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1.
Philos Trans A Math Phys Eng Sci ; 382(2273): 20230197, 2024 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-38736334

RESUMEN

The origin of micrometeorites (MMs) from asteroids and comets is well-established, but the relative contribution from these two classes remains poorly resolved. Likewise, determining the precise origin of individual MMs is an open challenge. Here, cosmic-ray exposure ages are used to resolve the spatial origins of 12 MMs collected from urban areas and Antarctica. Their 26Al and 10Be concentration, produced during cosmic-ray irradiation in space, were measured by accelerator mass spectrometry. These data are compared to results from a model simulating the transport and irradiation of the MM precursors in space. This model, for the first time, considers a variety of orbits, precursor particle sizes, compositions and densities and incorporates non-isotropic solar and galactic cosmic-ray flux profiles, depth-dependent production rates, as well as spherical evaporation during atmospheric entry. While the origin for six MMs remains ambiguous, two MMs show a preferential tendency towards an origin in the Inner Solar System (Near Earth Objects to the Asteroid Belt) and four towards an origin in the Outer Solar System (Jupiter Family Comets to the Kuiper Belt). These findings challenge the notion that dust originating from the Outer Solar System is unlikely to survive long-term transport and delivery to the terrestrial planets. This article is part of the theme issue 'Dust in the Solar System and beyond'.

2.
Sci Adv ; 5(12): eaay2670, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31897430

RESUMEN

The cellular and the molecular mechanisms by which long noncoding RNAs (lncRNAs) may regulate presynaptic function and neuronal activity are largely unexplored. Here, we established an integrated screening strategy to discover lncRNAs implicated in neurotransmitter and synaptic vesicle release. With this approach, we identified neuroLNC, a neuron-specific nuclear lncRNA conserved from rodents to humans. NeuroLNC is tuned by synaptic activity and influences several other essential aspects of neuronal development including calcium influx, neuritogenesis, and neuronal migration in vivo. We defined the molecular interactors of neuroLNC in detail using chromatin isolation by RNA purification, RNA interactome analysis, and protein mass spectrometry. We found that the effects of neuroLNC on synaptic vesicle release require interaction with the RNA-binding protein TDP-43 (TAR DNA binding protein-43) and the selective stabilization of mRNAs encoding for presynaptic proteins. These results provide the first proof of an lncRNA that orchestrates neuronal excitability by influencing presynaptic function.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , ARN Largo no Codificante/metabolismo , Vesículas Sinápticas/metabolismo , Animales , Movimiento Celular/genética , Proteínas de Unión al ADN/genética , Células HEK293 , Hipocampo/citología , Humanos , Ratones , Ratones Transgénicos , Neurogénesis/genética , Neuronas/metabolismo , Neurotransmisores/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Transfección
3.
Int J Popul Data Sci ; 4(1): 581, 2019 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-34095527

RESUMEN

INTRODUCTION: Excessive alcohol consumption has adverse effects on health and there is a recognised need for the longitudinal analysis of population data to improve our understanding of the patterns of alcohol use, harms to consumers and those in their immediate environment. The UK has a number of linkable, longitudinal databases that if assembled properly could support valuable research on this topic. AIMS AND OBJECTIVES: This paper describes the development of a broad set of cross-linked cohorts, e-cohorts, surveys and linked electronic healthcare records (EHRs) to construct an alcohol-specific analytical platform in the United Kingdom using datasets on the population of Wales.The objective of this paper is to provide a description of existing key datasets integrated with existing, routinely collected electronic health data on a secure platform, and relevant derived variables to enable population-based research on alcohol-related harm in Wales. We illustrate our use of these data with some exemplar research questions that are currently under investigation. METHODS: Record-linkage of routine and observational datasets. Routine data includes hospital admissions, general practice, and cohorts specific to children. Two observational studies were included. Routine socioeconomic descriptors and mortality data were also linked. CONCLUSION: We described a record-linked, population-based research protocol for alcohol related harm on a secure platform. As the datasets used here are available in many countries, ELAStiC provides a template for setting up similar initiatives in other countries. We have also defined a number of alcohol specific variables using routinely-collected available data that can be used in other epidemiological studies into alcohol related outcomes. With over 10 years of longitudinal data, it will help to understand alcohol-related disease and health trajectories across the lifespan.

