Luis Federico Batiz
Full Text Available Adult neurogenesis has been convincingly demonstrated in two regions of the mammalian brain: the sub-granular zone (SGZ of the dentate gyrus (DG in the hippocampus, and the sub-ventricular zone (SVZ of the lateral ventricles. SGZ newborn neurons are destined to the granular cell layer of the DG, while new neurons from the SVZ neurons migrate rostrally into the olfactory bulb. The process of adult neurogenesis persists throughout life and is supported by a pool of neural stem cells (NSCs, which reside in a unique and specialized microenvironment known as neurogenic niche. Neurogenic niches are structured by a complex organization of different cell types, including the NSC-neuron lineage, glial cells and vascular cells. Thus, cell-to-cell communication plays a key role in the dynamic modulation of homeostasis and plasticity of the adult neurogenic process. Specific cell-cell contacts and extracellular signals originated locally provide the necessary support and regulate the balance between self-renewal and differentiation of NSCs. Furthermore, extracellular signals originated at distant locations, including other brain regions or systemic organs, may reach the niche through the cerebrospinal fluid or the vasculature and influence its nature. The role of several secreted molecules, such as cytokines, growth factors, neurotransmitters, and hormones, in the biology of adult NSCs, has been systematically addressed. Interestingly, in addition to these well-recognized signals, a novel type of intercellular messengers has been identified recently: the extracellular vesicles (EVs. EVs, and particularly exosomes, are implicated in the transfer of mRNAs, microRNAs (miRNAs, proteins and lipids between cells and thus are able to modify the function of recipient cells. Exosomes appear to play a significant role in different stem cell niches such as the mesenchymal stem cell niche, cancer stem cell niche and pre-metastatic niche; however, their roles in adult
Full Text Available When does adult hippocampal neurogenesis begin? We describe the development of the neurogenic niche in the subgranular zone (SGZ of the hippocampal dentate gyrus. We did so from the perspective of the situation in the adult.Ontogeny of the dentate gyrus is complex and results in an ectopic neurogenic niche that lifelong generates new granule cells. Neurogenesis during the fetal and early postnatal periods builds the dentate gyrus and gives way to activity-dependent adult neurogenesis. We used markers most relevant to adult neurogenesis research to describe this transition: Nestin, Sox2, BLBP, GFAP, Tbr2, Doublecortin (DCX, NeuroD1 and Prox1. We found that massive changes and a local condensation of proliferating precursor cells occurs between postnatal day 7 (P7, near the peak in proliferation, and P14. Before and around P7, the spatial distribution of cells and the co-localization of markers were distinct from the situation in the adult. Unlike the adult SGZ, the marker pair Nestin/Sox2 and the radial glial marker BLBP were not overlapping during embryonic development, presumably indicating different types of radial glia-like cells. Before P7 GFAP-positive cells in the hilus lacked the radial orientation that is characteristic of the adult type-1 cells. DCX, which is concentrated in type-2b and type-3 progenitor cells and early postmitotic neurons in the adult, showed diffuse expression before P7. Intermediate progenitor cell marker Tbr2 became restricted to the SGZ but was found in the granule cell layer and hilus before. Lineage markers NeuroD1 and Prox1 confirmed this pattern.We conclude that the neurogenic niche of adult neurogenesis is in place well before true adulthood. This might indicate that consistent with the hypothesized function of adult neurogenesis in activity-dependent plasticity, the early transition from postnatal neurogenesis to adult neurogenesis coincides with the time, when the young mice start to become active themselves.
Ali, Amira A H; Schwarz-Herzke, Beryl; Stahr, Anna; Prozorovski, Timour; Aktas, Orhan; von Gall, Charlotte
Hippocampal neurogenesis undergoes dramatic age-related changes. Mice with targeted deletion of the clock geneBmal1 (Bmal1(-/-)) show disrupted regulation of reactive oxygen species homeostasis, accelerated aging, neurodegeneration and cognitive deficits. As proliferation of neuronal progenitor/precursor cells (NPCs) is enhanced in young Bmal1(-/-) mice, we tested the hypothesis that this results in premature aging of hippocampal neurogenic niche in adult Bmal1(-/-) mice as compared to wildtype littermates. We found significantly reduced pool of hippocampal NPCs, scattered distribution, enhanced survival of NPCs and an increased differentiation of NPCs into the astroglial lineage at the expense of the neuronal lineage. Immunoreaction of the redox sensitive histone deacetylase Sirtuine 1, peroxisomal membrane protein at 70 kDa and expression of the cell cycle inhibitor p21(Waf1/CIP1) were increased in adult Bmal1(-/-) mice. In conclusion, genetic disruption of the molecular clockwork leads to accelerated age-dependent decline in adult neurogenesis presumably as a consequence of oxidative stress.
Michael R Foret
Full Text Available Histone 3 Lysine 9 (H3K9 methylation is known to be associated with pericentric heterochromatin and important in genomic stability. In this study, we show that trimethylation at H3K9 (H3K9me3 is enriched in an adult neural stem cell niche- the subventricular zone (SVZ on the walls of the lateral ventricle in both rodent and non-human primate baboon brain. Previous studies have shown that there is significant correlation between baboon and human regarding genomic similarity and brain structure, suggesting that findings in baboon are relevant to human. To understand the function of H3K9me3 in this adult neurogenic niche, we performed genome-wide analyses using ChIP-Seq (chromatin immunoprecipitation and deep-sequencing and RNA-Seq for in vivo SVZ cells purified from baboon brain. Through integrated analyses of ChIP-Seq and RNA-Seq, we found that H3K9me3-enriched genes associated with cellular maintenance, post-transcriptional and translational modifications, signaling pathways, and DNA replication are expressed, while genes involved in axon/neuron, hepatic stellate cell, or immune-response activation are not expressed. As neurogenesis progresses in the adult SVZ, cell fate restriction is essential to direct proper lineage commitment. Our findings highlight that H3K9me3 repression in undifferentiated SVZ cells is engaged in the maintenance of cell type integrity, implicating a role for H3K9me3 as an epigenetic mechanism to control cell fate transition within this adult germinal niche.
Adriano Barreto Nogueira
Full Text Available The subgranular zone (SGZ of the dentate gyrus and the subventricular zone (SVZ are known neurogenic niches in adult mammals. Nonetheless, the existence of neurogenic niches in adult humans is controversial. We hypothesized that mapping neurogenic niches in the human temporal lobe could clarify this issue. Neurogenic niches and neurogenesis were investigated in 28 temporal lobes via immunostaining for nestin and doublecortin (DCX, respectively. Nestin was observed in a continuous layer formed by the SVZ, the subpial zone of the medial temporal lobe and the SGZ, terminating in the subiculum. In the subiculum, remarkable DCX expression was observed through the principal efferent pathway of the hippocampus to the fimbria. A possible explanation for the results is that the SVZ, the subpial zone of the medial temporal lobe and the SGZ form a unit containing neural stem cells that differentiate into neurons in the subiculum. Curiously, the area previously identified as the human rostral migratory stream may in truth be the fornix, which contains axons that originate in the subiculum. This study suggests that neurogenesis may occur in an orchestrated manner in a broad area of the human temporal lobe.
Full Text Available The niche concept of stem cell biology proposes a functional unit between the precursor cells and their local microenvironment, to which several cell types might contribute by cell–cell contacts, extracellular matrix, and humoral factors. We here established three co-culture models (with cell types separated by membrane for both adherent monolayers and neurospheres to address the potential influence of different niche cell types in the neurogenic zone of the adult hippocampus of mice. Astrocytes and endothelial cells enhanced precursor cell proliferation and neurosphere formation. Endothelial factors also led to a prolonged increase in proliferation after growth factor withdrawal, which otherwise induces differentiation. All niche cell types enhanced cell survival in monolayer cultures, endothelial cells also stimulated neuronal differentiation. A parallel trend elicited by astrocytes did not reach conventional statistical significance. Pericytes had variable effects here. We did not observe changes in differentiation in neurosphere co-cultures. In summary, our data indicate that in precursor cell culture protocols survival could be improved by adding as yet unknown factors physiologically contributed by astrocytes and endothelial cells. Our findings also underscore the complexity of the niche and the differential impact of factors from the different sources on distinct aspects of neuronal development. With the help of the models presented here, identification of these factors and their specific biological activity can now be initiated.
Full Text Available Although therapeutic use of stem cells is already available in some tissues (cornea, blood, skin, in most organs we are far from reaching the translational goal of regenerative medicine. In the nervous system, due to intrinsic features which make it refractory to regeneration/repair,it is very hard to obtainfunctionally-integrated regenerative outcomes, evenstarting from its own stem cells(the neural stem cells; NSCs. Besides NSCs, mesenchymal stem cells (MSCs have also been proposed for therapeutic purposes in neurological diseases. Yet, direct (regenerative and indirect (bystander effects are often confused, as are MSCs and bone marrow-derived (stromal, osteogenic stem cells (BMSCs, whoseplasticity isactually overestimated (i.e. trans-differentiation along non-mesodermal lineages, including neural fates.In order to better understand failure in the regenerative use of stem cells for neurological disorders,it could be helpful to understand how NSCs and BMSCs have adapted to their respective organ niches. In this perspective, here the adult osteogenic and neurogenic niches are considered and compared within their in vivo environment.
Full Text Available Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer’s Disease, Parkinson’s Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have been explored. Stem cells, as well as most cells, release extracellular vesicles such as exosomes, which are nanovesicles able to target specific cell types and thus to modify their function by delivering proteins, lipids, and nucleic acids. Exosomes have recently been tested in vivo and in vitro as therapeutic conveyors for the treatment of diseases. As such, they could be engineered to target specific populations of cells within the CNS. Considering the fact that many degenerative brain diseases have an impact on adult neurogenesis, we discuss how the modulation of the adult neurogenic niches may be a therapeutic target of stem cell-derived exosomes. These novel approaches should be examined in cellular and animal models to provide better, more effective, and specific therapeutic tools in the future.
Full Text Available Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL12-abundant reticular (CAR cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs, which have been recently identified as neural crest-derived cells (NCSCs. Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-to-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.
Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard
Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC) function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL) 12-abundant reticular (CAR) cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs), which have been recently identified as neural crest-derived cells (NCSCs). Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.
Parolisi, Roberta; Cozzi, Bruno; Bonfanti, Luca
Adult neurogenesis has been implicated in brain plasticity and brain repair. In mammals, it is mostly restricted to specific brain regions and specific physiological functions. The function and evolutionary history of mammalian adult neurogenesis has been elusive so far. The largest neurogenic site in mammals (subventricular zone, SVZ) generates neurons destined to populate the olfactory bulb. The SVZ neurogenic activity appears to be related to the dependence of the species on olfaction since it occurs at high rates throughout life in animals strongly dependent on this function for their survival. Indeed, it dramatically decreases in humans, who do not depend so much on it. This study investigates whether the SVZ neurogenic site exists in mammals devoid of olfaction and olfactory brain structures, such as dolphins. Our results demonstate that a small SVZ-like region persists in these aquatic mammals. However, this region seems to have lost its neurogenic capabilities since neonatal stages. In addition, instead of the typical newly generated neuroblasts, some mature neurons were observed in the dolphin SVZ. Since cetaceans evolved from terrestrial ancestors, non-neurogenic SVZ may indicate extinction of adult neurogenesis in the absence of olfactory function, with the retention of an SVZ-like anatomical region either vestigial or of still unknown role.
Pastor, Patricia; Cisternas, Pedro; Salazar, Katterine; Silva-Alvarez, Carmen; Oyarce, Karina; Jara, Nery; Espinoza, Francisca; Martínez, Agustín D.; Nualart, Francisco
Known as a critical antioxidant, recent studies suggest that vitamin C plays an important role in stem cell generation, proliferation and differentiation. Vitamin C also enhances neural differentiation during cerebral development, a function that has not been studied in brain precursor cells. We observed that the rat neurogenic niche is structurally organized at day 15 of postnatal development, and proliferation and neural differentiation increase at day 21. In the human brain, a similar subventricular niche was observed at 1-month of postnatal development. Using immunohistochemistry, sodium-vitamin C cotransporter 2 (SVCT2) expression was detected in the subventricular zone (SVZ) and rostral migratory stream (RMS). Low co-distribution of SVCT2 and βIII-tubulin in neuroblasts or type-A cells was detected, and minimal co-localization of SVCT2 and GFAP in type-B or precursor cells was observed. Similar results were obtained in the human neurogenic niche. However, BrdU-positive cells also expressed SVCT2, suggesting a role of vitamin C in neural progenitor proliferation. Primary neurospheres prepared from rat brain and the P19 teratocarcinoma cell line, which forms neurospheres in vitro, were used to analyze the effect of vitamin C in neural stem cells. Both cell types expressed functional SVCT2 in vitro, and ascorbic acid (AA) induced their neural differentiation, increased βIII-tubulin and SVCT2 expression, and amplified vitamin C uptake. PMID:23964197
Brenneis, Georg; Scholtz, Gerhard
Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i) immunolabeling, (ii) histology and (iii) scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida), the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions - traditionally designated as 'ventral organs' - detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult) replenishment of olfactory neurons - as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two transient posterior
Full Text Available Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i immunolabeling, (ii histology and (iii scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida, the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions - traditionally designated as 'ventral organs' - detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult replenishment of olfactory neurons - as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two
Full Text Available Neural stem cells (NSCs and mesenchymal stem cells (MSCs share few characteristics apart from self-renewal and multipotency. In fact, the neurogenic and osteogenic stem cell niches derive from two distinct embryonary structures; while the later originates from the mesoderm, as all the connective tissues do, the first derives from the ectoderm. Therefore, it is highly unlikely that stem cells isolated from one niche could form terminally differentiated cells from the other. Additionally, these two niches are associated to tissues/systems (e.g bone and central nervous system that have markedly different needs and display diverse functions within the human body. Nevertheless they do share common features. For instance, the differentiation of both NSCs and MSCs is intimately associated with the bone morphogenetic protein family. Moreover, both NSCs and MSCs secrete a panel of common growth factors, such as nerve growth factor (NGF, glial derived neurotrophic factor (GDNF, and brain derived neurotrophic factor (BDNF, among others. But it is not the features they share but the interaction between them that seem most important, and worth exploring; namely, it has already been shown that there are mutually beneficially effects when these cell types are co-cultured in vitro. In fact the use of MSCs, and their secretome, become a strong candidate to be used as a therapeutic tool for CNS applications, namely by triggering the endogenous proliferation and differentiation of neural progenitors, among other mechanisms. Quite interestingly it was recently revealed that MSCs could be found in the human brain, in the vicinity of capillaries. In the present review we highlight how MSCs and NSCs in the neurogenic niches interact. Furthermore, we propose directions on this field and explore the future therapeutic possibilities that may arise from the combination/interaction of MSCs and NSCs.
Vanessa de Oliveira-Carlos
Full Text Available The adult zebrash brain has a remarkable constitutive neurogenic capacity. The regulation and maintenance of its adult neurogenic niches are poorly understood. In mammals, Notch signaling is involved in stem cell maintenance both in embryonic and adult CNS. To better understand how Notch signaling is involved in stem cell maintenance during adult neurogenesis in zebrafish we analysed Notch receptor expression in five neurogenic zones of the adult zebrafish brain. Combining proliferation and glial markers we identified several subsets of Notch receptor expressing cells. We found that 90 [Formula: see text] of proliferating radial glia express notch1a, notch1b and notch3. In contrast, the proliferating non-glial populations of the dorsal telencephalon and hypothalamus rarely express notch3 and about half express notch1a/1b. In the non-proliferating radial glia notch3 is the predominant receptor throughout the brain. In the ventral telencephalon and in the mitotic area of the optic tectum, where cells have neuroepithelial properties, notch1a/1b/3 are expressed in most proliferating cells. However, in the cerebellar niche, although progenitors also have neuroepithelial properties, only notch1a/1b are expressed in a high number of PCNA [Formula: see text] cells. In this region notch3 expression is mostly in Bergmann glia and at low levels in few PCNA [Formula: see text] cells. Additionally, we found that in the proliferation zone of the ventral telencephalon, Notch receptors display an apical high to basal low gradient of expression. Notch receptors are also expressed in subpopulations of oligodendrocytes, neurons and endothelial cells. We suggest that the partial regional heterogeneity observed for Notch expression in progenitor cells might be related to the cellular diversity present in each of these neurogenic niches.
Brenneis, Georg; Scholtz, Gerhard
Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i) immunolabeling, (ii) histology and (iii) scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida), the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions – traditionally designated as ‘ventral organs’ – detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult) replenishment of olfactory neurons – as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two transient
Gao, Chong; Wang, Qi; Chung, Sookja K; Shen, Jiangang
Metabolic disorders like diabetes and obesity are commonly companied with neurological diseases and psychiatric disorders. Accumulating evidences indicated that cellular metabolic factors affect adult neurogenesis and have modulating effects on neurodegenerative disorders and psychiatric diseases. Adult neurogenesis contains multiple steps including proliferation of neural stem cells, lineage commitments of neural progenitor cells, maturation into functional neurons, and integration into neuronal network. Many intrinsic and extrinsic factors produced from neural stem/progenitor cells and their microenvironment or neurogenic niche take roles in modulating neurogenesis and contribute to the brain repair and functional recoveries in many neurological diseases and psychiatric disorders. In this article, we review current progress about how different growth factors, neurotrophin, neurotransmitters and transcriptional factors work on regulating neurogenic process. In particular, we emphasize the roles of the cellular metabolic factors, such as insulin/IGF signaling, incretins, and lipid metabolic signaling molecules in modulating adult neurogenesis, and discuss their impacts on neurological behaviors. We propose that the metabolic factors could be the new therapeutic targets for adult neurogenesis. Plus, the metabolism-regulating drugs have the potentials for treatment of neurodegenerative diseases and mental disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.
Chaves da Silva, Paula Grazielle; Benton, Jeanne L; Sandeman, David C; Beltz, Barbara S
Neuronal stem cells residing in a niche on the surface of the adult crayfish (Procambarus clarkii) brain are not self-renewing. However, the neuronal precursors in the niche are not depleted despite continued neurogenesis and the exit of precursor cells from the niche throughout the organism's life. The neurogenic niche is therefore not a closed system, and we have previously proposed that the stem cell pool is replenished from the hematopoietic system. Noonin et al. (2012) demonstrated that the hematopoietic system in the crayfish Pacifastacus leniusculus includes an anterior proliferation center (APC) lying near the brain; they suggest that multipotent stem cells are concentrated in this region, and that the APC may provide neuronal stem cells for adult neurogenesis. The present study extends this work by describing the location and cellular organization of hematopoietic tissues in P. clarkii. We find that the APC lies within the cor frontale, or auxiliary heart, which pumps hemolymph to the brain and eyes through the cerebral and ophthalmic arteries, respectively. Vascular extensions of the cerebral artery converge on the neurogenic niche. APC cells lie in layered sheets within the cor frontale and form rosette-like structures reminiscent of stem cells in other developing tissues. We confirm here that APC cells in P. clarkii have characteristics of multipotent stem cells, and that their location within the cor frontale allows direct access to regions in the central nervous system in which adult neurogenesis occurs.
Full Text Available Adult neurogenesis is a lifelong process that occurs in two main neurogenic niches of the brain, namely in the subventricular zone (SVZ of the lateral ventricles and in the subgranular zone (SGZ of the dentate gyrus (DG in the hippocampus. In the 1960s, studies on adult neurogenesis have been hampered by the lack of established phenotypic markers. The precise tracing of neural stem/progenitor cells (NPCs was therefore, not properly feasible. After the (partial identification of those markers, it was the lack of specific tools that hindered a proper experimental elimination and tracing of those cells to demonstrate their terminal fate and commitment. Nowadays, irradia-tion, cytotoxic drugs as well as genetic tracing/ablation procedures have moved the field forward and increased our understanding of neurogenesis processes in both physiological and pathological conditions. Newly formed NPC progeny from the SVZ can replace granule cells in the olfactory bulbs of rodents, thus contributing to orchestrate sophisticated odour behaviour. SGZ-derived new granule cells, instead, integrate within the DG where they play an essential role in memory functions. Furthermore, converging evidence claim that endogenous NPCs not only exert neurogenic functions, but might also have non-neurogenic homeostatic functions by the release of different types of neuroprotective molecules. Remarkably, these non-neurogenic homeostatic functions seem to be necessary, both in healthy and diseased conditions, for example for preventing or limiting tissue damage. In this review, we will discuss the neurogenic and the non-neurogenic functions of adult NPCs both in physiological and pathological conditions.
Full Text Available The capacity of the brain to generate new adult neurons is a recent discovery that challenges the old theory of an immutable adult brain. A new and fascinating field of research now focuses on this regenerative process. The two brain systems that constantly produce new adult neurons, known as the adult neurogenic systems, are the dentate gyrus (DG of the hippocampus and the lateral ventricules/olfactory bulb system. Both systems are involved in memory and learning processes. Different drugs of abuse, such as cocaine and MDMA, have been shown to produce cellular and molecular changes that affect adult neurogenesis. This review summarizes the effects that these drugs have on the adult neurogenic systems. The functional relevance of adult neurogenesis is obscured by the functions of the systems that integrate adult neurons. Therefore, we explore the effects that cocaine and MDMA produce not only on adult neurogenesis, but also on the DG and olfactory bulbs. Finally, we discuss the possible role of new adult neurons in cocaine- and MDMA-induced impairments. We conclude that, although harmful drug effects are produced at multiple physiological and anatomical levels, the specific consequences of reduced hippocampus neurogenesis are unclear and require further exploration.
Goldfarb, Robert A; Pisansky, Andrew; Fleck, Joseph; Hoversten, Patrick; Cotter, Katherine J; Katorski, Jenna; Liberman, Daniel; Elliott, Sean P
Cerebral palsy is characterized by motor impairment following injury to the developing brain. Neurogenic lower urinary tract dysfunction is estimated to affect at least a third of children with cerebral palsy. However there are limited data as patients transition to adulthood. We sought to describe the symptoms, sequelae and management of neurogenic lower urinary tract dysfunction in adults with cerebral palsy. We retrospectively reviewed the charts of adult patients with cerebral palsy between 2011 and 2014. Patients with prior bladder reconstruction or catheterization based bladder drainage were excluded from study. Cerebral palsy severity was determined using GMFCS (Gross Motor Function Classification System). A conservative evaluation and treatment paradigm was used. Noninvasive treatments were encouraged. Specifically clean intermittent catheterization, which is often not feasible, is avoided unless urinary retention, hydronephrosis or refractory lower urinary tract symptoms develop. There were 121 patients included in final analysis. Median age was 25 and 61 patients (50%) had GMFCS level V. Noninvasive management failed in 28 of 121 patients (23%) as defined by hydronephrosis in 9, persistent urinary retention in 10 and refractory lower urinary tract symptoms/incontinence in 9. Urethral clean intermittent catheterization was poorly tolerated. Of all patients 25% showed evidence of urolithiasis during the study period. Surgical intervention was rare and associated with significant morbidity. Adults with cerebral palsy may present with variable signs and symptoms of neurogenic lower urinary tract dysfunction. Conservative treatment was successful in more than 75% of patients. Clean intermittent catheterization was poorly tolerated in patients in whom conservative treatment failed. Surgical intervention was rarely indicated and it should be reserved for select individuals. Copyright © 2016 American Urological Association Education and Research, Inc
Botulinum toxin A (BoNTA) is increasingly used for therapy of neurogenic detrusor overactivity (NDO) refractory to antimuscarinics or where patients are experiencing antimuscarinic-related side effects. The objective was to compare and critically discuss the reported efficacy and safety of BoNTA in adults with neurogenic bladder dysfunction. Studies published between January 1985 and July 2012 were identified in the MEDLINE (PubMed) and SCOPUS databases. A search for studies with onabotulinumtoxinA--the only formulation of BoNTA approved by the US FDA in adults with NDO--was performed. Exclusion criteria were urethral sphincter injection, no separate analysis between onabotulinumtoxinA and other formulations of BoNTA, mean follow-up ≤ 4 weeks and studies with ten or fewer patients. Clinical and urodynamic parameters for efficacy, adverse events (AEs) and tolerability were reviewed to offer recommendations for practice and future research. A total of 28 included studies revealed superior effects of onabotulinumtoxinA compared with placebo in achieving continence, reducing incontinence episodes, improving urodynamic parameters and health-related quality of life. The most frequently reported AEs were de novo intermittent catheterization, urinary retention and asymptomatic urinary infection. Limitations of this review are the inclusion of studies with the level-3 evidence (22/28 studies), the heterogenicity of outcome parameters and time points chosen for follow-up reported in the reviewed studies. OnabotulinumtoxinA therapy is effective, safe and well tolerated in adults with neurogenic bladder dysfunction. Further high-quality prospective trial data are required to determine the optimal dose, injection technique, long-term safety, favourable timing, indications for re-injections, and the impact of concomitant antimuscarinics on onabotulinumtoxinA therapy.
... your bladder at all Have signs of a bladder infection (fever, burning when you urinate, frequent urination) Urinate small amounts, frequently Alternative Names Neurogenic detrusor overactivity; NDO; Neurogenic bladder sphincter dysfunction; NBSD ...
Jeglinski, Jana W E; Goetz, Kimberley T; Werner, Christiane; Costa, Daniel P; Trillmich, Fritz
1. In vertebrates, patterns of resource utilization change throughout development according to age- and or size-specific abilities and requirements. Thus, interspecific competition affects different age classes differently. 2. Adults of sympatric species often show distinct foraging niche segregation, but juvenile resource use might overlap with adult competitors of similar body size. Resultant negative effects on juveniles can have important consequences for population dynamics, yet such interactions have received little attention in studies of mammalian communities. 3. Using GPS tracking devices, time-depth recorders and stable isotope data, we compared diving depth, activity time, trophic position and foraging habitat characteristics to investigate foraging niche overlap between similar-sized sympatric juvenile Galapagos sea lions (Zalophus wollebaeki) and adult Galapagos fur seals (Arctocephalus galapagoensis) and compared each group with much larger-bodied adult Galapagos sea lions. 4. We found little indication for direct competition but a complex pattern of foraging niche segregation: juvenile sea lions and adult fur seals dived to shallow depths at night, but foraged in different habitats with limited spatial overlap. Conversely, juvenile and adult sea lions employed different foraging patterns, but their foraging areas overlapped almost completely. 5. Consistency of foraging habitat characteristics between juvenile and adult sea lions suggests that avoidance of competition may be important in shaping foraging habitat utilization. Resultant specialization on a limited habitat could contribute to low sea lion numbers that contrast with high fur seal abundance. Our data suggest that exploitation by multiple predators within spatially restricted foraging ranges of juveniles might negatively impact juvenile foraging success and ultimately influence population dynamics. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.
Elena W. Adlaf
Full Text Available Throughout development, neural stem cells (NSCs give rise to differentiated neurons, astrocytes, and oligodendrocytes which together modulate perception, memory, and behavior in the adult nervous system. To understand how NSCs contribute to postnatal/adult brain remodeling and repair after injury, the lateral ventricular (LV neurogenic niche in the rodent postnatal brain serves as an excellent model system. It is a specialized area containing self-renewing GFAP+ astrocytes functioning as NSCs generating new neurons throughout life. In addition to this now well-studied regenerative process, the LV niche also generates astrocytes, playing an important role for glial scar formation after cortical injury. While LV NSCs can be clearly distinguished from their neuroblast and oligodendrocyte progeny via molecular markers, the astrocytic identity of NSCs has complicated their distinction from terminally-differentiated astrocytes in the niche. Our current models of postnatal/adult LV neurogenesis do not take into account local astrogenesis, or the possibility that cellular markers may be similar between non-dividing GFAP+ NSCs and their differentiated astrocyte daughters. Postnatal LV neurogenesis is regulated by NSC-intrinsic mechanisms interacting with extracellular/niche-driven cues. It is generally believed that these local effects are responsible for sustaining neurogenesis, though behavioral paradigms and disease states have suggested possibilities for neural circuit-level modulation. With recent experimental findings that neuronal stimulation can directly evoke responses in LV NSCs, it is possible that this exciting property will add a new dimension to identifying postnatal/adult NSCs. Here, we put forth a notion that neural circuit-level input can be a distinct characteristic defining postnatal/adult NSCs from non-neurogenic astroglia.
Aydogdu, Ibrahim; Kiylioglu, Nefati; Tarlaci, Sultan; Tanriverdi, Zeynep; Alpaydin, Sezin; Acarer, Ahmet; Baysal, Leyla; Arpaci, Esra; Yuceyar, Nur; Secil, Yaprak; Ozdemirkiran, Tolga; Ertekin, Cumhur
Neurogenic dysphagia (ND) is a prevalent condition that accounts for significant mortality and morbidity worldwide. Screening and follow-up are critical for early diagnosis and management which can mitigate its complications and be cost-saving. The aims of this study are to provide a comprehensive investigation of the dysphagia limit (DL) in a large diverse cohort and to provide a longitudinal assessment of dysphagia in a subset of subjects. We developed a quantitative and noninvasive method for objective assessment of dysphagia by using laryngeal sensor and submental electromyography. DL is the volume at which second or more swallows become necessary to swallow the whole amount of bolus. This study represents 17 years experience with the DL approach in assessing ND in a cohort of 1278 adult subjects consisting of 292 healthy controls, 784 patients with dysphagia, and 202 patients without dysphagia. A total of 192 of all patients were also reevaluated longitudinally over a period of 1-19 months. DL has 92% sensitivity, 91% specificity, 94% positive predictive value, and 88% negative predictive value with an accuracy of 0.92. Patients with ALS, stroke, and movement disorders have the highest sensitivity (85-97%) and positive predictive value (90-99%). The clinical severity of dysphagia has significant negative correlation with DL (r=-0.67, pdysphagia and it can be performed in an EMG laboratory. Our study provides specific quantitative features of DL test that can be readily utilized by the neurologic community and nominates DL as an objective and robust method to evaluate dysphagia in a wide range of neurologic conditions. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Full Text Available The testis produces sperm throughout the male reproductive lifespan by balancing self-renewal and differentiation of spermatogonial stem cells (SSCs. Part of the SSC niche is thought to lie outside the seminiferous tubules of the testis; however, specific interstitial components of the niche that regulate spermatogonial divisions and differentiation remain undefined. We identified distinct populations of testicular macrophages, one of which lies on the surface of seminiferous tubules, in close apposition to areas of tubules enriched for undifferentiated spermatogonia. These macrophages express spermatogonial proliferation- and differentiation-inducing factors, such as colony-stimulating factor 1 (CSF1 and enzymes involved in retinoic acid (RA biosynthesis. We show that transient depletion of macrophages leads to a disruption in spermatogonial differentiation. These findings reveal an unexpected role for macrophages in the spermatogonial niche in the testis and raise the possibility that macrophages play previously unappreciated roles in stem/progenitor cell regulation in other tissues.
Peter T. Dorsher
Full Text Available Congenital anomalies such as meningomyelocele and diseases/damage of the central, peripheral, or autonomic nervous systems may produce neurogenic bladder dysfunction, which untreated can result in progressive renal damage, adverse physical effects including decubiti and urinary tract infections, and psychological and social sequelae related to urinary incontinence. A comprehensive bladder-retraining program that incorporates appropriate education, training, medication, and surgical interventions can mitigate the adverse consequences of neurogenic bladder dysfunction and improve both quantity and quality of life. The goals of bladder retraining for neurogenic bladder dysfunction are prevention of urinary incontinence, urinary tract infections, detrusor overdistension, and progressive upper urinary tract damage due to chronic, excessive detrusor pressures. Understanding the physiology and pathophysiology of micturition is essential to select appropriate pharmacologic and surgical interventions to achieve these goals. Future perspectives on potential pharmacological, surgical, and regenerative medicine options for treating neurogenic bladder dysfunction are also presented.
Jamison, Jim; Maguire, Suzanne; McCann, John
Management of the neurogenic bladder has the primary objectives of maintaining continence, ensuring low bladder pressure (to avoid renal damage) and avoiding or minimising infection. Options include intermittent urethral catheterisation, indwelling urethral or suprapubic catheterisation, timed voiding, use of external catheter (for men), drug treatment, augmentation cystoplasty and urinary diversion. The primary objective was to determine the effects of different methods of managing long-term voiding problems (persisting after three months) with catheters in patients with neurogenic bladder.Specific hypotheses to be addressed included:1. that intermittent catheterisation is better than indwelling catheterisation;2. that indwelling urethral catheterisation is better than suprapubic catheterisation;3. that external (sheath) catheters are better than indwelling or intermittent urethral catheters;4. that external (sheath) catheters are better than suprapubic catheters;5. that intermittent catheterisation is better than timed voiding. We searched the Cochrane Incontinence Group Specialised Register (searched 3 July 2013), which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and MEDLINE in process, and handsearched journals and conference proceedings. We sought additional trials from other sources such as the reference lists of relevant articles and by contacting consultants in Spinal Cord Injury Centres throughout the United Kingdom. All randomised and quasi-randomised controlled trials comparing methods of using catheters to manage urinary voiding in people with neurogenic bladder. Abstracts were independently inspected by the reviewers and full papers were obtained where necessary. Approximately 400 studies were scrutinised. No trials were found that met the inclusion criteria, and five studies were excluded from the review. Despite a comprehensive search no evidence from randomised or quasi-randomised controlled
Full Text Available The piriform cortex receives input from the olfactory bulb and (via the entorhinal cortex sends efferents to the hippocampus, thereby connecting the two canonical neurogenic regions of the adult rodent brain. Doublecortin (DCX is a cytoskeleton-associated protein that is expressed transiently in the course of adult neurogenesis. Interestingly, the adult piriform cortex, which is usually considered non-neurogenic (even though some reports exist that state otherwise, also contains an abundant population of DCX-positive cells. We asked how similar these cells would be to DCX-positive cells in the course of adult hippocampal neurogenesis. Using BAC-generated transgenic mice that express GFP under the DCX promoter, we studied DCX-expression and electrophysiological properties of DCX-positive cells in the mouse piriform cortex in comparison with the dentate gyrus. While one class of cells in the piriform cortex indeed showed features similar to newly generated immature granule neurons, the majority of DCX cells in the piriform cortex was mature and revealed large Na+ currents and multiple action potentials. Furthermore, when proliferative activity was assessed, we found that all DCX-expressing cells in the piriform cortex were strictly postmitotic, suggesting that no DCX-positive "neuroblasts" exist here as they do in the dentate gyrus. We conclude that DCX in the piriform cortex marks a unique population of postmitotic neurons with a subpopulation that retains immature characteristics associated with synaptic plasticity. DCX is thus, per se, no marker of neurogenesis but might be associated more broadly with plasticity.
Full Text Available Niche dating sites have become a popular trend in the online dating industry; yet, little is known about the specialization strategies these sites use to cater to their users’ needs. Moreover, previous research alludes to the idea that many of these sites may be engaging in pseudo-individualization—a deceptive technique that creates an illusion of specialization. This study focuses on niche dating sites for older adults, one of the fastest growing niches in online dating. Through a qualitative content analysis and close reading of older-adult dating sites, I seek to determine how and to what extent online dating sites that target older adults actually customize their services to benefit this population. Three key findings emerge: (1 the use of mass segmentation, a strategy that combines elements of both mass marketing and market segmentation; (2 a strategic broadening of the boundaries of the older-adult niche; and (3 the use of deceptive advertising to attract users. These findings suggest that older-adult dating sites are, in fact, engaging in pseudo-individualization. They also highlight some of the unique aspects of online media that facilitate this practice. Implications for both online daters and site producers are discussed.
