to differences between populations in skeletal growth rate as determined by skeletochronological analyses. Especially, males grew faster at intermediate latitudes. While life-history trait variation was strongly associated with latitude, the direction and shape of these relationships were sex- and trait-specific. These context-dependent relationships may be the result of life-history trade-offs enforced by differences in future reproductive opportunities and time constraints among the populations. Thus, seasonality appears to be an important environmental factor shaping life-history trait variation in common frogs.


Asunto(s)
Tamaño Corporal , Rana temporaria/fisiología , Estaciones del Año , Factores de Edad , Animales , Evolución Biológica , Ambiente , Femenino , Longevidad , Masculino , Rana temporaria/crecimiento & desarrollo , Reproducción , Países Escandinavos y Nórdicos
12.
Magn Reson Chem ; 49(3): 117-24, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21274903

RESUMEN

An array of NMR spectroscopy experiments have been carried out to obtain conformationally dependent (1)H,(13)C- and (13)C,(13)C-spin-spin coupling constants in the trisaccharide α-L-Rhap-(1 → 2)[α-L-Rhap-(1 → 3)]-α-L-Rhap-OMe. The trisaccharide was synthesized with (13)C site-specific labeling at C2' and C2″, i.e. in the rhamnosyl groups in order to alleviate (1)H spectral overlap. This facilitated the measurement of a key trans-glycosidic proton-proton cross-relaxation rate using 1D (1)H,(1)H-T-ROESY experiments as well as a (3)J(C, H) coupling employing 1D (1)H,(13)C-long-range experiments, devoid of potential interference from additional J coupling. By means of both the natural abundance compound and the (13)C-labeled sample 2D (1)H,(13)C-J-HMBC and (1)H,(13)C-HSQC-HECADE NMR experiments, total line-shape analysis of (1)H NMR spectra and 1D (13)C NMR experiments were employed to extract (3)J(C, H) , (2)J(C, H), (3)J(C, C), and (1)J(C, C) coupling constants. The (13)C site-specific labeling facilitates straightforward determination of (n)J(C, C) as the splitting of the (13)C natural abundance resonances. This study resulted in eight conformationally dependent coupling constants for the trisaccharide and illustrates the use of (13)C site-specific labeling as a valuable approach that extends the 1D and 2D NMR methods in current use to attain both hetero- and homonuclear spin-spin coupling constants that subsequently can be utilized for conformational analysis.

13.
Sci Rep ; 11(1): 4861, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33649358

RESUMEN

Kristianstads Vattenrike Biosphere Reserve [KVBR] is a UNESCO designated area of Sweden possessing high biological value. Although several studies on tardigrades inhabiting Sweden have been performed, the KVBR area has been neglected. The current study investigates the tardigrade fauna of five areas of the biosphere reserve and includes 34 samples of different substrates analysed quantitatively and qualitatively. In total, 33 species of tardigrades were found in the samples, including 22 new records for the Skåne region, 15 new records for Sweden, and four species new to science. Mesobiotus emiliae sp. nov., Xerobiotus gretae sp. nov., Itaquascon magnussoni sp. nov., and Thulinius gustavi sp. nov. were described with an integrative approach (when possible) using morphological characters (light, electron scanning, and confocal laser scanning microscopies) and molecular markers (ITS2, 18S, 28S, cox1). A new protocol to increase morphological data was developed recovering mounted specimens within old slides for SEM analysis. Emended diagnoses for the genus Itaquascon and the transfer of Platicrista itaquasconoide to the genus Meplitumen are proposed. This study enriches the knowledge of the tardigrade biodiversity both within the KVBR and in Sweden and contributes to the rapidly increasing number of tardigrade species reported worldwide. The 33 species identified in the KVBR area represents 28% of all water bear species found in Sweden so far. The restricted study areas and limited number of samples collected suggests that the KVBR is very rich of tardigrades.