4.
Tectonics ; 37(12): 4535-4566, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31007340

RESUMEN

We present an extensive study of rehomogenized olivine-hosted melt inclusions, olivine phenocrysts, and chromian spinel inclusions to explore the link between geodynamic conditions and the origin and composition of Pliocene-Quaternary intraplate magmatism in Anatolia at Kula, Ceyhan-Osmaniye, and Karacadag. Exceptional compositional variability of these products reveals early and incomplete mixing of distinct parental melts in each volcanic center, reflecting asthenospheric and lithospheric mantle sources. The studied primitive magmas consist of (1) two variably enriched ocean island basalt (OIB)-type melts in Kula; (2) both OIB-type and plume mid-ocean ridge basalt (P-MORB)-like melts beneath Toprakkale and Üçtepeler (Ceyhan-Osmaniye); and (3) two variably enriched OIB-type melts beneath Karacadag. Estimated conditions of primary melt generation are 23-9 kbar, 75-30 km, and 1415-1215 °C for Kula; 28-19 kbar, 90-65 km, and 1430-1350 °C for Toprakkale; 23-18 kbar, 75-60 km, and 1400-1355 °C for Üçtepeler; and 35-27 kbar, 115-90 km, and 1530-1455 °C for Karacadag, the deepest levels of which correspond to the depth of the lithosphere-asthenosphere boundary in all regions. Although magma ascent was likely facilitated by local deformation structures, recent Anatolian intraplate magmatism seems to be triggered by large-scale mantle flow that also affects the wider Arabian and North African regions. We infer that these volcanics form part of a much wider Arabian-North African intraplate volcanic province, which was able to invade the Anatolian upper plate through slab gaps.

5.
Stem Cells Int ; 2014: 376918, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25379040

RESUMEN

Skeletal muscle has good regenerative capacity, but the extent of muscle injury and the developed fibrosis might prevent complete regeneration. The in vivo application of human mesenchymal stem cells (HMSCs) of the umbilical cord and the conditioned media (CM) where the HMSCs were cultured and expanded, associated with different vehicles to induce muscle regeneration, was evaluated in a rat myectomy model. Two commercially available vehicles and a spherical hydrogel developed by our research group were used. The treated groups obtained interesting results in terms of muscle regeneration, both in the histological and in the functional assessments. A less evident scar tissue, demonstrated by collagen type I quantification, was present in the muscles treated with HMSCs or their CM. In terms of the histological evaluation performed by ISO 10993-6 scoring, it was observed that HMSCs apparently have a long-term negative effect, since the groups treated with CM presented better scores. CM could be considered an alternative to the in vivo transplantation of these cells, as it can benefit from the local tissue response to secreted molecules with similar results in terms of muscular regeneration. Searching for an optimal vehicle might be the key point in the future of skeletal muscle tissue engineering.

6.
Biomed Res Int ; 2014: 302659, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25121094

RESUMEN

In peripheral nerves MSCs can modulate Wallerian degeneration and the overall regenerative response by acting through paracrine mechanisms directly on regenerating axons or upon the nerve-supporting Schwann cells. In the present study, the effect of human MSCs from Wharton's jelly (HMSCs), differentiated into neuroglial-like cells associated to poly (DL-lactide-ε-caprolactone) membrane, on nerve regeneration, was evaluated in the neurotmesis injury rat sciatic nerve model. Results in vitro showed successful differentiation of HMSCs into neuroglial-like cells, characterized by expression of specific neuroglial markers confirmed by immunocytochemistry and by RT-PCR and qPCR targeting specific genes expressed. In vivo testing evaluated during the healing period of 20 weeks, showed no evident positive effect of HMSCs or neuroglial-like cell enrichment at the sciatic nerve repair site on most of the functional and nerve morphometric predictors of nerve regeneration although the nociception function was almost normal. EPT on the other hand, recovered significantly better after HMSCs enriched membrane employment, to values of residual functional impairment compared to other treated groups. When the neurotmesis injury can be surgically reconstructed with an end-to-end suture or by grafting, the addition of a PLC membrane associated with HMSCs seems to bring significant advantage, especially concerning the motor function recovery.