Sun, Wei; Cornwell, Adam; Li, Jiashu; Peng, Sisi; Osorio, M Joana; Aalling, Nadia; Wang, Su; Benraiss, Abdellatif; Lou, Nanhong; Goldman, Steven A; Nedergaard, Maiken
Astrocytes have in recent years become the focus of intense experimental interest, yet markers for their definitive identification remain both scarce and imperfect. Astrocytes may be recognized as such by their expression of glial fibrillary acidic protein, glutamine synthetase, glutamate transporter 1 (GLT1), aquaporin-4, aldehyde dehydrogenase 1 family member L1, and other proteins. However, these proteins may all be regulated both developmentally and functionally, restricting their utility. To identify a nuclear marker pathognomonic of astrocytic phenotype, we assessed differential RNA expression by FACS-purified adult astrocytes and, on that basis, evaluated the expression of the transcription factor SOX9 in both mouse and human brain. We found that SOX9 is almost exclusively expressed by astrocytes in the adult brain except for ependymal cells and in the neurogenic regions, where SOX9 is also expressed by neural progenitor cells. Transcriptome comparisons of SOX9+ cells with GLT1+ cells showed that the two populations of cells exhibit largely overlapping gene expression. Expression of SOX9 did not decrease during aging and was instead upregulated by reactive astrocytes in a number of settings, including a murine model of amyotrophic lateral sclerosis (SOD1G93A), middle cerebral artery occlusion, and multiple mini-strokes. We quantified the relative number of astrocytes using the isotropic fractionator technique in combination with SOX9 immunolabeling. The analysis showed that SOX9+ astrocytes constitute ∼10-20% of the total cell number in most CNS regions, a smaller fraction of total cell number than previously estimated in the normal adult brain. SIGNIFICANCE STATEMENT Astrocytes are traditionally identified immunohistochemically by antibodies that target cell-specific antigens in the cytosol or plasma membrane. We show here that SOX9 is an astrocyte-specific nuclear marker in all major areas of the CNS outside of the neurogenic regions. Based on SOX9
Ninkovic, Jovica; Steiner-Mezzadri, Andrea; Jawerka, Melanie; Akinci, Umut; Masserdotti, Giacomo; Petricca, Stefania; Fischer, Judith; von Holst, Alexander; Beckers, Johanes; Lie, Chichung D; Petrik, David; Miller, Erik; Tang, Jiong; Wu, Jiang; Lefebvre, Veronique; Demmers, Jeroen; Eisch, Amelia; Metzger, Daniel; Crabtree, Gerald; Irmler, Martin; Poot, Raymond; Götz, Magdalena
Numerous transcriptional regulators of neurogenesis have been identified in the developing and adult brain, but how neurogenic fate is programmed at the epigenetic level remains poorly defined. Here, we report that the transcription factor Pax6 directly interacts with the Brg1-containing BAF complex in adult neural progenitors. Deletion of either Brg1 or Pax6 in the subependymal zone (SEZ) causes the progeny of adult neural stem cells to convert to the ependymal lineage within the SEZ while migrating neuroblasts convert to different glial lineages en route to or in the olfactory bulb (OB). Genome-wide analyses reveal that the majority of genes downregulated in the Brg1 null SEZ and OB contain Pax6 binding sites and are also downregulated in Pax6 null SEZ and OB. Downstream of the Pax6-BAF complex, we find that Sox11, Nfib, and Pou3f4 form a transcriptional cross-regulatory network that drives neurogenesis and can convert postnatal glia into neurons. Taken together, elements of our work identify a tripartite effector network activated by Pax6-BAF that programs neuronal fate. Copyright © 2013 Elsevier Inc. All rights reserved.
Chung, Eric; Lee, Dominic; Gani, Johan; Gillman, Michael; Maher, Christopher; Brennan, Janelle; Johns Putra, Lydia; Ahmad, Laura; Chan, Lewis Lw
Overactive bladder (OAB) is a highly prevalent medical condition that has an adverse impact on various health-related quality-of-life domains, including a significant psychosocial and financial burden. This position statement, formulated by members of the Urological Society of Australia and New Zealand and the UroGynaecological Society of Australasia, summarises the current recommendations for clinical diagnosis and treatment strategies in patients with non-neurogenic OAB, and guides clinicians in the decision-making process for managing the condition using evidence-based medicine. Main recommendations: Diagnosis and initial management should be based on thorough clinical history, examination and basic investigations to exclude underlying treatable causes such as urinary tract infection and urological malignancy. Initial treatment strategies for OAB involve conservative management with behavioural modification and bladder retraining. Second-line management involves medical therapy using anticholinergic or β3 agonist drugs provided there is adequate assessment of bladder emptying. If medical therapy is unsuccessful, further investigations with urodynamic studies and cystourethroscopy are recommended to guide further treatment. Intravesical botulinum toxin and sacral neuromodulation should be considered in medical refractory OAB. Changes in management as a result of this statement: OAB is a constellation of urinary symptoms and is a chronic condition with a low likelihood of cure; managing patient expectations is essential because OAB is challenging to treat. At present, the exact pathogenesis of OAB remains unclear and it is likely that there are multiple factors involved in this disease complex. Current medical treatment remains far from ideal, although minimally invasive surgery can be effective. Further research into the pathophysiology of this common condition will hopefully guide future developments in disease management.
Full Text Available Despite the presence of on-going neurogenesis in the adult mammalian brain, neurons are generally not replaced after injury. Using a rodent model of excitotoxic cell loss and retroviral (RV lineage tracing, we previously demonstrated transient recruitment of precursor cells from the subventricular zone (SVZ into the lesioned striatum. In the current study we determined that these cells included migratory neuroblasts and oligodendrocyte precursor cells (OPC, with the predominant response from glial cells. We attempted to override this glial response by ectopic expression of the pro-neurogenic genes Pax6 or Dlx2 in the adult rat SVZ following quinolinic acid lesioning. RV-Dlx2 over-expression stimulated repair at a previously non-neurogenic time point by enhancing neuroblast recruitment and the percentage of cells that retained a neuronal fate within the lesioned area, compared to RV-GFP controls. RV-Pax6 expression was unsuccessful at inhibiting glial fate and intriguingly, increased OPC cell numbers with no change in neuronal recruitment. These findings suggest that gene choice is important when attempting to augment endogenous repair as the lesioned environment can overcome pro-neurogenic gene expression. Dlx2 over-expression however was able to partially overcome an anti-neuronal environment and therefore is a promising candidate for further study of striatal regeneration.
Full Text Available Transcription factor Runx1 (Runt Related Transcription Factor 1, plays an important role in the differentiation of hematopoetic stem cells, angiogenesis and the development of nociceptive neurons. These known functions have in common that they relate to lineage decisions. We thus asked whether such role might also be found for Runx1 in adult hippocampal neurogenesis as a process, in which such decisions have to be regulated lifelong. Runx1 shows a widespread low expression in the adult mouse brain, not particularly prominent in the hippocampus and the resident neural precursor cells. Isoforms 1 and 2 of Runx1 (but not 3 to 5 driven by the proximal promoter were expressed in hippocampal precursor cells ex vivo, albeit again at very low levels, and were markedly increased after stimulation with TGF-β1. Under differentiation conditions (withdrawal of growth factors Runx1 became down-regulated. Overexpression of Runx1 in vitro reduced proliferation, increased survival of precursor cells by reducing apoptosis, and increased neuronal differentiation, while slightly reducing dendritic morphology and complexity. Transfection with dominant-negative Runx1 in hippocampal precursor cells in vitro did not result in differences in neurogenesis. Hippocampal expression of Runx1 correlated with adult neurogenesis (precursor cell proliferation across BXD recombinant strains of mice and covarying transcripts enriched in the GO categories "neural precursor cell proliferation" and "neuron differentiation". Runx1 is thus a plausible candidate gene to be involved in regulating initial differentiation-related steps of adult neurogenesis. It seems, however, that the relative contribution of Runx1 to such effect is complementary and will explain only small parts of the cell-autonomous pro-differentiation effect.
Harding, A E; Young, E P; Schon, F
An Ashkenazi Jewish brother and sister developed progressive ataxia and proximal neurogenic muscle weakness, associated with supranuclear ophthalmoplegia, in the fourth decade of life. Hexosaminidase A activity, assayed using both synthetic and natural substrates, was severely reduced in the patients' plasma, leukocytes, and skin fibroblasts. Enzyme activity in their parents was in a similar range to that seen in heterozygotes for Tay-Sachs disease. The increasing evidence for marked clinical and molecular heterogeneity in the GM2 gangliosidoses warrants their consideration in the diagnosis of multisystem degenerative neurological disorders, even if onset of symptoms is in adult life. Images PMID:2956362
Dutheil, Sophie; Lacour, Michel; Tighilet, Brahim
Functional and reactive neurogenesis and astrogenesis are observed in deafferented vestibular nuclei after unilateral vestibular nerve section in adult cats. The newborn cells survive up to one month and contribute actively to the successful recovery of posturo-locomotor functions. This study investigates whether the nature of vestibular deafferentation has an incidence on the neurogenic potential of the vestibular nuclei, and on the time course of behavioural recovery. Three animal models that mimic different vestibular pathologies were used: unilateral and permanent suppression of vestibular input by unilateral vestibular neurectomy (UVN), or by unilateral labyrinthectomy (UL, the mechanical destruction of peripheral vestibular receptors), or unilateral and reversible blockade of vestibular nerve input using tetrodotoxin (TTX). Neurogenesis and astrogenesis were revealed in the vestibular nuclei using bromodeoxyuridine (BrdU) as a newborn cell marker, while glial fibrillary acidic protein (GFAP) and glutamate decarboxylase 67 (GAD67) were used to identify astrocytes and GABAergic neurons, respectively. Spontaneous nystagmus and posturo-locomotor tests (static and dynamic balance performance) were carried out to quantify the behavioural recovery process. Results showed that the nature of vestibular loss determined the cellular plastic events occurring in the vestibular nuclei and affected the time course of behavioural recovery. Interestingly, the deafferented vestibular nuclei express neurogenic potential after acute and total vestibular loss only (UVN), while non-structural plastic processes are involved when the vestibular deafferentation is less drastic (UL, TTX). This is the first experimental evidence that the vestibular complex in the brainstem can become neurogenic under specific injury. These new data are of interest for understanding the factors favouring the expression of functional neurogenesis in adult mammals in a brain repair perspective, and are of
Rai, Bhavan Prasad; Cody, June D; Alhasso, Ammar; Stewart, Laurence
Overactive bladder syndrome is defined as urgency with or without urgency incontinence, usually with frequency and nocturia. Pharmacotherapy with anticholinergic drugs is often the first line medical therapy, either alone or as an adjunct to various non-pharmacological therapies after conservative options such as reducing intake of caffeine drinks have been tried. Non-pharmacologic therapies consist of bladder training, pelvic floor muscle training with or without biofeedback, behavioural modification, electrical stimulation and surgical interventions. To compare the effects of anticholinergic drugs with various non-pharmacologic therapies for non-neurogenic overactive bladder syndrome in adults. We searched the Cochrane Incontinence Group Specialised Register (searched 4 September 2012), which includes searches of the Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE, and the reference lists of relevant articles. All randomised or quasi-randomised, controlled trials of treatment with anticholinergic drugs for overactive bladder syndrome or urgency urinary incontinence in adults in which at least one management arm involved a non-drug therapy. Trials amongst patients with neurogenic bladder dysfunction were excluded. Two authors evaluated the trials for appropriateness for inclusion and risk of bias. Two authors were involved in the data extraction. Data extraction was based on predetermined criteria. Data analysis was based on standard statistical approaches used in Cochrane reviews. Twenty three trials were included with a total of 3685 participants, one was a cross-over trial and the other 22 were parallel group trials. The duration of follow up varied from two to 52 weeks. The trials were generally small and of poor methodological quality. During treatment, symptomatic improvement was more common amongst those participants on anticholinergic drugs compared with bladder training in seven small trials (73/174, 42% versus 98/172, 57% not
Hadley, David; Anderson, Kirk; Knopick, Christopher R; Shah, Ketul; Flynn, Brian J
To describe our technique and long-term results with creation of a continent urinary channel in adults with neurogenic bladder (NGB) using a single piece of bowel. From 2004 to 2013, 26 adult patients underwent creation of a continent urinary channel by a single surgeon. A retrospective medical record review was performed noting the indications, technique, concomitant procedures, complications, and outcomes. Continence outcome, ease of catheterization, and need for further surgical interventions are reported. Twenty women and 6 men were identified with a mean age of 48 years (range, 25-80) and a follow-up of 64 months (range, 22-100). The mean body mass index (BMI) was 30.5 kg/m(2) (range, 20.1-50.2). All patients had benign bladder disease, including 22 (85%) with known neurologic disease and 4 with a devastated bladder outlet. Creation of a continent urinary channel was performed using the single Monti tube in 1, double Monti tube in 7, and the Casale (Spiral Monti) in 18. Mean hospital stay was 10.5 days (range, 5-37). The most common complication was recurrent urinary tract infection that occurred in 14 patients (54%). There were 5 (19%) bowel complications and 1 (4%) bladder perforation. The percentage of patients continuing to catheterize via the stoma with a BMI of 40 kg/m(2) was 89%, 50%, and 25%, respectively. The Monti and Casale procedures are effective in creating a long continent urinary channel for catheterization in the adult population with neurogenic bladder, regardless of BMI. However, despite an intact channel, stomal self-catheterization appears to be challenging in morbidly obese patients. Copyright © 2014 Elsevier Inc. All rights reserved.
Binnani, Pooja; Gupta, Ruchi; Kedia, Nikhil; Pattewar, Sainath; Bahadur, Madan Mohan
Urinary diversion is indicated for the management of the neurogenic bladder. However, there is a risk for developing pyocystitis in this type of patients. We present a case of young female who presented with a history of frequent urinary tract infection (UTI) post urinary diversion for neurogenic bladder. Ever since she underwent simple cystectomy, there have been no further episodes of UTI.
Pooja Binnani; Ruchi Gupta; Nikhil Kedia; Sainath Pattewar; Madan Mohan Bahadur
Urinary diversion is indicated for the management of the neurogenic bladder. However, there is a risk for developing pyocystitis in this type of patients. We present a case of young female who presented with a history of frequent urinary tract infection (UTI) post urinary diversion for neurogenic bladder. Ever since she underwent simple cystectomy, there have been no further episodes of UTI.
Full Text Available Aim: to evaluate the effectiveness of short-term PTNS for non-neurogenic OAB in adults systematically by comparing with sham procedure and other treatments. Methods: we performed a systematic review of cohort study. Data sources were MEDLINE, EMBASE, CINAHL, National Library for Health, Cochrane, and google scholar from 2005 through 2015. Meta-analysis was performed using the random effects model. Heterogeneity of effects was assessed by calculating I2 statistic. Statistical analysis was performed using Review Manager 5.3 for RCT meta-analysis. Results: we analized 11 randomised controlled trial (RCT and five prospective non-comparative studies with variable success rate. Based on percentage of responders, the results were 37.3% - 81.8% in PTNS group, 0% - 20.9% in sham group, 54.8% in anti-muscarinic group, and 89.7% in multimodal group. The decrease of voiding symptoms episodes per day was found in PTNS (0.7-4.5, sham (0.3-1.5, and anti-muscarinic (0.6-2.9 groups. In meta-analysis of four RCTs, the results favour PTNS over sham procedure with overall risk ratio of 7.32(95% CI of 1.69-32.16, p=0.09, I2=54%. Conclusion: there is an evidence of effectiveness of short term PTNS in treatment of non-neurogenic OAB. PTNS is proven significantly better than sham procedure. Key words: overactive bladder, percutaneous tibial nerve stimulation, sham, anti-muscarinic, voiding symptoms.
Gregory Paul Marshall
Full Text Available Microglia isolated from the neurogenic subependymal zone (SEZ and hippocampus (HC are capable of massive in vitro population expansion that is not possible with microglia isolated from non-neurogenic regions. We asked if this regional heterogeneity in microglial proliferative capacity is cell intrinsic, or is conferred by interaction with respective neurogenic or non-neurogenic niches. By combining SEZ and cerebral cortex (CTX primary tissue dissociates to generate heterospatial cultures, we find that exposure to the SEZ environment does not enhance CTX microglia expansion; however, the CTX environment exerts a suppressive effect on SEZ microglia expansion. Furthermore, addition of purified donor SEZ microglia to either CTX- or SEZ-derived cultures suppresses the expansion of host microglia, while the addition of donor CTX microglia enhances the over-all microglia yield. These data suggest that SEZ and CTX microglia possess intrinsic, spatially restricted characteristics that are independent of their in vitro environment, and that they represent unique and functionally distinct populations. Finally, we determined that the repeated supplementation of neurogenic SEZ cultures with expanded SEZ microglia allows for sustained levels of inducible neurogenesis, provided that the ratio of microglia to total cells remains within a fairly narrow range.
Full Text Available Sarcopenia is an aging-associated condition, which is currently characterized by the loss of muscle mass and muscle strength. However, there is no consensus regarding its characterization hitherto. As the world older adult population is on the rise, the impact of sarcopenia becomes greater. Due to the lack of effective treatments, sarcopenia is still a persisting problem among the global older adults and should not be overlooked. As a result, it is vital to investigate deeper into the mechanism underlying the pathogenesis of sarcopenia in order to develop more effective therapeutic interventions and to inscribe a more uniform characterization. The etiology of sarcopenia is currently found to be multifactorial, and most of the pharmacological researches are focused on the muscular factors in aging. Although the complete mechanism underlying the development of sarcopenia is still waiting to be elucidated, we propose in this article that the primary trigger of sarcopenia may be neurogenic in origin based on the intimate relationship between the nervous and muscular system, namely, the motor neuron and its underlying muscle fibers. Both of them are affected by the cellular environment and their physiological activity.
Colak, D.; Mori, T.; Brill, M.S; Pfeifer, A.; Falk, S.; Deng, C.; Monteiro, R.; Mummery, C.L.; Sommer, L.; Gotz, M.
In the mammalian brain, neurogenesis continues only in few regions of the forebrain. The molecular signals governing neurogenesis in these unique neurogenic niches, however, are still ill defined. Here, we show that bone morphogenic protein (BMP)-mediated signaling is active in adult neural stem
Full Text Available Urinary diversion is indicated for the management of the neurogenic bladder. However, there is a risk for developing pyocystitis in this type of patients. We present a case of young female who presented with a history of frequent urinary tract infection (UTI post urinary diversion for neurogenic bladder. Ever since she underwent simple cystectomy, there have been no further episodes of UTI.
Busl, Katharina M; Bleck, Thomas P
Neurogenic pulmonary edema is an underrecognized and underdiagnosed form of pulmonary compromise that complicates acute neurologic illness and is not explained by cardiovascular or pulmonary pathology. This review aims to provide a concise overview on pathophysiology, epidemiology, clinical characteristics, impact on outcome and treatment of neurogenic pulmonary edema, and considerations for organ donation. Database searches and a review of the relevant medical literature. Selected studies included English-language articles concerning neurogenic pulmonary edema using the search terms "neurogenic" with "pulmonary oedema" or "pulmonary edema," "experimental neurogenic pulmonary edema," "donor brain death," and "donor lung injury." Selected studies were reviewed by both authors, and data extracted based on author consensus regarding relevance for this review. Existing evidence is organized to address: 1) pathophysiology, 2) epidemiology and association with different neurologic diseases, 3) clinical presentation, 4) impact on outcome, 5) treatment, and 6) implications for organ donation after brain death. Neurogenic pulmonary edema occurs as a complication of acute neurologic illness and may mimic acute lung injury of other etiology. Its presence is important to recognize in patients due to its impact on clinical course, prognosis, and treatment strategies.
Harabiš, F.; Dolný, A.; Šipoš, Jan
Roč. 54, č. 4 (2012), s. 549-556 ISSN 1438-3896 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Competition * Hibernation * Phenology * Sympecma * Temporal niche-partitioning Subject RIV: EH - Ecology, Behaviour Impact factor: 1.923, year: 2012
Full Text Available Restoring adult stem cell function provides an exciting approach for rejuvenating the aging brain. However, molecular mechanisms mediating neurogenic rejuvenation remain elusive. Here we report that the enzyme ten eleven translocation methylcytosine dioxygenase 2 (Tet2, which catalyzes the production of 5-hydroxymethylcytosine (5hmC, rescues age-related decline in adult neurogenesis and enhances cognition in mice. We detected a decrease in Tet2 expression and 5hmC levels in the aged hippocampus associated with adult neurogenesis. Mimicking an aged condition in young adults by abrogating Tet2 expression within the hippocampal neurogenic niche, or adult neural stem cells, decreased neurogenesis and impaired learning and memory. In a heterochronic parabiosis rejuvenation model, hippocampal Tet2 expression was restored. Overexpressing Tet2 in the hippocampal neurogenic niche of mature adults increased 5hmC associated with neurogenic processes, offset the precipitous age-related decline in neurogenesis, and enhanced learning and memory. Our data identify Tet2 as a key molecular mediator of neurogenic rejuvenation.
Neurogenic edema, in the strict sense of the term, has at the present time practically not benefitted from precise hemodynamic investigations in human clinical practice, and owing to this fact, authors still classify them under the heading "mixed edema or of unknown pathogenesis". In contrast with this lack of information in man, animal experimental works are surprising by their coherence and the experimental facility of producing neurogenic edema (cranial hypertension by a small inflatable balloon and cisternal infection of fibrin). If one excludes the now ancient vagal theories (CAMERON 1949; CAMPBELL, 1949) which were never confirmed, all of the most recent experimental works (SARNOFF, 1952; DUCKER, 1968; LUISADA, 1967; MORITZ, 1974) confirm the adrenergic disorder of central origin during neurogenic A.P.E. which from the hemodynamic standpoint is like an authentic hemodynamic A.P.E. with raised left atrial pressure, pulmonary venous pressure and pulmonary capillary pressure.
Esther Yoona Cho
Full Text Available Drawing on thirty in-depth interviews with Korean- and Mexican-origin undocumented young adults in California, this comparative analysis explores how the intersection of immigration status and ethnoracial background affects social and economic incorporation. Respective locations of principal ethnic niches, and access to these labor market structures, lead to divergent pathways of employment when no legal recourse exists. Despite similar levels of academic achievement, Korean respondents were more likely to enter into a greater diversity of occupations relative to Mexican respondents. However, the experiences of Mexican respondents varied depending on their connection to pan-ethnic Latino nonprofit organizations. Illegality, therefore, is conditioned by opportunity structures that vary strongly by membership in different ethnoracial communities, leading to structured heterogeneity in experiences with undocumented status.
Vainrib, Michael; Reyblat, Polina; Ginsberg, David A
To evaluate urodynamic parameters in myelomeningocele patients with native bladders and after augmentation, continence rates and check the longevity of these parameters after lower urinary tract (LUT) reconstruction. A retrospective review of adult myelomeningocele patients with UDS. 118 adult patients with NGB secondary to myelomeningocele were identified. 58/118 (49.1%) had UDS performed in our clinic: 18/58 (31%) after prior reconstruction ("Augment" group) and 40/58 (69%) during annual urologic follow up ("NoSx" group). Urodyanmic findings after augmentation included: Pdet@MCC 31.1 (1-95) cmH(2)O, MCC 495.9 ml, NDO in 3/18 (16.7%), mean DLPP 54.0 (48-60) cmH(2)O and mean ALPP 39.6 (20-110) cmH(2)O in 5/18 with an incompetent sphincter. Patients in "NoSx" group had the following findings: Pdet@MCC of 39.6 (1-60) cmH(2)O, MCC 407.5 ml, 18/40 (45%) had NDO, mean DLPP of 48.1 (15-95) cmH(2)O and mean ALPP = 51 (17-78) cmH(2)O in 10/40 with incompetent sphincter. In the "NoSx" group, 19/40 (47.5%) had normal bladder compliance. Mean time from the surgery to UDS was 10.4 years. Continent patients in the "NoSx" group had a significantly higher MCC than incontinent patients in the same group (475 vs. 352 ml, P = 0.029). 8/17 (47.1%) continent patients in "NoSx" group had normal UDS. Most patients after augmentation maintain low bladder pressures for more than 10 years. Close long-term follow up should be maintained, especially in those patients that have not had prior augmentation. Urinary incontinence may be secondary to poor sphincteric function in patients with and without prior augmentation. Moreover, we should continue to follow patients after reconstruction as elevated detrusor pressures can still be seen. Strict follow up after LUT reconstruction still continues to be important. Copyright © 2012 Wiley Periodicals, Inc.
Katzberg, Hans D
Muscle cramps are sustained, painful contractions of muscle and are prevalent in patients with and without medical conditions. The objective of this review is to present updates on the mechanism, investigation and treatment of neurogenic muscle cramps. PubMed and Embase databases were queried between January 1980 and July 2014 for English-language human studies. The American Academy of Neurology classification of studies (classes I-IV) was used to assess levels of evidence. Mechanical disruption, ephaptic transmission, disruption of sensory afferents and persistent inward currents have been implicated in the pathogenesis of neurogenic cramps. Investigations are directed toward identifying physiological triggers or medical conditions predisposing to cramps. Although cramps can be self-limiting, disabling or sustained muscle cramps should prompt investigation for underlying medical conditions. Lifestyle modifications, treatment of underlying conditions, stretching, B-complex vitamins, diltiezam, mexiletine, carbamazepine, tetrahydrocannabinoid, leveteracitam and quinine sulfate have shown evidence for treatment.
Georgopoulos, Petros; Apostolidis, Apostolos
This review aims to analyze and discuss all recently published articles associated with neurogenic voiding discussion providing readers with the most updated knowledge and trigger for further research. They include the proposal of a novel classification system for the pathophysiology of neurogenic lower urinary tract dysfunction (NLUTD) which combines neurological defect in a distinct anatomic location, and data on bowel dysfunction, autonomic dysreflexia and urine biomarkers; review of patient-reported outcome measures in NLUTD; review of the criteria for the diagnosis of clinically significant urinary infections; novel research findings on the pathophysiology of NLUTD; and review of data on minimally and more invasive treatments. Despite the extended evidence base on NLUTD, there is a paucity of high-quality new research concerning voiding dysfunction as opposed to storage problems. The update aims to inform clinicians about new developments in clinical practice, as well as ignite discussion for further clinical and basic research in the aforementioned areas of NLUTD.
Full Text Available The central nervous system of adult mammals has long been considered as a complex static structure unable to undergo any regenerative process to refurbish its dead nodes. This dogma was challenged by Altman in the 1960s and neuron self-renewal has been demonstrated ever since in many species, including humans. Aging, neurodegenerative, and some mental diseases are associated with an exponential decrease in brain neurogenesis. Therefore, the controlled pharmacological stimulation of the endogenous neural stem cells (NSCs niches might counteract the neuronal loss in Alzheimer’s disease (AD and other pathologies, opening an exciting new therapeutic avenue. In the last years, druggable molecular targets and signalling pathways involved in neurogenic processes have been identified, and as a consequence, different drug types have been developed and tested in neuronal plasticity. This review focuses on recent advances in neurogenic agents acting at serotonin and/or melatonin systems, Wnt/β-catenin pathway, sigma receptors, nicotinamide phosphoribosyltransferase (NAMPT and nuclear erythroid 2-related factor (Nrf2.
The stem cell niche refers to a specific microenvironment where stem cells proliferate and differentiate to produce new specialized cells throughout an organism's adulthood. Growth factors are crucial signaling molecules that diffuse through the extracellular space, reach the stem cell niche, and ultimately promote stem cell proliferation and differentiation. However, it is not well known how multiple growth factors, often with antagonistic activities, work together in the stem cell niche to select target stem cell populations and determine stem cell fate. There is accumulating evidence suggesting that extracellular matrix (ECM) molecules play an important role in promoting growth factor access and activity in the stem cell niche. In the adult brain neurogenic zone, where neural stem cells (NSCs) reside, there exist specialized ECM structures, which we have named fractones. The processes of NSC allow them to come into contact with fractones and interact with its individual components, which include heparan sulfate proteoglycans (HSPGs) and laminins. We have demonstrated that fractone-associated HSPGs bind growth factors and regulate NSC proliferation in the neurogenic zone. Moreover, emerging results show that fractones are structurally altered in animal models with autism and adult hydrocephalus, as demonstrated by changes in fractone size, quantity, or HSPG content. Interestingly, ECM structures similar to fractones have been found throughout β-amyloid plaques in the brain of patients with Alzheimer's disease. Pathological fractones may cause imbalances in growth factor activity and impair neurogenesis, leading to inflammation and disorder. Generally speaking, these stem cell niche structures play a potentially vital role in controlling growth factor activity during both health and disease.
Giannakis, Marios; Stappenbeck, Thaddeus S; Mills, Jason C
We have sequenced 36,641 expressed sequence tags from laser capture microdissected adult mouse gastric and small intestinal epithelial progenitors, obtaining 4031 and 3324 unique transcripts, respectively. Using Gene Ontology (GO) terms, each data set was compared with cDNA libraries from intact ...
Jarmundowicz, W; Haftek, J
In the period 1971-1981 operations were carried out in 1114 cases of discopathy or lumbar spondylosis. Three patients in this group had pains of the type of intermittent claudication as the main symptoms. In all these cases narrowing of the vertebral canal was found in the lumbar part caused in two cases by degenerative changes and herniation of the intervertebral discs, and in a third case it was due to an extensive connective tissue scar at the site of previously done laminectomy. The nerve roots of the cauda were relieved from pressure surgically and in all cases pains disappeared. The authors discuss factors contributing to the development of neurogenic intermittent claudication.
Roč. 160, 5-6 (2010), s. 152-154 ISSN 0043-5341 Institutional research plan: CEZ:AV0Z50390512 Keywords : neurogenic pulmonary edema * intracranial pressure * sympathetic system Subject RIV: FH - Neurology
Bruneton, J.N.; Drouillard, J.; Roux, P.; Ettore, F.; Lecomte, P.
The general and radiologic features of neurogenic tumors of the stomach are reviewed in connection with 18 cases (16 benign and 2 maglignant tumors). Such neurogenic tumors are rare in the stomach, representing less than 0.5% of all tumors. Solitary neurogenic tumors must be differentiated from those encountered during von Recklinghausen's disease. Radiological or endoscopic examination can generally determine the benign or malignant nature of solitary neurogenic tumors, which are essentially represented by schwannomas. Since these tumors are submucosal, a deep biopsy is imperative; furthermore, since such tumors are subject to hemorrhage, prior investigation by CT appears advisable to detect possible hypervascularization after injection of contrast material. For patients with von Recklinghausen's disease, a neurofibroma is usually diagnosed when faced with a digestive hemorrhage. Radiological exploration of the entire digestive tract appears essential to confirm the solitary nature of the gastric lesion and to be sure it is responsible for the clinical symptoms.
Koyama, K; Moda, Y; Sone, A; Tanaka, H; Hino, Y
We encountered a rare patient with Hunter's syndrome who exhibited urinary retention as a result of a neurogenic bladder, uninhibited detrusor contractions, and detrusor-sphincter dyssynergia. Neurological findings were consistent with cervical myelopathy and cervical MR imaging showed very narrow segments at the cord level C2-4. We speculate that this Hunter's syndrome patient has cervical myelopathy and that this neurological dysfunction causes the neurogenic bladder. PMID:8014981
Schmelz, M; Petersen, Lars Jelstrup
The combination of vasodilation and protein extravasation following activation of nociceptors has been termed "neurogenic inflammation." In contrast to rodents, no neurogenic protein extravasation can be elicited in healthy human skin. Dermal microdialysis has considerably increased our knowledge...... about neurogenic inflammation in human skin, including the involvement of mast cells.......The combination of vasodilation and protein extravasation following activation of nociceptors has been termed "neurogenic inflammation." In contrast to rodents, no neurogenic protein extravasation can be elicited in healthy human skin. Dermal microdialysis has considerably increased our knowledge...
de Carvalho, Mamede; Swash, Michael
Monomelic neurogenic syndromes are rare. Their classification and prognostic features have not been addressed in the European population. A prospective study of 17 patients with monomelic neurogenic amyotrophy, of upper or lower limb onset, with progression limited to one limb for three or more years. Clinical and neurophysiological studies were performed in the subsequent 3 or more years. Fifteen patients were of European origin and two were Asian. Those presenting with proximal monomelic weakness or with involvement of the posterior compartment of the lower leg showed no further progression after the initial period of development of the syndrome. Brisk reflexes in wasted muscles did not predict progression. Electromyographic signs of denervation in the opposite limb at presentation did not predict later progression. Transcranial magnetic stimulation (TMS) features of corticospinal dysfunction were a useful predictor of subsequent progression (p=0.01). One patient with lower limb onset developed conduction block with weakness in an upper limb nine years after presentation, and this upper limb weakness responded to IVIg therapy. This adult-onset European group of patients is different as compared with juvenile-onset Asian cases. The clinical syndromes appear heterogeneous, but neurophysiological investigations, in particular TMS, can be helpful in determining prognosis. Multifocal motor neuropathy should be considered when there is progression, even years after onset.
Full Text Available Adult hippocampal neurogenesis results in the continuous formation of new neurons and is a process of brain plasticity involved in learning and memory. The neurogenic niche regulates the stem cell proliferation and the differentiation and survival of new neurons and a major contributor to the neurogenic niche are astrocytes. Among the molecules secreted by astrocytes, D-serine is an important gliotransmitter and is a co-agonist of the glutamate, N-methyl-D-aspartate (NMDA receptor. D-serine has been shown to enhance the proliferation of neural stem cells in vitro, but its effect on adult neurogenesis in vivo is unknown. Here, we tested the effect of exogenous administration of D-serine on adult neurogenesis in the mouse dentate gyrus. We found that 1 week of treatment with D-serine increased cell proliferation in vivo and in vitro and increased the density of neural stem cells and transit amplifying progenitors. Furthermore, D-serine increased the survival of newborn neurons. Together, these results indicate that D-serine treatment resulted in the improvement of several steps of adult neurogenesis in vivo.
Yang, K S; Ho, C S; Tai, P A; Kung, W M
Most lumbar intradural schwannomas present initially as radiculopathies with sensory disturbances. However, neurogenic bladder dysfunction may be one of the earliest manifestations and can cause long-term disability. We present the case of a patient with a L3-4 schwannoma (newly diagnosed owing to recurrent urinary retention and urinary tract infection) who finally underwent surgical resection. Improvement of bladder sensation was documented by urodynamic study and the patient was subsequently weaned off her Foley catheter with satisfactory outcome.
Harzsch, Steffen; von Bohlen Und Halbach, Oliver
Persistent neurogenesis in the adult brain of both vertebrates and invertebrates was previously considered to be driven by self-renewing neuronal stem cells of ectodermal origin. Recent findings in an invertebrate model challenge this view and instead provide evidence for a recruitment of neuronal precursors from a non-neuronal source. In the brain of adult crayfish, a neurogenic niche was identified that contributes progeny to the adult central olfactory pathway. The niche may function in attracting cells from the hemolymph and transforming them into cells with a neuronal fate. This finding implies that the first-generation neuronal precursors located in the crayfish neurogenic niche are not self-renewing. Evidence is summarized in support of a critical re-evaluation of long-term self-renewal of mammalian neuronal stem cells. Latest findings suggest that a tight link between the immune system and the system driving adult neurogenesis may not only exist in the crayfish but also in mammals. Copyright © 2015 Elsevier GmbH. All rights reserved.
Laure Anne D'Amico
Full Text Available In contrast to mammals that have limited proliferation and neurogenesis capacities, the Xenopus frog exhibit a great potential regarding proliferation and production of new cells in the adult brain. This ability makes Xenopus a useful model for understanding the molecular programs required for adult neurogenesis. Transcriptional factors that control adult neurogenesis in vertebrate species undergoing widespread neurogenesis are unknown. NeuroD1 is a member of the family of proneural genes, which function during embryonic neurogenesis as a potent neuronal differentiation factor. Here, we study in detail the expression of NeuroD1 gene in the juvenile and adult Xenopus brains by in situ hybridization combined with immunodetections for proliferation markers (PCNA, BrdU or in situ hybridizations for cell type markers (Vimentin, Sox2. We found NeuroD1 gene activity in many brain regions, including olfactory bulbs, pallial regions of cerebral hemispheres, preoptic area, habenula, hypothalamus, cerebellum and medulla oblongata. We also demonstrated by double staining NeuroD1/BrdU experiments, after long post-BrdU administration survival times, that NeuroD1 gene activity was turned on in new born neurons during post-metamorphic neurogenesis. Importantly, we provided evidence that NeuroD1-expressing cells at this brain developmental stage were post-mitotic (PCNA- cells and not radial glial (Vimentin+ or progenitors (Sox2+ cells.
