439 research outputs found
Topological Analysis of Metabolic Networks Integrating Co-Segregating Transcriptomes and Metabolomes in Type 2 Diabetic Rat Congenic Series
Background: The genetic regulation of metabolic phenotypes (i.e., metabotypes) in type 2 diabetes mellitus is caused by complex organ-specific cellular mechanisms contributing to impaired insulin secretion and insulin resistance. Methods: We used systematic metabotyping by 1H NMR spectroscopy and genome-wide gene expression in white adipose tissue to map molecular phenotypes to genomic blocks associated with obesity and insulin secretion in a series of rat congenic strains derived from spontaneously diabetic Goto-Kakizaki (GK) and normoglycemic Brown-Norway (BN) rats. We implemented a network biology strategy approach to visualise shortest paths between metabolites and genes significantly associated with each genomic block. Results: Despite strong genomic similarities (95-99%) among congenics, each strain exhibited specific patterns of gene expression and metabotypes, reflecting metabolic consequences of series of linked genetic polymorphisms in the congenic intervals. We subsequently used the congenic panel to map quantitative trait loci underlying specific metabotypes (mQTL) and genome-wide expression traits (eQTL). Variation in key metabolites like glucose, succinate, lactate or 3-hydroxybutyrate, and second messenger precursors like inositol was associated with several independent genomic intervals, indicating functional redundancy in these regions. To navigate through the complexity of these association networks we mapped candidate genes and metabolites onto metabolic pathways and implemented a shortest path strategy to highlight potential mechanistic links between metabolites and transcripts at colocalized mQTLs and eQTLs. Minimizing shortest path length drove prioritization of biological validations by gene silencing. Conclusions: These results underline the importance of network-based integration of multilevel systems genetics datasets to improve understanding of the genetic architecture of metabotype and transcriptomic regulations and to characterize novel functional roles for genes determining tissue-specific metabolism
Heat shock protein amplification improves cerebellar myelination in the Npc1nih mouse model.
BACKGROUND: Niemann-Pick disease type C (NPC) is a rare prematurely fatal lysosomal lipid storage disease with limited therapeutic options. The prominent neuropathological hallmarks include hypomyelination and cerebellar atrophy. We previously demonstrated the efficacy of recombinant human heat shock protein 70 (rhHSP70) in preclinical models of the disease. It reduced glycosphingolipid levels in the central nervous system (CNS), improving cerebellar myelination and improved behavioural phenotypes in Npc1nih (Npc1-/-) mice. Furthermore, treatment with arimoclomol, a well-characterised HSP amplifier, attenuated lysosomal storage in NPC patient fibroblasts and improved neurological symptoms in Npc1-/- mice. Taken together, these findings prompted the investigation of the effects of HSP amplification on CNS myelination. METHODS: We administered bimoclomol daily or rhHSP70 6 times per week to Npc1-/- (BALB/cNctr-Npc1m1N/J, also named Npc1nih) mice by intraperitoneal injection from P7 through P34 to investigate the impact on CNS myelination. The Src-kinase inhibitor saracatinib was administered with/without bimoclomol twice daily to explore the contribution of Fyn kinase to bimoclomol's effects. FINDINGS: Treatment with either bimoclomol or rhHSP70 improved myelination and increased the numbers of mature oligodendrocytes (OLs) as well as the ratio of active-to-inactive forms of phosphorylated Fyn kinase in the cerebellum of Npc1-/- mice. Additionally, treatment with bimoclomol preserved cerebellar weight, an effect that was abrogated when co-administered with saracatinib, an inhibitor of Fyn kinase. Bimoclomol-treated mice also exhibited increased numbers of immature OLs within the cortex. INTERPRETATION: These data increase our understanding of the mechanisms by which HSP70 regulates myelination and provide further support for the clinical development of HSP-amplifying therapies in the treatment of NPC. FUNDING: Funding for this study was provided by Orphazyme A/S (Copenhagen, Denmark) and a Pathfinder Award from The Wellcome Trust
Unbiased yeast screens identify cellular pathways affected in Niemann-Pick disease type C
Niemann–Pick disease type C (NPC) is a rare lysosomal storage
disease caused by mutations in either the NPC1 or NPC2 genes.