Asunto(s)
Modelos Animales de Enfermedad , Células Madre Mesenquimatosas/citología , Regeneración Nerviosa/efectos de los fármacos , Traumatismos de los Nervios Periféricos/fisiopatología , Traumatismos de los Nervios Periféricos/terapia , Poliésteres/farmacología , Gelatina de Wharton/citología , Animales , Fenómenos Biomecánicos/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Humanos , Inmunohistoquímica , Cariotipificación , Membranas Artificiales , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/efectos de los fármacos , Neuroglía/citología , Neuroglía/efectos de los fármacos , Traumatismos de los Nervios Periféricos/patología , Ratas , Tiempo de Reacción , Reflejo/efectos de los fármacos , Reproducibilidad de los Resultados , Nervio Ciático/efectos de los fármacos , Nervio Ciático/patología , Nervio Ciático/fisiopatología
7.
J Stem Cells Regen Med ; 10(1): 14-26, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25075157

RESUMEN

Peripheral nerves have the intrinsic capacity of self-regeneration after traumatic injury but the extent of the regeneration is often very poor. Increasing evidence demonstrates that mesenchymal stem/stromal cells (MSCs) may play an important role in tissue regeneration through the secretion of soluble trophic factors that enhance and assist in repair by paracrine activation of surrounding cells. In the present study, the therapeutic value of a population of umbilical cord tissue-derived MSCs, obtained by a proprietary method (UCX(®)), was evaluated on end-to-end rat sciatic nerve repair. Furthermore, in order to promote both, end-to-end nerve fiber contacts and MSC cell-cell interaction, as well as reduce the flush away effect of the cells after administration, a commercially available haemostatic sealant, Floseal(®), was used as vehicle. Both, functional and morphologic recoveries were evaluated along the healing period using extensor postural thrust (EPT), withdrawal reflex latency (WRL), ankle kinematics analysis, and either histological analysis or stereology, in the hyper-acute, acute and chronic phases of healing. The histological analysis of the hyper-acute and acute phase studies revealed that in the group treated with UCX(®) alone the Wallerian degeneration was improved for the subsequent process of regeneration, the fiber organization was higher, and the extent of fibrosis was lower. The chronic phase experimental groups revealed that treatment with UCX(®) induced an increased number of regenerated fibers and thickening of the myelin sheet. Kinematics analysis showed that the ankle joint angle determined for untreated animals was significantly different from any of the treated groups at the instant of initial contact (IC). At opposite toe off (OT) and heel rise (HR), differences were found between untreated animals and the groups treated with either uCx(®) alone or UCX(®) administered with Floseal(®). Overall, the UCX(®) application presented positive effects in functional and morphologic recovery, in both the acute and chronic phases of the regeneration process. Kinematics analysis has revealed positive synergistic effects brought by Floseal(®) as vehicle for MSCs.

8.
J Hum Nutr Diet ; 27 Suppl 2: 152-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23682834

RESUMEN

BACKGROUND: In the context of a rapidly increasing prevalence of noncommunicable diseases, fruit and vegetables could play a key preventive role. To date, there is no rapid assessment tool available for measuring the fruit and vegetable intakes of North-African women. The present study aimed to investigate the reproducibility and relative validity of an eight-item quantitative food frequency questionnaire that measures the fruit and vegetable intakes (FV-FFQ) of Moroccan women. METHODS: During a 1-week period, 100 women, living in the city of Rabat, Morocco (aged 20-49 years) completed the short FV-FFQ twice: once at baseline (FV-FFQ1) and once at the end of the study (FV-FFQ2). In the mean time, participants completed three 24-h dietary recalls. All questionnaires were administered by interviewers. Reproducibility was assessed by computing Spearman's correlation coefficients, intraclass correlation (ICC) coefficients and kappa statistics. Relative validity was assessed by computing Wilcoxon signed-rank tests and Spearman's correlation coefficients, as well as by performing Bland-Altman plots. RESULTS: In terms of reproducibility, Spearman's correlation coefficient was 0.56; ICC coefficient was 0.68; and weighted kappa was 0.35. In terms of relative validity, compared with the three 24-h recalls, the FV-FFQ slightly underestimated mean fruit and vegetable intakes (-10.9%; P = 0.006); Spearman's correlation coefficient was 0.69; at the individual level, intakes measured by the FV-FFQ were between 0.39 and 2.19 times those measured by the 24-h recalls. CONCLUSIONS: The brief eight-item FV-FFQ is a reliable and relatively valid tool for measuring mean fruit and vegetable intakes at the population level, although this is not the case at the individual level.