Full Text Available Summary: Adult neurogenesis is regulated by stem cell niche-derived extrinsic factors and cell-intrinsic regulators, yet the mechanisms by which niche signals impinge on the activity of intrinsic neurogenic transcription factors remain poorly defined. Here, we report that MEIS2, an essential regulator of adult SVZ neurogenesis, is subject to posttranslational regulation in the SVZ olfactory bulb neurogenic system. Nuclear accumulation of MEIS2 in adult SVZ-derived progenitor cells follows downregulation of EGFR signaling and is modulated by methylation of MEIS2 on a conserved arginine, which lies in close proximity to nested binding sites for the nuclear export receptor CRM1 and the MEIS dimerization partner PBX1. Methylation impairs interaction with CRM1 without affecting PBX1 dimerization and thereby allows MEIS2 nuclear accumulation, a prerequisite for neuronal differentiation. Our results describe a form of posttranscriptional modulation of adult SVZ neurogenesis whereby an extrinsic signal fine-tunes neurogenesis through posttranslational modification of a transcriptional regulator of cell fate. : A hallmark of adult neurogenesis is its strong dependence on physiological stimuli and environmental signals. Schulte and colleagues show that the nuclear localization and activity of a transcriptional regulator of adult neurogenesis is controlled by posttranslational modification. Their results link intrinsic control over neuron production to external signals and help to explain how adult neurogenesis can occur “on demand.” Keywords: subventricular zone, stem cell niche, posttranslational modification, controlled nuclear import, TALE-homdomain protein, MEIS2, PBX1, CRM1, neurogenesis, stem cell niche
Full Text Available In Parkinson’s disease (PD and other synucleinopathies, chronic neurodegeneration occurs within different areas of the central nervous system leading to progressive motor and nonmotor symptoms. The symptomatic treatment options that are currently available do not slow or halt disease progression. This highlights the need of a better understanding of disease mechanisms and disease models. The generation of newborn neurons in the adult hippocampus and in the subventricular zone/olfactory bulb system is affected by many different regulators and possibly involved in memory processing, depression, and olfaction, symptoms which commonly occur in PD. The pathology of the adult neurogenic niches in human PD patients is still mostly elusive, but different preclinical models have shown profound alterations of adult neurogenesis. Alterations in stem cell proliferation, differentiation, and survival as well as neurite outgrowth and spine formation have been related to different aspects in PD pathogenesis. Therefore, neurogenesis in the adult brain provides an ideal model to study disease mechanisms and compounds. In addition, adult newborn neurons have been proposed as a source of endogenous repair. Herein, we review current knowledge about the adult neurogenic niches in PD and highlight areas of future research.
Geil, Chelsea R.; Hayes, Dayna M.; McClain, Justin A.; Liput, Daniel J.; Marshall, S. Alex; Chen, Kevin Y.; Nixon, Kimberly
Adult neurogenesis is now widely accepted as an important contributor to hippocampal integrity and function but also dysfunction when adult neurogenesis is affected in neuropsychiatric diseases such as alcohol use disorders. Excessive alcohol consumption, the defining characteristic of alcohol use disorders, results in a variety of cognitive and behavioral impairments related wholly or in part to hippocampal structure and function. Recent preclinical work has shown that adult neurogenesis may be one route by which alcohol produces hippocampal neuropathology. Alcohol is a pharmacologically promiscuous drug capable of interfering with adult neurogenesis through multiple mechanisms. This review will discuss the primary mechanisms underlying alcohol-induced changes in adult hippocampal neurogenesis including alcohol's effects on neurotransmitters, CREB and its downstream effectors, and the neurogenic niche. PMID:24842804
Spéder, Pauline; Brand, Andrea H
Successful neurogenesis requires adequate proliferation of neural stem cells (NSCs) and their progeny, followed by neuronal differentiation, maturation and survival. NSCs inhabit a complex cellular microenvironment, the niche, which influences their behaviour. To ensure sustained neurogenesis, niche cells must respond to extrinsic, environmental changes whilst fulfilling the intrinsic requirements of the neurogenic program and adapting their roles accordingly. However, very little is known about how different niche cells adjust their properties to such inputs. Here, we show that nutritional and NSC-derived signals induce the remodelling of Drosophila cortex glia, adapting this glial niche to the evolving needs of NSCs. First, nutrition-induced activation of PI3K/Akt drives the cortex glia to expand their membrane processes. Second, when NSCs emerge from quiescence to resume proliferation, they signal to glia to promote membrane remodelling and the formation of a bespoke structure around each NSC lineage. The remodelled glial niche is essential for newborn neuron survival.
Carlos Arturo Levi D'Ancona
Full Text Available Purpose To evaluate the effects of botulinum toxin on urodynamic parameters and quality of life in patients with neurogenic detrusor overactivity. Methods Thirty four adult patients with spinal cord injury and detrusor overactivity were selected. The patients received 300 units of botulinum toxin type A. The endpoints evaluated with the episodes of urinary incontinence and measured the maximum cystometric capacity, maximum amplitude of detrusor pressure and bladder compliance at the beginning and end of the study (24 weeks and evaluated the quality of life by applying the Qualiveen questionnaire. Results A significant decrease in the episodes of urinary incontinence was observed. All urodynamic parameters presented a significant improvement. The same was observed in the quality of life index and the specific impact of urinary problems scores from the Qualiveen questionnaire. Six patients did not complete the study, two due to incomplete follow-up, and four violated protocol and were excluded from the analyses. No systemic adverse events of botulinum toxin type A were reported. Conclusions A botulinum toxin type A showed a significantly improved response in urodynamics parameters and specific and general quality of life.
Neurogenic bladder is a disorder of the lower urinary tract created by damage to or diseases of the nervous system. Found in many patients with neurologic disorders, including multiple sclerosis, Parkinson's disease, spinal cord injury, and spina bifida among others, neurogenic bladder can lead to problematic symptoms and complications including urinary incontinence, frequency, and urgency, along with risk for infection and involvement of the upper urinary tract and kidney disease. The disorder can also create substantial embarrassment resulting in social isolation for affected patients. Healthcare utilization may be excessive in patients with neurogenic bladder, including office and emergency department visits and subsequent hospitalizations. Because of its significant effects on quality of life, it is important to reassess the epidemiology and physiology of neurogenic bladder, its diagnosis and assessment, and the impact of the symptoms and complications associated with it to better manage patients with this disorder and improve outcomes.
James A. Waschek
Full Text Available New neurons are born throughout the life of mammals in germinal zones of the brain known as neurogenic niches: the subventricular zone of the lateral ventricles and the subgranular zone of the dentate gyrus of the hippocampus. These niches contain a subpopulation of cells known as adult neural progenitor cells (aNPCs, which self-renew and give rise to new neurons and glia. aNPCs are regulated by many factors present in the niche, including the extracellular matrix (ECM. We show that the neuropeptide PACAP (pituitary adenylate cyclase-activating polypeptide affects subventricular zone-derived aNPCs by increasing their surface adhesion. Gene array and reconstitution assays indicate that this effect can be attributed to the regulation of ECM components and ECM-modifying enzymes in aNPCs by PACAP. Our work suggests that PACAP regulates a bidirectional interaction between the aNPCs and their niche: PACAP modifies ECM production and remodeling, in turn the ECM regulates progenitor cell adherence. We speculate that PACAP may in this manner help restrict adult neural progenitors to the stem cell niche in vivo, with potential significance for aNPC function in physiological and pathological states.
Balashov, Iu S
On mammals and birds communities of ectoparasites are present, which can include scores of ticks, mites and insects species. The parasitizing of arthropods terrestrial vertebrates appeared as far back a the Cretaceous period, and after 70-100 mil. years of the coevolution ectoparasites have assimilated all food resources and localities of the hosts' bodies. To the present only spatial and (to the less extent) trophic niches of parasitic insects, ticks and mites are studied completely enough. The main results these investigations are discussed in the present paper. A high abundance of the communities is reached because of their partition into the number of ecological niches. Host is complex of ecological niches for many ectoparasites species. These niches reiterate in the populations of a species closely related species of hosts and repeat from generation to generation. The each part of host (niche) being assimilated be certain parasite species is available potentially for other species. The partition of host into ecological niches is clearer than the structure of ecosystems including free-living organisms. A real extent of the ecological niches occupation by different species of ticks, mites and insects is considerably lower than a potential maximum. The degree of ecological niches saturation depends on the history of the coevolution of parasites community components, previous colonization be new ectoparasite species and many other ecological factors affecting host-parasite system. The use of the ecological niche conception in parasitology is proved to be rather promising. Ectoparasites communities because of their species diversity, different types of feeding and a number of habitats on host represent convenient models and study of them can contribute significantly to the developmeht of the general conception of ecological niche.
Full Text Available Mediastinal neurogenic tumours generally arise as single benign lesions and their typical location is the costovertebral sulcus. In about 10% of cases mediastinal neurogenic tumours may extend to the spinal canal; occasionally they may extend to the cervical region and, more rarely, may be multiple or associated with other synchronous mediastinal lesions. The treatment of choice is surgical resection. This report describes three cases of unusual presentation of mediastinal benign schwannomas successfully treated at our Hospital. In the first case multiple simultaneous paravertebral lesions were resected through a posterior approach. In the second case a tumour of the posterior mediastinum extending to the cervical region was excised through a one-stage combined supraclavicular incision followed by left mini-invasive video-assisted thoracoscopic surgical techniques. The third case describes a patient with a posterior neurogenic mediastinal tumour with a synchronous parathyroid adenoma of the anterior mediastinum, which were both successfully resected by video-assisted thoracoscopic surgery.
J. D. Duffy
Full Text Available A case of neurogenic stuttering induced by the monoamine oxidase inhibitor tranylcypromine is described. The association of neurogenic stuttering with acquired lateralized motor deficits in the patient described is discussed with reference to current theories regarding the pathogenesis of neurogenic stuttering.
Rikken, Berend; Blok, Bertil F M
Preventive measurements are obligatory for optimal treatment of neurogenic bladder patients. We investigated Dutch urological practice in neurogenic bladder patients in relation to the available guidelines on neurogenic bladder. A 12-point survey was sent to all 304 certified urologists of the Dutch Urological Association in July 2007. Management of urinary tract infections (UTI), follow-up of the lower and upper urinary tract and treatment techniques were topics of inquiry. The response rate was 46% of which 94% were involved in treatment of neurogenic bladder patients. Follow-up was performed every 6 or 12 months in 86%, urine analysis respectively in 85% and upper urinary tract imaging with ultrasound in 60%; only 12% routinely repeated urodynamics. Uncomplicated UTI was treated for 7.1 days in women and 9.2 days in males. Eighteen percent used the EAU guidelines on neurogenic bladder frequently, 35% did occasionally and 47% did not use them at all. Urologists, that used these guidelines frequently, treated asymptomatic UTIs significantly less frequent in patients on intermittent catheterization (5% vs. 25%; P = 0.008); no difference was found in frequency of follow-up, urine analysis, surveillance of upper urinary tract, use of routine urodynamics, and availability of treatment techniques. Video urodynamics, the golden standard, was used by only 11% of the adult urologists. The majority of Dutch urologists is involved in the treatment of neurogenic bladder, which suggests a less prominent role for specialized centers. Furthermore, urodynamics are not performed routinely. These observations are contrary to the recommendations of the available guidelines. (c) 2008 Wiley-Liss, Inc.
Full Text Available Blayne Welk,1 Sarah A Morrow,2 Wendy Madarasz,3 Patrick Potter,4 Keith Sequeira41Department of Surgery, Division of Urology, 2Department of Clinical Neurosciences, Western University, London, ON, Canada; 3St Joseph's Health Care, London Ontario, Canada; 4Department of Physical Medicine and Rehabilitation, Western University, London, ON, CanadaBackground: There is no single patient-reported instrument that was developed specifically to assess symptoms and bladder-related consequences for neurogenic bladder dysfunction. The purpose of this study was to identify and consolidate items for a novel measurement tool for this population.Methods: Item generation was based on a literature review of existing instruments, open-ended semistructured interviews with patients, and expert opinion. Judgment-based item reduction was performed by a multidisciplinary expert group. The proposed questionnaire was sent to external experts for review.Results: Eight neurogenic quality of life measures and 29 urinary symptom-specific instruments were identified. From these, 266 relevant items were extracted and used in the creation of the new neurogenic symptom score. Qualitative interviews with 16 adult patients with neurogenic bladder dysfunction as a result of spinal cord injury, multiple sclerosis, or spina bifida were completed. Dominant themes included urinary incontinence, urinary tract infections, urgency, and bladder spasms. Using the literature review and interview data, 25 proposed items were reviewed by 12 external experts, and the questions evaluated based on importance on a scale of 1 (not important to 5 (very important. Retained question domains had high mean importance ratings of 3.1 to 4.3 and good agreement with answer hierarchy.Conclusion: The proposed neurogenic bladder symptom score is a novel patient-reported outcome measure. Further work is underway to perform a data-based item reduction and to assess the validity and reliability of this instrument
Rendell, Luke; Fogarty, Laurel; Laland, Kevin N.
Cultural niche construction is a uniquely potent source of selection on human populations, and a major cause of recent human evolution. Previous theoretical analyses have not, however, explored the local effects of cultural niche construction. Here, we use spatially explicit coevolutionary models to investigate how cultural processes could drive selection on human genes by modifying local resources. We show that cultural learning, expressed in local niche construction, can trigger a process with dynamics that resemble runaway sexual selection. Under a broad range of conditions, cultural niche-constructing practices generate selection for gene-based traits and hitchhike to fixation through the build up of statistical associations between practice and trait. This process can occur even when the cultural practice is costly, or is subject to counteracting transmission biases, or the genetic trait is selected against. Under some conditions a secondary hitchhiking occurs, through which genetic variants that enhance the capability for cultural learning are also favoured by similar dynamics. We suggest that runaway cultural niche construction could have played an important role in human evolution, helping to explain why humans are simultaneously the species with the largest relative brain size, the most potent capacity for niche construction and the greatest reliance on culture. PMID:21320897
Zutelija Fattorini, Matija; Gagro, Alenka; Dapic, Tomislav; Krakar, Goran; Marjanovic, Josip
Muscular hypertrophy secondary to denervation is very rare, but well-documented phenomena in adults. This is the first report of a child with neurogenic unilateral hypertrophy due to S1 radiculopathy. A 12-year-old girl presented with left calf hypertrophy and negative history of low back pain or trauma. The serum creatinine kinase level and inflammatory markers were normal. Magnetic resonance imaging showed muscle hypertrophy of the left gastrocnemius and revealed a protruded lumbar disc at the L5-S1 level. The protruded disc abuts the S1 root on the left side. Electromyography showed mild left S1 radiculopathy. Passive stretching and work load might clarify the origin of neurogenic hypertrophy but there is still a need for further evidence. Clinical, laboratory, magnetic resonance imaging and electromyography findings showed that S1 radiculopathy could be a cause of unilateral calf swelling in youth even in the absence of a history of back or leg pain. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
Šedý, Jiří; Kuneš, Jaroslav; Zicha, Josef
Roč. 32, č. 15 (2015), s. 1135-1145 ISSN 0897-7151 R&D Projects: GA ČR(CZ) GAP304/12/0259 Institutional support: RVO:67985823 Keywords : baroreflex-induced bradycardia * blood pressure rise * blood volume redistribution * neurogenic pulmonary edema * spinal cord injury * sympathetic nervous system Subject RIV: ED - Physiology Impact factor: 4.377, year: 2015
Charlotte Q. Wu
Full Text Available Vesicoureteral reflux (VUR is a significant risk factor for pyelonephritis and renal scarring. VUR can occur through a defective ureterovesical junction (UVJ or an overwhelmed normal UVJ mechanism such as in bladder dysfunction of congenital, acquired, or behavioral etiology. There are numerous causes for the development of a neurogenic bladder from spinal dysraphisms to spinal cord trauma and even centrally based abnormalities in children with apparently normal motor function (inappropriately termed nonneurogenic neurogenic bladder. The foundation of managing reflux in these neurogenic bladders is to maintain low bladder pressures which will commonly mean that compliance will be normal as well. There have been several publications that have shown that if bladder pressures are lowered simply with clean intermittent catheterization and medications that the reflux can resolve spontaneously. Alternatively, the patients that are in need of bladder augmentation can have spontaneous resolution of their reflux with the resulting increase in capacity. Surgical intervention is called for when bladder capacity is adequate and the reflux persists or if it is part of a larger operation to increase capacity and to manage outlet resistance. In some instances, reimplantation is necessary because the ureters interfere with the bladder neck procedure. Aside from open and robotic surgical intervention the use of endoscopic injectable agents is beginning to become more popular especially when combined with intravesical botulinum toxin A injections. Great strides are being made in the management of patients with neurogenic bladders and we are seeing more choices for the urologist to be able to manage these patients.
Full Text Available Current advances in imaging techniques have extended the possibility of visualizing small structures within large volumes of both fixed and live specimens without sectioning. These techniques have contributed valuable information to study neuronal plasticity in the adult brain. However, technical limits still hamper the use of these approaches to investigate neurogenic regions located far from the ventricular surface such as parenchymal neurogenic niches, or the scattered neuroblasts induced by brain lesions. Here, we present a method to combine confocal laser scanning microscopy (CLSM and serial section reconstruction in order to reconstruct large volumes of brain tissue at cellular resolution. In this method a series of thick sections are imaged with CLSM and the resulting stacks of images are registered and 3D reconstructed. This approach is based on existing freeware software and can be performed on ordinary laboratory personal computers (PC. By using this technique we have investigated the morphology and spatial organization of a group of doublecortin (DCX+ neuroblasts located in the lateral striatum of the late post-natal guinea pig. The 3D study unravelled a complex network of long and poorly ramified cell processes, often fascicled and mostly oriented along the internal capsule fibre bundles. These data support CLSM serial section reconstruction as a reliable alternative to the whole mount approaches to analyze cyto-architectural features of adult germinative niches.
Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas
Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.
Full Text Available Gonadotropin-releasing hormone (GnRH is a hypothalamic decapeptide essential for fertility in vertebrates. Human male patients lacking GnRH and treated with hormone therapy can remain fertile after cessation of treatment suggesting that new GnRH neurons can be generated during adult life. We used zebrafish to investigate the neurogenic potential of the adult hypothalamus. Previously we have characterized the development of GnRH cells in the zebrafish linking genetic pathways to the differentiation of neuromodulatory and endocrine GnRH cells in specific regions of the brain. Here, we developed a new method to obtain neural progenitors from the adult hypothalamus in vitro. Using this system, we show that neurospheres derived from the adult hypothalamus can be maintained in culture and subsequently differentiate glia and neurons. Importantly, the adult derived progenitors differentiate into neurons containing GnRH and the number of cells is increased through exposure to either testosterone or GnRH, hormones used in therapeutic treatment in humans. Finally, we show in vivo that a neurogenic niche in the hypothalamus contains GnRH positive neurons. Thus, we demonstrated for the first time that neurospheres can be derived from the hypothalamus of the adult zebrafish and that these neural progenitors are capable of producing GnRH containing neurons.
Peterson T. Leivas
Full Text Available Lithobates catesbeianus (Shaw, 1802 is an invasive anuran introduced in Brazil that is associated with the displacement and the decline of populations of native species worldwide. There is evidence that biological invasions are facilitated by certain attributes of the invading species, for instance niche breath, and that invasive species have a broader ecological niche with respect to native ones. We designed a study to ascertain the temporal, ontogenetic, and sex differences in the niche dynamics of the American bullfrog. We sampled monthly from June 2008 to May 2009 in the state of Paraná, southern Brazil. For each individual, we gathered biometric and stomach content data. We then estimated the niche breath of the juveniles and adults, and compared it between the sexes. A total of 104 females and 77 males were sampled. Lithobates catesbeianus has a generalist diet, preying upon invertebrates and vertebrates. Even though the diet of the studied population varied seasonally, it did not differ between the sexes nor did it respond to biometric variables. Niche breadth was more restricted in the winter than in the autumn. The trophic niche of juveniles and adults did not overlap much when compared with the trophic niche overlap between males and females. Adult males and females had a considerable niche overlap, but females had a broader trophic niche than males in the winter and in the spring. These niche characteristics point to an opportunistic predation strategy that may have facilitated the process of invasion and establishment of this species in the study area.
Jahromi, Mona S; Mure, Amanda; Gomez, Christopher S
Urinary tract infections (UTI) remain one of the most prevalent and frustrating morbidities for neurogenic bladder patients, and death attributed to urosepsis in the spinal cord injury (SCI) patient is higher when compared to the general population. Risk factors include urinary stasis, high bladder pressures, bladder stones, and catheter use. While classic symptoms of UTI include dysuria, increased frequency and urgency, neurogenic bladder patients present differently with increased spasticity, autonomic dysreflexia, urinary incontinence, and vague pains. Multiple modalities have been assessed for prevention including catheter type, oral supplements, bladder irrigation, detrusor injections and prophylactic antimicrobials. Of these, bladder inoculation with E. coli HU2117, irrigation with iAluRil(®), detrusor injections, and weekly prophylaxis with alternating antibiotics appear to have a positive reduction in UTI but require further study. Ultimately, treatment for symptomatic UTI should account for the varied flora and possible antibiotic resistances including relying on urine cultures to guide antibiotic therapy.
Gebara, Elias; Bonaguidi, Michael Anthony; Beckervordersandforth, Ruth; Sultan, Sébastien; Udry, Florian; Gijs, Pieter-Jan; Lie, Dieter Chichung; Ming, Guo-Li; Song, Hongjun; Toni, Nicolas
Adult neurogenesis is tightly regulated by the neurogenic niche. Cellular contacts between niche cells and neural stem cells are hypothesized to regulate stem cell proliferation or lineage choice. However, the structure of adult neural stem cells and the contact they form with niche cells are poorly described. Here, we characterized the morphology of radial glia-like (RGL) cells, their molecular identity, proliferative activity, and fate determination in the adult mouse hippocampus. We found the coexistence of two morphotypes of cells with prototypical morphological characteristics of RGL stem cells: Type α cells, which represented 76% of all RGL cells, displayed a long primary process modestly branching into the molecular layer and type β cells, which represented 24% of all RGL cells, with a shorter radial process highly branching into the outer granule cell layer-inner molecular layer border. Stem cell markers were expressed in type α cells and coexpressed with astrocytic markers in type β cells. Consistently, in vivo lineage tracing indicated that type α cells can give rise to neurons, astrocytes, and type β cells, whereas type β cells do not proliferate. Our results reveal that the adult subgranular zone of the dentate gyrus harbors two functionally different RGL cells, which can be distinguished by simple morphological criteria, supporting a morphofunctional role of their thin cellular processes. Type β cells may represent an intermediate state in the transformation of type α, RGL stem cells, into astrocytes. © 2016 AlphaMed Press.
Taweel, Waleed Al; Seyam, Raouf
Waleed Al Taweel, Raouf SeyamDepartment of Urology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi ArabiaAbstract: Neurogenic bladder dysfunction due to spinal cord injury poses a significant threat to the well-being of patients. Incontinence, renal impairment, urinary tract infection, stones, and poor quality of life are some complications of this condition. The majority of patients will require management to ensure low pressure reservoir function of the bladder, complete...
Project focusing on developing a public affairs advice for the corporate business case aiming at development of LNG niche market. The advice is based on research in five areas: (1) an overview of existent regulatory framework with regard to the use of LNG in a small scale market in the EU and
Peinado, Héctor; Zhang, Haiying; Matei, Irina R.
-secreted factors and tumour-shed extracellular vesicles that enable the 'soil' at distant metastatic sites to encourage the outgrowth of incoming cancer cells. In this Review, we summarize the main processes and new mechanisms involved in the formation of the pre-metastatic niche....
Al Taweel W
Full Text Available Waleed Al Taweel, Raouf SeyamDepartment of Urology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi ArabiaAbstract: Neurogenic bladder dysfunction due to spinal cord injury poses a significant threat to the well-being of patients. Incontinence, renal impairment, urinary tract infection, stones, and poor quality of life are some complications of this condition. The majority of patients will require management to ensure low pressure reservoir function of the bladder, complete emptying, and dryness. Management typically begins with anticholinergic medications and clean intermittent catheterization. Patients who fail this treatment because of inefficacy or intolerability are candidates for a spectrum of more invasive procedures. Endoscopic managements to relieve the bladder outlet resistance include sphincterotomy, botulinum toxin injection, and stent insertion. In contrast, patients with incompetent sphincters are candidates for transobturator tape insertion, sling surgery, or artificial sphincter implantation. Coordinated bladder emptying is possible with neuromodulation in selected patients. Bladder augmentation, usually with an intestinal segment, and urinary diversion are the last resort. Tissue engineering is promising in experimental settings; however, its role in clinical bladder management is still evolving. In this review, we summarize the current literature pertaining to the pathology and management of neurogenic bladder dysfunction in patients with spinal cord injury.Keywords: neurogenic bladder, spinal cord injury, urodynamics, intestine, intermittent catheterization
Lakkireddigari, Siva Kumar Reddy; Durga, Padmaja; Nayak, Madhukar; Ramchandran, Gopinath
Neurogenic pulmonary edema may be a less-recognized consequence of obstructive hydrocephalus. The authors report a patient with acute obstructive hydrocephalus due to cerebellar metastatic lesion, who presented with neurogenic pulmonary edema. The edema resolved on placement of the ventriculoperitonial shunt. This report addresses the importance of recognition of neurogenic pulmonary edema as a possible perioperative complication resulting from an increase in intracranial pressure and the iss...
OLANDOSKI, Karen Previdi; KOCH, Vera; TRIGO-ROCHA, Flavio Eduardo
AIMS: Preservation of renal function in children with congenital neurogenic bladder is an important goal of treatment for the disease. This study analyzed the evolution of renal function in patients with congenital neurogenic bladder. METHODS: We reviewed the records of 58 pediatric patients with respect to the following attributes: gender, age, etiology of neurogenic bladder, reason for referral, medical/surgical management, episodes of treated urinary tract infections, urodynamics, DMSA sci...
Siva Kumar Reddy Lakkireddigari
Full Text Available Neurogenic pulmonary edema may be a less-recognized consequence of obstructive hydrocephalus. The authors report a patient with acute obstructive hydrocephalus due to cerebellar metastatic lesion, who presented with neurogenic pulmonary edema. The edema resolved on placement of the ventriculoperitonial shunt. This report addresses the importance of recognition of neurogenic pulmonary edema as a possible perioperative complication resulting from an increase in intracranial pressure and the issues involved with anesthetic management of co-existing neurogenic pulmonary edema and intracranial hypertension.
Rufus H. Gouws
Full Text Available
Abstract: Niching is a macrostructural procedure of textual condensation which results in different dictionary articles being clustered into one textblock as subarticles headed by sublemmata. This article offers an identification and critical discussion of different types of niching. Examples from dictionaries are used to examine problems which dictionary users experience as a result of the application of niching. The emphasis is on problems regarding the search route of users via the outer access structure of dictionaries. A distinction is made between single niching and multiple niching. Different aspects of multiple niching receive attention, e.g. the use of remote and exclusively remote multiple niching. The focus is also on an increased degree of textual condensation resulting from these procedures as well as problems in the domain of the access structure. Attention is drawn to the influence of the inclusion of homonym pairs on the application of multiple niching. Problems arising from an inconsistent application of multiple niching are identified and solutions are suggested for these problems in order to enhance the quality of the lexicographic practice. It is shown that a user-driven dictionary would rather opt for the application of procedures of single niching and first level nesting instead of multiple niching.
Keywords: EXCLUSIVELY REMOTE MULTIPLE NICHING, FIRST LEVEL NESTING, HETEROGENEOUS NICHING, HOMOGENEOUS NICHING, HYBRID NICHING, MULTIPLE NICHING, NESTING, NICHING, PARTIAL ARTICLE STRETCH, REMOTE NICHING, SINGLE NICHING, TEXTUAL CONDENSATION
Opsomming: Nisting as 'n makrostrukturele prosedure. Nisting is 'n makrostrukturele teksverdigtingsprosedure waardeur woordeboekartikels in een teksblok as subartikels met sublemmata gegroepeer word. Hierdie artikel bevat 'n beskrywing en kritiese bespreking van verskillende tipes nisting. Aan die hand van woordeboekvoorbeelde word probleme wat gebruikers met die toepassing
Full Text Available Calretinin (CR and calbindin D-28k (CB are cytosolic EF-hand Ca2+-binding proteins and function as Ca2+ buffers affecting the spatiotemporal aspects of Ca2+ transients and possibly also as Ca2+ sensors modulating signaling cascades. In the adult hippocampal circuitry, CR and CB are expressed in specific principal neurons and subsets of interneurons. In addition, CR is transiently expressed within the neurogenic dentate gyrus (DG niche. CR and CB expression during adult neurogenesis mark critical transition stages, onset of differentiation for CR and the switch to adult-like connectivity for CB. Absence of either protein during these stages in null-mutant mice may have functional consequences and contribute to some aspects of the identified phenotypes. We report the impact of CR- and CB-deficiency on the proliferation and differentiation of progenitor cells within the subgranular zone (SGZ neurogenic niche of the DG. Effects were evaluated I 2 and 4 weeks postnatally, during the transition period of the proliferative matrix to the adult state, and II in adult animals (3 months to trace possible permanent changes in adult neurogenesis. The absence of CB from differentiated DG granule cells has no retrograde effect on the proliferative activity of progenitor cells, nor affects survival or migration/differentiation of newborn neurons in the adult DG including the SGZ. On the contrary, lack of CR from immature early postmitotic granule cells causes an early loss in proliferative capacity of the SGZ that is maintained into adult age, when it has a further impact on the migration/survival of newborn granule cells. The transient CR expression at the onset of adult neurogenesis differentiation may thus have two functions: I to serve as a self-maintenance signal for the pool of cells at the same stage of neurogenesis contributing to their survival/differentiation, and II it may contribute to retrograde signaling required for maintenance of the progenitor
McKibben, Maxim J; Seed, Patrick; Ross, Sherry S; Borawski, Kristy M
Urinary tract infections (UTIs) are frequent, recurrent, and lifelong for patients with neurogenic bladder and present challenges in diagnosis and treatment. Patients often present without classic symptoms of UTI but with abdominal or back pain, increased spasticity, and urinary incontinence. Failure to recognize and treat infections can quickly lead to life-threatening autonomic dysreflexia or sepsis, whereas overtreatment contributes to antibiotic resistance, thus limiting future treatment options. Multiple prevention methods are used but evidence-based practices are few. Prevention and treatment of symptomatic UTI requires a multimodal approach that focuses on bladder management as well as accurate diagnosis and appropriate antibiotic treatment. Copyright © 2015 Elsevier Inc. All rights reserved.
Šedý, Jiří; Zicha, Josef; Kuneš, Jaroslav; Jendelová, Pavla; Syková, Eva
Roč. 57, č. 4 (2008), s. 499-506 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA ČR GA309/06/1246; GA MŠk 1M0538 Grant - others:GA MZd(CZ) 1A8697; GA MZd(CZ) NR8339 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50110509 Keywords : Neurogenic pulmonary edema * Rat * Lung Subject RIV: FH - Neurology Impact factor: 1.653, year: 2008
Ben W. Dulken
Full Text Available Neural stem cells (NSCs in the adult mammalian brain serve as a reservoir for the generation of new neurons, oligodendrocytes, and astrocytes. Here, we use single-cell RNA sequencing to characterize adult NSC populations and examine the molecular identities and heterogeneity of in vivo NSC populations. We find that cells in the NSC lineage exist on a continuum through the processes of activation and differentiation. Interestingly, rare intermediate states with distinct molecular profiles can be identified and experimentally validated, and our analysis identifies putative surface markers and key intracellular regulators for these subpopulations of NSCs. Finally, using the power of single-cell profiling, we conduct a meta-analysis to compare in vivo NSCs and in vitro cultures, distinct fluorescence-activated cell sorting strategies, and different neurogenic niches. These data provide a resource for the field and contribute to an integrative understanding of the adult NSC lineage.
Batailler, Martine; Derouet, Laura; Butruille, Lucile; Migaud, Martine
Adult neurogenesis, a process that consists in the generation of new neurons from adult neural stem cells, represents a remarkable illustration of the brain structural plasticity abilities. The hypothalamus, a brain region that plays a key role in the neuroendocrine regulations including reproduction, metabolism or food intake, houses neural stem cells located within a hypothalamic neurogenic niche. In adult sheep, a seasonal mammalian species, previous recent studies have revealed photoperiod-dependent changes in the hypothalamic cell proliferation rate. In addition, doublecortin (DCX), a microtubule-associated protein expressed in immature migrating neurons, is highly present in the vicinity of the hypothalamic neurogenic niche. With the aim to further explore the mechanism underlying adult sheep hypothalamic neurogenesis, we first show that new neuron production is also seasonally regulated since the density of DCX-positive cells changes according to the photoperiodic conditions at various time points of the year. We then demonstrate that cyclin-dependant kinase-5 (Cdk5) and p35, two proteins involved in DCX phosphorylation and known to be critically involved in migration processes, are co-expressed with DCX in young hypothalamic neurons and are capable of in vivo interaction. Finally, to examine the migratory potential of these adult-born neurons, we reveal the rostro-caudal extent of DCX labeling on hypothalamic sagittal planes. DCX-positive cells are found in the most rostral nuclei of the hypothalamus, including the preoptic area many of which co-expressed estrogen receptor-α. Thus, beyond the confirmation of the high level of neuron production during short photoperiod in sheep, our results bring new and compelling elements in support of the existence of a hypothalamic migratory path that is responsive to seasonal stimuli.
Terradas, J.; Penuelas, J.; Lloret, F.; Penuelas, J.
Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and eco physiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and inter annual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.
Full Text Available Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and ecophysiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and interannual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.
Taweel, Waleed Al; Seyam, Raouf
Neurogenic bladder dysfunction due to spinal cord injury poses a significant threat to the well-being of patients. Incontinence, renal impairment, urinary tract infection, stones, and poor quality of life are some complications of this condition. The majority of patients will require management to ensure low pressure reservoir function of the bladder, complete emptying, and dryness. Management typically begins with anticholinergic medications and clean intermittent catheterization. Patients who fail this treatment because of inefficacy or intolerability are candidates for a spectrum of more invasive procedures. Endoscopic managements to relieve the bladder outlet resistance include sphincterotomy, botulinum toxin injection, and stent insertion. In contrast, patients with incompetent sphincters are candidates for transobturator tape insertion, sling surgery, or artificial sphincter implantation. Coordinated bladder emptying is possible with neuromodulation in selected patients. Bladder augmentation, usually with an intestinal segment, and urinary diversion are the last resort. Tissue engineering is promising in experimental settings; however, its role in clinical bladder management is still evolving. In this review, we summarize the current literature pertaining to the pathology and management of neurogenic bladder dysfunction in patients with spinal cord injury.
Salomon, J; Gory, A; Bernard, L; Ruffion, A; Denys, P; Chartier-Kastler, E
One of the main complications of spinal cord injury is neurogenic bladder when the bladder fails to empty spontaneously. Urinary tract infection is the leading cause of morbidity and the second cause of mortality in these subjects. Patient education and personalized medical follow-up must ensure adapted management depending on the risk factors and the voiding mode. The risk of urinary tract infection can be decreased by perfect neurological control of detrusor activity combined with a method of drainage: intermittent self-catheterization. Despite these measures, many patients experience recurrent symptomatic urinary tract infections. Repeated antibiotic therapy increases the risk of selection of multiresistant bacteria without reducing either the incidence or the severity of symptomatic urinary tract infections. Asymptomatic bacteriuria is very frequent in patients treated by intermittent catheterization and does not justify antibiotic therapy, as antiseptics and urinary alkalinizers or acidifiers have been shown to be effective. "Antibiocycle" strategies could have a beneficial role by significantly decreasing the number of infections and hospitalizations with no major ecological risks, by using molecules that are well tolerated orally with a low selection pressure. All febrile urinary tract infections require rapid investigation and an urgent urological and infectious diseases opinion (abscess, severe sepsis, resistance). The SPILF-AFU 2002 consensus conference provided answers to major questions concerning the definition, treatment and prevention of nosocomial urinary tract infection, especially in a context of neurogenic bladder.