14.
BMC Evol Biol ; 10: 317, 2010 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-20964816

RESUMEN

BACKGROUND: The thermal benefits of melanism in ectothermic animals are widely recognized, but relatively little is known about population differentiation in the degree of melanism along thermal gradients, and the relative contributions of genetic vs. environmental components into the level of melanism expressed. We investigated variation in the degree of melanism in the common frog (Rana temporaria; an active heliotherm thermoregulator) by comparing the degree of melanism (i) among twelve populations spanning over 1500 km long latitudinal gradient across the Scandinavian Peninsula and (ii) between two populations from latitudinal extremes subjected to larval temperature treatments in a common garden experiment. RESULTS: We found that the degree of melanism increased steeply in the wild as a function of latitude. Comparison of the degree of population differentiation in melanism (PST) and neutral marker loci (FST) revealed that the PST >FST, indicating that the differences cannot be explained by random genetic drift alone. However, the latitudinal trend observed in the wild was not present in the common garden data, suggesting that the cline in nature is not attributable to direct genetic differences. CONCLUSIONS: As straightforward local adaptation can be ruled out, the observed trend is likely to result from environment-driven phenotypic plasticity or ontogenetic plasticity coupled with population differences in age structure. In general, our results provide an example how phenotypic plasticity or even plain ontogeny can drive latitudinal clines and result in patterns perfectly matching the genetic differences expected under adaptive hypotheses.


Asunto(s)
Adaptación Fisiológica , Ambiente , Melaninas/metabolismo , Rana temporaria/fisiología , Animales , Variación Genética/genética , Variación Genética/fisiología , Rana temporaria/genética , Selección Genética/genética
15.
J Am Chem Soc ; 132(5): 1724-30, 2010 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-20078120

RESUMEN

Glycosynthases are precise molecular instruments for making specifically linked oligosaccharides. X-ray crystallography screening of ligands bound to the 1,3(4)-beta-D-glucanase nucleophile mutant E115S of Phanerochaete chrysosporium Laminarinase 16A (Lam16A) showed that laminariheptaose (L7) bound in an arch with the reducing and nonreducing ends occupying either side of the catalytic cleft of the enzyme. The X-ray structure of Lam16A E115S in complex with alpha-laminariheptaosyl fluoride (alphaL7F) revealed how alphaL7F could make a nucleophilic attack upon itself. Indeed, when Lam16A E115S was allowed to react with alphaL7F the major product was a cyclic beta-1,3-heptaglucan, as shown by mass spectrometry. NMR confirmed uniquely beta-1,3-linkages and no reducing end. Molecular dynamics simulations indicate that the cyclic laminariheptaose molecule is not completely planar and that torsion angles at the glycosidic linkages fluctuate between two energy minima. This is the first report of a glycosynthase that joins the reducing and nonreducing ends of a single oligosaccharide and the first reported synthesis of cyclic beta-glucan.


Asunto(s)
Celulasas/metabolismo , Phanerochaete/enzimología , beta-Glucanos/metabolismo , Dominio Catalítico , Celulasas/química , Celulasas/genética , Cristalografía por Rayos X , Ligandos , Simulación de Dinámica Molecular , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , beta-Glucanos/química
16.
Osteoporos Int ; 20(7): 1167-73, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18974917

RESUMEN

SUMMARY: We evaluated the relation between serum FGF23 and bone mineral density (BMD) in a community-based cohort of elderly men. There was a weak correlation between FGF23 and BMD, which was primarily dependent on body weight. INTRODUCTION: FGF23 is a hormonal factor produced in bone and regulates serum levels of phosphate (Pi) and vitamin D. FGF23 over-expression is associated with skeletal abnormalities, including rickets/osteomalacia. The relation between FGF23 and Bone Mineral Density (BMD) in the community remains unexplored. METHODS: We employed a large, population-based cohort of 3014 Swedish men aged 69-80 years, without known renal disease. BMD was measured with dual X-ray absorptiometry (DXA) in the hip and lumbar spine. Serum intact FGF23 was analyzed with a two-site monoclonal ELISA. RESULTS: There was a weak but significant correlation between FGF23 and BMD in femoral neck (r = 0.04, p < 0.05), femoral trochanter (r = 0.05, p = 0.004), total hip (r = 0.06, p = 0.0015) and lumbar spine (r = 0.07, p = 0.0004). The correlations remained significant when adjusting for biochemical covariates (Pi, calcium, PTH, 25(OH)D and renal function). However, the association became insignificant in all regions when adjusting for established confounding variables including age, height, weight and smoking. Further analysis confirmed a significant correlation between FGF23 and body weight (r = 0.13, p < 0.0001). CONCLUSIONS: The weak correlation between FGF23 and BMD in elderly male subjects is mainly due to an association between FGF23 and body weight. Therefore, FGF23 may not play a significant role in the hormonal regulation of BMD.