Asunto(s)
Conducta Alimentaria , Frutas , Encuestas y Cuestionarios , Verduras , Adulto , Bases de Datos Factuales , Registros de Dieta , Estudios de Evaluación como Asunto , Femenino , Humanos , Recuerdo Mental , Persona de Mediana Edad , Marruecos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Adulto Joven
9.
Differentiation ; 84(5): 355-65, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23142731

RESUMEN

Cellular systems implanted into an injured nerve may produce growth factors or extracellular matrix molecules, modulate the inflammatory process and eventually improve nerve regeneration. In the present study, we evaluated the therapeutic value of human umbilical cord matrix MSCs (HMSCs) on rat sciatic nerve after axonotmesis injury associated to Vivosorb® membrane. During HMSCs expansion and differentiation in neuroglial-like cells, the culture medium was collected at 48, 72 and 96 h for nuclear magnetic resonance (NMR) analysis in order to evaluate the metabolic profile. To correlate the HMSCs ability to differentiate and survival capacity in the presence of the Vivosorb® membrane, the [Ca(2+)]i of undifferentiated HMSCs or neuroglial-differentiated HMSCs was determined by the epifluorescence technique using the Fura-2AM probe. The Vivosorb® membrane proved to be adequate and used as scaffold associated with undifferentiated HMSCs or neuroglial-differentiated HMSCs. In vivo testing was carried out in adult rats where a sciatic nerve axonotmesis injury was treated with undifferentiated HMSCs or neuroglial differentiated HMSCs with or without the Vivosorb® membrane. Motor and sensory functional recovery was evaluated throughout a healing period of 12 weeks using sciatic functional index (SFI), extensor postural thrust (EPT), and withdrawal reflex latency (WRL). Stereological analysis was carried out on regenerated nerve fibers. In vitro investigation showed the formation of typical neuroglial cells after differentiation, which were positively stained for the typical specific neuroglial markers such as the GFAP, the GAP-43 and NeuN. NMR showed clear evidence that HMSCs expansion is glycolysis-dependent but their differentiation requires the switch of the metabolic profile to oxidative metabolism. In vivo studies showed enhanced recovery of motor and sensory function in animals treated with transplanted undifferentiated and differentiated HMSCs that was accompanied by an increase in myelin sheath. Taken together, HMSC from the umbilical cord Wharton jelly might be useful for improving the clinical outcome after peripheral nerve lesion.


Asunto(s)
Trasplante de Células Madre Mesenquimatosas , Regeneración Nerviosa , Poliésteres/uso terapéutico , Animales , Antígenos Nucleares/análisis , Diferenciación Celular , Línea Celular , Proteína GAP-43/análisis , Proteína Ácida Fibrilar de la Glía/análisis , Glucólisis , Humanos , Espectroscopía de Resonancia Magnética , Membranas Artificiales , Células Madre Mesenquimatosas/citología , Actividad Motora , Vaina de Mielina/metabolismo , Compresión Nerviosa , Proteínas del Tejido Nervioso/análisis , Neuroglía/citología , Traumatismos de los Nervios Periféricos/terapia , Ratas , Nervio Ciático/química , Nervio Ciático/fisiología , Nervio Ciático/cirugía , Sensación , Gelatina de Wharton/citología
10.
Cell Death Differ ; 19(3): 406-15, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21886181

RESUMEN

In C. elegans, the BH3-only domain protein EGL-1, the Apaf-1 homolog CED-4 and the CED-3 caspase are required for apoptosis induction, whereas the Bcl-2 homolog CED-9 prevents apoptosis. Mammalian B-cell lymphoma 2 (Bcl-2) inhibits apoptosis by preventing the release of the Apaf-1 (apoptotic protease-activating factor 1) activator cytochrome c from mitochondria. In contrast, C. elegans CED-9 is thought to inhibit CED-4 by sequestering it at the outer mitochondrial membrane by direct binding. We show that CED-9 associates with the outer mitochondrial membrane within distinct foci that do not overlap with CED-4, which is predominantly perinuclear and does not localize to mitochondria. CED-4 further accumulates in the perinuclear space in response to proapoptotic stimuli such as ionizing radiation. This increased accumulation depends on EGL-1 and is abrogated in ced-9 gain-of-function mutants. CED-4 accumulation is not sufficient to trigger apoptosis execution, even though it may prime cells for apoptosis. Our results suggest that the cell death protection conferred by CED-9 cannot be solely explained by a direct interaction with CED-4.


