251 research outputs found
¿Afecta la calidad del hábitat alimentario a la capacidad reproductiva de la garceta común, Egretta garzetta?
In order to understand the role of foraging habitat quality on fecundity parameters we measured habitat use, breeding parameters, and body condition of chicks in six colonies of Little Egrets in southern France. The foraging habitat available differed between colonies; it was mainly natural marshes around the Carrelet colony, agricultural lands (rice fields and dry crops) around the Agon colony, a mix of agricultural and natural lands around the Redon and FiĂ©louse colonies, a mix of natural and urbanised/industrial lands around the Palissade colony, and mainly cultivated and urbanised lands around the Chaumont colony. The habitat attractiveness to adult Little Egret breeding was higher for natural marshes than for other habitat types. Agricultural marshes (rice fields) came next. Other human–made habitats came last. Clutch size and body condition index of chicks did not differ between colonies. Brood size was influenced by both the association of the proportion of natural marshes in the foraging area and clutch size, and the association of clutch size and the total number of heron pairs in the colony. The effect of the proportion of natural marshes could not be distinguished from the effects of the colony size. The potential influence of other parameters not taken into account in this study is discussed.Con la finalidad de conocer el papel que ejerce la calidad del hábitat alimentario sobre los parámetros de fecundidad, se evaluaron el uso del hábitat, los parámetros reproductivos y las condiciones fĂsicas de los polluelos de seis colonias de garceta comĂşn en el sur de Francia. El hábitat alimentario disponible variaba de unas colonias a otras, siendo principalmente marismas naturales en el entorno de la colonia de Carrelet, terrenos agrĂcolas (campos de arroz y cultivos de secano) alrededor de la colonia de Agon, una combinaciĂłn de terrenos agrĂcolas y naturales alrededor de las colonias de Redon y FiĂ©louse, una combinaciĂłn de terrenos naturales y urbanizados/industriales alrededor de la colonia de Palissade, y principalmente terrenos cultivados y urbanizados alrededor de la colonia de Chaumont. En la Ă©poca de reproducciĂłn, los adultos de garceta comĂşn se sienten atraĂdos principalmente por las marismas naturales, en detrimento de otros tipos de hábitat. Las tierras agrĂcolas anegadas (campos de arroz) siguen en orden de preferencia, mientras los hábitats construidos por el hombre ocupan el Ăşltimo lugar. El tamaño de la puesta y el Ăndice de estado fĂsico de los polluelos no mostraron diferencias entre las colonias. El tamaño de la nidada estuvo influenciado tanto por la asociaciĂłn de la proporciĂłn de marismas naturales en el hábitat alimentario y el tamaño de la puesta, como por la asociaciĂłn del tamaño de la puesta y el nĂşmero total de parejas de garzas de la colonia. El efecto de la proporciĂłn de marismas naturales no se puede diferenciar del ejercido por el tamaño de la colonia. Se discute tambiĂ©n la influencia potencial de otros parámetros que no se han tenido en cuenta en este estudio
A novel tool to predict food intake: The Visual Meal Creator
Subjective appetite is commonly measured using an abstract visual analogue scale (VAS) technique, that provides no direct information about desired portion size or food choice. The purpose of this investigation was to develop and validate a user-friendly tool – the Visual Meal Creator (VIMEC) – that would allow for independent, repeated measures of subjective appetite and provide a prediction of food intake. Twelve participants experienced dietary control over a 5-hour period to manipulate hunger state on three occasions (small breakfast (SB) vs. large breakfast (LB) vs. large breakfast + snacks (LB+S)). Appetite measures were obtained every 60 minutes using the VIMEC and VAS. At 4.5 hours, participants were presented with an ad libitum test meal, from which energy intake (EI) was measured. The efficacy of the VIMEC was assessed by its ability to detect expected patterns of appetite and its strength as a predictor of energy intake. Day-to-day reproducibility and test-retest repeatability were assessed. Between- and within-condition differences in VAS and VIMEC scores (represented as mm and kcal of the “created” meal, respectively) were significantly correlated with one another throughout. Between- and within-condition changes in appetite scores obtained with the VIMEC exhibited a stronger correlation with EI at the test meal than those obtained with VAS. Pearson correlation coefficients for within-condition comparisons were 0.951, 0.914 and 0.875 (all p < 0.001) for SB, LB and LB+S respectively. Correlation coefficients for between-condition differences in VIMEC and EI were 0.273, 0.940 (p < 0.001) and 0.525 (p < 0.05) for SB – LB+S, SB – LB and LB – LB+S respectively. The VIMEC exhibited a similar degree of reproducibility to VAS. These findings suggest that the VIMEC appears to be a stronger predictor of energy intake than VAS