Mohammad A. Al-Drees
Full Text Available Approximately one-quarter of all cells in the adult human body are blood cells. The haematopoietic system is therefore massive in scale and requires exquisite regulation to be maintained under homeostatic conditions. It must also be able to respond when needed, such as during infection or following blood loss, to produce more blood cells. Supporting cells serve to maintain haematopoietic stem and progenitor cells during homeostatic and pathological conditions. This coalition of supportive cell types, organised in specific tissues, is termed the haematopoietic niche. Haematopoietic stem and progenitor cells are generated in a number of distinct locations during mammalian embryogenesis. These stem and progenitor cells migrate to a variety of anatomical locations through the conceptus until finally homing to the bone marrow shortly before birth. Under stress, extramedullary haematopoiesis can take place in regions that are typically lacking in blood-producing activity. Our aim in this review is to examine blood production throughout the embryo and adult, under normal and pathological conditions, to identify commonalities and distinctions between each niche. A clearer understanding of the mechanism underlying each haematopoietic niche can be applied to improving ex vivo cultures of haematopoietic stem cells and potentially lead to new directions for transplantation medicine.
Wang, Su; Gao, Yuan; Song, Xiaoqing; Ma, Xing; Zhu, Xiujuan; Mao, Ying; Yang, Zhihao; Ni, Jianquan; Li, Hua; Malanowski, Kathryn E; Anoja, Perera; Park, Jungeun; Haug, Jeff; Xie, Ting
Adult stem cells continuously undergo self-renewal and generate differentiated cells. In the Drosophila ovary, two separate niches control germ line stem cell (GSC) self-renewal and differentiation processes. Compared to the self-renewing niche, relatively little is known about the maintenance and function of the differentiation niche. In this study, we show that the cellular redox state regulated by Wnt signaling is critical for the maintenance and function of the differentiation niche to promote GSC progeny differentiation. Defective Wnt signaling causes the loss of the differentiation niche and the upregulated BMP signaling in differentiated GSC progeny, thereby disrupting germ cell differentiation. Mechanistically, Wnt signaling controls the expression of multiple glutathione-S-transferase family genes and the cellular redox state. Finally, Wnt2 and Wnt4 function redundantly to maintain active Wnt signaling in the differentiation niche. Therefore, this study has revealed a novel strategy for Wnt signaling in regulating the cellular redox state and maintaining the differentiation niche.
Fatima, Nikhat; Khan, Aleem A; Vishwakarma, Sandeep K
Growing evidence shows that dental pulp (DP) tissues could be a potential source of adult stem cells for the treatment of devastating neurological diseases and several other conditions. Exploration of the expression profile of several key molecular markers to evaluate the molecular dynamics in undifferentiated and differentiated DP-derived stem cells (DPSCs) in vitro . The characteristics and multilineage differentiation ability of DPSCs were determined by cellular and molecular kinetics. DPSCs were further induced to form adherent (ADH) and non-ADH (NADH) neurospheres under serum-free condition which was further induced into neurogenic lineage cells and characterized for their molecular and cellular diversity at each stage. Statistical analysis used one-way analysis of variance, Student's t -test, Livak method for relative quantification, and R programming. Immunophenotypic analysis of DPSCs revealed >80% cells positive for mesenchymal markers CD90 and CD105, >70% positive for transferring receptor (CD71), and >30% for chemotactic factor (CXCR3). These cells showed mesodermal differentiation also and confirmed by specific staining and molecular analysis. Activation of neuronal lineage markers and neurogenic growth factors was observed during lineage differentiation of cells derived from NADH and ADH spheroids. Greater than 80% of cells were found to express β-tubulin III in both differentiation conditions. The present study reported a cascade of immunophenotypic and molecular markers to characterize neurogenic differentiation of DPSCs under serum-free condition. These findings trigger the future analyses for clinical applicability of DP-derived cells in regenerative applications.
Seipel, R.; Langner, S.; Lippa, M.; Kuehn, J.P.; Hosten, N.; Platz, T.
To retrospectively evaluate neurogenic heterotopic ossification in an early neurological rehabilitation population (phases B and C) with respect to epidemiology and morphology on conventional radiographs. Over a 4-year period, 1,463 patients treated at a clinic for early neurological rehabilitation were evaluated for clinical symptoms of neurogenic heterotopic ossification. In case of clinical suspicion, plain radiographs of the expected sites were obtained. If heterotopic ossification was detected, the initial and subsequent radiographs were retrospectively analyzed for sites, size, and morphology. Immature lesions were categorized as small (<10 mm) or large (10-100 mm). The prevalence rate of neurogenic heterotopic ossification was 2.05%. The condition was most common in young male adults. The hip was the most common site accounting for more than half of the cases. Two or more ossifications were seen in 56.7% of the affected patients with approximately two-thirds showing bilateral symmetric involvement of corresponding joint regions. The size of ossifications strongly varied interindividually. Small immature lesions demonstrated less progression in size than large lesions during maturation (P < 0.05). Standard radiographs, as a fast and inexpensive technique, allow the expected size progression of heterotopic ossifications during maturation to be estimated, which is relevant in terms of therapeutic decisions, patient mobilization, and neurological rehabilitation. (orig.)
Ribeiro Xavier, Anna L.; Kress, Benjamin T.; Goldman, Steven A.
Microglia are involved in synaptic pruning both in development and in the mature CNS. In this study, we investigated whether microglia might further contribute to circuit plasticity by modulating neuronal recruitment from the neurogenic subventricular zone (SVZ) of the adult mouse striatum. We fo...... toward olfactory bulb layers. In addition to other unique populations residing in the SVZ niche, microglia display distinct morphofunctional properties that boost neuronal progenitor survival and migration in the mammalian brain.......Microglia are involved in synaptic pruning both in development and in the mature CNS. In this study, we investigated whether microglia might further contribute to circuit plasticity by modulating neuronal recruitment from the neurogenic subventricular zone (SVZ) of the adult mouse striatum. We...... that is selectively adapted to the support and direction of neuronal integration into the olfactory circuitry. Therefore, this unique microglial subpopulation may serve as a novel target with which to modulate cellular addition from endogenous neural stem and progenitor cells of the adult brain. SIGNIFICANCE...
Greenspan, Leah J; Matunis, Erika L
Live imaging of adult tissue stem cell niches provides key insights into the dynamic behavior of stem cells, their differentiating progeny, and their neighboring support cells, but few niches are amenable to this approach. Here we discuss a technique for long-term live imaging of the Drosophila testis stem cell niche. Culturing whole testes ex vivo for up to 12.5 h allows for tracking of cell-type specific behaviors under normal and various chemically or genetically modified conditions. Fixing and staining tissues after live imaging allows for the molecular confirmation of cell identity and behavior. Utilization of live imaging in intact niches will facilitate further understanding of the cellular and molecular mechanisms that regulate stem cell function in vivo.
Vigil, Humberto R.
There is a high incidence of urinary tract infection (UTI) in patients with neurogenic lower urinary tract function. This results in significant morbidity and health care utilization. Multiple well-established risk factors unique to a neurogenic bladder (NB) exist while others require ongoing investigation. It is important for care providers to have a good understanding of the different structural, physiological, immunological and catheter-related risk factors so that they may be modified when possible. Diagnosis remains complicated. Appropriate specimen collection is of paramount importance and a UTI cannot be diagnosed based on urinalysis or clinical presentation alone. A culture result with a bacterial concentration of ≥103 CFU/mL in combination with symptoms represents an acceptable definition for UTI diagnosis in NB patients. Cystoscopy, ultrasound and urodynamics should be utilized for the evaluation of recurrent infections in NB patients. An acute, symptomatic UTI should be treated with antibiotics for 5–14 days depending on the severity of the presentation. Antibiotic selection should be based on local and patient-based resistance patterns and the spectrum should be as narrow as possible if there are no concerns regarding urosepsis. Asymptomatic bacteriuria (AB) should not be treated because of rising resistance patterns and lack of clinical efficacy. The most important preventative measures include closed catheter drainage in patients with an indwelling catheter and the use of clean intermittent catheterization (CIC) over other methods of bladder management if possible. The use of hydrophilic or impregnated catheters is not recommended. Intravesical Botox, bacterial interference and sacral neuromodulation show significant promise for the prevention of UTIs in higher risk NB patients and future, multi-center, randomized controlled trials are required. PMID:26904414
Vigil, Humberto R; Hickling, Duane R
There is a high incidence of urinary tract infection (UTI) in patients with neurogenic lower urinary tract function. This results in significant morbidity and health care utilization. Multiple well-established risk factors unique to a neurogenic bladder (NB) exist while others require ongoing investigation. It is important for care providers to have a good understanding of the different structural, physiological, immunological and catheter-related risk factors so that they may be modified when possible. Diagnosis remains complicated. Appropriate specimen collection is of paramount importance and a UTI cannot be diagnosed based on urinalysis or clinical presentation alone. A culture result with a bacterial concentration of ≥10(3) CFU/mL in combination with symptoms represents an acceptable definition for UTI diagnosis in NB patients. Cystoscopy, ultrasound and urodynamics should be utilized for the evaluation of recurrent infections in NB patients. An acute, symptomatic UTI should be treated with antibiotics for 5-14 days depending on the severity of the presentation. Antibiotic selection should be based on local and patient-based resistance patterns and the spectrum should be as narrow as possible if there are no concerns regarding urosepsis. Asymptomatic bacteriuria (AB) should not be treated because of rising resistance patterns and lack of clinical efficacy. The most important preventative measures include closed catheter drainage in patients with an indwelling catheter and the use of clean intermittent catheterization (CIC) over other methods of bladder management if possible. The use of hydrophilic or impregnated catheters is not recommended. Intravesical Botox, bacterial interference and sacral neuromodulation show significant promise for the prevention of UTIs in higher risk NB patients and future, multi-center, randomized controlled trials are required.
Yu.B. Bielan; T.A. Morozova
Introduction. Among all the diseases of the urinary system, microbial-inflammatory lesions dominate, their prevalence is 29 per 1,000 of child population. Neurogenic bladder dysfunction leads to the chronicity and recurrence of urinary tract infections. Objective. To study the etiologic spectrum in children with urinary tract infection associated with neurogenic bladder dysfunction. Materials and methods. The study involved 434 children aged 4 to 15 years, who were hospitalized and out-patien...
de Miranda, Aline Silva; Zhang, Cun-Jin; Katsumoto, Atsuko; Teixeira, Antônio Lúcio
Adult hippocampal neurogenesis involves proliferation, survival, differentiation and integration of newborn neurons into pre-existing neuronal networks. Although its functional significance in the central nervous system (CNS) has not comprehensively elucidated, adult neurogenesis has been attributed a role in cognition, learning and memory. There is a growing body of evidence that CNS resident as well as peripheral immune cells participate in regulating hippocampal adult neurogenesis. Microglial cells are closely associated with neural stem/progenitor cell (NSPC) in the neurogenic niche engaged in a bidirectional communication with neurons, which may be important for adult neurogenesis. Microglial and neuronal crosstalk is mediated in part by CX3CL1/CX3CR1 signaling and a disruption in this pathway has been associated with impaired neurogenesis. It has been also reported that microglial neuroprotective or neurotoxic effects in adult neurogenesis occur in a context-dependent manner. Apart from microglia other brain resident and peripheral immune cells including pericytes, perivascular macrophages, mast cells and T-cells also modulate this phenomenon. It is worth mentioning that under some physiological circumstances such as normal aging there is a significant decrease in hippocampal neurogenesis. A role for innate and adaptive immune system in adult neurogenesis has been also reported during aging. Here, we review the current evidence regarding neuro-immune interactions in the regulation of neurogenesis under distinct conditions, including aging. Copyright © 2016 Elsevier B.V. All rights reserved.
Sung, Bong Mo; Oh, Dong-Jin; Choi, Moon Hee; Choi, Hye Min
It was believed that neurogenic bladder (NB) might be a risk factor of chronic kidney disease (CKD). However, data are limited regarding the real incidence or risk of CKD in NB. In addition, serum creatinine (sCr), a classical marker of renal function, is not reliable in NB patients because they present muscle wasting due to disuse or denervation. The aim of the study was to estimate the prevalence of CKD in NB patients using serum Cystatin-C. Secondly, we aimed to identify the risk factors for CKD development in NB. This was a cross-sectional study in a public hospital, a specialized center for patients who were victims of industrial accidents. Serum Cystatin-C was checked at the regular laboratory test in the structured NB programme of the hospital, and 313 patients were included in the study. The overall prevalence of CKD, defined as estimated glomerular filtration rate (eGFR) bladder volume, recurrent urinary tract infection, and proteinuria were significantly associated with CKD in the multivariable analysis. Chronic kidney disease prevalence was more than three times higher in NB patients than in the general population despite recent progress in the medical care of NB. Co-morbid diabetes, small bladder volume, recurrent urinary tract infection, and proteinuria seem to be the risk factors for CKD development in NB. © 2016 Asian Pacific Society of Nephrology.
Dumont, Courtney M; Piselli, Jennifer M; Kazi, Nadeem; Bowman, Evan; Li, Guoyun; Linhardt, Robert J; Temple, Sally; Dai, Guohao; Thompson, Deanna M
The microvasculature within the neural stem cell (NSC) niche promotes self-renewal and regulates lineage progression. Previous work identified endothelial-produced soluble factors as key regulators of neural progenitor cell (NPC) fate and proliferation; however, endothelial cells (ECs) are sensitive to local hemodynamics, and the effect of this key physiological process has not been defined. In this study, we evaluated adult mouse NPC response to soluble factors isolated from static or dynamic (flow) EC cultures. Endothelial factors generated under dynamic conditions significantly increased neuronal differentiation, while those released under static conditions stimulated oligodendrocyte differentiation. Flow increases EC release of neurogenic factors and of heparin sulfate glycosaminoglycans that increase their bioactivity, likely underlying the enhanced neuronal differentiation. Additionally, endothelial factors, especially from static conditions, promoted adherent growth. Together, our data suggest that blood flow may impact proliferation, adhesion, and the neuron-glial fate choice of adult NPCs, with implications for diseases and aging that reduce flow.
Joussain, C; Denys, P
Management of lower urinary tract dysfunction (LUTD) in neurological diseases remains a priority because it leads to many complications such as incontinence, renal failure and decreased quality of life. A pharmacological approach remains the first-line treatment for patients with neurogenic LUTD, but electrical stimulation is a well-validated and recommended second-line treatment. However, clinicians must be aware of the indications, advantages and side effects of the therapy. This report provides an update on the 2 main electrical stimulation therapies for neurogenic LUTD - inducing direct bladder contraction with the Brindley procedure and modulating LUT physiology (sacral neuromodulation, tibial posterior nerve stimulation or pudendal nerve stimulation). We also describe the indications of these therapies for neurogenic LUTD, following international guidelines, as illustrated by their efficacy in patients with neurologic disorders. Electrical stimulation could be proposed for neurogenic LUTD as second-line treatment after failure of oral pharmacologic approaches. Nevertheless, further investigations are needed for a better understanding of the mechanisms of action of these techniques and to confirm their efficacy. Other electrical investigations, such as deep-brain stimulation and repetitive transcranial magnetic stimulation, or improved sacral anterior root stimulation, which could be associated with non-invasive and highly specific deafferentation of posterior roots, may open new fields in the management of neurogenic LUTD. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Arantes de Araújo, Liubiana; Ferraz de Arruda Musegante, André; de Oliveira Damasceno, Edjane; Barroso, Ubirajara; Badaro, Roberto
During the follow-up of children who had been diagnosed with arthrogryposis multiplex congenita (AMC), it was noted that some were experiencing dysfunctional voiding. Further investigation into these cases led to a diagnosis of neurogenic bladder. Few studies have investigated the relationship between AMC and neurogenic bladder, this being the first to describe the clinical characteristics of neurogenic bladder among these patients. A series of 26 cases were obtained from the electronic medical records of patients with AMC who were admitted to Hospital Sarah in Salvador between 1994 and 2007. The patients had all been diagnosed with neurogenic bladder through clinical symptoms, lower urinary tract exams, and urodynamic findings. There was urinary incontinence in 21 patients (81%), and 50% had a history of urinary tract infections. Renal function was altered in 4 patients (15%) and normal in 22 (85%). In the urodynamic study, 14 patients (64%) had detrusor overactivity and 6 (27%) had underactivity. Patients with AMC may show changes in the urinary tract, including neurogenic bladder. It is mandatory to study these symptomatic children with urinary disorders. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Dion, Gregory R; Teng, Stephanie E; Achlatis, Efstratios; Fang, Yixin; Amin, Milan R
This study employs validated cough assessment tools to prospectively determine the impact of tramadol on cough severity and quality of life in subjects with neurogenic cough. The study was a prospective case series with planned data collection at a tertiary care academic medical center laryngology practice. Sixteen consecutive collected subjects with neurogenic cough prospectively completed pre- and posttreatment validated cough assessment tools, the cough severity index (CSI) and Leicester Cough Questionnaire (LCQ). All subjects in the study reported at least some improvement in their cough symptoms. In a Wilcoxon signed rank test that compared paired results, CSI scores improved from 23 to 14 and LCQ scores improved from 74 to 103 ( P = .003 and P = .005, respectively). This small preliminary assessment suggests that tramadol warrants additional evaluation as a treatment for neurogenic cough.
Weaver, M. Libby; Lum, Ying Wei
Neurogenic thoracic outlet syndrome is a widely recognized, yet controversial, syndrome. The lack of specific objective diagnostic modalities makes diagnosis difficult. This is compounded by a lack of agreed upon definitive criteria to confirm diagnosis. Recent efforts have been made to more clearly define a set of diagnostic criteria that will bring consistency to the diagnosis of neurogenic thoracic syndrome. Additionally, advancements have been made in the quality and techniques of various imaging modalities that may aid in providing more accurate diagnoses. Surgical decompression remains the mainstay of operative treatment; and minimally invasive techniques are currently in development to further minimize the risks of this procedure. Medical management continues to be refined to provide non-operative treatment modalities for certain patients, as well. The aim of the present work is to review these updates in the diagnosis and treatment of neurogenic thoracic outlet syndrome. PMID:28555024
Full Text Available Background: Growing evidence shows that dental pulp (DP tissues could be a potential source of adult stem cells for the treatment of devastating neurological diseases and several other conditions. Aims: Exploration of the expression profile of several key molecular markers to evaluate the molecular dynamics in undifferentiated and differentiated DP-derived stem cells (DPSCs in vitro. Settings and Design: The characteristics and multilineage differentiation ability of DPSCs were determined by cellular and molecular kinetics. DPSCs were further induced to form adherent (ADH and non-ADH (NADH neurospheres under serum-free condition which was further induced into neurogenic lineage cells and characterized for their molecular and cellular diversity at each stage. Statistical Analysis Used: Statistical analysis used one-way analysis of variance, Student's t-test, Livak method for relative quantification, and R programming. Results: Immunophenotypic analysis of DPSCs revealed> 80% cells positive for mesenchymal markers CD90 and CD105, >70% positive for transferring receptor (CD71, and> 30% for chemotactic factor (CXCR3. These cells showed mesodermal differentiation also and confirmed by specific staining and molecular analysis. Activation of neuronal lineage markers and neurogenic growth factors was observed during lineage differentiation of cells derived from NADH and ADH spheroids. Greater than 80% of cells were found to express β-tubulin III in both differentiation conditions. Conclusions: The present study reported a cascade of immunophenotypic and molecular markers to characterize neurogenic differentiation of DPSCs under serum-free condition. These findings trigger the future analyses for clinical applicability of DP-derived cells in regenerative applications.
Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.
Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.
Horgusluoglu, Emrin; Nudelman, Kelly; Nho, Kwangsik; Saykin, Andrew J
New neurons are generated throughout adulthood in two regions of the brain, the olfactory bulb and dentate gyrus of the hippocampus, and are incorporated into the hippocampal network circuitry; disruption of this process has been postulated to contribute to neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. Known modulators of adult neurogenesis include signal transduction pathways, the vascular and immune systems, metabolic factors, and epigenetic regulation. Multiple intrinsic and extrinsic factors such as neurotrophic factors, transcription factors, and cell cycle regulators control neural stem cell proliferation, maintenance in the adult neurogenic niche, and differentiation into mature neurons; these factors act in networks of signaling molecules that influence each other during construction and maintenance of neural circuits, and in turn contribute to learning and memory. The immune system and vascular system are necessary for neuronal formation and neural stem cell fate determination. Inflammatory cytokines regulate adult neurogenesis in response to immune system activation, whereas the vasculature regulates the neural stem cell niche. Vasculature, immune/support cell populations (microglia/astrocytes), adhesion molecules, growth factors, and the extracellular matrix also provide a homing environment for neural stem cells. Epigenetic changes during hippocampal neurogenesis also impact memory and learning. Some genetic variations in neurogenesis related genes may play important roles in the alteration of neural stem cells differentiation into new born neurons during adult neurogenesis, with important therapeutic implications. In this review, we discuss mechanisms of and interactions between these modulators of adult neurogenesis, as well as implications for neurodegenerative disease and current therapeutic research. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Horgusluoglu, Emrin; Nudelman, Kelly; Nho, Kwangsik; Saykin, Andrew J.
New neurons are generated throughout adulthood in two regions of the brain, the olfactory bulb and dentate gyrus of the hippocampus, and are incorporated into the hippocampal network circuitry; disruption of this process has been postulated to contribute to neurodegenerative diseases including Alzheimer’s disease and Parkinson’s disease. Known modulators of adult neurogenesis include signal transduction pathways, the vascular and immune systems, metabolic factors, and epigenetic regulation. Multiple intrinsic and extrinsic factors such as neurotrophic factors, transcription factors, and cell cycle regulators control neural stem cell proliferation, maintenance in the adult neurogenic niche, and differentiation into mature neurons; these factors act in networks of signaling molecules that influence each other during construction and maintenance of neural circuits, and in turn contribute to learning and memory. The immune system and vascular system are necessary for neuronal formation and neural stem cell fate determination. Inflammatory cytokines regulate adult neurogenesis in response to immune system activation, whereas the vasculature regulates the neural stem cell niche. Vasculature, immune/support cell populations (microglia/astrocytes), adhesion molecules, growth factors, and the extracellular matrix also provide a homing environment for neural stem cells. Epigenetic changes during hippocampal neurogenesis also impact memory and learning. Some genetic variations in neurogenesis related genes may play important roles in the alteration of neural stem cells differentiation into new born neurons during adult neurogenesis, with important therapeutic implications. In this review, we discuss mechanisms of and interactions between these modulators of adult neurogenesis, as well as implications for neurodegenerative disease and current therapeutic research. PMID:26879907
aspiration or any other risk factor for developement of adult respiratory distress syndrom. In the first case, with severe head trauma, neurogenic pulmonary edema was diagnosed at admission one hour after trauma, associated with severe systemic inflammatory reaction, and good outcome in three days. The second case, with hemorragic vascular insult, developed neurogenic pulmonary edema the fourth day after drenage of intracerebral hematom and died.
Ramírez-Albores, Jorge E; Bustamante, Ramiro O; Badano, Ernesto I
Climatic niche models for invasive plants are usually constructed with occurrence records taken from literature and collections. Because these data neither discriminate among life-cycle stages of plants (adult or juvenile) nor the origin of individuals (naturally established or man-planted), the resulting models may mispredict the distribution ranges of these species. We propose that more accurate predictions could be obtained by modelling climatic niches with data of naturally established individuals, particularly with occurrence records of juvenile plants because this would restrict the predictions of models to those sites where climatic conditions allow the recruitment of the species. To test this proposal, we focused on the Peruvian peppertree (Schinus molle), a South American species that has largely invaded Mexico. Three climatic niche models were constructed for this species using high-resolution dataset gathered in the field. The first model included all occurrence records, irrespective of the life-cycle stage or origin of peppertrees (generalized niche model). The second model only included occurrence records of naturally established mature individuals (adult niche model), while the third model was constructed with occurrence records of naturally established juvenile plants (regeneration niche model). When models were compared, the generalized climatic niche model predicted the presence of peppertrees in sites located farther beyond the climatic thresholds that naturally established individuals can tolerate, suggesting that human activities influence the distribution of this invasive species. The adult and regeneration climatic niche models concurred in their predictions about the distribution of peppertrees, suggesting that naturally established adult trees only occur in sites where climatic conditions allow the recruitment of juvenile stages. These results support the proposal that climatic niches of invasive plants should be modelled with data of
Examples from dictionaries are used to examine problems which dictionary users experience as a result of the application of niching. The emphasis is on problems regarding the search route of users via the outer access structure of dictionaries. A distinction is made between single niching and multiple niching. Different ...
Full Text Available Introduction. Among all the diseases of the urinary system, microbial-inflammatory lesions dominate, their prevalence is 29 per 1,000 of child population. Neurogenic bladder dysfunction leads to the chronicity and recurrence of urinary tract infections. Objective. To study the etiologic spectrum in children with urinary tract infection associated with neurogenic bladder dysfunction. Materials and methods. The study involved 434 children aged 4 to 15 years, who were hospitalized and out-patient treatment in Omsk from 2008 to 2014. Bacteriological urine culture on the microflora with determining the sensitivity to antibiotics was performed using Urin System Plus (Liofilchem, Italy. At the same time, the urine was examined for the presence of Cytomegalovirus, Herpes simplex virus I–II, Mycoplasma genitalium, Chlamydiae trachomatis, Ureaplasma urealyticum by polymerase chain reaction and enzyme immunoassay. Data processing was performed using Statistica 10.0 software package. Results. It was found that in the urine microbial landscape of children with urinary tract infection and neurogenic bladder dysfunction, Staphylococcus family dominated, unlike the spectrum of uropathogens in patirnts with urinary tract infection without functional obstruction, which is characterized by the predominance of Escherichia coli. The detection rate of cytomegalovirus in the urine indicates a significant decrease in the immunity of children with urinary tract infection and neurogenic bladder dysfunction. Conclusion. The shown differences in microbial landscape of the urine in urinary tract infection associated with neurogenic bladder dysfunction and without functional obstruction must be considered in the selection of an adequate therapy for patients of different groups, including immunocorrective approaches.
Walsh, M.; McCarthy, S.
The objective of this project is the development of a standard methodology for integrating non-food crops in rural areas with niche energy markets. This has involved a number of steps including (i) identification of 3 niche markets for energy crops which are of common interest to the partners, (ii) application of the standard costing methodology to investigate these three niche markets and (iii) comparison of the results from this work in three workshops (one for each market). Three tightly defined niche markets were identified; these were chosen following an examination of the national energy marekts in each of the partners countries (Ireland, Germany, Netherlands, UK, Greece and Portugal). This paper gives an overview of the national energy markets which were examined. The three niche markets are introduced and the reasons for their selection given. The application of the methodology to each of the niche markets is presented along with the conclusions of the partners regarding the niche markets. (Author)
Full Text Available Stem cells and their niches constitute units that act cooperatively to achieve adult body homeostasis. How such units form and whether stem cell and niche precursors might be coordinated already during organogenesis are unknown. In fruit flies, primordial germ cells (PGCs, the precursors of germ line stem cells (GSCs, and somatic niche precursors develop within the larval ovary. Together they form the 16-20 GSC units of the adult ovary. We show that ecdysone receptors are required to coordinate the development of niche and GSC precursors. At early third instar, ecdysone receptors repress precocious differentiation of both niches and PGCs. Early repression is required for correct morphogenesis of the ovary and for protecting future GSCs from differentiation. At mid-third instar, ecdysone signaling is required for niche formation. Finally, and concurrent with the initiation of wandering behavior, ecdysone signaling initiates PGC differentiation by allowing the expression of the differentiation gene bag of marbles in PGCs that are not protected by the newly formed niches. All the ovarian functions of ecdysone receptors are mediated through early repression, and late activation, of the ecdysone target gene broad. These results show that, similar to mammals, a brain-gland-gonad axis controls the initiation of oogenesis in insects. They further exemplify how a physiological cue coordinates the formation of a stem cell unit within an organ: it is required for niche establishment and to ensure that precursor cells to adult stem cells remain undifferentiated until the niches can accommodate them. Similar principles might govern the formation of additional stem cell units during organogenesis.
Hulgard, K.; Ratcliffe, J. M.
Related species with different diets are predicted to rely on different cognitive strategies: those best suited for locating available and appropriate foods. Here we tested two predictions of the niche-specific cognitive strategies hypothesis in bats, which suggests that predatory species should ...... the niche-specific cognitive strategies hypothesis and suggest that for gleaning and clutter-resistant aerial hawking bats, learning to associate shape with food interferes with subsequent spatial memory learning.......Related species with different diets are predicted to rely on different cognitive strategies: those best suited for locating available and appropriate foods. Here we tested two predictions of the niche-specific cognitive strategies hypothesis in bats, which suggests that predatory species should...... rely more on object memory than on spatial memory for finding food and that the opposite is true of frugivorous and nectivorous species. Specifically, we predicted that: (1) predatory bats would readily learn to associate shapes with palatable prey and (2) once bats had made such associations...
Desai, Mina; Han, Guang; Ross, Michael G
Maternal overnutrition results in programmed offspring obesity, mediated in part, by hyperphagia. This is remarkably similar to the effects of maternal undernutrition on offspring hyperphagia and obesity. In view of the marked differences in the energy environment of the over and under-nutrition exposures, we studied the expression of select epigenetic modifiers associated with energy imbalance including neurogenic factors and appetite/satiety neuropeptides which are indicative of neurogenic differentiation. HF offspring were exposed to maternal overnutrition (high fat diet; HF) during pregnancy and lactation. We determined the protein expression of energy sensors (mTOR, pAMPK), epigenetic factors (DNA methylase, DNMT1; histone deacetylase, SIRT1/HDAC1), neurogenic factors (Hes1, Mash1, Ngn3) and appetite/satiety neuropeptides (AgRP/POMC) in newborn hypothalamus and adult arcuate nucleus (ARC). Despite maternal obesity, male offspring born to obese dams had similar body weight at birth as Controls. However, when nursed by the same dams, male offspring of obese dams exhibited marked adiposity. At 1 day of age, HF newborn males had significantly decreased energy sensors, DNMT1 including Hes1 and Mash1, which may impact neuroprogenitor cell proliferation and differentiation. This is consistent with increased AgRP in HF newborns. At 6 months of age, HF adult males had significantly increased energy sensors and decreased histone deactylases. In addition, the persistent decreased Hes1, Mash1 as well as Ngn3 are consistent with increased AgRP and decreased POMC. Thus, altered energy sensors and epigenetic responses which modulate gene expression and adult neuronal differentiation may contribute to hyperphagia and obesity in HF male offspring. Copyright © 2016 Elsevier Ltd. All rights reserved.
Fisher-Reid, M Caitlin; Kozak, Kenneth H; Wiens, John J
The rate of climatic-niche evolution is important to many research areas in ecology, evolution, and conservation biology, including responses of species to global climate change, spread of invasive species, speciation, biogeography, and patterns of species richness. Previous studies have implied that clades with higher rates of climatic-niche evolution among species should have species with narrower niche breadths, but there is also evidence suggesting the opposite pattern. However, the relationships between rate and breadth have not been explicitly analyzed. Here, we examine the relationships between the rate of climatic-niche evolution and climatic-niche breadth using phylogenetic and climatic data for 250 species in the salamander family Plethodontidae, a group showing considerable variation in both rates of climatic-niche evolution and climatic-niche breadths. Contrary to some expectations, we find no general relationship between climatic-niche breadth and the rate of climatic-niche evolution. Climatic-niche breadths for some ecologically important climatic variables considered separately (temperature seasonality and annual precipitation) do show significant relationships with the rate of climatic-niche evolution, but rates are faster in clades in which species have broader (not narrower) niche breadths. In summary, our results show that narrower niche breadths are not necessarily associated with faster rates of niche evolution. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Christesen, Henrik Thybo; Brusgaard, Klaus; Hussain, Khalid
Background: Hypoglycaemia-associated autonomic failure (HAAF) with impaired neurogenic and neuroglycopaenic responses occurs in adults following recent, repeated hypoglycaemia. Objective and hypotheses: We aimed to evaluate, whether HAAF also occurs in infants with congenital hyperinsulinism (CHI......). Methods: The autonomic, neuroglycopaenic, and glucose counter-regulatory hormonal responses were assessed in a) seven infants with CHI during a controlled fast following initial symptomatic hypoglycaemia and three recent episodes of spontaneous recurrent hypoglycaemia each lasting less than 5 minutes......; and in b) seven infants with ketotic hypoglycaemia for control. Results: When repeated hypoglycaemia was provoked, all CHI patients exhibited a complete loss of hypoglycaemic symptoms and signs, along with a global blunting of the counter-regulatory cortisol, glucagon, growth hormone, epinephrine and nor...
Full Text Available Antidepressants increase the proliferation of neural precursors in adult dentate gyrus (DG, which is considered to be involved in the therapeutic action of antidepressants. However, the mechanism underlying it remains unclear. By using cultured adult rat DG-derived neural precursors (ADP, we have already shown that antidepressants have no direct effects on ADP. Therefore, antidepressants may increase the proliferation of neural precursors in adult DG via unknown indirect mechanism. We have also shown that amitriptyline (AMI, a tricyclic antidepressant, induces the expressions of GDNF, BDNF, FGF2 and VEGF, common neurogenic factors, in primary cultured astrocytes (PCA. These suggest that AMI-induced factors in astrocytes may increase the proliferation of neural precursors in adult DG. To test this hypothesis, we examined the effects of AMI-induced factors and conditioned medium (CM from PCA treated with AMI on ADP proliferation. The effects of CM and factors on ADP proliferation were examined with BrdU immunocytochemistry. AMI had no effect on ADP proliferation, but AMI-treated CM increased it. The receptors of GDNF, BDNF and FGF2, but not VEGF, were expressed in ADP. FGF2 significantly increased ADP proliferation, but not BDNF and GDNF. In addition, both of a specific inhibitor of FGF receptors and anti-FGF2 antibody significantly counteracted the increasing effect of CM on ADP proliferation. In addition, FGF2 in brain is mainly derived from astrocytes that are key components of the neurogenic niches in adult DG. These suggest that AMI may increase ADP proliferation indirectly via PCA and that FGF2 may a potential candidate to mediate such an indirect effect of AMI on ADP proliferation via astrocytes.
Cooper, Natalie; Freckleton, Rob P; Jetz, Walter
Phylogenetic niche conservatism is the pattern where close relatives occupy similar niches, whereas distant relatives are more dissimilar. We suggest that niche conservatism will vary across clades in relation to their characteristics. Specifically, we investigate how conservatism of environmental niches varies among mammals according to their latitude, range size, body size and specialization. We use the Brownian rate parameter, σ(2), to measure the rate of evolution in key variables related to the ecological niche and define the more conserved group as the one with the slower rate of evolution. We find that tropical, small-ranged and specialized mammals have more conserved thermal niches than temperate, large-ranged or generalized mammals. Partitioning niche conservatism into its spatial and phylogenetic components, we find that spatial effects on niche variables are generally greater than phylogenetic effects. This suggests that recent evolution and dispersal have more influence on species' niches than more distant evolutionary events. These results have implications for our understanding of the role of niche conservatism in species richness patterns and for gauging the potential for species to adapt to global change.
Kim, Chanyang; Kim, Sehee; Park, Seungjoon
Mammalian neurogenesis continues throughout adulthood in the subventricular zone of the lateral ventricle and in the subgranular zone of the dentate gyrus in the hippocampus. It is well known that hippocampal neurogenesis is essential in mediating hippocampus-dependent learning and memory. Ghrelin, a peptide hormone mainly synthesized in the stomach, has been shown to play a major role in the regulation of energy metabolism. A plethora of evidence indicates that ghrelin can also exert important effects on neurogenesis in the hippocampus of the adult brain. The aim of this review is to discuss the current role of ghrelin on the in vivo and in vitro regulation of neurogenesis in the adult hippocampus. We will also discuss the possible role of ghrelin in dietary restriction-induced hippocampal neurogenesis and the link between ghrelin-induced hippocampal neurogenesis and cognitive functions.