Asunto(s)
Apoptosis/fisiología , Factor Apoptótico 1 Activador de Proteasas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Unión al Calcio/metabolismo , Modelos Biológicos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Animales , Apoptosis/efectos de la radiación , Factor Apoptótico 1 Activador de Proteasas/genética , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Unión al Calcio/genética , Mitocondrias/genética , Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Radiación Ionizante
11.
Acta Med Port ; 24(1): 43-52, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21672441

RESUMEN

Tissue regeneration over a large defect with a subsequent satisfactory functional recovery still stands as a major problem in areas such as nerve regeneration or bone healing. The routine technique for the reconstruction of a nerve gap is the use of autologous nerve grafting, but still with severe complications. Over the last decades several attempts have been made to overcome this problem by using biomaterials as scaffolds for guided tissue regeneration. Despite the wide range of biomaterials available, functional recovery after a serious nerve injury is still far from acceptable. Prior to the use of a new biomaterial on healing tissues, an evaluation of the host's inflammatory response is mandatory. In this study, three chitosan membranes were tested in vitro and in vivo for later use as nerve guides for the reconstruction of peripheral nerves submitted to axonotmesis or neurotmesis lesions. Chitosan membranes, with different compositions, were tested in vitro, with a nerve growth factor cellular producing system, N1E-115 cell line, cultured over each of the three membranes and differentiated for 48h in the presence of 1.5% of DMSO. The intracellular calcium concentrations of the non-differentiated and of the 48h-differentiated cells cultured on the three types of the chitosan membranes were measured to determine the cell culture viability. In vivo, the chitosan membranes were implanted subcutaneously in a rat model, and histological evaluations were performed from material retrieved on weeks 1, 2, 4 and 8 after implantation. The three types of chitosan membranes were a viable substrate for the N1E-115 cell multiplication, survival and differentiation. Furthermore, the in vivo studies suggested that these chitosan membranes are promising candidates as a supporting material for tissue engineering applications on the peripheral nerve, possibly owing to their porous structure, their chemical modifications and high affinity to cellular systems.


Asunto(s)
Materiales Biocompatibles , Quitosano , Regeneración Tisular Dirigida , Membranas Artificiales , Procedimientos Neuroquirúrgicos/métodos , Nervios Periféricos/cirugía , Andamios del Tejido , Animales , Células Cultivadas , Femenino , Regeneración Nerviosa , Ratas , Ratas Wistar
12.
Rev. centroam. obstet. ginecol ; 16(2): 34-36, abr.-jun. 2011.
Artículo en Español | LILACS | ID: lil-733805

RESUMEN

Los departamentos de ginecología oncológica y educación al usuario encontró una incidencia de cáncer de cérvix en un período de un año de un 30.2% del total de las pacientes que acuden a la institución, de los cuales el 45% estaba entre los 30-49 años de edad al momento del diagnóstico. Como parte de su tratamiento los pacientes recibieron radioterapia externa y braquiterapia por encontrarse en un estadio avanzado y presentar estenosis vaginal como uno de los efectos secundarios más conocidos...