Implantable cardioverter defibrillator therapy for primary prevention of sudden cardiac death in the real world: Main findings from the French multicentre DAI-PP programme (pilot phase)
This review summarizes the main findings of the French multicentre DAI-PP pilot programme, and discusses the related clinical and research perspectives. This project included retrospectively (2002–2012 period) more than 5000 subjects with structural heart disease who received an implantable cardioverter defibrillator (ICD) for primary prevention of sudden cardiac death, and were followed for a mean period of 3 years. The pilot phase of the DAI-PP programme has provided valuable information on several practical and clinically relevant aspects of primary prevention ICD implantation in the real-world population, which are summarized in this review. This pilot has led to a prospective evaluation that started in May 2018, assessing ICD therapy in primary and secondary prevention in patients with structural and electrical heart diseases, with remote monitoring follow-up using a dedicated platform. This should further enhance our understanding of sudden cardiac death, to eventually optimize the field of preventative actions
Botulinum toxin in gastric submucosa reduces stimulated HCl production in rats
BACKGROUND: Botulinum toxin blocks acetylcholine release from nerve endings and acts as a long term, reversible inhibitor of muscle contraction as well as of salivary, sweat gland, adrenal and prostatic secretions. The aim of the present study is to investigate whether gastric submucosal injection of botulinum toxin type A reduces stimulated gastric production of HCl. METHODS: Sixty-four rats were randomized in two groups and laparotomized. One group was treated with botulinum toxin-A 10 U by multiple submucosal gastric injections, while the second group was injected with saline. Two weeks later, acid secretion was stimulated by pyloric ligation and acid output was measured. Body weight, food and water intake were also recorded daily. RESULTS: HCl production after pyloric ligation was found to be significantly lower in botulinum toxin-treated rats (657 ± 90.25 micromol HCl vs. 1247 ± 152. P = 0.0017). Botulinum toxin-treated rats also showed significantly lower food intake and weight gain. CONCLUSIONS: Botulinum toxin type A reduces stimulated gastric acidity. This is likely due either to inhibition of the cholinergic stimulation of gastric parietal cells, or to an action on the myenteric nervous plexuses. Reduction of growth and food intake may reflect both impaired digestion and decreased gastric motility
Allosteric modulation of AMPA-type glutamate receptors increases activity of the promoter for the neural cell adhesion molecule, N-CAM
Embryonic Stem Cell-Derived L1 Overexpressing Neural Aggregates Enhance Recovery after Spinal Cord Injury in Mice
An obstacle to early stem cell transplantation into the acutely injured spinal cord is poor survival of transplanted cells. Transplantation of embryonic stem cells as substrate adherent embryonic stem cell-derived neural aggregates (SENAs) consisting mainly of neurons and radial glial cells has been shown to enhance survival of grafted cells in the injured mouse brain. In the attempt to promote the beneficial function of these SENAs, murine embryonic stem cells constitutively overexpressing the neural cell adhesion molecule L1 which favors axonal growth and survival of grafted and imperiled cells in the inhibitory environment of the adult mammalian central nervous system were differentiated into SENAs and transplanted into the spinal cord three days after compression lesion. Mice transplanted with L1 overexpressing SENAs showed improved locomotor function when compared to mice injected with wild-type SENAs. L1 overexpressing SENAs showed an increased number of surviving cells, enhanced neuronal differentiation and reduced glial differentiation after transplantation when compared to SENAs not engineered to overexpress L1. Furthermore, L1 overexpressing SENAs rescued imperiled host motoneurons and parvalbumin-positive interneurons and increased numbers of catecholaminergic nerve fibers distal to the lesion. In addition to encouraging the use of embryonic stem cells for early therapy after spinal cord injury L1 overexpression in the microenvironment of the lesioned spinal cord is a novel finding in its functions that would make it more attractive for pre-clinical studies in spinal cord regeneration and most likely other diseases of the nervous system
The proteasome inhibitor MG-132 sensitizes PC-3 prostate cancer cells to ionizing radiation by a DNA-PK-independent mechanism