Daniel Cabezalí Barbancho
Full Text Available Spontaneous bladder perforation is an uncommon event in childhood. It is usually associated with bladder augmentation. We are presenting a case of bladder rupture in an infant with neurogenic bladder without prior bladder surgery. Three days after lipomyelomeningocele excision the patient showed signs and symptoms of acute abdomen. The ultrasound exploration revealed significant amount of intraperitoneal free fluid and therefore a laparoscopic exploration was performed. A posterior bladder rupture was diagnosed and repaired laparoscopically. Currently, being 3 years old, she keeps successfully dry with clean intermittent catheterization. Neurogenic bladder voiding function can change at any time of its evolution and lead to complications. Early diagnosis of spontaneous bladder rupture is of paramount importance, so it is essential to think about it in the differential diagnosis of acute abdomen.
Lee, Chan Ho; Shim, Su Jung; Kim, Hyun Jung; Yang, Hyuna; Kang, Youn Joo
Heterotopic ossification (HO) is frequently seen on rehabilitation units after spinal cord injuries, fractures, brain injuries, and limb amputations. Currently, there is no effective treatment for HO other than prophylaxis with anti-inflammatory medications, irradiation, and bisphosphonate administration. These prophylactic treatments are not effective for managing ectopic bone once it has formed. Here we describe three cases of established neurogenic HO treated with radiation therapy (RT). All patients had decreased serum alkaline phosphatase (ALP) and bone-specific ALP levels with decreased pain but increased range of motion immediately after RT. Post-treatment X-rays revealed no further growth of the HO. All patients maintained clinical and laboratory improvements 4 or 6 months after the RT. Our results suggest that RT is safe and effective in decreasing pain and activity of neurogenic HO.
Not only neurologists but also ENT-physicians and phoniatricians have to prescribe speech and language therapy for patients with communication disorders. Complementary and alternative medicine (CAM) has gained increasing popularity among patients. Many studies have investigated these procedures and positive effects on certain physical e. g., chronic pain and anxiety disorders could be validated. Unfortunately only few empirical investigations have targeted the use of CAM to treat neurogenic disorders of communication or cognition. In this review we provide an overview over general therapeutical principals of two widely used approaches, relaxation therapy and acupuncture. Then we survey the literature and summarize existent research literature regarding the effects of the treatment of neurogenic disorders including dementia.
Alados Arboledas, F J; Millán-Miralles, L; Millán-Bueno, M P; Expósito-Montes, J F; Santiago-Gutierrez, C; Martínez Padilla, M C
Neurogenic stunned myocardium is an unusual clinical entity. It mimics an acute coronary syndrome with electrocardiographic abnormalities, cardiac dysfunction and elevated cardiac enzymes with absence of obstructive coronary disease. It may occur after a neurosurgical procedure. A case is presented of neurogenic stunned myocardium occurring in a child after removal of a posterior fossa medulloblastoma. The patient developed nodal tachycardia with hemodynamic impairment. The clinical course was satisfactory due to antiarrhythmic therapy, with biochemical, echocardiographic, and clinical improvement within a week. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
Ganz, Julia; Kaslin, Jan; Hochmann, Sarah; Freudenreich, Dorian; Brand, Michael
Adult telencephalic neurogenesis is a conserved trait of all vertebrates studied. It has been investigated in detail in rodents, but very little is known about the composition of neurogenic niches and the cellular nature of progenitors in nonmammalian vertebrates. To understand the components of the progenitor zones in the adult zebrafish telencephalon and the link between glial characteristics and progenitor state, we examined whether canonical glial markers are colocalized with proliferation markers. In the adult zebrafish telencephalon, we identify heterogeneous progenitors that reside in two distinct glial domains. We find that the glial composition of the progenitor zone is linked to its proliferative behavior. Analyzing both fast-cycling proliferating cells as well as slowly cycling progenitors, we find four distinct progenitor types characterized by differential expression of glial markers. Importantly, a significant proportion of progenitors do not display typical radial glia characteristics. By blocking or activating Fgf signaling by misexpression of a dominant negative Fgf-receptor 1 or Fgf8a, respectively, we find that ventral and dorsal progenitors in the telencephalon also differ in their requirement for Fgf signaling. Together with data on the expression of Fgf signaling components in the ventricular zone of the telencephalon, this suggests that Fgf signaling directly regulates proliferation of specific subsets of adult telencephalic progenitors in vivo. Taken together our results show that adult neural progenitor cells are heterogeneous with their respect to distribution into two distinct glial domains and their dependence upon Fgf signaling as a proliferative cue in the zebrafish telencephalon.
Sasaji, Tatsuro; Yamada, Noboru; Iwai, Kazuo
A 76-year-old man presented with a Denis Zone III sacral fracture after a traffic accident. He also developed urinary retention and perineal numbness. The patient was diagnosed with neurogenic bladder dysfunction caused by the sacral fracture. A computed tomogram (CT) revealed that third sacral lamina was fractured and displaced into the spinal canal, but vertebral body did not displace. The fracture lines began at the center of lamina and extended bilateraly. The fracture pattern was unique....
Feng, Jun-Tao; Zhu, Yi; Hua, Xu-Yun; Zhu, Yu; Gu, Yu-Dong; Xu, Jian-Guang; Xu, Wen-Dong
We assessed the diagnostic value of triple stimulation technique (TST) in eight patients with neurogenic thoracic outlet syndrome (TOS) by revealing the conduction block of the proximal lower trunk of the brachial plexus and locating the compression site. Eight patients fulfilling the conventional criteria of the lower-trunk neurogenic TOS were enrolled in our study. TST along with the central motor-conduction time was evaluated. The parameters including the TST amplitude ratio and the TST area ratio were compared between patients and controls. The amplitude ratio was significantly lower in the patient group than in the control group (patients: 0.518 ± 0.113; control: 0.954 ± 0.020, P<0.01), so was the area ratio (patients: 0.453 ± 0.194; control group: 0.955 ± 0.192, P<0.01). No significant difference of central motor-conduction time (CMCT) was seen between the patient group and the control group (patients: 6.62 ± 0.36 ms; control: 6.54 ± 0.36 ms; P=0.528). Surgical procedures proved the compression of the lower trunk in all patients. Our results indicated that there was conduction block besides axon loss in neurogenic TOS patients, and the conduction block was located between the nerve root emerging site and the supraclavicular stimulation site. We first applied TST in diagnosing neurogenic TOS, and we showed that the patient's TST ratio was significantly lower than normal. Combined with clinical manifestations, TOS can be more precisely diagnosed. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Abreu, Evandro [Service de Radiologie et Imagerie Musculosquelettique, Centre de Consultation et Imagerie de l’Appareil Locomoteur, CHRU de Lille, 59037 Lille (France); Aubert, Sébastien, E-mail: email@example.com [Institut de Pathologie, Centre de Biologie-Pathologie, CHRU de Lille, 59037 Lille (France); Wavreille, Guillaume, E-mail: firstname.lastname@example.org [Service d’Orthopédie B, Hôpital R Salengro, CHRU de Lille, 59037 Lille (France); Gheno, Ramon; Canella, Clarissa [Service de Radiologie et Imagerie Musculosquelettique, Centre de Consultation et Imagerie de l’Appareil Locomoteur, CHRU de Lille, 59037 Lille (France); Cotten, Anne, E-mail: email@example.com [Service de Radiologie et Imagerie Musculosquelettique, Centre de Consultation et Imagerie de l’Appareil Locomoteur, CHRU de Lille, 59037 Lille (France)
Neoplasms of neurogenic origin account for about 12% of all benign and 8% of all malignant soft tissue neoplasms. Traumatic neuroma, Morton neuroma, lipomatosis of a nerve, nerve sheath ganglion, perineurioma, benign and malignant peripheral nerve sheath tumors (PNST) are included in this group of pathologies. Clinical and radiologic evaluation of patients with neurogenic tumors and pseudotumors often reveals distinctive features. In this context, advanced imaging techniques, especially ultrasound (US) and magnetic resonance (MR) play an important role in the characterization of these lesions. Imaging findings such as location of a soft tissue mass in the region of a major nerve, nerve entering or exiting the mass, fusiform shape, abnormalities of the muscle supplied by the nerve, split-fat sign, target sign and fascicular appearance should always evoke a peripheric nerve sheath neoplasm. Although no single imaging finding or combination of findings allows definitive differentiation between benign from malign peripheric neurogenic tumors, both US and MR imaging may show useful features that can lead us to a correct diagnosis and improve patient treatment. Traumatic neuromas and Morton neuromas are commonly associated to an amputation stump or are located in the intermetatarsal space. Lipomatosis of a nerve usually appears as a nerve enlargement, with thickened nerve fascicles, embedded in evenly distributed fat. Nerve sheath ganglion has a cystic appearance and commonly occurs at the level of the knee. Intraneural perineuroma usually affects young people and manifests as a focal and fusiform nerve enlargement. In this article, we review clinical characteristics and radiologic appearances of these neurogenic lesions, observing pathologic correlation, when possible.
Full Text Available Niche construction theory regards organisms not only as the object of natural selection but also an active subject that can change their own selective pressure through eco-evolutionary feedbacks. Through reviewing the existing works on the theoretical models of niche construction, here we present the progress made on how niche construction influences genetic structure of spatially structured populations and the spatial-temporal dynamics of metapopulations, with special focuses on mathematical models and simulation methods. The majority of results confirmed that niche construction can significantly alter the evolutionary trajectories of structured populations. Organism-environmental interactions induced by niche construction can have profound influence on the dynamics, competition and diversity of metapopulations. It can affect fine-scale spatially distribution of species and spatial heterogeneity of the environment. We further propose a few research directions with potentials, such as applying adaptive dynamics or spatial game theory to explore the effect of niche construction on phenotypic evolution and diversification.
Kendal, Jeremy; Tehrani, Jamshid J.; Odling-Smee, John
Niche construction is an endogenous causal process in evolution, reciprocal to the causal process of natural selection. It works by adding ecological inheritance, comprising the inheritance of natural selection pressures previously modified by niche construction, to genetic inheritance in evolution. Human niche construction modifies selection pressures in environments in ways that affect both human evolution, and the evolution of other species. Human ecological inheritance is exceptionally po...
Gómez, Camila; Tenorio, Elkin A; Montoya, Paola; Cadena, Carlos Daniel
Differences in life-history traits between tropical and temperate lineages are often attributed to differences in their climatic niche dynamics. For example, the more frequent appearance of migratory behaviour in temperate-breeding species than in species originally breeding in the tropics is believed to have resulted partly from tropical climatic stability and niche conservatism constraining tropical species from shifting their ranges. However, little is known about the patterns and processes underlying climatic niche evolution in migrant and resident animals. We evaluated the evolution of overlap in climatic niches between seasons and its relationship to migratory behaviour in the Parulidae, a family of New World passerine birds. We used ordination methods to measure seasonal niche overlap and niche breadth of 54 resident and 49 migrant species and used phylogenetic comparative methods to assess patterns of climatic niche evolution. We found that despite travelling thousands of kilometres, migrants tracked climatic conditions across the year to a greater extent than tropical residents. Migrant species had wider niches than resident species, although residents as a group occupied a wider climatic space and niches of migrants and residents overlapped extensively. Neither breeding latitude nor migratory distance explained variation among species in climatic niche overlap between seasons. Our findings support the notion that tropical species have narrower niches than temperate-breeders, but does not necessarily constrain their ability to shift or expand their geographical ranges and become migratory. Overall, the tropics may have been historically less likely to experience the suite of components that generate strong selection pressures for the evolution of migratory behaviour. © 2016 The Author(s).
Gómez, Camila; Tenorio, Elkin A.; Montoya, Paola; Cadena, Carlos Daniel
Differences in life-history traits between tropical and temperate lineages are often attributed to differences in their climatic niche dynamics. For example, the more frequent appearance of migratory behaviour in temperate-breeding species than in species originally breeding in the tropics is believed to have resulted partly from tropical climatic stability and niche conservatism constraining tropical species from shifting their ranges. However, little is known about the patterns and processes underlying climatic niche evolution in migrant and resident animals. We evaluated the evolution of overlap in climatic niches between seasons and its relationship to migratory behaviour in the Parulidae, a family of New World passerine birds. We used ordination methods to measure seasonal niche overlap and niche breadth of 54 resident and 49 migrant species and used phylogenetic comparative methods to assess patterns of climatic niche evolution. We found that despite travelling thousands of kilometres, migrants tracked climatic conditions across the year to a greater extent than tropical residents. Migrant species had wider niches than resident species, although residents as a group occupied a wider climatic space and niches of migrants and residents overlapped extensively. Neither breeding latitude nor migratory distance explained variation among species in climatic niche overlap between seasons. Our findings support the notion that tropical species have narrower niches than temperate-breeders, but does not necessarily constrain their ability to shift or expand their geographical ranges and become migratory. Overall, the tropics may have been historically less likely to experience the suite of components that generate strong selection pressures for the evolution of migratory behaviour. PMID:26865303
McInerny, Greg J.; Etienne, Rampal S.
By over-focusing on precise definitions, ecology has produced a confused idea of the niche concept. This, our second paper, develops a practical philosophy for the niche that approaches the concept at the correct level of abstraction. We deconstruct the niche into effect and response components and
Hira, Vashendriya V. V.; Wormer, Jill R.; Kakar, Hala; Breznik, Barbara; van der Swaan, Britt; Hulsbos, Renske; Tigchelaar, Wikky; Tonar, Zbynek; Khurshed, Mohammed; Molenaar, Remco J.; van Noorden, Cornelis J. F.
In glioblastoma, a fraction of malignant cells consists of therapy-resistant glioblastoma stem cells (GSCs) residing in protective niches that recapitulate hematopoietic stem cell (HSC) niches in bone marrow. We have previously shown that HSC niche proteins stromal cell-derived factor-1α (SDF-1α),
Otsuki, Leo; Brand, Andrea H
Neural stem cells (NSCs) are multipotent, self-renewing progenitors that generate progeny that differentiate into neurons and glia. NSCs in the adult mammalian brain are generally quiescent. Environmental stimuli such as learning or exercise can activate quiescent NSCs, inducing them to proliferate and produce new neurons and glia. How are these behaviours coordinated? The neurovasculature, the circulatory system of the brain, is a key component of the NSC microenvironment, or 'niche'. Instructive signals from the neurovasculature direct NSC quiescence, proliferation, self-renewal and differentiation. During ageing, a breakdown in the niche accompanies NSC dysfunction and cognitive decline. There is much interest in reversing these changes and enhancing NSC activity by targeting the neurovasculature therapeutically. Here we discuss principles of neurovasculature-NSC crosstalk, and the implications for the design of NSC-based therapies. We also consider the emerging contributions to this field of the model organism Drosophila melanogaster. Copyright © 2017 Elsevier Inc. All rights reserved.
Elias Georges Gebara
Full Text Available Adult hippocampal neurogenesis results in the formation of new neurons and is a process of brain plasticity involved in learning and memory. The proliferation of adult neural stem or progenitor cells is regulated by several extrinsic factors such as experience, disease or aging and intrinsic factors originating from the neurogenic niche. Microglia is very abundant in the dentate gyrus and increasing evidence indicates that these cells mediate the inflammation-induced reduction in neurogenesis. However, the role of microglia in neurogenesis in physiological conditions remains poorly understood. In this study, we monitored microglia and the proliferation of adult hippocampal stem/progenitor cells in physiological conditions known to increase or decrease adult neurogenesis, voluntary running and aging respectively. We found that the number of microglia in the dentate gyrus was strongly inversely correlated with the number of stem/progenitor cells and cell proliferation in the granule cell layer. Accordingly, co-cultures of decreasing neural progenitor/glia ratio showed that microglia but not astroglia reduced the number of progenitor cells. Together, these results suggest that microglia inhibits the proliferation of neural stem/progenitor cells despite the absence of inflammatory stimulus.
Lai, Chun-Ming; Lin, Kun-Yang; Kao, Shih-Han; Chen, Yi-Ning; Huang, Fu; Hsu, Hwei-Jan
Stem cells require different types of supporting cells, or niches, to control stem cell maintenance and differentiation. However, little is known about how those niches are formed. We report that in the development of the Drosophila melanogaster ovary, the Hedgehog (Hh) gradient sets differential cell affinity for somatic gonadal precursors to specify stromal intermingled cells, which contributes to both germline stem cell maintenance and differentiation niches in the adult. We also report that Traffic Jam (an orthologue of a large Maf transcription factor in mammals) is a novel transcriptional target of Hh signaling to control cell-cell adhesion by negative regulation of E-cadherin expression. Our results demonstrate the role of Hh signaling in niche establishment by segregating somatic cell lineages for differentiation. © 2017 Lai et al.
Noll, J E; Williams, S A; Purton, L E; Zannettino, A C W
In the adult mammal, normal haematopoiesis occurs predominantly in the bone marrow, where primitive haematopoietic stem cells (HSC) and their progeny reside in specialised microenvironments. The bone marrow microenvironment contains specific anatomical areas (termed niches) that are highly specialised for the development of certain blood cell types, for example HSCs. The HSC niche provides important cell-cell interactions and signalling molecules that regulate HSC self-renewal and differentiation processes. These same signals and interactions are also important in the progression of haematological malignancies, such as multiple myeloma (MM). This review provides an overview of the bone marrow microenvironment and its involvement in normal, physiological HSC maintenance and plasma cell growth throughout MM disease progression.
Li, Yue; Stockton, Michael E; Bhuiyan, Ismat; Eisinger, Brian E; Gao, Yu; Miller, Jessica L; Bhattacharyya, Anita; Zhao, Xinyu
Fragile X syndrome, the most common form of inherited intellectual disability, is caused by loss of the fragile X mental retardation protein (FMRP). However, the mechanism remains unclear, and effective treatment is lacking. We show that loss of FMRP leads to activation of adult mouse neural stem cells (NSCs) and a subsequent reduction in the production of neurons. We identified the ubiquitin ligase mouse double minute 2 homolog (MDM2) as a target of FMRP. FMRP regulates Mdm2 mRNA stability, and loss of FMRP resulted in elevated MDM2 mRNA and protein. Further, we found that increased MDM2 expression led to reduced P53 expression in adult mouse NSCs, leading to alterations in NSC proliferation and differentiation. Treatment with Nutlin-3, a small molecule undergoing clinical trials for treating cancer, specifically inhibited the interaction of MDM2 with P53, and rescued neurogenic and cognitive deficits in FMRP-deficient mice. Our data reveal a potential regulatory role for FMRP in the balance between adult NSC activation and quiescence, and identify a potential new treatment for fragile X syndrome. Copyright © 2016, American Association for the Advancement of Science.
Bruggeman, J.P.; Ó Nualláin, Breanndán
Niche width theory, a part of organizational ecology, predicts whether “specialist” or “generalist” forms of organizations have higher “fitness,” in a continually changing environment. To this end, niche width theory uses a mathematical model borrowed from biology. In this paper, we first loosen the
Flynn, Emma G.; Laland, Kevin N.; Kendal, Rachel L.; Kendal, Jeremy R.
Niche construction is the modification of components of the environment through an organism's activities. Humans modify their environments mainly through ontogenetic and cultural processes, and it is this reliance on learning, plasticity and culture that lends human niche construction a special potency. In this paper we aim to facilitate…
Constant, Axel; Ramstead, Maxwell J D; Veissière, Samuel P L; Campbell, John O; Friston, Karl J
In evolutionary biology, niche construction is sometimes described as a genuine evolutionary process whereby organisms, through their activities and regulatory mechanisms, modify their environment such as to steer their own evolutionary trajectory, and that of other species. There is ongoing debate, however, on the extent to which niche construction ought to be considered a bona fide evolutionary force, on a par with natural selection. Recent formulations of the variational free-energy principle as applied to the life sciences describe the properties of living systems, and their selection in evolution, in terms of variational inference. We argue that niche construction can be described using a variational approach. We propose new arguments to support the niche construction perspective, and to extend the variational approach to niche construction to current perspectives in various scientific fields. © 2018 The Authors.
Bruggeman, J.; Grunow, D.; Leenders, M.A.A.M.; Vermeulen, I.; Kuilman, J.G.
Organizational ecology models of market dynamics emphasize the competition-inducing role of inter-organizational niche overlap—targeting similar market niches increases competitive pressure and thus reduces organizations’ fitness. Recent studies, however, have suggested that moderate niche overlap
Bruggeman, J.; Grunow, D.; Leenders, M.A.A.M.; Vermeulen, I.; Kuilman, J.G.
Organizational ecology models of market dynamics emphasize the competition-inducing role of inter-organizational niche overlap—targeting similar market niches increases competitive pressure and thus reduces organizations’ fitness. Recent studies, however, have suggested that moderate niche overlap
Pınar Bingöl Kızıltunç
Full Text Available Purpose: To evaluate the clinical and treatment features of orbital neurogenic tumors. Material and Method: The records of 35 patients with orbital neurogenic tumors who were diagnosed and treated at Ankara University Faculty of Medicine, Department of Ophthalmology, between 1998 and 2011 were evaluated retrospectively. Results: Orbitotomy via a cutaneous approach was performed in 21 (60% cases and orbitotomy via a transconjunctival approach was performed in 7 (20% cases. Three (8% cases had been operated at different centers. Four (12% cases were diagnosed clinically. Total excisional biopsy was performed in 11 (31.4% cases, subtotal excisional biopsy was performed in 7 (20%, and incisional biopsy was performed in 10 (28.6% cases. 14 (40% 35 cases were diagnosed as meningioma, 12 (34% as peripheral nerve sheath tumor, and 9 (26% cases were diagnosed as optic nerve glioma. Six (43% meningioma cases were optic nerve sheath meningioma, 5 (36% were sphenoid wing meningioma, 2 (14% were ectopic meningioma, and 1 (7% was perisellar meningioma. Six (50% of peripheral nerve sheath tumors were schwannoma, 2 (16% were solitary neurofibroma, 4 (34% were plexiform neurofibroma. External beam radiotherapy was performed in 15 (42.8% cases, cyberknife radiosurgery in 1 (2.8% , chemotherapy in 1 (2.8%, and enucleation ( because of neovascular glaucoma and vitreous hemorrhage was performed in 1 (2.8% case. Discussion: The most common orbital neurogenic tumors are meningioma, peripheral nerve sheath tumor, and optic nerve glioma. For meningioma and glioma, external beam radiotherapy is required; for schwannoma and solitary neurofibroma, total excisional biopsy is the preferred treatment. The success of visual and anatomic results are high after treatment. (Turk J Ophthalmol 2013; 43: 335-9
Fei, G; Fang, X; Wang, GD; Liu, S; Wang, XY; Xia, Y; Wood, JD
Background and Purpose To test a hypothesis that: (i) duodenal pH and osmolarity are individually controlled at constant set points by negative feedback control centred in the enteric nervous system (ENS); (ii) the purinergic P2Y1 receptor subtype is expressed by non-cholinergic secretomotor/vasodilator neurons, which represent the final common excitatory pathway from the ENS to the bicarbonate secretory glands. Experimental Approach Ussing chamber and pH-stat methods investigated involvement of the P2Y1 receptor in neurogenic stimulation of mucosal bicarbonate (HCO3−) secretion in guinea pig duodenum. Key Results ATP increased HCO3− secretion with an EC50 of 160 nM. MRS2179, a selective P2Y1 purinergic receptor antagonist, suppressed ATP-evoked HCO3− secretion by 47% and Cl− secretion by 63%. Enteric neuronal blockade by tetrodotoxin or exposure to a selective vasoactive intestinal peptide (VIP, VPAC1) receptor antagonist suppressed ATP-evoked HCO3− secretion by 61 and 41%, respectively, and Cl- by 97 and 70% respectively. Pretreatment with the muscarinic antagonist, scopolamine did not alter ATP-evoked HCO3− or Cl− secretion. Conclusion and Implications Whereas acid directly stimulates the mucosa to release ATP and stimulate HCO3− secretion in a cytoprotective manner, neurogenically evoked HCO3− secretion accounts for feedback control of optimal luminal pH for digestion. ATP stimulates duodenal HCO3− secretion through an excitatory action at purinergic P2Y1 receptors on neurons in the submucosal division of the ENS. Stimulation of the VIPergic non-cholinergic secretomotor/vasodilator neurons, which are one of three classes of secretomotor neurons, accounts for most, if not all, of the neurogenic secretory response evoked by ATP. PMID:22994306
Beuerle, John R; Barrueto, Fermin
The use of 3,4-methylenedioxymethamphetamine (MDMA, known as "ecstasy"), a synthetic amphetamine and "club drug," has been associated with acute, transient urinary retention. We report a case of neurogenic bladder and chronic urinary retention associated with MDMA abuse. A 21-year-old male presented to the emergency department (ED) because he had abdominal pain and difficulty urinating. He had experienced difficulty in initiating urination over the past 1.5 months, with periods of 24 to 36 hours between voids and large volumes of urine. The patient had a chronic pattern of MDMA use, taking 4 tablets/day for 3 months. Two weeks before coming to the ED, he had been admitted to an inpatient drug rehabilitation center. During the time since that admission, the patient had visited EDs repeatedly for insertion and removal of Foley catheters to relieve the urinary retention until he could be admitted to a urologic service. Cystometrogram was abnormal, finding no sensation of bladder fullness after instillation of 350 mL of saline and inability to generate a voluntary voiding pressure. Cystoscopy revealed no outlet obstruction. The findings were consistent with neurogenic bladder. The patient was given prescriptions for bethanecol and phenazopyridine, and told to continue a 10-day course of sulfamethoxazole/trimethoprim for urinary tract infection. He was discharged with a Foley catheter in place. Symptoms of urinary retention persisted at 1-year follow-up, despite self-catheterization and complete cessation of MDMA use. Chronic MDMA use may lead to neurogenic bladder and chronic urinary retention.
Karen Previdi Olandoski
Full Text Available AIMS: Preservation of renal function in children with congenital neurogenic bladder is an important goal of treatment for the disease. This study analyzed the evolution of renal function in patients with congenital neurogenic bladder. METHODS: We reviewed the records of 58 pediatric patients with respect to the following attributes: gender, age, etiology of neurogenic bladder, reason for referral, medical/surgical management, episodes of treated urinary tract infections, urodynamics, DMSA scintigraphy, weight, height, blood pressure, glomerular filtration rate, microalbuminuria and metabolic acidosis. Statistical analysis was performed, adopting the 5% significance level. RESULTS: The mean age at presentation was 4.2 ± 3.5 years. Myelomeningocele was the most frequent etiology (71.4%. Recurrent urinary tract infection was the reason for referral in 82.8% of the patients. Recurrent urinary tract infections were diagnosed in 84.5% of the patients initially; 83.7% of those patients experienced improvement during follow-up. The initial mean glomerular filtration rate was 146.7 ± 70.1 mL/1.73 m²/min, and the final mean was 193.6 ± 93.6 mL/1.73 m²/min, p = 0.0004. Microalbuminuria was diagnosed in 54.1% of the patients initially and in 69% in the final evaluation. Metabolic acidosis was present in 19% of the patients initially and in 32.8% in the final assessment. CONCLUSIONS: Patient referral to a pediatric nephrologist was late. A reduction in the number of urinary tract infections was observed with adequate treatment, but microalbuminuria and metabolic acidosis occurred frequently despite adequate management.
Olandoski, Karen Previdi; Koch, Vera; Trigo-Rocha, Flavio Eduardo
Preservation of renal function in children with congenital neurogenic bladder is an important goal of treatment for the disease. This study analyzed the evolution of renal function in patients with congenital neurogenic bladder. We reviewed the records of 58 pediatric patients with respect to the following attributes: gender, age, etiology of neurogenic bladder, reason for referral, medical/surgical management, episodes of treated urinary tract infections, urodynamics, DMSA scintigraphy, weight, height, blood pressure, glomerular filtration rate, microalbuminuria and metabolic acidosis. Statistical analysis was performed, adopting the 5% significance level. The mean age at presentation was 4.2 ± 3.5 years. Myelomeningocele was the most frequent etiology (71.4%). Recurrent urinary tract infection was the reason for referral in 82.8% of the patients. Recurrent urinary tract infections were diagnosed in 84.5% of the patients initially; 83.7% of those patients experienced improvement during follow-up. The initial mean glomerular filtration rate was 146.7 ± 70.1 mL/1.73 m²/min, and the final mean was 193.6 ± 93.6 mL/1.73 m²/min, p = 0.0004. Microalbuminuria was diagnosed in 54.1% of the patients initially and in 69% in the final evaluation. Metabolic acidosis was present in 19% of the patients initially and in 32.8% in the final assessment. Patient referral to a pediatric nephrologist was late. A reduction in the number of urinary tract infections was observed with adequate treatment, but microalbuminuria and metabolic acidosis occurred frequently despite adequate management.
Fei, G; Fang, X; Wang, G D; Liu, S; Wang, X Y; Xia, Y; Wood, J D
To test a hypothesis that: (i) duodenal pH and osmolarity are individually controlled at constant set points by negative feedback control centred in the enteric nervous system (ENS); (ii) the purinergic P2Y(1) receptor subtype is expressed by non-cholinergic secretomotor/vasodilator neurons, which represent the final common excitatory pathway from the ENS to the bicarbonate secretory glands. Ussing chamber and pH-stat methods investigated involvement of the P2Y(1) receptor in neurogenic stimulation of mucosal bicarbonate (HCO(3)(-)) secretion in guinea pig duodenum. ATP increased HCO(3)(-) secretion with an EC(50) of 160 nM. MRS2179, a selective P2Y(1) purinergic receptor antagonist, suppressed ATP-evoked HCO(3)(-) secretion by 47% and Cl(-) secretion by 63%. Enteric neuronal blockade by tetrodotoxin or exposure to a selective vasoactive intestinal peptide (VIP, VPAC(1)) receptor antagonist suppressed ATP-evoked HCO(3)(-) secretion by 61 and 41%, respectively, and Cl- by 97 and 70% respectively. Pretreatment with the muscarinic antagonist, scopolamine did not alter ATP-evoked HCO3(-) or Cl(-) secretion. Whereas acid directly stimulates the mucosa to release ATP and stimulate HCO(3)(-) secretion in a cytoprotective manner, neurogenically evoked HCO(3)(-) secretion accounts for feedback control of optimal luminal pH for digestion. ATP stimulates duodenal HCO(3)(-) secretion through an excitatory action at purinergic P2Y(1) receptors on neurons in the submucosal division of the ENS. Stimulation of the VIPergic non-cholinergic secretomotor/vasodilator neurons, which are one of three classes of secretomotor neurons, accounts for most, if not all, of the neurogenic secretory response evoked by ATP. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.
Theys, C.; van Wieringen, A.; Sunaert, S.; Thijs, V.; De Nil, L. F.
In this prospective study, data on incidence, stuttering characteristics, co-occurring speech disorders, and recovery of neurogenic stuttering in a large sample of stroke participants were assessed. Following stroke onset, 17 of 319 participants (5.3%; 95% CI, 3.2-8.3) met the criteria for neurogenic stuttering. Stuttering persisted in at least…
Scola Rosana Herminia
Full Text Available We report the case of a 3-1/2-year-old girl with hypotonia, multiple joint contractures, hip luxation, arachnodactyly, adducted thumbs, dolichostenomelia, and abnormal external ears suggesting the diagnosis of congenital contractural arachnodactyly (CCA. The serum muscle enzimes were normal and the needle electromyography showed active and chronic denervation. The muscle biopsy demonstrated active and chronic denervation compatible with spinal muscular atrophy. Analysis of exons 7 and 8 of survival motor neuron gene through polymerase chain reaction did not show deletions. Neurogenic muscular atrophy is a new abnormality associated with CCA, suggesting that CCA is clinically heterogeneous.
Franklin, Gary M
Outcomes of surgery for neurogenic thoracic outlet syndrome (NTOS) in workers' compensation are poor in a majority of patients, partly due to nonspecificity of diagnosis. Most cases have no objective evidence of the presence of brachial plexus dysfunction. Up to 20% of patients experience a new adverse event. Objective neurologic signs and electrodiagnostic evidence of brachial plexus dysfunction must be present before proceeding with invasive procedures. This guideline includes objective criteria that must be met before thoracic outlet syndrome surgery can be approved in Washington State. Evidence does not support the use of scalene blocks, botulinum toxin therapy, or vascular studies to diagnose NTOS. Copyright © 2015 Elsevier Inc. All rights reserved.
Bergman, Aviv; Gligorijevic, Bojana
Niche construction concept was originally defined in evolutionary biology as the continuous interplay between natural selection via environmental conditions and the modification of these conditions by the organism itself. Processes unraveling during cancer metastasis include construction of niches, which cancer cells use towards more efficient survival, transport into new environments and preparation of the remote sites for their arrival. Many elegant experiments were done lately illustrating, for example, the premetastatic niche construction, but there is practically no mathematical modeling done which would apply the niche construction framework. To create models useful for understanding niche construction role in cancer progression, we argue that a) genetic, b) phenotypic and c) ecological levels are to be included. While the model proposed here is phenomenological in its current form, it can be converted into a predictive outcome model via experimental measurement of the model parameters. Here we give an overview of an experimentally formulated problem in cancer metastasis and propose how niche construction framework can be utilized and broadened to model it. Other life science disciplines, such as host-parasite coevolution, may also benefit from niche construction framework adaptation, to satisfy growing need for theoretical considerations of data collected by experimental biology.
Scott-Phillips, Thomas C; Laland, Kevin N; Shuker, David M; Dickins, Thomas E; West, Stuart A
Niche construction refers to the activities of organisms that bring about changes in their environments, many of which are evolutionarily and ecologically consequential. Advocates of niche construction theory (NCT) believe that standard evolutionary theory fails to recognize the full importance of niche construction, and consequently propose a novel view of evolution, in which niche construction and its legacy over time (ecological inheritance) are described as evolutionary processes, equivalent in importance to natural selection. Here, we subject NCT to critical evaluation, in the form of a collaboration between one prominent advocate of NCT, and a team of skeptics. We discuss whether niche construction is an evolutionary process, whether NCT obscures or clarifies how natural selection leads to organismal adaptation, and whether niche construction and natural selection are of equivalent explanatory importance. We also consider whether the literature that promotes NCT overstates the significance of niche construction, whether it is internally coherent, and whether it accurately portrays standard evolutionary theory. Our disagreements reflect a wider dispute within evolutionary theory over whether the neo-Darwinian synthesis is in need of reformulation, as well as different usages of some key terms (e.g., evolutionary process). © 2013 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.
Bergman, Aviv; Gligorijevic, Bojana
Niche construction concept was originally defined in evolutionary biology as the continuous interplay between natural selection via environmental conditions and the modification of these conditions by the organism itself. Processes unraveling during cancer metastasis include construction of niches, which cancer cells use towards more efficient survival, transport into new environments and preparation of the remote sites for their arrival. Many elegant experiments were done lately illustrating, for example, the premetastatic niche construction, but there is practically no mathematical modeling done which would apply the niche construction framework. To create models useful for understanding niche construction role in cancer progression, we argue that a) genetic, b) phenotypic and c) ecological levels are to be included. While the model proposed here is phenomenological in its current form, it can be converted into a predictive outcome model via experimental measurement of the model parameters. Here we give an overview of an experimentally formulated problem in cancer metastasis and propose how niche construction framework can be utilized and broadened to model it. Other life science disciplines, such as host-parasite coevolution, may also benefit from niche construction framework adaptation, to satisfy growing need for theoretical considerations of data collected by experimental biology.