Asunto(s)
Femenino , Braquiterapia/métodos , Fibrosis/complicaciones , Neoplasias Abdominales/diagnóstico , Neoplasias Abdominales/radioterapia
13.
J Pharm Biomed Anal ; 49(2): 295-303, 2009 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-19135817

RESUMEN

Angiotensin-converting enzyme (ACE) inhibitors are a group of active substances binding to an active site of ACE. Many authors who studied the structure activity relationship suggested the structural elements needed for a potent ACE inhibitor. While many authors studied the activity of ACE inhibitor substances only a few structure stability studies have been presented. In this paper the stability properties of molecule xPRIL were studied by determination of degradation path and rate of degradation in aqueous solutions with different pH (2.0, 6.8 and 12.0) and temperatures (40, 60 and 80 degrees C). The degradation of molecule through two main degradation paths was identified and confirmed by liquid chromatography and mass spectroscopy (LC-MS). Stability properties of xPRIL were determined in a stability study evaluated by high-performance liquid chromatography (HPLC). The first order kinetics of degradation reaction of xPRIL and Arrhenius equations for each pH were determined at observed conditions. xPRIL showed the highest stability at pH 2 solution. The degradation kinetics of xPRIL was compared to the degradation kinetics of enalapril maleate (EM) and perindopril (PER) in bio relevant solutions with pH 2.0 and 6.8. In addition to the stability study of xPRIL the forced degradation study of all three molecules at rigorous conditions was conducted. From the obtained results the structural element having the highest influence on stability properties of the studied molecules was identified. The fragmentation paths of xPRIL, its cyclization degradation product and its hydrolysis degradation product were identified and confirmed by MS/MS method.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/química , Agua/química , Sitios de Unión , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida/métodos , Estabilidad de Medicamentos , Enalapril/química , Guías como Asunto , Concentración de Iones de Hidrógeno , Hidrólisis , Cinética , Espectrometría de Masas/métodos , Modelos Biológicos , Estructura Molecular , Perindopril/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Soluciones , Espectrometría de Masas en Tándem/métodos , Temperatura
14.
Bull Entomol Res ; 98(5): 449-56, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18423078

RESUMEN

Dry, oligotrophic ecosystems are highly threatened in Europe due to massive changes in land use and eutrophication. The conservation of these xeric habitats has received much attention, whereas the ecotones between xeric habitats and other habitat types are often disregarded. One species which mainly inhabits the transition zone between pine forests and adjacent xeric habitats is the heath grasshopper, Chorthippus vagans. This species is endangered in large parts of Europe. One of the largest populations in northern Germany is found on a degraded inland dune near Hanover. This population is threatened by dense growth of deciduous trees and litter accumulation. We analyzed changes in the distribution of this population after the implementation of conservation measures (thinning out the forest and removal of leaf litter). Moreover, we examined dispersal distances of the species in order to assess its colonization potential. We also studied the microhabitat preferences of C. vagans to assess key factors influencing its local distribution. Our data show a substantial growth in population size, which might be a consequence of the conservation measures. New patches on the dune were colonized, promoting dispersal between the subpopulations. We propose that restoration of forest-dune ecotones should be considered more often in landscape planning and conservation management.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Ecosistema , Saltamontes/fisiología , Animales , Conducta Animal , Densidad de Población
15.
Int J Pharm ; 356(1-2): 200-5, 2008 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-18304767

RESUMEN

Perindopril Erbumine (PER) is one of the newly used angiotensin-converting enzyme inhibitors (ACE inhibitors) and is used for the treatment of patients with hypertension and symptomatic heart failure. It has two main degradation pathways, i.e. the degradation by hydrolysis and the degradation by cyclization. An isothermal heat conduction microcalorimetry (MC) and high pressure liquid chromatography (HPLC) were used for the characterization of aqueous solutions of PER and its stability properties. The rates of heat evolved during degradation of perindopril were measured by MC as a function of temperature and pH and from these data rate constant and change in enthalpy of the reactions were determined. With the HPLC method the concentration of perindopril and its degradation products were measured as a function of time in aqueous solutions of different pH that were stored at different temperatures. We demonstrated that reactions of degradation of perindopril at observed conditions follow the first order kinetics. The Arrhenius equation for each pH was determined. At pH 6.8 only one degradation pathway is present, i.e. the degradation by hydrolysis. Degradation constants for this pathway calculated from MC data are in good agreement with those obtained from HPLC. MC as a non-specific technique was shown to be useful in studies of PER when one reaction was present in the sample and also when more chemical and physical processes were simultaneously running.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/química , Perindopril/química , Termodinámica , Calorimetría/métodos , Química Farmacéutica , Cromatografía Líquida de Alta Presión/métodos , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Concentración de Iones de Hidrógeno , Cinética , Soluciones Farmacéuticas
16.
Int J Immunogenet ; 34(5): 359-67, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17845307