BACKGROUND: By modulating the expression levels of specific signal transduction molecules, the 26S proteasome plays a central role in determining cell cycle progression or arrest and cell survival or death in response to stress stimuli, including ionizing radiation. Inhibition of proteasome function by specific drugs results in cell cycle arrest, apoptosis and radiosensitization of many cancer cell lines. This study investigates whether there is also a concomitant increase in cellular radiosensitivity if proteasome inhibition occurs only transiently before radiation. Further, since proteasome inhibition has been shown to activate caspase-3, which is involved in apoptosis, and caspase-3 can cleave DNA-PKcs, which is involved in DNA-double strand repair, the hypothesis was tested that caspase-3 activation was essential for both apoptosis and radiosensitization following proteasome inhibition. METHODS: Prostate carcinoma PC-3 cells were treated with the reversible proteasome inhibitor MG-132. Cell cycle distribution, apoptosis, caspase-3 activity, DNA-PKcs protein levels and DNA-PK activity were monitored. Radiosensitivity was assessed using a clonogenic assay. RESULTS: Inhibition of proteasome function caused cell cycle arrest and apoptosis but this did not involve early activation of caspase-3. Short-time inhibition of proteasome function also caused radiosensitization but this did not involve a decrease in DNA-PKcs protein levels or DNA-PK activity. CONCLUSION: We conclude that caspase-dependent cleavage of DNA-PKcs during apoptosis does not contribute to the radiosensitizing effects of MG-132
Device complications with addition of defibrillation to cardiac resynchronisation therapy for primary prevention
Objective: In patients indicated for cardiac resynchronisation therapy (CRT), the choice between a CRT-pacemaker (CRT-P) versus defibrillator (CRT-D) remains controversial and indications in this setting have not been well delineated. Apart from inappropriate therapies, which are inherent to the presence of a defibrillator, whether adding defibrillator to CRT in the primary prevention setting impacts risk of other acute and late device-related complications has not been well studied and may bear relevance for device selection. //
Methods: Observational multicentre European cohort study of 3008 consecutive patients with ischaemic or non-ischaemic dilated cardiomyopathy and no history of sustained ventricular arrhythmias, undergoing CRT implantation with (CRT-D, n=1785) or without (CRT-P, n=1223) defibrillator. Using propensity score and competing risk analyses, we assessed the risk of significant device-related complications requiring surgical reintervention. Inappropriate shocks were not considered except those due to lead malfunction requiring lead revision. //
Results: Acute complications occurred in 148 patients (4.9%), without significant difference between groups, even after considering potential confounders (OR=1.20, 95% CI 0.72 to 2.00, p=0.47). During a mean follow-up of 41.4±29 months, late complications occurred in 475 patients, giving an annual incidence rate of 26 (95% CI 9 to 43) and 15 (95% CI 6 to 24) per 1000 patient-years in CRT-D and CRT-P patients, respectively. CRT-D was independently associated with increased occurrence of late complications (HR=1.68, 95% CI 1.27 to 2.23, p=0.001). In particular, when compared with CRT-P, CRT-D was associated with an increased risk of device-related infection (HR 2.10, 95% CI 1.18 to 3.45, p=0.004). Acute complications did not predict overall late complications, but predicted device-related infection (HR 2.85, 95% CI 1.71 to 4.56, p<0.001). //
Conclusions: Compared with CRT-P, CRT-D is associated with a similar risk of periprocedural complications but increased risk of long-term complications, mainly infection. This needs to be considered in the decision of implanting CRT with or without a defibrillator
The Caenorhabditis elegans Elongator Complex Regulates Neuronal α-tubulin Acetylation
Although acetylated α-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate α-tubulin acetylation are, to date, largely unknown. Therefore, a genetic screen was employed in the nematode Caenorhabditis elegans that identified the Elongator complex as a possible regulator of α-tubulin acetylation. Detailed characterization of mutant animals revealed that the acetyltransferase activity of the Elongator is indeed required for correct acetylation of microtubules and for neuronal development. Moreover, the velocity of vesicles on microtubules was affected by mutations in Elongator. Elongator mutants also displayed defects in neurotransmitter levels. Furthermore, acetylation of α-tubulin was shown to act as a novel signal for the fine-tuning of microtubules dynamics by modulating α-tubulin turnover, which in turn affected neuronal shape. Given that mutations in the acetyltransferase subunit of the Elongator (Elp3) and in a scaffold subunit (Elp1) have previously been linked to human neurodegenerative diseases, namely Amyotrophic Lateral Sclerosis and Familial Dysautonomia respectively highlights the importance of this work and offers new insights to understand their etiology
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