Pianka, Eric R; Vitt, Laurie J; Pelegrin, Nicolás; Fitzgerald, Daniel B; Winemiller, Kirk O
Widespread niche convergence suggests that species can be organized according to functional trait combinations to create a framework analogous to a periodic table. We compiled ecological data for lizards to examine patterns of global and regional niche diversification, and we used multivariate statistical approaches to develop the beginnings for a periodic table of niches. Data (50+ variables) for five major niche dimensions (habitat, diet, life history, metabolism, defense) were compiled for 134 species of lizards representing 24 of the 38 extant families. Principal coordinates analyses were performed on niche dimensional data sets, and species scores for the first three axes were used as input for a principal components analysis to ordinate species in continuous niche space and for a regression tree analysis to separate species into discrete niche categories. Three-dimensional models facilitate exploration of species positions in relation to major gradients within the niche hypervolume. The first gradient loads on body size, foraging mode, and clutch size. The second was influenced by metabolism and terrestrial versus arboreal microhabitat. The third was influenced by activity time, life history, and diet. Natural dichotomies are activity time, foraging mode, parity mode, and habitat. Regression tree analysis identified 103 cases of extreme niche conservatism within clades and 100 convergences between clades. Extending this approach to other taxa should lead to a wider understanding of niche evolution.
Wei, Zheng; Angerer, Lynne M; Angerer, Robert C
During embryogenesis the sea urchin early pluteus larva differentiates 40-50 neurons marked by expression of the pan-neural marker synaptotagmin B (SynB) that are distributed along the ciliary band, in the apical plate and pharyngeal endoderm, and 4-6 serotonergic neurons that are confined to the apical plate. Development of all neurons has been shown to depend on the function of Six3. Using a combination of molecular screens and tests of gene function by morpholino-mediated knockdown, we identified SoxC and Brn1/2/4, which function sequentially in the neurogenic regulatory pathway and are also required for the differentiation of all neurons. Misexpression of Brn1/2/4 at low dose caused an increase in the number of serotonin-expressing cells and at higher dose converted most of the embryo to a neurogenic epithelial sphere expressing the Hnf6 ciliary band marker. A third factor, Z167, was shown to work downstream of the Six3 and SoxC core factors and to define a branch specific for the differentiation of serotonergic neurons. These results provide a framework for building a gene regulatory network for neurogenesis in the sea urchin embryo. © 2016. Published by The Company of Biologists Ltd.
Gratzke, Christian; Bachmann, Alexander; Descazeaud, Aurelien; Drake, Marcus J; Madersbacher, Stephan; Mamoulakis, Charalampos; Oelke, Matthias; Tikkinen, Kari A O; Gravas, Stavros
Lower urinary tract symptoms (LUTS) represent one of the most common clinical complaints in adult men and have multifactorial aetiology. To develop European Association of Urology (EAU) guidelines on the assessment of men with non-neurogenic LUTS. A structured literature search on the assessment of non-neurogenic male LUTS was conducted. Articles with the highest available level of evidence were selected. The Delphi technique consensus approach was used to develop the recommendations. As a routine part of the initial assessment of male LUTS, a medical history must be taken, a validated symptom score questionnaire with quality-of-life question(s) should be completed, a physical examination including digital rectal examination should be performed, urinalysis must be ordered, post-void residual urine (PVR) should be measured, and uroflowmetry may be performed. Micturition frequency-volume charts or bladder diaries should be used to assess male LUTS with a prominent storage component or nocturia. Prostate-specific antigen (PSA) should be measured only if a diagnosis of prostate cancer will change the management or if PSA can assist in decision-making for patients at risk of symptom progression and complications. Renal function must be assessed if renal impairment is suspected from the history and clinical examination, if the patient has hydronephrosis, or when considering surgical treatment for male LUTS. Uroflowmetry should be performed before any treatment. Imaging of the upper urinary tract in men with LUTS should be performed in patients with large PVR, haematuria, or a history of urolithiasis. Imaging of the prostate should be performed if this assists in choosing the appropriate drug and when considering surgical treatment. Urethrocystoscopy should only be performed in men with LUTS to exclude suspected bladder or urethral pathology and/or before minimally invasive/surgical therapies if the findings may change treatment. Pressure-flow studies should be performed
Honeyman, M S; Pirog, R S; Huber, G H; Lammers, P J; Hermann, J R
After the broad industrialization of the US pork industry, there has been a development of niche markets for export and domestic pork; that is, there is a pork niche market phenomenon. The US pork niche market phenomenon is characterized, and 2 of the major markets are explained in detail. With the Midwest's tradition of a diversified family-based agriculture and record low hog prices of the late 1990s, the conditions were conducive for this phenomenon to develop. Pork niche markets utilize various sales methods including Internet sales, local abattoir sales, direct marketing, farmer networks, and targeting to organized groups. In 2003, there were approximately 35 to 40 active pork niche marketing efforts in Iowa. The Berkshire breed is an example of a swine breed that has had a recent resurgence because of niche markets. Berkshire pork is known for tenderness and excellent quality. Berkshire registrations have increased 4-fold in the last 10 yr. One of the larger niche marketers of "natural pork" is Niman Ranch Pork, which has more than 400 farmer-producers and processes about 2,500 pigs weekly. Many US consumers of pork are interested in issues concerning the environment, food safety, pig welfare, and pig farm ownership and structure. These consumers may be willing to pay more for pork from farmers who are also concerned about these issues. Small- and medium-sized swine farmers are active in pork niche markets. Niche markets claim product differentiation by superior or unique product quality and social attributes. Quality attributes include certain swine breeds, and meat quality, freshness, taste or flavor, and tenderness. Social or credence attributes often are claimed and include freedom from antibiotics and growth promotants; local family farm production; natural, organic, outdoor, or bedded rearing; humane rearing; known origin; environmentally friendly production; and the absence of animal by-products in the feed. Niche pork markets and alternative swine
Malandraki, Georgia A; Rajappa, Akila; Kantarcigil, Cagla; Wagner, Elise; Ivey, Chandra; Youse, Kathleen
To examine the effects of the Intensive Dysphagia Rehabilitation approach on physiological and functional swallowing outcomes in adults with neurogenic dysphagia. Intervention study; before-after trial with 4-week follow-up through an online survey. Outpatient university clinics. A consecutive sample of subjects (N=10) recruited from outpatient university clinics. All subjects were diagnosed with adult-onset neurologic injury or disease. Dysphagia diagnosis was confirmed through clinical and endoscopic swallowing evaluations. No subjects withdrew from the study. Participants completed the 4-week Intensive Dysphagia Rehabilitation protocol, including 2 oropharyngeal exercise regimens, a targeted swallowing routine using salient stimuli, and caregiver participation. Treatment included hourly sessions twice per week and home practice for approximately 45 min/d. Outcome measures assessed pre- and posttreatment included airway safety using an 8-point Penetration Aspiration Scale, lingual isometric pressures, self-reported swallowing-related quality of life (QOL), and level of oral intake. Also, patients were monitored for adverse dysphagia-related effects. QOL and adverse effects were also assessed at the 4-week follow-up (online survey). The Intensive Dysphagia Rehabilitation approach was effective in improving maximum and mean Penetration Aspiration Scale scores (PDysphagia Rehabilitation approach was safe and improved physiological and some functional swallowing outcomes in our sample; however, further investigation is needed before it can be widely applied. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Juliana S. Philippsen
Full Text Available This study investigated the isotopic niches of two fish species, one exotic and one native. It was hypothesized that these species would show little or no isotopic niche overlap. This hypothesis was tested with the isotopic niche concept and the trophic Layman's metrics. A considerable isotopic niche overlap was observed between the species, mainly for the exotic that showed the greater percentage of overlapping, indicating an interspecific competition for food resources. Layman's metrics also showed this species probably exploits a more specific array of food resources when compared with the native species. The native species probably has the ability to exploit a wider array of resources, highlighted by the higher values given for the Layman's metrics. The juveniles and adults of native species showed minor overlapping between the isotopic niches. This indicates that they have probably adopted different foraging strategies, minimizing intraspecific competition. Evidences that the exotic species explores a narrower range of resources and that the native species has a greater isotopic niche and possibly suffer less intraspecific competition, indicates that the native species can tolerate the presence of the exotic species and promote survival and maintenance of its population even under possible competition effects imposed by the exotic species.
Seike, Masanari; Omatsu, Yoshiki; Watanabe, Hitomi; Kondoh, Gen; Nagasawa, Takashi
Bone marrow is the tissue filling the space between bone surfaces. Hematopoietic stem cells (HSCs) are maintained by special microenvironments known as niches within bone marrow cavities. Mesenchymal cells, termed CXC chemokine ligand 12 (CXCL12)-abundant reticular (CAR) cells or leptin receptor-positive (LepR + ) cells, are a major cellular component of HSC niches that gives rise to osteoblasts in bone marrow. However, it remains unclear how osteogenesis is prevented in most CAR/LepR + cells to maintain HSC niches and marrow cavities. Here, using lineage tracing, we found that the transcription factor early B-cell factor 3 (Ebf3) is preferentially expressed in CAR/LepR + cells and that Ebf3-expressing cells are self-renewing mesenchymal stem cells in adult marrow. When Ebf3 is deleted in CAR/LepR + cells, HSC niche function is severely impaired, and bone marrow is osteosclerotic with increased bone in aged mice. In mice lacking Ebf1 and Ebf3 , CAR/LepR + cells exhibiting a normal morphology are abundantly present, but their niche function is markedly impaired with depleted HSCs in infant marrow. Subsequently, the mutants become progressively more osteosclerotic, leading to the complete occlusion of marrow cavities in early adulthood. CAR/LepR + cells differentiate into bone-producing cells with reduced HSC niche factor expression in the absence of Ebf1/Ebf3 Thus, HSC cellular niches express Ebf3 that is required to create HSC niches, to inhibit their osteoblast differentiation, and to maintain spaces for HSCs. © 2018 Seike et al.; Published by Cold Spring Harbor Laboratory Press.
The purpose of this analysis is to provide the design basis and general arrangement requirements of the non-potable water, waste water, compressed air and ventilation (post excavation) utilities required in support of the Cross Drift alcoves and niches
The $15 billion assisted-living industry has captured a profitable market niche and created a star on Wall Street. Sunrise Retirement Home of Falls Church (Va.), right, is a facility of the nation's largest assisted-living provider.
Brun, Philipp Georg; Vogt, Meike; Payne, Mark
We characterize the realized ecological niches of 133 phytoplankton taxa in the open ocean based on observations from the MAREDAT initiative and a statistical species distribution model (MaxEnt). The models find that the physical conditions (mixed layer depth, temperature, light) govern large......-scale patterns in phytoplankton biogeography over nutrient availability. Strongest differences in the realized niche centers were found between diatoms and coccolithophores. Diatoms (87 species) occur in habitats with significantly lower temperatures, light intensity and salinity, with deeper mixed layers...... conditions in the open ocean. Our estimates of the realized niches roughly match the predictions of Reynolds' C-S-R model for the global ocean, namely that taxa classified as nutrient stress tolerant have niches at lower nutrient and higher irradiance conditions than light stress tolerant taxa. Yet...
Full Text Available In this study, we aimed to determine gastrointestinal problems associated with neurogenic bowel dysfunction in spinal cord injury patients and to assess the efficacy of bowel program on gastrointestinal problems and the severity of neurogenic bowel dysfunction. Fifty-five spinal cord injury patients were included in this study. A bowel program according to the characteristics of neurogenic bowel dysfunction was performed for each patient. Before and after bowel program, gastrointestinal problems (constipation, difficult intestinal evacuation, incontinence, abdominal pain, abdominal distension, loss of appetite, hemorrhoids, rectal bleeding and gastrointestinal induced autonomic dysreflexia and bowel evacuation methods (digital stimulation, oral medication, suppositories, abdominal massage, Valsalva maneuver and manual evacuation were determined. Neurogenic bowel dysfunction score was used to assess the severity of neurogenic bowel dysfunction. At least one gastrointestinal problem was identified in 44 (80% of the 55 patients before bowel program. Constipation (56%, 31/55 and incontinence (42%, 23/55 were the most common gastrointestinal problems. Digital rectal stimulation was the most common method for bowel evacuation, both before (76%, 42/55 and after (73%, 40/55 bowel program. Oral medication, enema and manual evacuation application rates were significantly decreased and constipation, difficult intestinal evacuation, abdominal distention, and abdominal pain rates were significantly reduced after bowel program. In addition, mean neurogenic bowel dysfunction score was decreased after bowel program. An effective bowel program decreases the severity of neurogenic bowel dysfunction and reduces associated gastrointestinal problems in patients with spinal cord injury.
Full Text Available Neurogenic bladder is a dysfunction of the lower urinary tract caused by nervous system disorder. We investigated the trends in publication of articles under the topic "neurogenic bladder" using bibliometric analysis. Articles on neurogenic bladder, published between 1995 and 2014, were retrieved from the ISI Web of Science citation database. We analyzed the search results for authors, countries, institutions, journals, and top-cited papers. A total of 1,904 articles were retrieved. There was a small increase in the number of articles on neurogenic bladder from 1995 (n = 43 to 2014 (n = 117. The USA was the leading country in the total number of articles (n = 598. However, the number of publications from China has rapidly increased, and China was ranked second in 2014. Emmanuel Chartier-Kastler (n = 65 was the most productive author, and University of Paris VI (Paris 6 (n = 61 was the most productive institution. The Journal of Urology published the greatest number of articles on this topic (n = 285. Articles on neurogenic bladder were often published in a professional journal under the category Urology & Nephrology, Neurosciences & Neurology, or Rehabilitation. Visualization analysis based on co-citation networks was conducted using CiteSpace III. Visualization analysis revealed that the hot spots in neurogenic bladder were botulinum toxin-A, prazosin, bethanechol, and afferent pathways. These findings provide new insight into the publication trends and hot spots in neurogenic bladder.
Christman, Matthew S; Kalmus, Angela; Casale, Pasquale
There is a lack of information on the safety and efficacy of ureteroscopy in the neurogenic bladder population. We hypothesized that ureteroscopy in patients with neurogenic bladder would be associated with an increased risk of complications and a lower stone clearance rate than in patients without neurological impairment. We reviewed a local registry of patients with ICD-9 codes for urolithiasis between 2004 and 2012. The study cohort was assembled from all eligible patients with neurogenic bladder and a randomly selected control group that had undergone ureteroscopy. Statistical analysis of demographic variables and surgical outcomes was performed. Complications were classified according to the Clavien system. Clearance was defined by computerized tomography, renal/bladder ultrasound or direct ureterorenoscopy. Ureteroscopy was performed a total of 173 times in 127 controls and a total of 45 times in 20 patients with neurogenic bladder. There was no difference between presenting episodes by gender (p = 1.0), race (p = 0.654) or body mass index (p = 0.519). Bacteriuria was associated with the stone episode in 16.4% of controls and 67% of neurogenic bladder cases (p neurogenic bladder (80.5 minutes, IQR 50-110.5 vs 52, IQR 33-78, p = 0.0003). The proportion of complications was significantly different (p = 0.013). Stones cleared in 86.6% of controls compared to 63% of neurogenic bladder cases (p = 0.004). Patients with neurogenic bladder have increased morbidity after ureteroscopy for upper tract calculi compared to neurologically unaffected controls. Infection has a role in this morbidity. The clearance rate is lower but the stone burden is more significant in those with neurogenic bladder. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Kitchen, W J; Mohamed, Mohamed; Bhojak, Manesh; Wilby, Martin
This study examines the efficacy and long-term safety of a midline sparing decompression for patients with degenerative spondylolisthesis (DS). We specifically looked at the rate of re-operation with a lumbar fusion. Of the patients that did require a secondary fusion procedure, we examined retrospectively any risk factors (both clinical and radiological) that could have been identified pre-operatively to predict the necessity of a primary fusion procedure. Data was collected prospectively within a single surgeon practice at our institution. All patients had a diagnosis of neurogenic claudication secondary to DS. Radiological and clinical risk factors that could have predicted the requirement of a fusion procedure were retrospectively analysed. This is a study of 70 patients (46F:24M). The median age at surgery was 68 years. All patients had a diagnosis of neurogenic claudication and were treated with a mid-line sparing decompression. Following the primary procedure, patients' VAS and ODI scores for both leg and back pain improved significantly both at short-term follow-up (mean seven months) and sustained at long-term follow-up (range 16-57 months, mean 33 months; p < 0.0001 Wilcoxon matched pair ranks). Eight (11%) patients had symptom progression and required a further fusion procedure. We found that if on the pre-operative MRI, the patient had a facet joint angle of greater than 60°, and a preserved disc height (greater than 7 mm) this would increase the likelihood of the requirement for fusion. Of the patients that required a secondary fusion procedure, 6/8 patients (75%) had sagittal facets, hyperlordosis and a preserved disc height pre-operatively. A primary decompression using a midline sparing osteotomy is an effective procedure for the treatment of neurogenic claudication caused by DS. The second message is that on inspection of the pre-operative imaging, sagittally placed facet joints, a hyperlordosis and a preserved disc height then a fusion
Hadiprojo, Angelia Cindy
Penelitian ini bertujuan untuk meneliti bagaimana cara perusahaan mengidentifikasi niche market, menentukan faktor yang penting untuk kesuksesan niche market, dan menjelaskan manfaat penerapan niche market strategy bagi perusahaan, serta menemukan peran niche market dalam industri keramik di masa depan. Pengumpulan data dalam penelitian ini menggunakan metode wawancara dan observasi. Penelitian dilakukan terhadap perusahaan keramik di Kasongan, Bantul, Yogyakarta yang termasuk di dalam ind...
Guha, Suman K; Tillu, Rucha; Sood, Ankit; Patgaonkar, Mandar; Nanavaty, Ishira N; Sengupta, Arjun; Sharma, Shobhona; Vaidya, Vidita A; Pathak, Sulabha
Cerebral malaria is associated with cerebrovascular damage and neurological sequelae. However, the neurological consequences of uncomplicated malaria, the most prevalent form of the disease, remain uninvestigated. Here, using a mild malaria model, we show that a single Plasmodium chabaudi adami infection in adult mice induces neuroinflammation, neurogenic, and behavioral changes in the absence of a blood-brain barrier breach. Using cytokine arrays we show that the infection induces differential serum and brain cytokine profiles, both at peak parasitemia and 15days post-parasite clearance. At the peak of infection, along with the serum, the brain also exhibited a definitive pro-inflammatory cytokine profile, and gene expression analysis revealed that pro-inflammatory cytokines were also produced locally in the hippocampus, an adult neurogenic niche. Hippocampal microglia numbers were enhanced, and we noted a shift to an activated profile at this time point, accompanied by a striking redistribution of the microglia to the subgranular zone adjacent to hippocampal neuronal progenitors. In the hippocampus, a distinct decline in progenitor turnover and survival was observed at peak parasitemia, accompanied by a shift from neuronal to glial fate specification. Studies in transgenic Nestin-GFP reporter mice demonstrated a decline in the Nestin-GFP(+)/GFAP(+) quiescent neural stem cell pool at peak parasitemia. Although these cellular changes reverted to normal 15days post-parasite clearance, specific brain cytokines continued to exhibit dysregulation. Behavioral analysis revealed selective deficits in social and anxiety-like behaviors, with no change observed in locomotor, cognitive, and depression-like behaviors, with a return to baseline at recovery. Collectively, these findings indicate that even a single episode of mild malaria results in alterations of the brain cytokine profile, causes specific behavioral dysfunction, is accompanied by hippocampal microglial
Full Text Available A 76-year-old man presented with a Denis Zone III sacral fracture after a traffic accident. He also developed urinary retention and perineal numbness. The patient was diagnosed with neurogenic bladder dysfunction caused by the sacral fracture. A computed tomogram (CT revealed that third sacral lamina was fractured and displaced into the spinal canal, but vertebral body did not displace. The fracture lines began at the center of lamina and extended bilateraly. The fracture pattern was unique. The sacrum was osteoporosis, and this fracture may be based on osteoporosis. We performed laminectomy to decompress sacral nerve roots. One month after surgery, the patient was able to urinate. Three months after surgery, his bladder function recovered normally. One year after surgery, he returned to a normal daily life and had no complaints regarding urination. One-year postoperative CT showed the decompressed third sacrum without displacement.
Šedý, Jiří; Zicha, Josef; Kuneš, Jaroslav; Syková, Eva
Roč. 73, č. 1 (2009), s. 42-44 ISSN 0306-9877 R&D Projects: GA ČR GA309/06/1246; GA MŠk(CZ) LC554 Grant - others:GA MŠk(CZ) 1M0510; GA MZd(CZ) 1A8697; GA MŠk(CZ) 1M0538; EC FP6 RESCUE(FR) LSHB-CT-2005-518233; GA MŠk(CZ) 1M0021620803 Program:1M; 1M Institutional research plan: CEZ:AV0Z50390703; CEZ:AV0Z50110509; CEZ:AV0Z50390512 Keywords : central nervous system * neurogenic pulmonary edema Subject RIV: FH - Neurology Impact factor: 1.393, year: 2009
Breinbjerg, Anders; Rittig, Søren; Kamperis, Konstantinos
We present a child, 5 months of age, diagnosed with infantile botulism, showing the signs of neurogenic bladder dysfunction. The patient presented with progressive muscle weakness, hypotonia, suckling and swallowing problems and absent peripheral reflexes at clinical examination. Botulinum neurotoxin type A was detected in her serum, confirming the diagnosis. Starting at day 6, the girl presented with a urinary retention initially necessitating free bladder drainage and subsequently intermittent catheterisation. After 6 weeks in intensive care, the patient recovered but the bladder underactivity persisted. Four months following recovery, a urodynamic evaluation was performed, showing a near normal detrusor activity and normal bladder emptying, and the catheterisation was ceased. At 6 months, the girl was diagnosed with a urinary tract infection and bladder emptying problems, which persisted, and clean intermittent catheterisation was started. The final urodynamic evaluation, a year and a half after her initial presentation, revealed a normal detrusor activity and an adequate bladder emptying.
Full Text Available Traumatic neuromas are uncommon and benign lesions arising from a peripheral nerve injury during surgery. Here we describe a case with histopathologic features of both a traumatic neuroma and neurofibroma in a patient without integumentary physical exam findings nor prior surgical history. A 54 year old male was admitted for surgical debridement of a foot ulcer. During pre-operative evaluation and review of imaging multiple CT scans revealed a stable, 4 mm endobronchial lesion in the left lower lobe. Given history of nicotine abuse, bronchoscopy was performed. Bronchoscopy showed a pearly, polypoid lesion. Histopathological results showed strong positivity for S-100 protein and spindle cell proliferation. Repeat CT chest showed no new lesions in the bronchial tree. The rarity of this case is noted not only by the limited number of bronchial neurogenic tumors, but the combined features in this case of a traumatic neuroma and neurofibroma which has not been described.
Kristiansen, Kim Anker; Edvinsson, Lars
Calcitonin gene-related peptide (CGRP) is linked to neurogenic inflammation and to migraine. Activation of the trigeminovascular system plays a prominent role during migraine attacks with the release of CGRP. The trigeminal ganglion (TG) contains three main cell types: neurons, satellite glial...... cells (SGC) and Schwann cells; the first two have before been studied in vitro separately. Culture of rat TG provides a method to induce inflammation and the possibility to evaluate the different cell types in the TG simultaneously. We investigated expression levels of various inflammatory cytokines...... inhibitor SP600125. This method may be of value to examine local TG inflammation, putatively involved in the pathophysiology of some forms of primary headaches....
Schneider-Mizell, Casey M.; Parent, Jack M.; Ben-Jacob, Eshel; Zochowski, Michal R.; Sander, Leonard M.
Networks can be dynamical systems that undergo functional and structural reorganization. One example of such a process is adult hippocampal neurogenesis, in which new cells are continuously born and incorporate into the existing network of the dentate gyrus region of the hippocampus. Many of these introduced cells mature and become indistinguishable from established neurons, joining the existing network. Activity in the network environment is known to promote birth, survival and incorporation of new cells. However, after epileptogenic injury, changes to the connectivity structure around the neurogenic niche are known to correlate with aberrant neurogenesis. The possible role of network-level changes in the development of epilepsy is not well understood. In this paper, we use a computational model to investigate how the structural and functional outcomes of network reorganization, driven by addition of new cells during neurogenesis, depend on the original network structure. We find that there is a stable network topology that allows the network to incorporate new neurons in a manner that enhances activity of the persistently active region, but maintains global network properties. In networks having other connectivity structures, new cells can greatly alter the distribution of firing activity and destroy the initial activity patterns. We thus find that new cells are able to provide focused enhancement of network only for small-world networks with sufficient inhibition. Network-level deviations from this topology, such as those caused by epileptogenic injury, can set the network down a path that develops toward pathological dynamics and aberrant structural integration of new cells.
Schneider-Mizell, Casey M; Zochowski, Michal R; Sander, Leonard M; Parent, Jack M; Ben-Jacob, Eshel
Networks can be dynamical systems that undergo functional and structural reorganization. One example of such a process is adult hippocampal neurogenesis, in which new cells are continuously born and incorporate into the existing network of the dentate gyrus region of the hippocampus. Many of these introduced cells mature and become indistinguishable from established neurons, joining the existing network. Activity in the network environment is known to promote birth, survival and incorporation of new cells. However, after epileptogenic injury, changes to the connectivity structure around the neurogenic niche are known to correlate with aberrant neurogenesis. The possible role of network-level changes in the development of epilepsy is not well understood. In this paper, we use a computational model to investigate how the structural and functional outcomes of network reorganization, driven by addition of new cells during neurogenesis, depend on the original network structure. We find that there is a stable network topology that allows the network to incorporate new neurons in a manner that enhances activity of the persistently active region, but maintains global network properties. In networks having other connectivity structures, new cells can greatly alter the distribution of firing activity and destroy the initial activity patterns. We thus find that new cells are able to provide focused enhancement of network only for small-world networks with sufficient inhibition. Network-level deviations from this topology, such as those caused by epileptogenic injury, can set the network down a path that develops toward pathological dynamics and aberrant structural integration of new cells
Tomás P. Bachor
Full Text Available Experimental diabetes in rodents rapidly affects the neurogenic niches of the adult brain. Moreover, behavioral disorders suggest that a similar dysfunction of the neurogenic niches most likely affects diabetic and prediabetic patients. Here, we review our present knowledge about adult neural stem cells, the methods used for their study in diabetic models, and the effects of experimental diabetes. Variations in diet and even a short hyperglycemia profoundly change the structure and the proliferative dynamics of the neurogenic niches. Moreover, alterations of diabetic neurogenic niches appear to be associated with diabetic cognitive disorders. Available evidence supports the hypothesis that, in the adult, early changes of the neurogenic niches might enhance development of the diabetic disease.
Formicola, Luigi; Marazzi, Giovanna; Sassoon, David A.
Specific muscles are spared in many degenerative myopathies. Most notably, the extraocular muscles (EOMs) do not show clinical signs of late stage myopathies including the accumulation of fibrosis and fat. It has been proposed that an altered stem cell niche underlies the resistance of EOMs in these pathologies, however, to date, no reports have provided a detailed characterization of the EOM stem cell niche. PW1/Peg3 is expressed in progenitor cells in all adult tissues including satellite cells and a subset of interstitial non-satellite cell progenitors in muscle. These PW1-positive interstitial cells (PICs) include a fibroadipogenic progenitor population (FAP) that give rise to fat and fibrosis in late stage myopathies. PICs/FAPs are mobilized following injury and FAPs exert a promyogenic role upon myoblasts in vitro but require the presence of a minimal population of satellite cells in vivo. We and others recently described that FAPs express promyogenic factors while satellite cells express antimyogenic factors suggesting that PICs/FAPs act as support niche cells in skeletal muscle through paracrine interactions. We analyzed the EOM stem cell niche in young adult and aged wild-type mice and found that the balance between PICs and satellite cells within the EOM stem cell niche is maintained throughout life. Moreover, in the adult mdx mouse model for Duchenne muscular dystrophy (DMD), the EOM stem cell niche is unperturbed compared to normal mice, in contrast to Tibialis Anterior (TA) muscle, which displays signs of ongoing degeneration/regeneration. Regenerating mdx TA shows increased levels of both PICs and satellite cells, comparable to normal unaffected EOMs. We propose that the increase in PICs that we observe in normal EOMs contributes to preserving the integrity of the myofibers and satellite cells. Our data suggest that molecular cues regulating muscle regeneration are intrinsic properties of EOMs. PMID:25520657
Full Text Available Specific muscles are spared in many degenerative myopathies. Most notably, the extraocular muscles (EOMs do not show clinical signs of late stage myopathies including the accumulation of fibrosis and fat. It has been proposed that an altered stem cell niche underlies the resistance of EOMs in these pathologies, however, to date, no reports have provided a detailed characterization of the EOM stem cell niche. PW1/Peg3 is expressed in progenitor cells in all adult tissues including satellite cells and a subset of interstitial non-satellite cell progenitors in muscle. These PW1-positive interstitial cells (PICs include a fibroadipogenic progenitor population (FAPs that give rise to fat and fibrosis in late stage myopathies. PICs/FAPs are mobilized following injury and FAPs exert a promyogenic role upon myoblasts in vitro but require the presence of a minimal population of satellite cells in vivo. We and others recently described that FAPs express promyogenic factors while satellite cells express antimyogenic factors suggesting that PICs/FAPs act as support niche cells in skeletal muscle through paracrine interactions. We analyzed the EOM stem cell niche in young adult and aged wild-type mice and found that the balance between PICs and satellite cells within the EOM stem cell niche is maintained throughout life. Moreover, in the adult mdx mouse model for Duchenne muscular dystrophy, the EOM stem cell niche is unperturbed compared to normal mice, in contrast to Tibialis Anterior (TA muscle, which displays signs of ongoing degeneration/regeneration. Regenerating mdx TA shows increased levels of both PICs and satellite cells, comparable to normal unaffected EOMs. We propose that the increase in PICs that we observe in normal EOMs contributes to preserving the integrity of the myofibers and satellite cells. Our data suggest that molecular cues regulating muscle regeneration are intrinsic properties of EOMs.
Christine T eEkdahl
Full Text Available Adult born neurons are encountering numerous choices during their development from neural stem cells to mature functionally integrated neurons in the brain. Microglia are part of the microenvironment within the neurogenic niches and possibly involved during the entire decision process. Mounting evidence suggest that microglia act as local equalizers capable of amplifying as well as filtering homeostatic signals. Depending on their state of activation, they may induce or facilitate different fundamental decisions in neurogenesis, such as proliferation or quiescence, cell survival or death, migration or establishment, growth or retraction of dendrites and axons, synaptic assembly or pruning, or tuning of synaptic transmission. Microglia are activated as a first line of defence against infections and participate in transforming the innate immunity into an adaptive immune response by recruiting systemic immune cells. So far, most studies have reported an acute decrease in the survival of new neurons following this classically activated microglial reaction. However, the long-term effects are more complex. In several neurodegenerative diseases the microglial activation is also evident, including a heterogeneous population of microglial phenotypes and a plethora of immune mediators, where the initiating agent may be protein deposits or cell debris. The transformation from a pro- to an anti-inflammatory cytokine profile and the de-activation of microglia is not clearly defined, or even dysregulated, and the adaptive response is often sparse. The diverse role of microglial activation in neurodegenerative diseases is reflected by the numerous studies reporting both beneficial and detrimental effects on the different steps of neurogenesis. This review will highlight the most recent findings on how microglial activation modulates adult neurogenesis, and specifically discuss the role of microglia in synaptic integration, currently a fast expanding research
In the last decade, niche construction has been heralded as the neglected process in evolution. But niche construction is just one way in which the organism's interaction with and construction of the environment can have potential evolutionary significance. The constructed environment does not just select for , it also produces new variation. Nearly 3 decades ago, and in parallel with Odling-Smee's article 'Niche-constructing phenotypes', West and King introduced the 'ontogenetic niche' to give the phenomena of exo genetic inheritance a formal name. Since then, a range of fields in the life sciences and medicine has amassed evidence that parents influence their offspring by means other than DNA (parental effects), and proposed mechanisms for how heritable variation can be environmentally induced and developmentally regulated. The concept of 'developmental niche construction' (DNC) elucidates how a diverse range of mechanisms contributes to the transgenerational transfer of developmental resources. My most central of claims is that whereas the selective niche of niche construction theory is primarily used to explain the active role of the organism in its selective environment, DNC is meant to indicate the active role of the organism in its developmental environment. The paper highlights the differences between the construction of the selective and the developmental niche, and explores the overall significance of DNC for evolutionary theory.
McMaster Marianne E
Full Text Available Abstract Background In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS. In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. Presentation of the hypothesis Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected. Testing the hypothesis In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity. Implications of the hypothesis The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.
McMaster, Marianne E
In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected. In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity. The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.
Lundie, Mariska; Erasmus, Zandria; Zsilavecz, Ursula; Van der Linde, Jeannie
Neurogenic stuttering (NS) is the most frequently occurring acquired form of stuttering in children and adults. This form of stuttering is primarily caused by neurological incidents. Owing to controversies with regard to similarities between developmental stuttering (DS) and NS symptomatology, differential diagnosis is problematic. Differential diagnosis will guide the appropriate management of persons who stutter (PWS). The aim of this study was to describe and highlight the characteristics of NS in order to compile a preliminary checklist for accurate diagnosis and intervention. An explorative, applied mixed method, multiple case study research design was followed. Purposive sampling was used to select four participants. A comprehensive assessment battery was compiled for data collection. The results revealed a distinct pattern of core stuttering behaviours in NS, although discrepancies existed regarding stuttering severity and frequency. It was also found that DS and NS can co-occur. The case history and the core stuttering pattern are important considerations during differential diagnosis, as these are the only consistent characteristics in people with NS. It is unlikely that all the symptoms of NS are present in an individual. The researchers scrutinised the findings of this study and the findings of previous literature to compile a potentially workable checklist.
Full Text Available Neural stem/progenitor cells (NSC have the potential for treatment of a wide range of neurological diseases such as Parkinson Disease and multiple sclerosis. Currently, NSC have been isolated only from hippocampus and subventricular zone (SVZ of the adult brain. It is not known whether NSC can be found in all parts of the developing mid-trimester central nervous system (CNS when the brain undergoes massive transformation and growth. Multipotent NSC from the mid-trimester cerebra, thalamus, SVZ, hippocampus, thalamus, cerebellum, brain stem and spinal cord can be derived and propagated as clonal neurospheres with increasing frequencies with increasing gestations. These NSC can undergo multi-lineage differentiation both in vitro and in vivo, and engraft in a developmental murine model. Regionally-derived NSC are phenotypically distinct, with hippocampal NSC having a significantly higher neurogenic potential (53.6% over other sources (range of 0%-27.5%, p<0.004. Whole genome expression analysis showed differential gene expression between these regionally-derived NSC, which involved the Notch, epidermal growth factor as well as interleukin pathways. We have shown the presence of phenotypically-distinct regionally-derived NSC from the mid-trimester CNS, which may reflect the ontological differences occurring within the CNS. Aside from informing on the role of such cells during fetal growth, they may be useful for different cellular therapy applications.
Mutlu, Hatice; Ekinci, Zelal
Objectives. The aim of this randomized controlled prospective study is to evaluate the efficacy of cranberry capsules for prevention of UTI in children with neurogenic bladder caused by myelomeningocele. Patients and Methods. To be eligible for this study, patients had to be diagnosed as neurogenic bladder caused by myelomeningocele, evaluated urodynamically, followed up with clean intermittent catheterization and anticholinergic drugs. Intervention. Six months of treatment with placebo; afte...
Nakashima, Misako; Iohara, Koichiro; Sugiyama, Masahiko
Dental caries is a common public health problem, causing early loss of dental pulp and resultant tooth loss. Dental pulp has important functions to sustain teeth providing nutrient and oxygen supply, innervation, reactionary/reparative dentin formation and immune response. Regeneration of pulp is an unmet need in endodontic therapy, and angiogenesis/vasculogenesis and neurogenesis are critical for pulp regeneration. Permanent and deciduous pulp tissue is easily available from teeth after extraction without ethical issues and has potential for clinical use. In this review, we introduce some stem cell subfractions, CD31(-)/CD146(-) SP cells and CD105(+) cells with high angiogenic and neurogenic potential, derived from human adult dental pulp tissue. Potential utility of these cells is addressed as a source of cells for treatment of cerebral and limb ischemia and pulp inflammation complete with angiogenesis and vasculogenesis.