RESUMEN

Significant associations between human leucocyte antigen (HLA)-A and -B alleles and CD8+ T-lymphocyte numbers have been reported in the literature in both healthy populations and in HFE-haemochromatosis patients. In order to address whether HLA alleles themselves or alleles at linked genes are responsible for these associations, several genetic markers at the MHC class I region were typed on a population of 147 apparently healthy unrelated subjects phenotypically characterized for their CD8+ and CD4+ T-lymphocyte numbers. By using a machine learning approach, a set of rules was generated that predict the number of CD8+ T-lymphocyte numbers on the basis of the information of the D6S105 microsatellite alleles only. We demonstrate that the previously reported associations with HLA-A and -B alleles are due to the presence of common long (up to 4 megabases long) haplotypes that increased in frequency recently due to positive selection and that encompass a region where a putative gene contributing to the setting of CD8+ T lymphocytes is located, in the neighbourhood of microsatellite locus D6S105, in the 6p21.3 region.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Genes MHC Clase I/genética , Alelos , Marcadores Genéticos , Antígenos HLA-A/genética , Antígeno HLA-A1 , Antígenos HLA-B/genética , Haplotipos , Proteína de la Hemocromatosis , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Recuento de Linfocitos , Proteínas de la Membrana/genética , Repeticiones de Microsatélite/genética
17.
Int J Pharm ; 342(1-2): 145-51, 2007 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-17597314

RESUMEN

The stability properties of enalapril maleate (EM) and of different tablet formulations including EM were studied by isothermal microcalorimetry and by high performance liquid chromatography (HPLC). It was shown that water content of the sample and elevated temperature have a high impact on stability properties of the substance itself and of the formulations including this substance. The degradation is more extensive at higher water content and at elevated temperature. The type of the tablet formulation (5 or 20mg EM tablet formulation) also has an impact: the 5 EM tablet formulation is the less stable one. The heat output of individual tablet formulations was used to evaluate the enthalpy changes and to calculate the difference in the amount of degraded EM between various samples. These results agreed satisfactorily with those obtained by HPLC. Isothermal microcalorimetry proved to be a fast and predictive method that could be used in preformulation studies to accelerate the pharmaceutical development and shorten the time before launching the product to the market.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/química , Enalapril/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Polvos , Comprimidos , Termodinámica , Agua/análisis
18.
Public Health Nutr ; 9(8): 982-90, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17125560

RESUMEN

OBJECTIVE: To study individual determinants of differential benefit from the Senegal Community Nutrition Project (CNP) by monitoring improvement in children's weight-for-age index (WA) or underweight status (WA < -2 Z-scores) during participation. DESIGN: A follow-up study using the CNP child monitoring data. Linear general models compared variations in WA according to 14 factors describing the beneficiaries and CNP services. SETTING: Poor neighbourhoods of Diourbel, a large city in Senegal, West Africa. Over a 6-month period, the CNP provided underweight or nutritionally at-risk 6-35-month-old children with monthly growth monitoring and promotion and weekly food supplementation, provided that mothers attended weekly nutrition education sessions. SUBJECTS: All the children who participated in the first two years of the project (n=4084). RESULTS: Mean WA varied from -2.13 (standard deviation (SD) 0.82) to -1.58 (SD 0.81) Z-scores between recruitment and the end of the follow-up. The lower the child's initial WA, the greater was their increase in WA but the lower was the probability of recovery from underweight. Only 61% of underweight children recovered. Six months of CNP services may not be sufficient for catch-up growth of severely underweight children. The number of food supplement rations received was not a direct indicator of the probability of recovery. After adjustment for services received and initial WA, probability of recovery was lower in girls, in younger children, in twins and when mothers belonged to a specific ethnic group. CONCLUSIONS: Determinants of benefit from CNP differed from the risk factors for underweight. Identification of participants with a lower probability of recovery can help improve outcome. Moreover, an explanation for the lack of recovery could be that many underweight children are stunted but not necessarily wasted.