Mutations in the NPC1 gene lead to the majority of clinical cases
(95%); however, the function of NPC1 remains unknown. To gain
further insights into the biology of NPC1, we took advantage of
the homology between the human NPC1 protein and its yeast
orthologue, Niemann–Pick C–related protein 1 (Ncr1). We recreated the NCR1 mutant in yeast and performed screens to identify
compensatory or redundant pathways that may be involved in
NPC pathology, as well as proteins that were mislocalized in
NCR1-deficient yeast. We also identified binding partners of the
yeast Ncr1 orthologue. These screens identified several processes
and pathways that may contribute to NPC pathogenesis. These
included alterations in mitochondrial function, cytoskeleton
organization, metal ion homeostasis, lipid trafficking, calcium
signalling, and nutrient sensing. The mitochondrial and cytoskeletal abnormalities were validated in patient cells carrying
mutations in NPC1, confirming their dysfunction in NPC disease
Orodispersible tablets: therapeutic and technological advantages of development
Los comprimidos bucodispersables se definen como comprimidos no recubiertos destinados a ser colocados en la boca, donde se dispersan rápidamente antes de ser tragados. Estas formulaciones son conocidas por las siglas FDDT´s (Fast Dissolving Disintegrating Tablets). Son Ăştiles para la administraciĂłn a pacientes con dificultades en la degluciĂłn, presentan una elevada aceptaciĂłn por parte del paciente, mejoran de la biodisponibilidad del principio activo y suponen una nueva alternativa para la industria farmacĂ©utica. Dentro de sus inconvenientes destacan el poco conocimiento por parte del paciente, la baja resistencia mecánica, su mayor susceptibilidad a la degradaciĂłn por temperatura y humedad; la falta, a veces, de bioequivalencia con las formulaciones convencionales, y la dificultad de obtener liberaciones prolongadas o retardadas del principio activo.A nivel tecnolĂłgico, existen varios procesos que se pueden aplicar en su elaboraciĂłn. Con los mĂ©todos clásicos de elaboraciĂłn de comprimidos, mediante la correcta selecciĂłn de los excipientes y de las variables de la etapa de compresiĂłn se obtienen unos comprimidos en los que existe un equilibrio entre dureza y disgregaciĂłn. Han surgido una serie de tecnologĂas novedosas: Flashtab, Wowtab, Orasolv y Durasolv. Otra opciĂłn es el empleo de tĂ©cnicas de liofilizaciĂłn, aunque presenta como desventaja su alto coste. Algunas tecnologĂas especiales patentadas como son Lyoc, QuickSolv y Zydis. Por Ăşltimo, estos comprimidos se pueden elaborar por el mĂ©todo de los polĂmeros entrecruzados, tambiĂ©n conocido como FlashDose y se basa en la formaciĂłn de una matriz de hilos de azĂşcares entrelazados.The orally disintegrating tablets are defined as non-coated tablets intended to be placed in the mouth where they disperse rapidly before being swallowed. These formulations are known by the acronym FDDT's (Fast Dissolving Disintegrating Tablets). They are useful for administration to patients with swallowing difficulties, have a high acceptance by the patient, improve bioavailability of the active ingredient and represent a new alternative for the pharmaceutical industry. Among its disadvantages include limited knowledge by the patient, low mechanical strength, increased susceptibility to degradation by temperature and humidity; lack sometimes bioequivalence with conventional formulations, and the difficulty of obtaining prolonged release or delayed active ingredient. At the technological level, there are several processes that can be applied in their preparation. With classical methods of tabletting, by proper selection of excipients and the variables of the compression stage a tablet in which there is a balance between hardness and disintegration are obtained. Flashtab, Wowtab, Orasolv and Durasolv: They have a number of new technologies emerged. Another option is the use of freeze drying techniques, but has the disadvantage of its high cost. Some special patented technologies such as Lyoc, QuickSolv and Zydis. Finally, these tablets may be made by the method of Crosslinked polymers, also known as FlashDose and is based on the formation of a matrix of interwoven threads sugars
Unusual presentation of cactus spines in the flank of an elderly man: a case report