Asunto(s)
Peso Corporal/fisiología , Densidad Ósea/fisiología , Factores de Crecimiento de Fibroblastos/sangre , Absorciometría de Fotón , Anciano , Anciano de 80 o más Años , Fémur/diagnóstico por imagen , Cuello Femoral/diagnóstico por imagen , Factor-23 de Crecimiento de Fibroblastos , Humanos , Vértebras Lumbares/diagnóstico por imagen , Masculino , Estudios Prospectivos , Suecia
17.
J Pathol ; 216(3): 345-55, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18729070

RESUMEN

Genetic ablation of fibroblast growth factor 23 from mice (Fgf-23(-/-)) results in a short lifespan with numerous abnormal biochemical and morphological features. Such features include kyphosis, hypogonadism and associated infertility, osteopenia, pulmonary emphysema, severe vascular and soft tissue calcifications, and generalized atrophy of various tissues. To determine whether these widespread anomalies in Fgf-23(-/-) mice can be ameliorated by genetically restoring the systemic actions of FGF-23, we generated Fgf-23(-/-) mice expressing the human FGF-23 transgene in osteoblasts under the control of the 2.3 kb alpha1(I) collagen promoter (Fgf-23(-/-) /hFGF-23-Tg double mutants). This novel mouse model is completely void of all endogenous Fgf-23 activity, but produces human FGF-23 in bone cells that is subsequently released into the circulation. Our results suggest that lack of Fgf-23 activities results in extensive premature ageing-like features and early mortality of Fgf-23(-/-) mice, while restoring the systemic effects of FGF-23 significantly ameliorates these phenotypes, with the resultant effect being improved growth, restored fertility, and significantly prolonged survival of double mutants. With regard to their serum biochemistry, double mutants reversed the severe hyperphosphataemia, hypercalcaemia, and hypervitaminosis D found in Fgf-23(-/-) littermates; rather, double mutants show hypophosphataemia and normal serum 1,25-dihydroxyvitamin D(3) levels similar to pure FGF-23 Tg mice. These changes were associated with reduced renal expression of NaPi2a and 1 alpha-hydroxylase, compared to Fgf-23(-/-) mice. FGF-23 acts to prevent widespread abnormal features by acting systemically to regulate phosphate homeostasis and vitamin D metabolism. This novel mouse model provides us with an in vivo tool to study the systemic effects of FGF-23 in regulating mineral ion metabolism and preventing multiple abnormal phenotypes without the interference of native Fgf-23.


Asunto(s)
Envejecimiento Prematuro/genética , Factores de Crecimiento de Fibroblastos/genética , Osteoblastos/metabolismo , Envejecimiento Prematuro/metabolismo , Envejecimiento Prematuro/patología , Animales , Biomarcadores/sangre , Huesos/diagnóstico por imagen , Huesos/metabolismo , Huesos/patología , Calcitriol/sangre , Calcio/sangre , Femenino , Factor-23 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/metabolismo , Expresión Génica , Ingeniería Genética , Genotipo , Miembro Posterior , Humanos , Mucosa Intestinal/patología , Pulmón/patología , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Modelos Animales , Hormona Paratiroidea/sangre , Fosfatos/sangre , Radiografía , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Piel/patología , Transgenes
18.
Eur Surg Res ; 42(2): 122-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19155629