Asunto(s)
Estado Nutricional , Características de la Residencia , Salud Urbana , Adulto , Pesos y Medidas Corporales , Desarrollo Infantil/fisiología , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Trastornos de la Nutrición del Lactante/dietoterapia , Trastornos de la Nutrición del Lactante/epidemiología , Masculino , Madres/educación , Terapia Nutricional/métodos , Senegal/epidemiología , Delgadez/dietoterapia , Delgadez/epidemiología
19.
Cell Death Differ ; 12(2): 153-61, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15605074

RESUMEN

The p53 tumor suppressor promotes apoptosis in response to DNA damage. Here we describe the Caenorhabditis elegans gene ced-13, which encodes a conserved BH3-only protein. We show that ced-13 mRNA accumulates following DNA damage, and that this accumulation is dependent on an intact C. elegans cep-1/p53 gene. We demonstrate that CED-13 protein physically interacts with the antiapoptotic Bcl-2-related protein CED-9. Furthermore, overexpression of ced-13 in somatic cells leads to the death of cells that normally survive, and this death requires the core apoptotic pathway of C. elegans. Recent studies have implicated two BH3-only proteins, Noxa and PUMA, in p53-induced apoptosis in mammals. Our studies suggest that in addition to the BH3-only protein EGL-1, CED-13 might also promote apoptosis in the C. elegans germ line in response to p53 activation. We propose that an evolutionarily conserved pathway exists in which p53 promotes cell death by inducing expression of two BH3-only genes.


Asunto(s)
Apoptosis/fisiología , Proteínas de Caenorhabditis elegans/fisiología , Caenorhabditis elegans/fisiología , Daño del ADN , Secuencia de Aminoácidos , Animales , Proteínas Reguladoras de la Apoptosis , Caenorhabditis/genética , Caenorhabditis elegans/embriología , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , ADN/genética , ADN/efectos de la radiación , Eliminación de Gen , Regulación del Desarrollo de la Expresión Génica/efectos de la radiación , Proteínas de Choque Térmico/genética , Modelos Biológicos , Datos de Secuencia Molecular , Mutación , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2 , Proteínas Represoras/genética , Homología de Secuencia de Aminoácido , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/fisiología , Rayos X
20.
Int J Obes Relat Metab Disord ; 28(12): 1561-8, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15278107

RESUMEN

OBJECTIVE: To examine the cultural ideals for body size held by urban Senegalese women; to determine the body size that women associate with health; and to estimate the change in prevalence of female obesity in an urban neighbourhood of Dakar. DESIGN: Cross-sectional, population-based study in the subject's home, using a structured interviewer-administered questionnaire, conducted in the same Dakar neighbourhood as that of a previous survey conducted in 1996. SUBJECTS: A total of 301 randomly selected women, aged 20-50 y, living in a specific Dakar neighbourhood, Senegal. MEASUREMENTS: A total of 32 items concerning body satisfaction, social status, health and individual attributes to associate with one of six photographic silhouettes; body mass index (BMI), waist circumference, waist-to-hip ratio by anthropometry; and measures of economic status. RESULTS: In all, 26.6% of women were overweight (BMI 25-29.9 kg/m2) and 18.6% were obese (BMI > or =30 kg/m2) compared with 22.4 and 8.0% respectively in 1996. Overweight was the most socially desirable body size, although obesity itself was seen as undesirable, associated with greediness and the development of diabetes and heart disease. Lay definitions of overweight and normal weight differed substantially from health definitions, as one-third of the sample saw the 'overweight' category as normal. Over a third of women with BMI > or =25 kg/m2 wanted to gain more weight. CONCLUSION: There has been a sharp rise in the prevalence of obesity in Senegalese women living in a Dakar neighbourhood over the last 7 y. In general, overweight body sizes (but not obese) were seen in a positive light. The finding that the term 'overweight' made little sense to these Senegalese women could have important implications for developing public health policies.


Asunto(s)
Actitud Frente a la Salud , Imagen Corporal , Tamaño Corporal/etnología , Países en Desarrollo , Obesidad/epidemiología , Adulto , Antropometría , Femenino , Humanos , Persona de Mediana Edad , Obesidad/psicología , Prevalencia , Autoimagen , Senegal/epidemiología , Factores Socioeconómicos , Salud Urbana/estadística & datos numéricos
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