<p>Abstract</p> <p>Introduction</p> <p>Splinters and spines of plant matter are common foreign bodies in skin wounds of the extremities, and often present embedded in the dermis or subcutaneous tissue. Vegetative foreign bodies are highly inflammatory and, if not completely removed, can cause infection, toxic reactions, or granuloma formation. Older patients are at increased risk for infection from untreated plant foreign bodies. The most common error in plant splinter and spine management is failure to detect their presence.</p> <p>Case presentation</p> <p>Here we report a case of cactus spines in an 84-year-old Caucasian man presenting on the right flank as multiple, red papules with spiny extensions. This presentation was unusual both in location and the spinous character of the lesions, and only after punch biopsy analysis was a diagnosis of cactus matter spines made.</p> <p>Conclusions</p> <p>Our patient presented with an unusual case of cactus spines that required histopathology for identification. Skin lesions with neglected foreign bodies are a common cause of malpractice claims. If not removed, foreign bodies of the skin, particularly in elderly individuals, can result in inflammatory and infectious sequela. This report underscores the importance of thoroughly evaluating penetrating skin lesions for the presence of foreign bodies, such as splinters and spines.</p
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4D printing: processability and measurement of recovery force in shape memory polymers
BAE Systems Applied Intelligence (UK); Defence Science and Technology Laboratory (UK
First evidence for Wollemi Pine-type pollen (Dilwynites: Araucariaceae) in South America
We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America.Mike Macphail, Raymond J. Carpenter, Ari Iglesias, Peter Wil
International Veterinary Epilepsy Task Force recommendations for systematic sampling and processing of brains from epileptic dogs and cats
Traditionally, histological investigations of the epileptic brain are required to identify epileptogenic brain lesions, to evaluate the impact of seizure activity, to search for mechanisms of drug-resistance and to look for comorbidities. For many instances, however, neuropathological studies fail to add substantial data on patients with complete clinical work-up. This may be due to sparse training in epilepsy pathology and or due to lack of neuropathological guidelines for companion animals.
The protocols introduced herein shall facilitate systematic sampling and processing of epileptic brains and therefore increase the efficacy, reliability and reproducibility of morphological studies in animals suffering from seizures.
Brain dissection protocols of two neuropathological centres with research focus in epilepsy have been optimised with regards to their diagnostic yield and accuracy, their practicability and their feasibility concerning clinical research requirements.
The recommended guidelines allow for easy, standardised and ubiquitous collection of brain regions, relevant for seizure generation. Tissues harvested the prescribed way will increase the diagnostic efficacy and provide reliable material for scientific investigations
Positive psychology of Malaysian students: impacts of engagement, motivation, self-compassion and wellbeing on mental health
Malaysia plays a key role in education of the Asia Pacific, expanding its scholarly output rapidly. However, mental health of Malaysian students is challenging, and their help-seeking is low because of stigma. This study explored the relationships between mental health and positive psychological constructs (academic engagement, motivation, self-compassion, and wellbeing), and evaluated the relative contribution of each positive psychological construct to mental health in Malaysian students. An opportunity sample of 153 students completed the measures regarding these constructs. Correlation, regression, and mediation analyses were conducted. Engagement, amotivation, self-compassion, and wellbeing were associated with, and predicted large variance in mental health. Self-compassion was the strongest independent predictor of mental health among all the positive psychological constructs. Findings can imply the strong links between mental health and positive psychology, especially selfcompassion. Moreover, intervention studies to examine the effects of self-compassion training on mental health of Malaysian students appear to be warranted.N/
Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model
Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures
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