RESUMEN

BACKGROUND: The first tissues to be deprived of perfusion and oxygenation in a hypovolemic situation and the last ones to be reperfused are the subcutaneous tissue and the gastrointestinal mucosa. We hypothesized that measurements of subcutaneous tissue gases and pH might reflect simultaneous changes in oxygenation of the intestinal mucosa. The aim of this study was to evaluate tissue gases and pH as measures of tissue oxygenation and tissue oxygen metabolism in subcutaneous and intestinal tissues simultaneously. MATERIAL AND METHODS: Five out of 17 domestic pigs (weight 21-25 kg) were used as controls without bleeding. Twelve animals were bled in 3 steps, 10% of their calculated blood volume at each step. The removed blood, crystalloid and colloid were thereafter infused, and animals were stabilized for 30 min. Measurements were made after each step of bleeding, retransfusion and stabilization. Before bleeding, all animals had a sensor (Paratrend 7) implanted subcutaneously in the left groin for measurements of tissue gases and pH (P(sc)O(2), P(sc)CO(2) and pH(sc)). Catheters were positioned in the jugular vein, portal vein, carotid artery, pulmonary artery and femoral artery for infusion, bleeding and oxygen monitoring. Via a midline laparotomy, 2 silicon tonometers (TRIP sigmoid catheters) were positioned in the ileum and sigmoid colon for measurements of PCO(2) and pH (P(iI)CO(2), P(si)CO(2), pH(iI) and pH(si)). Blood flow in the portal vein was measured by an ultrasound probe (H6SB) and a Clark electrode (Cardiff tissue oxymeter) was used for serosal PO(2) measurements of the ileum (P(iI)O(2)) and sigmoid colon (P(si)O(2)). RESULTS: After the first step of bleeding, P(sc)O(2) decreased from 64 +/- 17 to 56 +/- 22 mm Hg (SD; p < 0.05). P(sc)CO(2) and pH(sc) did not change. P(iI)CO(2) increased from 64 +/- 14 to 79 +/- 14 mm Hg (p < 0.05), P(si)CO(2) increased from 77 +/- 16 to 90 +/- 18 mm Hg (p < 0.05). pH(iI) decreased from 7.15 +/- 0.09 to 7.03 +/- 0.09 (p < 0.05). P(iI)O(2) and P(si)O(2) decreased, but not significantly until steps of further bleeding. After re-transfusion and stabilization, P(sc)O(2) and P(iI)CO(2) returned to baseline. CONCLUSION: Measurements of subcutaneous PO(2) are sensitive to bleeding and resuscitation and reflect oxygen metabolism in the small intestinal mucosa as measured by PCO(2) and pH.


Asunto(s)
Mucosa Intestinal/metabolismo , Oxígeno/metabolismo , Resucitación , Choque Hemorrágico/metabolismo , Circulación Esplácnica , Tejido Subcutáneo/metabolismo , Animales , Presión Sanguínea , Temperatura Corporal , Dióxido de Carbono/metabolismo , Gasto Cardíaco , Concentración de Iones de Hidrógeno , Peritoneo/metabolismo , Choque Hemorrágico/terapia , Porcinos
19.
Cancers (Basel) ; 11(9)2019 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-31505739

RESUMEN

Tardigrades represent a phylum of very small aquatic animals in which many species have evolved adaptations to survive under extreme environmental conditions, such as desiccation and freezing. Studies on several species have documented that tardigrades also belong to the most radiation-tolerant animals on Earth. This paper gives an overview of our current knowledge on radiation tolerance of tardigrades, with respect to dose-responses, developmental stages, and different radiation sources. The molecular mechanisms behind radiation tolerance in tardigrades are still largely unknown, but omics studies suggest that both mechanisms related to the avoidance of DNA damage and mechanisms of DNA repair are involved. The potential of tardigrades to provide knowledge of importance for medical sciences has long been recognized, but it is not until recently that more apparent evidence of such potential has appeared. Recent studies show that stress-related tardigrade genes may be transfected to human cells and provide increased tolerance to osmotic stress and ionizing radiation. With the recent sequencing of the tardigrade genome, more studies applying tardigrade omics to relevant aspects of human medicine are expected. In particular, the cancer research field has potential to learn from studies on tardigrades about molecular mechanisms evolved to maintain genome integrity.

20.
Results Probl Cell Differ ; 68: 231-249, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31598859

RESUMEN

The invertebrate phylum Tardigrada has received much attention for containing species adapted to the most challenging environmental conditions where an ability to survive complete desiccation or freezing in a cryptobiotic state is necessary for persistence. Although research on tardigrades has a long history, the last decade has seen a dramatic increase in molecular biological ("omics") studies, most of them with the aim to reveal the biochemical mechanisms behind desiccation tolerance of tardigrades. Several other aspects of tardigrade cell biology have been studied, and we review some of them, including karyology, embryology, the role of storage cells, and the question of whether tardigrades are eutelic animals. We also review some of the theories about how anhydrobiotic organisms are able to maintain cell integrity under dry conditions, and our current knowledge on the role of vitrification and DNA protection and repair. Many aspects of tardigrade stress tolerance have relevance for human medicine, and the first transfers of tardigrade stress genes to human cells have now appeared. We expect this field to develop rapidly in the coming years, as more genomic information becomes available. However, many basic cell biological aspects remain to be investigated, such as immunology, cell cycle kinetics, cell metabolism, and culturing of tardigrade cells. Such development will be necessary to allow tardigrades to move from a nonmodel organism position to a true model organism with interesting associations with the current models C. elegans and D. melanogaster.


Asunto(s)
Modelos Animales , Tardigrada/citología , Animales , Caenorhabditis elegans , Deshidratación , Drosophila melanogaster
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