623 research outputs found
Superspreading: Mechanisms and Molecular Design
The
intriguing ability of certain surfactant molecules to drive
the superspreading of liquids to complete wetting on hydrophobic substrates
is central to numerous applications that range from coating flow technology
to enhanced oil recovery. Despite significant experimental efforts,
the precise mechanisms underlying superspreading remain unknown to
date. Here, we isolate these mechanisms by analyzing coarse-grained
molecular dynamics simulations of surfactant molecules of varying
molecular architecture and substrate affinity. We observe that for
superspreading to occur, two key conditions must be simultaneously
satisfied: the adsorption of surfactants from the liquid–vapor
surface onto the three-phase contact line augmented by local bilayer
formation. Crucially, this must be coordinated with the rapid replenishment
of liquid–vapor and solid–liquid interfaces with surfactants
from the interior of the droplet. This article also highlights and
explores the differences between superspreading and conventional surfactants,
paving the way for the design of molecular architectures tailored
specifically for applications that rely on the control of wetting
International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe
In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible
The G67E mutation in hMLH1 is associated with an unusual presentation of Lynch syndrome
Germline mutations in the mismatch repair (MMR) genes are associated with Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC) syndrome. Here, we characterise a variant of hMLH1 that confers a loss-of-function MMR phenotype. The mutation changes the highly conserved Gly67 residue to a glutamate (G67E) and is reminiscent of the hMLH1-p.Gly67Arg mutation, which is present in several Lynch syndrome cohorts. hMLH1-Gly67Arg has previously been shown to confer loss-of-function (Shimodaira et al, 1998), and two functional assays suggest that the hMLH1-Gly67Glu protein fails to sustain normal MMR functions. In the first assay, hMLH1-Gly67Glu abolishes the protein's ability to interfere with MMR in yeast. In the second assay, mutation of the analogous residue in yMLH1 (yMLH1-Gly64Glu) causes a loss-of-function mutator phenotype similar to yMLH1-Gly64Arg. Despite these molecular similarities, an unusual spectrum of tumours is associated with hMLH1-Gly67Glu, which is not typical of those associated with Lynch syndrome and differs from those found in families carrying the hMLH1-Gly67Arg allele. This suggests that hMLH1 may have different functions in certain tissues and/or that additional factors may modify the influence of hMLH1 mutations in causing Lynch syndrome
Cdk5 Is Required for Memory Function and Hippocampal Plasticity via the cAMP Signaling Pathway
Memory formation is modulated by pre- and post-synaptic signaling events in neurons. The neuronal protein kinase Cyclin-Dependent Kinase 5 (Cdk5) phosphorylates a variety of synaptic substrates and is implicated in memory formation. It has also been shown to play a role in homeostatic regulation of synaptic plasticity in cultured neurons. Surprisingly, we found that Cdk5 loss of function in hippocampal circuits results in severe impairments in memory formation and retrieval. Moreover, Cdk5 loss of function in the hippocampus disrupts cAMP signaling due to an aberrant increase in phosphodiesterase (PDE) proteins. Dysregulation of cAMP is associated with defective CREB phosphorylation and disrupted composition of synaptic proteins in Cdk5-deficient mice. Rolipram, a PDE4 inhibitor that prevents cAMP depletion, restores synaptic plasticity and memory formation in Cdk5-deficient mice. Collectively, our results demonstrate a critical role for Cdk5 in the regulation of cAMP-mediated hippocampal functions essential for synaptic plasticity and memory formation.Norman B. Leventhal FellowshipUnited States. National Institutes of Health (NIH T32 MH074249)United States. National Institutes of Health (NIH RO1 NS051874
Allergen specificity of early peanut consumption and effect on development of allergic disease in the Learning Early About Peanut Allergy study cohort
BACKGROUND: Early introduction of dietary peanut in high-risk infants with severe eczema, egg allergy, or both prevented peanut allergy at 5 years of age in the Learning Early About Peanut Allergy (LEAP) study. The protective effect persisted after 12 months of avoiding peanuts in the 12-month extension of the LEAP study (LEAP-On). It is unclear whether this benefit is allergen and allergic disease specific. Objective: We sought to assess the effect of early introduction of peanut on the development of allergic disease, food sensitization, and aeroallergen sensitization. METHODS: Asthma, eczema, and rhinoconjunctivitis were diagnosed based on clinical assessment. Reported allergic reactions and consumption of tree nuts and sesame were recorded by questionnaire. Sensitization to food allergens and aeroallergens was determined by means of skin prick testing and specific IgE measurement. RESULTS: A high and increasing burden of food allergen and aeroallergen sensitization and allergic disease was noted across study time points; 76% of LEAP participants had at least 1 allergic disease at 60 months of age. There were no differences in allergic disease between LEAP groups. There were small differences in sensitization and reported allergic reactions for select tree nuts, with levels being higher in the LEAP consumption group. Significant resolution of eczema and sensitization to egg and milk occurred in LEAP participants and was not affected by peanut consumption. CONCLUSION: Early consumption of peanut in infants at high risk of peanut allergy is allergen specific and does not prevent the development of other allergic disease, sensitization to other food allergens and aeroallergens, or reported allergic reactions to tree nuts and sesame. Furthermore, peanut consumption does not hasten the resolution of eczema or egg allergy
A hippocampal Cdk5 pathway regulates extinction of contextual fear