Full Text Available Introduction Neurogenic bladder can develop as a result of various degrees of neurogenic lesion in spina bifida. The degree of bladder dysfunction depends on the level and type of spina bifida. Due to results upon complete diagnostic protocols, treatment options are applied. Objective Comparison of therapy results of patients with occult spinal dysraphism with neurogenic bladder that under-went medicamentous therapy and medicamentous with electrotherapy treatment. Methods We had 49 patients with neurogenic bladder that were treated at the University Children's Hospital in Belgrade in the period 2003-2008. The first group of children received medicamentous therapy and the second group received medicamentous therapy with transcutaneous electric nerve stimulation. In both groups we evaluated 4 symptoms: daily enuresis, enuresis nocturna, urgency and frequency and 4 urodynamic parameters: lower bladder capacity, unstable contractions and residual urine and detrusor sphincter dyssynergia. Follow-up urodynamic evaluation was done after 3, 6 and 12 months respectively. Results Our findings pointed out a high statistical significance of improvement in all evaluated urodynamic parameters of neurogenic bladder (predominantly in bladder capacity in the group of children with combined therapy as well in resolution of symptoms (predominantly enuresis nocturna, urgency and frequency. Conclusion Combined therapy is more efficient in treatment of children with neurogenic bladder. Electrotherapy is non-invasive, easily applicable and has had a significant place in treatment of children with dysfunctional voiding.
Full Text Available Divergence in trophic niche between the sexes may function to reduce competition between the sexes ("intersexual niche partitioning hypothesis", or may be result from differential selection among the sexes on maximizing reproductive output ("sexual selection hypothesis". The latter may lead to higher energy demands in females driven by fecundity selection, while males invest in mate searching. We tested predictions of the two hypotheses underlying intersexual trophic niche partitioning in a natural population of spiders. Zodarion jozefienae spiders specialize on Messor barbarus ants that are polymorphic in body size and hence comprise potential trophic niches for the spider, making this system well-suited to study intersexual trophic niche partitioning.Comparative analysis of trophic morphology (the chelicerae and body size of males, females and juveniles demonstrated highly female biased SSD (Sexual Size Dimorphism in body size, body weight, and in the size of chelicerae, the latter arising from sex-specific growth patterns in trophic morphology. In the field, female spiders actively selected ant sub-castes that were larger than the average prey size, and larger than ants captured by juveniles and males. Female fecundity was highly positively correlated with female body mass, which reflects foraging success during the adult stage. Females in laboratory experiments preferred the large ant sub-castes and displayed higher capture efficiency. In contrast, males occupied a different trophic niche and showed reduced foraging effort and reduced prey capture and feeding efficiency compared with females and juveniles.Our data indicate that female-biased dimorphism in trophic morphology and body size correlate with sex-specific reproductive strategies. We propose that intersexual trophic niche partitioning is shaped primarily by fecundity selection in females, and results from sex-differences in the route to successful reproduction where females are
Full Text Available Mashups enable end-users to "mix and match" data and services available on the web to create applications. Their creation is supported by a complex ecosystem of i data providers who offer open APIs to users, ii users who combine APIs into mashups, and iii platforms, such as the ProgrammableWeb or Mashape, that facilitate the construction and publication of mashups. In this article, we argue that the evolution of the mashup ecosystem can be explained in terms of ecosystem niches anchored around hub or keystone APIs. The members of a niche are focused on an area of specialization (e.g., mapping applications and contribute their knowledge to the value proposition of the ecosystem as a whole. To demonstrate the formation of niches in the mashup ecosystem, we model groups of related mashups as species, and we reconstruct the evolution of mashup species through phylogenetic analysis.
Mourik, R.; Raven, R.P.J.M.
Strategic Niche Management (SNM) is a tool to support the societal introduction of radical sustainable innovations. However, it has been mainly used in retrospective to analyse historical case studies. This report discusses SNM from a practioner's perspective with the main aim to articulate questions that should be addressed for translating SNM from an ex-post to an ex-ante tool. The main conclusion is that an SNM tool should focus on the level of 'niches' rather than single projects, i.e. SNM should aim to support (program) managers who aim at orchestrating the interaction between multiple experiments
Full Text Available As a matter of fact, humans continuously delegate and distribute cognitive functions to the environment to lessen their limits. They build models, representations, and other various mediating structures that are thought to be good constructions. In doing this, humans are engaged in a process of cognitive niche construction. More precisely, we argue that a cognitive niche emerges from a network of continuous interplay between individuals and environment, in which people alter and modify the environment by mimetically externalizing fleeting thoughts, private ideas, etc., into external supports. This can turn out to be useful, especially for all those situations that require information transmission, shared knowledge, and more generally, cognitive resources.
Full Text Available Neurogenic, heterotopic ossification is characterised by the formation of new, extraosseous (ectopic bone in soft tissue in patients with neurological disorders. A 33-year-old female, who was born with spina bifida, paraplegia, and diastasis of symphysis pubis, had indwelling urethral catheter drainage and was using oxybutynin bladder instillations. She was prescribed diuretic for swelling of feet, which aggravated bypassing of catheter. Hence, suprapubic cystostomy was performed. Despite anticholinergic therapy, there was chronic urine leak around the suprapubic catheter and per urethra. Therefore, the urethra was mobilised and closed. After closure of the urethra, there was no urine leak from the urethra, but urine leak persisted around the suprapubic catheter. Cystogram confirmed the presence of a Foley balloon inside the bladder; there was no urinary fistula. The Foley balloon ruptured frequently, leading to extrusion of the Foley catheter. X-ray of abdomen showed heterotopic bone formation bridging the gap across diastasis of symphysis pubis. CT of pelvis revealed heterotopic bone lying in close proximity to the balloon of the Foley catheter; the sharp edge of heterotopic bone probably acted like a saw and led to frequent rupture of the balloon of the Foley catheter. Unique features of this case are: (1 temporal relationship of heterotopic bone formation to suprapubic cystostomy and chronic urine leak; (2 occurrence of heterotopic ossification in pubic region; (3 complications of heterotopic bone formation viz. frequent rupture of the balloon of the Foley catheter by the irregular margin of heterotopic bone and difficulty in insertion of suprapubic catheter because the heterotopic bone encroached on the suprapubic track; (4 synostosis between pubic bones as a result of heterotopic ossification..Common aetiological factors for neurogenic, heterotopic ossification, such as forceful manipulation, trauma, or spasticity, were absent in this
Full Text Available Interferon-alpha (IFN-α is a proinflammatory cytokine that is widely used for the treatment of chronic viral hepatitis and malignancy, because of its immune-activating, antiviral, and antiproliferative properties. However, long-term IFN-α treatment frequently causes depression, which limits its clinical utility. The precise molecular and cellular mechanisms of IFN-α-induced depression are not currently understood. Neural stem cells (NSCs in the hippocampus continuously generate new neurons, and some evidence suggests that decreased neurogenesis plays a role in the neuropathology of depression. We previously reported that IFN-α treatment suppressed hippocampal neurogenesis and induced depression-like behaviors via its receptors in the brain in adult mice. However, it is unclear how systemic IFN-α administration induces IFN-α signaling in the hippocampus. In this study, we analyzed the role of microglia, immune cells in the brain, in mediating the IFN-α-induced neurogenic defects and depressive behaviors. In vitro studies demonstrated that IFN-α treatment induced the secretion of endogenous IFN-α from microglia, which suppressed NSC proliferation. In vivo treatment of adult mice with IFN-α for five weeks increased the production of proinflammatory cytokines, including IFN-α, and reduced neurogenesis in the hippocampus. Both effects were prevented by simultaneous treatment with minocycline, an inhibitor of microglial activation. Furthermore, minocycline treatment significantly suppressed IFN-α-induced depressive behaviors in mice. These results suggest that microglial activation plays a critical role in the development of IFN-α-induced depression, and that minocycline is a promising drug for the treatment of IFN-α-induced depression in patients, especially those who are low responders to conventional antidepressant treatments.
Morgan, Julie A; Olagunju, Andrew T; Corrigan, Frances; Baune, Bernhard T
Regular exercise in adults improves depressive symptoms (DS) and major depressive disorder (MDD), however the clinical effects of ceasing exercise are largely unknown. Seven databases were searched from inception to December 2017. Eligibility criteria included English language studies investigating the effects of ceasing exercise on DS or MDD in regularly active adults with or without prior DS or MDD. Blood based markers related to exercise cessation (EC) were assessed, if recorded. Studies investigating exercise follow-up periods were excluded. No studies investigated EC in MDD. Six studies including two RCTS and three studies investigating neurogenic and immune biological markers associated with DS met inclusion criteria (152 healthy adults, females n = 50/32.89%). Compared to baseline, EC increased DS after three days, one week, and two weeks. Female participants had significantly more DS than male participants. Following EC, no changes in brain derived neurotrophic factor (BDNF) or tumour necrosis factor alpha (TNF) were evident, however C-reactive protein (CRP) at week one and interleukin 6 (IL6) at week two were reduced. Quality concerns including risks of attrition and reporting bias limit our confidence in these results. Ceasing regular exercise increases DS in healthy adults, with greater DS in females than males. Contrary to the cytokine/inflammatory hypothesis of depression, DS were associated with reduced CRP and IL6 and without increased TNF. High quality trials are needed to extend this field of research in both healthy and MDD populations. Copyright © 2018 Elsevier B.V. All rights reserved.
Conclusion: Simultaneous ureteral reimplantation reduces postop HVUR significantly. We recommend augmentation and simultaneous ureteral reimplantation in children with HVUR and neurogenic bladder if technically feasible.
Yin, Hang; Price, Feodor
Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process involving the activation of various cellular and molecular responses. As skeletal muscle stem cells, satellite cells play an indispensible role in this process. The self-renewing proliferation of satellite cells not only maintains the stem cell population but also provides numerous myogenic cells, which proliferate, differentiate, fuse, and lead to new myofiber formation and reconstitution of a functional contractile apparatus. The complex behavior of satellite cells during skeletal muscle regeneration is tightly regulated through the dynamic interplay between intrinsic factors within satellite cells and extrinsic factors constituting the muscle stem cell niche/microenvironment. For the last half century, the advance of molecular biology, cell biology, and genetics has greatly improved our understanding of skeletal muscle biology. Here, we review some recent advances, with focuses on functions of satellite cells and their niche during the process of skeletal muscle regeneration. PMID:23303905
Merenkov, Vladimir V; Kovalev, Alexey N; Gorbunov, Vyacheslav V
Neurogenic pulmonary edema (NPE) is an acute life-threatening complication associated with many forms of central nervous system injury. NPE usually appears within minutes to hours after injury and has a high mortality rate if not recognized and treated appropriately. Lung ultrasound quickly provides at the bedside relevant information on the state of aeration and ventilation of the lung. We describe a case report of acute respiratory insufficiency after posterior cranial fossa surgery. The patient underwent a subtotal meningiomectomy. Postoperative course was complicated by respiratory failure with unstable hemodynamic parameters. The pulmonary edema was suspected, and sonography examination was performed. Lung ultrasound showed typical signs for non-cardiogenic pulmonary edema. Transthoracic echocardiography showed preserved left ventricle systolic function, but signs of the severe hypovolemia were found. We corrected for the preload and ventilator support settings. Within 24 h, her respiratory status improved with a resolution of the pulmonary edema. Lung ultrasound at the bedside can provide accurate information on lung status in neurocritically ill patients with acute respiratory failure. The addition of transthoracic echocardiography to lung sonography provides an additive insight on the eventual pulmonary involvement. Lung ultrasound has the potential to become a reference tool for bedside dynamic respiratory monitoring in the Neuro ICU.
Yaseen, Ziyad; Baram, Aram
Thoracic outlet syndrome refers to compression of one or more of the neurovascular structures traversing the superior aperture of the thoracic cavity. A symptom-based patient-directed questionnaire was used to evaluate the outcome of the supraclavicular approach for treatment of neurogenic thoracic outlet syndrome. A prospective study was performed between April 2007 and October 2010. During this period, 97 patients in different age groups, with signs and symptoms of thoracic outlet syndrome, were surgically treated by the supraclavicular approach. The patients were aged between 14 and 60 years (mean 32.5 years), and the majority were female (89.69%). Surgery was performed on the left side in 52 patients and on the right side in 48, including 3 who had bilateral operations. The median follow-up was 11.2 months. In 78% of the 100 operations, excellent improvement in symptoms was noted, there was partial improvement in 18%, and 4% resulted in no response. First rib resection remains an important and essential step in the management of the thoracic outlet syndrome, in the absence of bony abnormalities. The supraclavicular approach can be employed with minimal morbidity and an excellent outcome.
Full Text Available Though discovered later than osteoblastic niche, vascular niche has been regarded as an alternative indispensable niche operating regulation on hematopoietic stem cells (HSCs. As significant progresses gained on this type niche, it is gradually clear that the main work of vascular niche is undertaking to support hematopoiesis. However, compared to what have been defined in the mechanisms through which the osteoblastic niche regulates hematopoiesis, we know less in vascular niche. In this review, based on research data hitherto we will focus on component foundation and various functions of vascular niche that guarantee the normal hematopoiesis process within bone marrow microenvironments. And the possible pathways raised by various research results through which this environment undergoes its function will be discussed as well.
Michael Kalyuzhny; Efrat Seri; Rachel Chocron; Curtis H. Flather; Ronen Kadmon; Nadav M. Shnerb
Understanding the forces shaping ecological communities is of crucial importance for basic science and conservation. After 50 years in which ecological theory has focused on either stable communities driven by niche-based forces or nonstable âneutralâ communities driven by demographic stochasticity, contemporary theories suggest that ecological communities are driven...
Pulaski, M J
Society is split between a desire for access to quality health care and a reluctance, by some, to pay for it. Looking at this cost/access dichotomy historically enables one to recognize an emerging niche market--discriminating, affluent consumers willing to pay for better health care.
Carnicero, E; Alonso, M I; Carretero, R; Lamus, F; Moro, J A; de la Mano, A; Fernández, J M F; Gato, A
There is a nondeveloped neurogenic potential in the adult mammalian brain, which could be the basis for neuroregenerative strategies. Many research efforts have been made to understand the control mechanisms which regulate the transition from a neural precursor to a neuron in the adult brain. Embryonic cerebrospinal fluid (CSF) is a complex fluid which has been shown to play a key role in neural precursor behavior during development, working as a powerful neurogenic inductor. We tested if the neurogenic properties of embryonic CSF are able to increase the neurogenic activity of neuronal precursors from the subventricular zone (SVZ) in the brains of adult mice. Our results show that mouse embryonic CSF significantly increases the neurogenic activity in precursor cells from adult brain SVZ. This intense neurogenic effect was specific for embryonic CSF and was not induced by adult CSF. Embryonic CSF is a powerful neurogenesis inductor in homologous neuronal precursors in the adult brain. This property of embryonic CSF could be a useful tool in neuroregeneration strategies.
Lin, Ruihe; Iacovitti, Lorraine
Neural stem cells (NSCs) critical for the continued production of new neurons and glia are sequestered in distinct areas of the brain called stem cell niches. Until recently, only two forebrain sites, the subventricular zone (SVZ) of the anterolateral ventricle and the subgranular zone (SGZ) of the hippocampus, have been recognized adult stem cell niches (Alvarez-Buylla and Lim, 2004; Doetsch et al., 1999a, 1999b; Doetsch, 2003a, 2003b; Lie et al., 2004; Ming and Song, 2005). Nonetheless, the last decade has been witness to a growing literature suggesting that in fact the adult brain contains stem cell niches along the entire extent of the ventricular system. These niches are capable of widespread neurogenesis and gliogenesis, particularly after injury (Barnabé-Heider et al., 2010; Carlén et al., 2009; Decimo et al., 2012; Lin et al., 2015; Lindvall and Kokaia, 2008; Robins et al., 2013) or other inductive stimuli (Bennett et al., 2009; Cunningham et al., 2012; Decimo et al., 2011; Kokoeva et al., 2007, 2005; Lee et al., 2012a, 2012b; Migaud et al., 2010; Pencea et al., 2001b; Sanin et al., 2013; Suh et al., 2007; Sundholm-Peters et al., 2004; Xu et al., 2005; Zhang et al., 2007). This review focuses on the role of these novel and classic brain niches in maintaining adult neurogenesis and gliogenesis in response to normal physiological and injury-related pathological cues. This article is part of a Special Issue entitled SI: Neuroprotection. Copyright © 2015 Elsevier B.V. All rights reserved.
Soley?Guardia, Mariano; Guti?rrez, Eli?cer E.; Thomas, Darla M.; Ochoa?G, Jos?; Aguilera, Marisol; Anderson, Robert P.
Abstract Correlative ecological niche models (ENMs) estimate species niches using occurrence records and environmental data. These tools are valuable to the field of biogeography, where they are commonly used to infer potential connectivity among populations. However, a recent study showed that when locally relevant environmental data are not available, records from patches of suitable habitat protruding into otherwise unsuitable regions (e.g., gallery forests within dry areas) can lead to ov...
Ortt, J.R.; Langley, D.J.; Pals, N.
There are serious gaps in the scientific literature relating to niche strategies as a means for commercializing new high-tech products. In particular, there is no clarity about what types of niche strategies can be distinguished, or how a niche strategy can be selected to suit a certain ituation. In
Winemiller, Kirk O; Fitzgerald, Daniel B; Bower, Luke M; Pianka, Eric R
Ecology is often said to lack general theories sufficiently predictive for applications. Here, we examine the concept of a periodic table of niches and feasibility of niche classification schemes from functional trait and performance data. Niche differences and their influence on ecological patterns and processes could be revealed effectively by first performing data reduction/ordination analyses separately on matrices of trait and performance data compiled according to logical associations with five basic niche 'dimensions', or aspects: habitat, life history, trophic, defence and metabolic. Resultant patterns then are integrated to produce interpretable niche gradients, ordinations and classifications. Degree of scheme periodicity would depend on degrees of niche conservatism and convergence causing species clustering across multiple niche dimensions. We analysed a sample data set containing trait and performance data to contrast two approaches for producing niche schemes: species ordination within niche gradient space, and niche categorisation according to trait-value thresholds. Creation of niche schemes useful for advancing ecological knowledge and its applications will depend on research that produces functional trait and performance datasets directly related to niche dimensions along with criteria for data standardisation and quality. As larger databases are compiled, opportunities will emerge to explore new methods for data reduction, ordination and classification. © 2015 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.
Sareni, Bruno; Krähenbühl, Laurent; Nicolas, Alain
Niching methods extend genetic algorithms and permit the investigation of multiple optimal solutions in the search space. In this paper, we review and discuss various strategies of niching for optimization in electromagnetics. Traditional mathematical problems and an electromagnetic benchmark are solved using niching genetic algorithms to show their interest in real world optimization.
Pozhilenkova, Elena A; Lopatina, Olga L; Komleva, Yulia K; Salmin, Vladimir V; Salmina, Alla B
Adult neurogenesis is one of the most important mechanisms contributing to brain development, learning, and memory. Alterations in neurogenesis underlie a wide spectrum of brain diseases. Neurogenesis takes place in highly specialized neurogenic niches. The concept of neurogenic niches is becoming widely accepted due to growing evidence of the important role of the microenvironment established in the close vicinity to stem cells in order to provide adequate control of cell proliferation, differentiation, and apoptosis. Neurogenic niches represent the platform for tight integration of neurogenesis and angiogenesis supported by specific properties of cerebral microvessel endothelial cells contributing to establishment of partially compromised blood-brain barrier (BBB) for the adjustment of local conditions to the current metabolic needs of stem and progenitor cells. Here, we review up-to-date data on microvascular dynamics in activity-dependent neurogenesis, specific properties of BBB in neurogenic niches, endothelial-driven mechanisms of clonogenic activity, and future perspectives for reconstructing the neurogenic niches in vitro.
Raup, Valary T; Eswara, Jairam R; Weese, Jonathan R; Potretzke, Aaron M; Brandes, Steven B
To review our experience with neurogenic bladder (NGB) patients who developed urinary-cutaneous fistulae (UCF). Patients with NGB can form UCF of multiple etiologies; however, little is known about the characteristics or long-term outcomes of these defects. We reviewed 21 patients with NGB who developed UCF between 1998 and 2013. The clinical end points of the study were development of UCF, fistula repair failure, and need for permanent urinary diversion. Possible risk factors associated with repair failures were examined. We evaluated 21 patients with a mean age of 39.5 years (23-76) and median follow-up of 67 months (1-179). Causes of UCF included decubitus ulcers (7), wound infections or abscess formation (5), condom catheter complications (4), traumatic catheterization (4), and pelvic trauma (1). Thirteen patients had their fistulae repaired surgically, with 9 patients eventually requiring urinary diversion with a suprapubic (SP) tube (7) or ileal conduit (2) (9 of 13, 69%). Eight patients had their urine diverted upon presentation, with ileal conduit (5 of 8, 63%), SP tube (2 of 8, 25%), or perineal urethrostomy (1 of 8, 12%). In total, 17 eventually required permanent surgical or SP tube urinary diversion (81%), of which 9 were with an SP tube (53%), 4 with an ileal conduit (23%), 3 with a conduit catheter (18%), and 1 with a perineal urethrostomy (6%). UCF repairs in patients with NGB are a challenge to manage. Patients who undergo surgical repair of their fistula are likely to require repeat repairs with eventual need for a permanent urinary diversion. Copyright © 2015 Elsevier Inc. All rights reserved.
Campos-Ordoñez, Tania; Herranz-Pérez, Vicente; Chaichana, Kaisorn L.; Rincon-Torroella, Jordina; Rigamonti, Daniele; García-Verdugo, Jose M.; Quiñones-Hinojosa, Alfredo; Gonzalez-Perez, Oscar
Hydrocephalus can develop secondarily to a disturbance in production, flow and/or absorption of cerebrospinal fluid. Experimental models of hydrocephalus, especially subacute and chronic hydrocephalus, are few and limited, and the effects of hydrocephalus on the subventricular zone are unclear. The aim of this study was to analyze the effects of long-term obstructive hydrocephalus on the subventricular zone, which is the neurogenic niche lining the lateral ventricles. We developed a new method to induce hydrocephalus by obstructing the aqueduct of Sylvius in the mouse brain, thus simulating aqueductal stenosis in humans. In 120-day-old rodents (n = 18 per group), the degree of ventricular dilatation and cellular composition of the subventricular zone were studied by immunofluorescence and transmission electron microscopy. In adult patients (age > 18 years), the sizes of the subventricular zone, corpus callosum, and internal capsule were analyzed by magnetic resonance images obtained from patients with and without aqueductal stenosis (n=25 per group). Mice with 60-day hydrocephalus had a reduced number of Ki67+ and doublecortin+ cells on immunofluorescence, as well as decreased number of neural progenitors and neuroblasts in the subventricular zone on electron microscopy analysis as compared to non-hydrocephalic mice. Remarkably, a number of extracellular matrix structures (fractones) contacting the ventricular lumen and blood vessels were also observed around the subventricular zone in mice with hydrocephalus. In humans, the widths of the subventricular zone, corpus callosum, and internal capsule in patients with aqueductal stenosis were significantly smaller than age and gender-matched patients without aqueductal stenosis. In summary, supratentorial hydrocephalus reduces the proliferation rate of neural progenitors and modifies the cytoarchitecture and extracellular matrix compounds of the subventricular zone. In humans, this similar process reduces the
Conclusion: In elderly male patients with non-neurogenic OAB, more severe storage symptoms are associated with a lower maximum flow rate and a more prominent IPP, indicating that a significant cause of male non-neurogenic OAB is prostate associated.
Biering-Sørensen, F; Læssøe, Line; Sønksen, J
Present the possibility for treatment of male infertility, spasticity, and neurogenic detrusor overactivity in spinal cord lesioned (SCL) individuals with penile vibratory stimulation (PVS).......Present the possibility for treatment of male infertility, spasticity, and neurogenic detrusor overactivity in spinal cord lesioned (SCL) individuals with penile vibratory stimulation (PVS)....
Full Text Available The HTLV-1 virus is a known agent involved in the development of HAM/TSP. Past studies have typically observed patients with autonomic dysfunction consisting of detrusor overactivity and detrusor-sphincter dyssynergia, with the occasional observation of underactive detrusor or detrusor arreflexia. However, studies have not yet evaluated the progression of neurogenic bladder over time. In this paper, we describe a HAM/TSP patient with the initial development of overactive detrusor, and subsequent development of detrusor arreflexia. Given a paucity of studies characterizing the effects of HTLV-1 on the autonomic nervous system, particularly aspects controlling continence, this patient's clinical course may represent one type of end point for patients with HAM/TSP and neurogenic bladder. Further cohort or case-series studies, with particular emphasis on the progression of neurogenic bladder, are needed to evaluate the significance of this described case in relation to typical disease progression patterns.
Lewis, Kate Marie; Turner, Renée Jade; Vink, Robert
Classical inflammation is a well-characterized secondary response to many acute disorders of the central nervous system. However, in recent years, the role of neurogenic inflammation in the pathogenesis of neurological diseases has gained increasing attention, with a particular focus on its effects on modulation of the blood-brain barrier BBB. The neuropeptide substance P has been shown to increase blood-brain barrier permeability following acute injury to the brain and is associated with marked cerebral edema. Its release has also been shown to modulate classical inflammation. Accordingly, blocking substance P NK1 receptors may provide a novel alternative treatment to ameliorate the deleterious effects of neurogenic inflammation in the central nervous system. The purpose of this paper is to provide an overview of the role of substance P and neurogenic inflammation in acute injury to the central nervous system following traumatic brain injury, spinal cord injury, stroke, and meningitis.
Kate Marie Lewis
Full Text Available Classical inflammation is a well-characterized secondary response to many acute disorders of the central nervous system. However, in recent years, the role of neurogenic inflammation in the pathogenesis of neurological diseases has gained increasing attention, with a particular focus on its effects on modulation of the blood-brain barrier BBB. The neuropeptide substance P has been shown to increase blood-brain barrier permeability following acute injury to the brain and is associated with marked cerebral edema. Its release has also been shown to modulate classical inflammation. Accordingly, blocking substance P NK1 receptors may provide a novel alternative treatment to ameliorate the deleterious effects of neurogenic inflammation in the central nervous system. The purpose of this paper is to provide an overview of the role of substance P and neurogenic inflammation in acute injury to the central nervous system following traumatic brain injury, spinal cord injury, stroke, and meningitis.
Full Text Available Long- term ventilator dependence in patients with neurogenic hypoventilation is associated with significant morbidity and restricts mobility. Diaphragmatic pacing by phrenic nerve stimulation (PNS is a viable alternative. This is a case report of patient with Arnold-Chiari malformation with extensive syrinx who had neurogenic hypoventilation during sleep even after foramen magnum decompression and resolution of the syrinx. Unilateral PNS was done using spinal cord stimulator. With intermittent stimulation for 8 h while asleep, patient could be weaned off the ventilator completely. At 2 years follow- up, patient is ambulant and has returned to his routine activities. PNS is a good treatment tool in patients with neurogenic hypoventilation. Spinal cord stimulator can be used with optimal results. This is first such reported case of using spinal cord stimulator for PNS from India.
Lévy, Frederic; Batailler, Martine; Meurisse, Maryse; Migaud, Martine
Sheep have many advantages to study neurogenesis in comparison to the well-known rodent models. Their development and life expectancy are relatively long and they possess a gyrencephalic brain. Sheep are also seasonal breeders, a characteristic that allows studying the involvement of hypothalamic neurogenesis in the control of seasonal reproduction. Sheep are also able to individually recognize their conspecifics and develop selective and lasting bonds. Adult olfactory neurogenesis could be adapted to social behavior by supporting recognition of conspecifics. The present review reveals the distinctive features of the hippocampal, olfactory, and hypothalamic neurogenesis in sheep. In particular, the organization of the subventricular zone and the dynamic of neuronal maturation differs from that of rodents. In addition, we show that various physiological conditions, such as seasonal reproduction, gestation, and lactation differently modulate these three neurogenic niches. Last, we discuss recent evidence indicating that hypothalamic neurogenesis acts as an important regulator of the seasonal control of reproduction and that olfactory neurogenesis could be involved in odor processing in the context of maternal behavior. PMID:29109674
Chen, Ming-Jun; Huang, Bo; Li, Zeng-Zhi
An investigation was made on the quantitative composition, niche width, and niche overlap of dominant entomopathogenic fungi in three different forest ecosystems, i.e., natural broad-leaved forest, natural secondary broad-leaved forest, and pure Masson' s pine plantation. In the three forest ecosystems, Beauveria bassiana was the first dominant species in natural secondary broad-leaved forest, the second in pure Masson's pine plantation, and the third in natural broad-leaved forest. B. bassiana had the broadest temporal niche width and nutritional niche width, whereas the dominant species Isaria cateinannulata, L. farinose, and I. tenuipes had much smaller niche widths. Meanwhile, B. bassiana had larger temporal niche overlaps but smaller nutritional niche overlaps with other dominant entomopathogenic fungi. It was suggested that in the three forest ecosystems, B. bassiana had the longest occurrence duration, widest host range, and strongest environmental adaptability.
Keenan, G F; Ashcroft, G P; Roditi, G H; Hutchison, J D; Evans, N T; Mikecz, P; Chaloner, F; Dodd, M; Leonard, C; Porter, R W
Ten subjects (seven with neurogenic claudication and three control subjects) underwent examination of lower limb muscle blood flow before and after exercise using positron emission tomography. To investigate the hypothesis that lower limb muscle ischemia was the origin of symptoms in neurogenic claudication. Patients with neurogenic claudication secondary to spinal stenosis experience lower limb discomfort after exercise similar to that of ischemic claudication. However, they do not have clinical evidence of peripheral vascular disease. The authors postulated that the lower limb discomfort in patients with neurogenic claudication may arise from muscle ischemia due to inadequate dilatation of arterioles in response to exercise, this itself arising secondary to sympathetic dysfunction due to spinal stenosis. Using O15-labeled water and positron emission tomography measured thigh and leg muscle blood flow response to exercise bilaterally in seven patients with unilateral neurogenic claudication and three control subjects were measured. The average values obtained for mid-thigh and mid-calf muscle perfusion at rest were 2.57 ml/min/100 g tissue (2.23-3.90) and 2.39 ml/min/100 g tissue (2.03-3.46), respectively. The average values obtained from mid-thigh and mid-calf perfusion after exercise were 4.41 ml/min/100 g tissue (2.8-6.0) and 4.87 ml/min/100 g (2.2-11.7). We found no difference in muscle perfusion between symptomatic and asymptomatic limbs in this group of patients. These studies suggest that muscle ischemia is not the origin of symptoms in most patients with neurogenic claudication.
Larisa R G DeSantis
Full Text Available Climate change alters species distributions, causing plants and animals to move north or to higher elevations with current warming. Bioclimatic models predict species distributions based on extant realized niches and assume niche conservation. Here, we evaluate if proxies for niches (i.e., range areas are conserved at the family level through deep time, from the Eocene to the Pleistocene. We analyze the occurrence of all mammalian families in the continental USA, calculating range area, percent range area occupied, range area rank, and range polygon centroids during each epoch. Percent range area occupied significantly increases from the Oligocene to the Miocene and again from the Pliocene to the Pleistocene; however, mammalian families maintain statistical concordance between rank orders across time. Families with greater taxonomic diversity occupy a greater percent of available range area during each epoch and net changes in taxonomic diversity are significantly positively related to changes in percent range area occupied from the Eocene to the Pleistocene. Furthermore, gains and losses in generic and species diversity are remarkably consistent with ~2.3 species gained per generic increase. Centroids demonstrate southeastern shifts from the Eocene through the Pleistocene that may correspond to major environmental events and/or climate changes during the Cenozoic. These results demonstrate range conservation at the family level and support the idea that niche conservation at higher taxonomic levels operates over deep time and may be controlled by life history traits. Furthermore, families containing megafauna and/or terminal Pleistocene extinction victims do not incur significantly greater declines in range area rank than families containing only smaller taxa and/or only survivors, from the Pliocene to Pleistocene. Collectively, these data evince the resilience of families to climate and/or environmental change in deep time, the absence of
The concept of a 'human nature' or 'human natures' retains a central role in theorizing about the human experience. In Homo sapiens it is clear that we have a suite of capacities generated via our evolutionary past, and present, and a flexible capacity to create and sustain particular kinds of cultures and to be shaped by them. Regardless of whether we label these capacities 'human natures' or not, humans occupy a distinctive niche and an evolutionary approach to examining it is critical. At present we are faced with a few different narratives as to exactly what such an evolutionary approach entails. There is a need for a robust and dynamic theoretical toolkit in order to develop a richer, and more nuanced, understanding of the cognitively sophisticated genus Homo and the diverse sorts of niches humans constructed and occupied across the Pleistocene, Holocene, and into the Anthropocene. Here I review current evolutionary approaches to 'human nature', arguing that we benefit from re-framing our investigations via the concept of the human niche and in the context of the extended evolutionary synthesis (EES). While not a replacement of standard evolutionary approaches, this is an expansion and enhancement of our toolkit. I offer brief examples from human evolution in support of these assertions.
Lewis, Kate M; Harford-Wright, Elizabeth; Vink, Robert; Ghabriel, Mounir N
Dexamethasone, the standard treatment for peritumoral brain oedema, inhibits classical inflammation. Neurogenic inflammation, which acts via substance P (SP), has been implicated in vasogenic oedema in animal models of CNS injury. SP is elevated within and outside CNS tumours. This study investigated the efficacy of NK1 receptor antagonists, which block SP, compared with dexamethasone treatment, in a rat model of tumorigenesis. Dexamethasone reverted normal brain water content and reduced Evans blue and albumin extravasation, while NK1 antagonists did not ameliorate oedema formation. We conclude that classical inflammation rather than neurogenic inflammation drives peritumoral oedema in this brain tumour model. Copyright © 2012 Elsevier B.V. All rights reserved.
Full Text Available Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells commit to becoming the functional cells from their tissue of origin. These cells are the most commonly used in cell-based therapy since they do not confer risk of teratomas, do not require fetal stem cell maneuvers and thus are free of ethical concerns, and they confer low immunogenicity (even if allogenous. The goal of this review is to summarize the current state of the art and advances in using stem cell therapy for tissue repair in solid organs. Here we address key factors in cell preparation, such as the source of adult stem cells, optimal cell types for implantation (universal mesenchymal stem cells vs. tissue-specific stem cells, or induced vs. non-induced stem cells, early or late passages of stem cells, stem cells with endogenous or exogenous growth factors, preconditioning of stem cells (hypoxia, growth factors, or conditioned medium, using various controlled release systems to deliver growth factors with hydrogels or microspheres to provide apposite interactions of stem cells and their niche. We also review several approaches of cell delivery that affect the outcomes of cell therapy, including the appropriate routes of cell administration (systemic, intravenous, or intraperitoneal vs. local administration, timing for cell therapy (immediate vs. a few days after injury, single injection of a large number of cells vs. multiple smaller injections, a single site for injection vs. multiple sites and use of rodents vs. larger animal models. Future directions of stem cell-based therapies are also discussed to guide potential clinical applications.