Treatment of emotional disorders involves the promotion of extinction processes, which are defined as the learned reduction of fear. The molecular mechanisms underlying extinction have only begun to be elucidated. By employing genetic and pharmacological approaches in mice, we show here that extinction requires downregulation of Rac-1 and cyclin-dependent kinase 5 (Cdk5), and upregulation of p21 activated kinase-1 (PAK-1) activity. This is physiologically achieved by a Rac-1–dependent relocation of the Cdk5 activator p35 from the membrane to the cytosol and dissociation of p35 from PAK-1. Moreover, our data suggest that Cdk5/p35 activity prevents extinction in part by inhibition of PAK-1 activity in a Rac-1–dependent manner. We propose that extinction of contextual fear is regulated by counteracting components of a molecular pathway involving Rac-1, Cdk5 and PAK-1. Our data suggest that this pathway could provide a suitable target for therapeutic treatment of emotional disorders.National Institutes of Health (U.S.) (Grant NS051874)Alexander von Humboldt-Stiftung (German Research Foundation Fellowship)European Neuroscience Institute Goettinge
Control of the Respiratory Diseases in a Pig Herd Using Data of the Respiratory Organs Examination of Fattening Pigs at a Slaughterhouse
In everyday farming practice, assessment of economical impact of respiratory diseases at herd level relies on the following information: data records on the diseases within the herd, productivity and slaughterhouse records. The data available from the slaughterhouse encompass the number and percentage of low weight pigs, number of diseased animals, the severity of lesions observed at slaughter as well as the amount of discarded organs and carcasses. The aim of this investigation is to improve the assessment of health status of pigs at herd level and design programs for the control of respiratory syndrome in swine based on the analysis of the data collected at slaughter line. In the slaughterhouse, the thoracic cavity organs from 105 fatlings that have reached the slaughter body mass, 20 underweight fatlings and 20 underdeveloped piglets were examined. The weight of both half-carcasses was measured. Tissue samples of altered organs (lungs, mediastinal lympho nodes, tonsils) were collected and subjected to bacteriological analysis. The average weight of both half-carcasses was 81.54kg in fatteners with full slaughter body mass, and 58.29kg and 14.95kg in low-weight fatlings and piglets, respectively. Changes affecting 10% of lung tissue were established in 9 animals, 11-20% in 10 and 21-32% in 10 fatlings. Pathological process is characterized by hepatization of lung tissue, inflammation of the pleura or, even more frequently, adhesions between the visceral and parietal pleura and pericardium. In underweight fatlings, the rates of lung changes were 20% in 5, 11-30% in 3, 40% in 4, and 40% in 6 animals. Applying bacteriological testing, the following microorganisms were isolated: Haemophilus parasuis, Arcanobacterium pyogenes, and Pasteurella multocida. The examination performed at the slaughter line strongly suggested the necessity of designing a new, updated vaccination program taking into consideration the causative agents and vaccination schedule
Hypericum sp.: essential oil composition and biological activities
Phytochemical composition of Hypericum
genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced
by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization
as well as biological activities of H. perforatum
crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett
in Nat Prod Commun 5(9):1493–1506, 2010;
Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/
13283/2003
Swine Dysentery: Practical Observations, Control And Diagnostics
Swine dysentery is a severe mucohemorrhagic enteric disease of pigs which has a large impact on pig production, with important losses caused by mortality and suboptimal performance. The causative agent is Brachyspirahyodysenteriae. The aim of the paper was to evaluate all the available data on B. hyodysenteriae presence on swine farms in Vojvodina region. The material for this research included five swine farms, where certain disorders and health problems in weaned, grower and fattening pigs were detected. Depending on the specificity of each evaluated case and available material, the applied research methods included: anamnestical and clinical evaluation, gross pathological examination, standard bacteriological testing for detection of the presence of aerobic and anaerobic bacteria in the tissue samples derived from diseased and/or died pigs. Besides this, in some cases the molecular diagnostic method (RT-PCR) was included. Swine dysentery is a common and important endemic problem in many swine farms in Vojvodina. On endemically infected swine farms transmission mainly occurs by ingestion of infected faeces. All the observed factors affecting disease persistence and transmission on the farm are thoroughly analysed and discussed. Finally, current prophylactic and therapeutic approaches to fight against disease are described
Comparison of a Label-Free Quantitative Proteomic Method Based on Peptide Ion Current Area to the Isotope Coded Affinity Tag Method
Recently, several research groups have published methods for the determination of proteomic expression profiling by mass spectrometry without the use of exogenously added stable isotopes or stable isotope dilution theory. These so-called label-free, methods have the advantage of allowing data on each sample to be acquired independently from all other samples to which they can later be compared in silico for the purpose of measuring changes in protein expression between various biological states. We developed label free software based on direct measurement of peptide ion current area (PICA) and compared it to two other methods, a simpler label free method known as spectral counting and the isotope coded affinity tag (ICAT) method. Data analysis by these methods of a standard mixture containing proteins of known, but varying, concentrations showed that they performed similarly with a mean squared error of 0.09. Additionally, complex bacterial protein mixtures spiked with known concentrations of standard proteins were analyzed using the PICA label-free method. These results indicated that the PICA method detected all levels of standard spiked proteins at the 90% confidence level in this complex biological sample. This finding confirms that label-free methods, based on direct measurement of the area under a single ion current trace, performed as well as the standard ICAT method. Given the fact that the label-free methods provide ease in experimental design well beyond pair-wise comparison, label-free methods such as our PICA method are well suited for proteomic expression profiling of large numbers of samples as is needed in clinical analysis
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