Full Text Available Azidothymidine (AZT is a synthetic, chain-terminating nucleoside analog used to treat HIV-1 infection. While AZT is not actively transported across the blood brain barrier, it does accumulate at high levels in cerebrospinal fluid, and subsequently diffuses into the overlying parenchyma. Due to the close anatomical proximity of the neurogenic niches to the ventricular system, we hypothesize that diffusion from CSF exposes neural stem/progenitor cells and their progeny to biologically relevant levels of AZT sufficient to perturb normal cell functions. We employed in vitro and in vivo models of mouse neurogenesis in order to assess the effects of AZT on developing and adult neurogenesis. Using in vitro assays we show that AZT reduces the population expansion potential of neural stem/progenitor cells by inducing senescence. Additionally, in a model of in vitro neurogenesis AZT severely attenuates neuroblast production. These effects are mirrored in vivo by clinically-relevant animal models. We show that in utero AZT exposure perturbs both population expansion and neurogenesis among neural stem/progenitor cells. Additionally, a short-term AZT regimen in adult mice suppresses subependymal zone neurogenesis. These data reveal novel negative effects of AZT on neural stem cell biology. Given that the sequelae of HIV infection often include neurologic deficits –subsumed under AIDS Dementia Complex (Brew, 1999 - it is important to determine to what extent AZT negatively affects neurological function in ways that contribute to, or exacerbate, ADC in order to avoid attributing iatrogenic drug effects to the underlying disease process, and thereby skewing the risk/benefit analysis of AZT therapy.
Chaker, Zayna; Codega, Paolo; Doetsch, Fiona
Neural stem cells (NSCs) reside in specialized niches in the adult mammalian brain. The ventricular-subventricular zone (V-SVZ), adjacent to the lateral ventricles, gives rise to olfactory bulb (OB) neurons, and some astrocytes and oligodendrocytes throughout life. In vitro assays have been widely used to retrospectively identify NSCs. However, cells that behave as stem cells in vitro do not reflect the identity, diversity, and behavior of NSCs in vivo. Novel tools including fluorescence activated cell sorting, lineage-tracing, and clonal analysis have uncovered multiple layers of adult V-SVZ NSC heterogeneity, including proliferation state and regional identity. In light of these findings, we reexamine the concept of adult NSCs, considering heterogeneity as a key parameter for analyzing their dynamics in vivo. V-SVZ NSCs form a mosaic of quiescent (qNSCs) and activated cells (aNSCs) that reside in regionally distinct microdomains, reflecting their regional embryonic origins, and give rise to specific subtypes of OB interneurons. Prospective purification and transcriptome analysis of qNSCs and aNSCs has illuminated their molecular and functional properties. qNSCs are slowly dividing, have slow kinetics of neurogenesis in vivo, can be recruited to regenerate the V-SVZ, and only rarely give rise to in vitro colonies. aNSCs are highly proliferative, undergo rapid clonal expansion of the neurogenic lineage in vivo, and readily form in vitro colonies. Key open questions remain about stem cell dynamics in vivo and the lineage relationship between qNSCs and aNSCs under homeostasis and regeneration, as well as context-dependent plasticity of regionally distinct adult NSCs under different external stimuli. WIREs Dev Biol 2016, 5:640-658. doi: 10.1002/wdev.248 For further resources related to this article, please visit the WIREs website. © 2016 The Authors. WIREs Developmental Biology published by Wiley Periodicals, Inc.
Jiang, Feng; Xun, Yanhan; Cai, Huiying; Jin, Guangze
Ecologists often determine the relative importance of niche- and dispersal-based processes via variation partitioning based on species composition. Functional traits and their proxies of phylogeny are expected to increase the detection of niche-based processes and reduce the unexplained variation relative to species identity. We collected eight adult tree traits and phylogenetic data of 41 species and employed a phylogenetic fuzzy weighting method to address this issue in a 9-ha temperate forest dynamics plot. We used redundancy analysis to relate species, phylogenetic and functional compositions to environmental (soil resources and topography) and spatial variables. We also performed multi-scaled analyses on spatial variables by adding environment as the covariates to determine if functional traits increase the detection of niche-based processes at broad scales. The functional traits and intraspecific variation of the wood density among ontogenetic stages could dramatically increase the detection of niche-based processes and reduce the unexplained variation relative to species identity. Phylogenetic and functional compositions were mainly driven by total soil P and elevation, while species composition was weakly affected by multiple environmental variables. After controlling for the environment, a larger amount of the compositional variations in seed mass and maximum height were explained by finer-scaled spatial variables, indicating that dispersal processes may be important at fine spatial scales. Our results suggested that considering functional traits and their intraspecific variations could improve our understanding of ecological processes and increase our ability to predict the responses of plants to environmental change.
Prakash, Raghu; Puri, Archana; Anand, Rama; Jain, Ajay K; Lal, Brahmanand; Garg, Vaibhav
Upper tract damage (UTD) is a life-threatening complication of neurogenic bladder (NB). Early identification of risk factors for UTD and institution of remedial measures may probably prevent UTD. The aim was to study the predictors of UTD in children 2 years or older with NB. This cross-sectional, observational study over 2 years included 30 children. UTD was defined as serum creatinine of >1 mg/dL or society of fetal urology grade III-IV hydronephrosis or hydroureteronephrosis on ultrasonography or renal scars on 99 m technetium dimercaptosuccinic scan or subnormal glomerular filtration rate (GFR) for age. The evaluated clinical variables were age at presentation, gender, palpable bladder lump, and recurrent urinary tract infection (UTI). Bladder wall thickness (BWT), grade and laterality of vesicoureteric reflux (VUR), status of the bladder neck, post-void residue (PVR), and level and type of intraspinal lesions were also noted. Urodynamic studies were performed for functional bladder assessment. A p-value 1 mg% (2, 6%), SFU III-IV (11, 36%), renal scars (12, 40%), and subnormal GFR in (2, 6%) patients. Clinical risk factors for UTD were delayed presentation (p = 0.034), palpable bladder lump (p ≤ 0.001; OR 38.5; CI 5.6-262.5), and recurrent UTI (p = 0.033, OR 4.125, CI 0.913-18.630). The presence of significant PVR, trabeculated bladder, spin-top urethra, and bilateral VUR were identified as radiological risk factors for UTD. Mean BWT in patients with and without UTD was 4.69 ± 1.78 mm and 2.91 ± 1.08 mm respectively. BWT predictive of UTD was 3.05 mm (Figure). The mean detrusor leak point pressure (DLPP) did not vary significantly in those with and without UTD (36.82 ± 14.74 and 29.09 ± 10.44 cmH 2 O, respectively), yet 75% patients with DLPP > 40 cmH 2 O had UTD (p = 0.038, OR 5.4, CI 0.84-34.84). DLPP bladder lump, recurrent UTI, increased BWT, bilateral VUR, increased PVR, and DLPP > 40 cm H 2 O were identified as potential
Pulla, Sandeep; Suresh, Hebbalalu S; Dattaraja, Handanakere S; Sukumar, Raman
The extent to which interspecific niche differences structure plant communities is highly debated, with extreme viewpoints ranging from fine-scaled niche partitioning, where every species in the community is specialized to a distinct niche, to neutrality, where species have no niche or fitness differences. However, there exists a default position wherein niches of species in a community are determined by their evolutionary and biogeographic histories, irrespective of other species within the community. According to this viewpoint, a broad range of pair-wise niche overlaps-from completely overlapping to completely distinct-are expected in any community without the need to invoke interspecific interactions. We develop a method that can test for both habitat associations and niche differences along an arbitrary number of spatial and temporal niche dimensions and apply it to a 24-yr data set of the eight dominant woody-plant species (representing 84% and 76% of total community abundance and basal area, respectively) from a 50-ha permanent plot in a southern Indian tropical dry forest, using edaphic, topographic, and precipitation variables as niche axes. Species separated into two broad groups in niche space-one consisting of three canopy species and the other of a canopy species and four understory species-along axes that corresponded mainly to variation in soil P, Al and a topographic index of wetness. Species within groups tended to have significantly greater niche overlap than expected by chance. Community-wide niche overlap in spatial and temporal niche axes was never smaller than expected by chance. Species-habitat associations were neither necessary nor sufficient preconditions for niche differences to be present. Our results suggest that this tropical dry-forest community consists of several tree species with broadly overlapping niches, and where significant niche differences do exist, they are not readily interpretable as evidence for niche differentiation. We
Novosolov, Maria; Rodda, Gordon H; Gainsbury, Alison M; Meiri, Shai
Insular species are predicted to broaden their niches, in response to having fewer competitors. They can thus exploit a greater proportion of the resource spectrum. In turn, broader niches are hypothesized to facilitate (or be a consequence of) increased population densities. We tested whether insular lizards have broader dietary niches than mainland species, how it relates to competitor and predator richness, and the nature of the relationship between population density and dietary niche breadth. We collected population density and dietary niche breadth data for 36 insular and 59 mainland lizard species, and estimated competitor and predator richness at the localities where diet data were collected. We estimated dietary niche shift by comparing island species to their mainland relatives. We controlled for phylogenetic relatedness, body mass and the size of the plots over which densities were estimated. We found that island and mainland species had similar niche breadths. Dietary niche breadth was unrelated to competitor and predator richness, on both islands and the mainland. Population density was unrelated to dietary niche breadth across island and mainland populations. Our results indicate that dietary generalism is not an effective way of increasing population density nor is it result of lower competitive pressure. A lower variety of resources on islands may prevent insular animals from increasing their niche breadths even in the face of few competitors. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.
Gómez, José María; Perfectti, Francisco; Abdelaziz, Mohamed; Lorite, Juan; Muñoz-Pajares, Antonio Jesús; Valverde, Javier
It is widely assumed that floral diversification occurs by adaptive shifts between pollination niches. In contrast to specialized flowers, identifying pollination niches of generalist flowers is a challenge. Consequently, how generalist pollination niches evolve is largely unknown. We apply tools from network theory and comparative methods to investigate the evolution of pollination niches among generalist species belonging to the genus Erysimum. These species have similar flowers. We found that the studied species may be grouped in several multidimensional niches separated not by a shift of pollinators, but instead by quantitative variation in the relative abundance of pollinator functional groups. These pollination niches did not vary in generalization degree; we did not find any evolutionary trend toward specialization within the studied clade. Furthermore, the evolution of pollination niche fitted to a Brownian motion model without phylogenetic signal, and was characterized by frequent events of niche convergences and divergences. We presume that the evolution of Erysimum pollination niches has occurred mostly by recurrent shifts between slightly different generalized pollinator assemblages varying spatially as a mosaic and without any change in specialization degree. Most changes in pollination niches do not prompt floral divergence, a reason why adaptation to pollinators is uncommon in generalist plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.
Daynac, Mathieu; Morizur, Lise; Kortulewski, Thierry; Gauthier, Laurent R; Ruat, Martial; Mouthon, Marc-André; Boussin, François D
Neural stem cells (NSCs) in the subventricular zone of the lateral ventricles (SVZ) sustain olfactory neurogenesis throughout life in the mammalian brain. They successively generate transit amplifying cells (TACs) and neuroblasts that differentiate into neurons once they integrate the olfactory bulbs. Emerging fluorescent activated cell sorting (FACS) techniques have allowed the isolation of NSCs as well as their progeny and have started to shed light on gene regulatory networks in adult neurogenic niches. We report here a cell sorting technique that allows to follow and distinguish the cell cycle dynamics of the above-mentioned cell populations from the adult SVZ with a LeX/EGFR/CD24 triple staining. Isolated cells are then plated as adherent cells to explore in details their cell cycle progression by time-lapse video microscopy. To this end, we use transgenic Fluorescence Ubiquitination Cell Cycle Indicator (FUCCI) mice in which cells are red-fluorescent during G1 phase due to a G1 specific red-Cdt1 reporter. This method has recently revealed that proliferating NSCs progressively lengthen their G1 phase during aging, leading to neurogenesis impairment. This method is easily transposable to other systems and could be of great interest for the study of the cell cycle dynamics of brain cells in the context of brain pathologies.
Sales, Lilian Patrícia; Ribeiro, Bruno R; Hayward, Matt Warrington; Paglia, Adriano; Passamani, Marcelo; Loyola, Rafael
Niche conservatism, i.e. the retention of a species' fundamental niche through evolutionary time, is cornerstone for biological invasion assessments. The fact that species tend to maintain their original climate niche allows predictive maps of invasion risk to anticipate potential invadable areas. Unravelling the mechanisms driving niche shifts can shed light on the management of invasive species. Here, we assessed niche shifts in one of the world's worst invasive species: the wild boar Sus scrofa. We also predicted potential invadable areas based on an ensemble of three ecological niche modelling methods, and evaluated the performance of models calibrated with native vs. pooled (native plus invaded) species records. By disentangling the drivers of change on the exotic wild boar population's niches, we found strong evidence for niche conservatism during biological invasion. Ecological niche models calibrated with both native and pooled range records predicted convergent areas. Also, observed niche shifts are mostly explained by niche unfilling, i.e. there are unoccupied areas in the exotic range where climate is analogous to the native range. Niche unfilling is expected as result of recent colonization and ongoing dispersal, and was potentially stronger for the Neotropics, where a recent wave of introductions for pig-farming and game-hunting has led to high wild boar population growth rates. The invasive potential of wild boar in the Neotropics is probably higher than in other regions, which has profound management implications if we are to prevent their invasion into species-rich areas, such as Amazonia, coupled with expansion of African swine fever and possibly great economic losses. Although the originally Eurasian-wide distribution suggests a pre-adaptation to a wide array of climates, the wild boar world-wide invasion does not exhibit evidence of niche evolution. The invasive potential of the wild boar therefore probably lies on the reproductive, dietary and
Cerveny, Kara L; Cavodeassi, Florencia; Turner, Katherine J; de Jong-Curtain, Tanya A; Heath, Joan K; Wilson, Stephen W
It is currently unclear how intrinsic and extrinsic mechanisms cooperate to control the progression from self-renewing to neurogenic divisions in retinal precursor cells. Here, we use the zebrafish flotte lotte (flo) mutant, which carries a mutation in the elys (ahctf1) gene, to study the relationship between cell cycle progression and neuronal differentiation by investigating how proliferating progenitor cells transition towards differentiation in a retinal stem cell niche termed the ciliary marginal zone (CMZ). In zebrafish embryos without Elys, CMZ cells retain the capacity to proliferate but lose the ability to enter their final neurogenic divisions to differentiate as neurons. However, mosaic retinae composed of wild-type and flo cells show that despite inherent cell cycle defects, flo mutant cells progress from proliferation to differentiation when in the vicinity of wild-type retinal neurons. We propose that the differentiated retinal environment limits the proliferation of precursors emerging from the CMZ in a manner that explains the spatial organisation of cells in the CMZ and ensures that proliferative retinal progenitors are driven towards differentiation.
Abdominal massage for neurogenic bowel dysfunction in people with multiple sclerosis (AMBER - Abdominal Massage for Bowel Dysfunction Effectiveness Research): study protocol for a randomised controlled trial.
McClurg, Doreen; Goodman, Kirsteen; Hagen, Suzanne; Harris, Fional; Treweek, Sean; Emmanuel, Anton; Norton, Christine; Coggrave, Maureen; Doran, Selina; Norrie, John; Donnan, Peter; Mason, Helen; Manoukian, Sarkis
Multiple sclerosis (MS) is a life-long condition primarily affecting younger adults. Neurogenic bowel dysfunction (NBD) occurs in 50-80% of these patients and is the term used to describe constipation and faecal incontinence, which often co-exist. Data from a pilot study suggested feasibility of using abdominal massage for the relief of constipation, but the effectiveness remains uncertain. This is a multi-centred patient randomised superiority trial comparing an experimental strategy of once daily abdominal massage for 6 weeks against a control strategy of no massage in people with MS who have stated that their constipation is bothersome. The primary outcome is the Neurogenic Bowel Dysfunction Score at 24 weeks. Both groups will receive optimised advice plus the MS Society booklet on bowel management in MS, and will continue to receive usual care. Participants and their clinicians will not be blinded to the allocated intervention. Outcome measures are primarily self-reported and submitted anonymously. Central trial staff who will manage and analyse the trial data will be unaware of participant allocations. Analysis will follow intention-to-treat principles. This pragmatic randomised controlled trial will demonstrate if abdominal massage is an effective, cost-effective and viable addition to the treatment of NBD in people with MS. ClinicalTrials.gov, ISRCTN85007023 . Registered on 10 June 2014.
Salinas Casado, J; Chamorro, M V; Samblas García, R; Esteban Fuertes, M; Aristizábal Agudelo, J M; Delgado Martín, J A; Blázquez Izquierdo, J; Resel Estévez, L
To determine the utility of the somatosensorial evoked potentials of the pudental nerve in the diagnosis of neurogenic impotence. 129 patients with impotence were evaluated by physical examination and neuroandrologic profile. The neuroandrologic profile was assessed by bulbocavernous electromyography, determination of S2-S4 evoked potentials, analysis of the somatosensorial potentials of the pudendal nerve, cavernous smooth muscle electromyography (SPACE), sympathetic skin response and cystometry. The patients with a neurologic lesion presented a significantly longer latency time of the somatosensorial potentials than those with no neurologic lesion. The sensitivity of the somatosensorial potentials was 63% and the specificity was 98%. The sensitivity could be enhanced without significantly lowering specificity by taking 49 msec as the upper limit of normal values in latency time. The determination of the voluntary anal control in the diagnosis of neurogenic impotence was found to have a high specificity (93%), but a low sensitivity (42%). The determination of the somatosensorial potentials, unlike other techniques, could allow diagnosis of lesions of the suprasacral inneveration in the evaluation of neurogenic impotence. The evoked somatosensorial potentials of the pudendal nerve and physical examination have the inconvenience of their low sensitivity in regard to the diagnosis of neurogenic lesion in impotence, mainly because some conditions only affect the peripheral autonomic innervation and the somatic element is spared.
Warrenburg, B.P.C. van de; Zwarts, M.J.; Engelen, B.G.M. van
Neurogenic muscle (pseudo) hypertrophy of the calf was diagnosed in a 60-year-old man, who presented with chronic, painless and unilateral calf enlargement caused by a chronic S1 radiculopathy due to a lumbar disc hernia in the L5-S1 interspace. The differential diagnosis of a swelling of the calf
Mutlu, Hatice; Ekinci, Zelal
Objectives. The aim of this randomized controlled prospective study is to evaluate the efficacy of cranberry capsules for prevention of UTI in children with neurogenic bladder caused by myelomeningocele. Patients and Methods. To be eligible for this study, patients had to be diagnosed as neurogenic bladder caused by myelomeningocele, evaluated urodynamically, followed up with clean intermittent catheterization and anticholinergic drugs. Intervention. Six months of treatment with placebo; after a week of wash-out period treatment of cranberry extract tablets (1 capsule/day) for an additional 6 months. Randomization was performed sequentially. Patients and care givers were blinded to drug assignment. Main outcome measure was infection rate. Group comparisons were performed with Wilcoxon test. Results. The study population included 20 (F/M: 13/7) patients with neurogenic bladder with the mean age of 7.25 ± 3.49 (4, 18) years. The median UTI rate was 0.5/year during placebo usage whereas 0/year during cranberry capsule usage. Decrease in infection rate was significant with cranberry capsule usage (P = 0.012). Decrease in the percentage of the pyuria was also recorded as significant (P = 0.000). Any adverse events or side effects were not recorded. Conclusion. We concluded that cranberry capsules could be an encouraging option for the prevention of recurrent UTI in children with neurogenic bladder caused by myelomeningocele.
Petronic, Ivana; Nikolic, Dejan; Cirovic, Dragana; Cvjeticanin, Suzana; Knezevic, Tatjana; Raicevic, Mirjana; Brdar, Radivoj; Dzamic, Dragana; Janic, Nenad; Golubovic, Zoran
Patients with spina bifida in the lumbosacral region usually have various degrees of motor and sensory dysfunctions of the lower extremities and anal sphincter. The aim of our study was to evaluate the distribution and differences in frequencies of affected muscles, number of affected muscles and degree of neurogenic lesion between patients with spina bifida occulta (SBO) and spina bifida aperta (SBA). In 100 patients with SB, 6 muscles in the lower limbs were separately analysed. Due to the number of affected muscles, we evaluated 5 groups of patients: with 1 affected muscle, 2 affected muscles, 3 affected muscles, 4 affected muscles and 5 affected muscles. Three degrees of neurogenic lesions were assessed: mild, moderate and severe. The tibialis anterior muscle was most frequently affected in SB patients. The outer anal sphincter was frequently affected in the group of SBA patients. Single muscle affection is frequent in the group of patients with SBO, while in the group of patients with SBA, 4 muscles were significantly frequently affected. The great majority of patients (45.46%) with affected outer anal sphincter (OAS) in the group of SBO were without affection of other muscles, while for the SBA group it was for every third patient. Mild neurogenic lesion was significantly frequent in SBO patients, while severe form was significantly frequent in SBA patients. Patients with SBO usually present with mild to moderate clinical presentation, while multiple root involvement and severe degree of neurogenic lesion is associated more frequently with SBA.
Full Text Available Central neurogenic hyperventilation (CNH is a rare clinical condition, whose mechanism is still unclear. Here, we report a 3-year-old male patient, who had bilateral thalamic, putaminal and globus pallideal infarction resulted in CNH without brainstem involvement. This case may illustrate a possible role for the thalamus in regulating ventilation.
Cruz, Ana Sofia; Menezes, Sónia; Silva, Maria
Pulmonary edema is caused by the accumulation of fluid within the air spaces and the interstitium of the lung. Neurogenic pulmonary edema is a clinical syndrome characterized by the acute onset of pulmonary edema following a significant central nervous system insult. It may be a less-recognized consequence of raised intracranial pressure due to obstructive hydrocephalus by blocked ventricular shunts. It usually appears within minutes to hours after the injury and has a high mortality rate if not recognized and treated appropriately. We report a patient with acute obstructive hydrocephalus due to ventriculo-atrial shunt dysfunction, proposed to urgent surgery for placement of external ventricular drainage, who presented with neurogenic pulmonary edema preoperatively. She was anesthetized and supportive treatment was instituted. At the end of the procedure the patient showed no clinical signs of respiratory distress, as prompt reduction in intracranial pressure facilitated the regression of the pulmonary edema. This report addresses the importance of recognition of neurogenic pulmonary edema as a possible perioperative complication resulting from an increase in intracranial pressure. If not recognized and treated appropriately, neurogenic pulmonary edema can lead to acute cardiopulmonary failure with global hypoperfusion and hypoxia. Therefore, awareness of and knowledge about the occurrence, clinical presentation and treatment are essential. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.
Fjorback, M.V.; Rey, F. van; Pal, F. van der; Rijkhoff, N.J.M.; Petersen, T.; Heesakkers, J.P.
OBJECTIVES: The aim of this study was to investigate whether acute electrical stimulation of the posterior tibial nerve could suppress detrusor contractions in multiple sclerosis (MS) patients with neurogenic detrusor overactivity. METHODS: Two successive slow-fill cystometries (16 ml/min) were
Maison, Patrick Opoku Manu; Lazarus, John
If untreated, paediatric neurogenic bladder can cause renal failure and urinary incontinence. It is usually caused by neural tube defects such as myelomeningocele. Children with a neurogenic bladder should be monitored from birth and management should aim to preserve renal function and achieve social continence. This article outlines the management options appropriate for these children in resource-poor settings. In most low- and middle-income countries, a general lack of awareness of the neurological effects on the urinary tract results in late presentation, usually with urological complications even when spina bifida is diagnosed early. Physical examination must include neurological examination for spinal deformities and intact sacral reflexes. About 90% of children with occult spinal dysraphisms will have cutaneous sacral lesions. The work-up includes urinalysis, serial ultrasound of the urinary tracts and urodynamics. Urodynamic assessment is essential for the diagnosis and prognosis of the paediatric neurogenic bladder. In poorly resourced settings, simple eyeball urodynamics can be performed in the absence of a conventional urodynamic set-up. Clean intermittent catheterisation (CIC), the mainstay of treatment, is most suitable for resource-poor settings because it is effective and inexpensive. Antimuscarinic drugs such as oxybutynin complement CIC by reducing detrusor overactivity. Intravesical injection of Botox and bladder augmentation surgery is required by a small subset of patients who fail to respond to combined CIC and oxybutynin therapy. Children with neurogenic bladder in resource-poor settings should have early bladder management to preserve renal function and provide social continence.
The anthropogenic biogeosphere or 'human niche' is the intersection of the biogeosphere and the sphere of human activities of social, economic, cultural and political nature. The application case for geoethics, namely "appropriate behaviours and practices, wherever human activities interact with the Earth system" , is about niche building. Geoethics is about the conduct of people and geoscientists, respectively their ordinary lifestyles and professional activities. Geoscience professionals notice the diverse economic, social and cultural living conditions of people, and the application cases of geosciences mirror the diversity of the global social sphere. Subsequently it is argued: A) when considering the ethical dimensions of global niche building then geosciences should feature 'citizen geoscience'; and B) when considering the functioning of a knowledge-based society under conditions of anthropogenic global change then 'citizen geoscience' facilitates applying that knowledge base. (A) Regarding 'niche building': The design of production systems and consumption patterns embeds geoscience know-how and relates it to the everyday life. Any citizen's activities purposefully interconnect to the biogeosphere for well-being, care-taking, and reproduction, although habitually without involving a geoscientist in professional capacity. In that implicit manner the everyday behaviours and practices of people influence Earth system dynamic. This renders their inherent geoscience know-how a public good as it makes their ignorance a public risk. A comfortable human niche for billions of people requires a global biogeosphere that is disrupted little by citizens' activities and exposes them to hazards that can be tamed. Quite the reverse, anthropogenic global change will disturb living conditions for many citizen. Much geoscience know-how will have to be deployed to tame disturbances in a socially sustainable manner. Sustainability in turn needs involvement of citizens in
Shaner, Pei-Jen L; Tsao, Tzu-Hsuan; Lin, Rong-Chien; Liang, Wei; Yeh, Chia-Fen; Yang, Xiao-Jun; Lei, Fu-Min; Zhou, Fang; Yang, Can-Chao; Hung, Le Manh; Hsu, Yu-Cheng; Li, Shou-Hsien
Niche evolution underpins the generation and maintenance of biological diversity, but niche conservatism, in which niches remain little changed over time in closely related taxa, and the role of ecology in niche evolution are continually debated. To test whether climate niches are conserved in two closely related passerines in East Asia - the vinous-throated (Paradoxornis webbianus) and ashy-throated (P. alphonsianus) parrotbills - we established their potential allopatric and sympatric regions using ecological niche models and compared differences in their climate niches using niche overlap indices in background tests and multivariate statistical analyses. We also used polymorphism data on 44 nuclear genes to infer their divergence demography. We found that these two parrotbills occupy different climate niches, in both their allopatric and potential sympatric regions. Because the potential sympatric region is the area predicted to be suitable for both parrotbills based on the ecological niche models, it can serve as a natural common garden. Therefore, their observed niche differences in this potential sympatry were not simply rendered by phenotypic plasticity and probably had a genetic basis. Our genetic analyses revealed that the two parrotbills are not evolutionarily independent for the most recent part of their divergence history. The two parrotbills diverged c. 856,000 years ago and have had substantial gene flow since a presumed secondary contact c. 290,000 years ago. This study provides an empirical case demonstrating that climate niches may not be homogenized in nascent species in spite of substantial, ongoing gene flow, which in turn suggests a role for ecology in promoting and maintaining diversification among incipient species. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.
Broennimann, Olivier; Treier, Urs A.; Müller-Schärer, Heinz; Thuiller, W.; Peterson, A. T.; Guisan, Antoine
Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species’ invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of th...
Taboada, Angela; von Wehrden, Henrik; Assmann, Thorsten
Detailed understanding of a species' natural history and environmental needs across spatial scales is a primary requisite for effective conservation planning, particularly for species with complex life cycles in which different life stages occupy different niches and respond to the environment at different scales. However, niche models applied to conservation often neglect early life stages and are mostly performed at broad spatial scales. Using the endangered heath tiger beetle (Cicindela sylvatica) as a model species, we relate presence/absence and abundance data of locally dispersing adults and sedentary larvae to abiotic and biotic variables measured in a multiscale approach within the geographic extent relevant to active conservation management. At the scale of hundreds of meters, fine-grained abiotic conditions (i.e., vegetation structure) are fundamental determinants of the occurrence of both life stages, whereas the effect of biotic factors is mostly contained in the abiotic signature. The combination of dense heath vegetation and bare ground areas is thus the first requirement for the species' preservation, provided that accessibility to the suitable habitat is ensured. At a smaller scale (centimetres), the influence of abiotic factors on larval occurrence becomes negligible, suggesting the existence of important additional variables acting within larval proximity. Sustained significant correlations between neighbouring larvae in the models provide an indication of the potential impact of neighbourhood crowding on the larval niche within a few centimetres. Since the species spends the majority of its life cycle in the larval stage, it is essential to consider the hierarchical abiotic and biotic processes affecting the larvae when designing practical conservation guidelines for the species. This underlines the necessity for a more critical evaluation of the consequences of disregarding niche variation between life stages when estimating niches and
Zhang, Peng; Yang, Yong; Wu, Zhi-jin; Zhang, Ning; Zhang, Chao-hua; Zhang, Xiao-dong
To assess the clinical and urodynamic outcomes of patients with low-compliance neurogenic bladder who were treated with sigmoid bladder augmentation (SBA) over a long-term follow-up. We retrospectively reviewed 52 patients with low-compliance neurogenic bladder who underwent SBA alone or with antireflux techniques in our hospital from 2006 to 2014. Clinical outcomes regarding bladder function, incontinence, medications, catheterization schedules, subsequent interventions, bowel function, and patient satisfaction were addressed. The mean follow-up was 49 months. All patients experienced significant increases in safe cystometric capacity from 113.8 ± 65.9 mL to 373.1 ± 66.7 mL (P bladder compliance from 2.96 ± 1.55 mL/cm H2O to 14.07 ± 5.45 mL/cm H2O (P neurogenic detrusor overactivity, and 11 (21.1%) had recurrent febrile urinary tract infections after SBA. Among 47 prehydronephrosis patients (grade I-II in 10 and III-V in 37), 16 still had minor hydronephrosis after SBA, but the hydronephrosis had been improved significantly (all posthydronephroses were grade I-II instead). All patients reported significant improvements in constipation, and no patient had obvious metabolic acidosis or bladder perforation after SBA. All patients expressed extreme satisfaction with the operation. SBA provided durable clinical and urodynamic improvement for patients with low-compliance neurogenic bladder and constipation. SBA alone, without ureteral reimplantation, seemed sufficient for neurogenic bladder. Furthermore, there was a high level of patient satisfaction with SBA. Copyright © 2014 Elsevier Inc. All rights reserved.
Costa Monteiro, Lucia Maria; Cruz, Glaura Nisya de Oliveira; Fontes, Juliana Marin; Saad Salles, Tania Regina Dias; Boechat, Marcia Cristina Bastos; Monteiro, Ana Carolina; Moreira, Maria Elizabeth Lopes
Congenital Zika Syndrome (CZS) has been associated with microcephaly and other central nervous system abnormalities including areas that have been implicated in the control of the lower urinary tract. As such, this descriptive case series has aimed to investigate whether CZS is linked with neurogenic bladder. Identifying such an association is paramount in the effort to recognize CZS complications that have putative treatment options that could mitigate the impact of CZS in infected children. Following IRB approval, urological assessment was performed in all patients referred to our clinic between June 2016 and May 2017 who presented with confirmed CZS-associated microcephaly. The research protocol consisted of obtaining clinical history, laboratory tests, lower and upper urinary tract ultrasounds, as well as a diagnostic urodynamic evaluation. ZIKA virus infection was previously confirmed by maternal history and positive PCR in babies and mothers. Microcephaly and other central nervous system abnormalities were established based on neurological assessment and associated imaging of the central nervous system (CT head and/or Brain MRI). Twenty-two consecutive CZS patients were tested and confirmed to have neurogenic bladder. Of the 22 patients assessed, 21 presented with an overactive bladder combined with reduced bladder capacity and elevated detrusor filling pressures. Clinically significant increases in postvoid residual (PVR) were confirmed in 40% of cases while a urinary tract infection (UTI) was identified in 23% of cases. Neurogenic bladder, a known treatable health condition, was confirmed in 100% of patients tested in this study, most presenting with high-risk urodynamic patterns known to lead to renal damage when left untreated. Follow up studies are necessary to provide further insight onto long-term disease progression and to investigate the response to standard therapies for neurogenic bladder. Nonetheless, we emphasize the importance of proactive
Full Text Available La neurogenética es una disciplina emergente en el Perú que vincula la investigación básica con la práctica clínica. El Centro de Investigación Básica en Neurogenética, es el único centro en el Perú dedicado a la atención especializada de enfermedades neurogenéticas. La investigación en esta área está estrechamente ligada a la enfermedad de Huntington, desde la genotipificación del gen HTT por PCR, hasta los actuales estudios de haplogrupos en esta enfermedad. La investigación en otras enfermedades monogénicas permitió la implementación de metodologías alternativas para la genotipificación del síndrome X frágil y distrofia miotónica tipo 1. Esfuerzos colaborativos nacionales e internacionales han permitido conocer nuevas variantes genéticas en enfermedades complejas, como la enfermedad de Parkinson y Alzheimer. El entrenamiento multidisciplinario y la mentoría fomentan la formación de nuevos especialistas en neurogenética, permitiendo el crecimiento sostenido de esta disciplina en el país. El impulso de la investigación en el Perú ha impulsado el crecimiento de la investigación en neurogenética; sin embargo, las limitaciones en infraestructura, tecnología y capacitación aún son un reto para el crecimiento de investigación en esta disciplina
Pesch, U.; Vernay, A.L.; van Bueren, E.M.; Pandis Iveroth, S
In many sustainable urban innovation projects, the efforts, endurance and enthusiasm of individuals at key positions are considered a crucial factor for success. This article studies the role of individual agency in sociotechnical niches by using Kingdon’s agenda-setting model. Although strategic
This article discusses the nature of market niche analysis in the casino gaming industry. It presents four approaches for conducting market niche analysis. An an example of one approach, the Las Vegas Visitor Profile Study is used to identify a premium niche in the Las Vegas Slot Target Market. A detailed examination of the premium niche profile provides a description of the typical premium slot player. The description of the typical premium player leads to hypotheses regarding needs (the unique preference set) of the premium player. An analysis of the unique preference set suggests an appropriate enhanced marketing program.
Full Text Available Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range.
Becerra López, Jorge Luis; Esparza Estrada, Citlalli Edith; Romero Méndez, Ulises; Sigala Rodríguez, José Jesús; Mayer Goyenechea, Irene Goyenechea; Castillo Cerón, Jesús Martín
Invasive alien species are one of most severe threats to biodiversity and natural resources. These biological invasions have been studied from the niche conservatism and niche shifts perspective. Niche differentiation may result from changes in fundamental niche or realized niche or both; in biological invasions, niche differences between native and non-native ranges can appear through niche expansion, niche unfilling and niche stability. The American bullfrog Lithobates catesbeianus is an in...
Fujii, Mutsumi; Sherchan, Prativa; Soejima, Yoshiteru; Doycheva, Desislava; Zhao, Diana; Zhang, John H
We evaluated whether JWH133, a selective cannabinoid type 2 receptor (CB2R) agonist, prevented neurogenic pulmonary edema (NPE) after subarachnoid hemorrhage (SAH) by attenuating inflammation. Adult male rats were assigned to six groups: sham-operated, SAH with vehicle, SAH with JWH133 (0.3, 1.0, or 3.0 mg/kg) treatment 1 h after surgery, and SAH with JWH133 (1.0 mg/kg) at 1 h with a selective CB2R antagonist, SR144528 (3.0 mg/kg). The perforation model of SAH was performed and pulmonary wet-to-dry weight ratio was evaluated 24 and 72 h after surgery. Western blot analyses and immunohistochemistry were evaluated 24 h after surgery. JWH133 (1.0 mg/kg) significantly and most strongly improved lung edema 24 h after SAH. SR144528 administration significantly reversed the effects of JWH133 (1.0 mg/kg). SAH-induced increasing levels of myeloperoxidase (MPO) and decreasing levels of a tight junction (TJ) protein, junctional adhesion molecule (JAM)-A, were ameliorated by JWH133 (1.0 mg/kg) administration 24 h after SAH. Immunohistochemical assessment also confirmed substantial leukocyte infiltration in the outside of vessels in SAH, which were attenuated by JWH133 (1.0 mg/kg) injection. CB2R agonist ameliorated lung permeability by inhibiting leukocyte trafficking and protecting tight junction proteins in the lung of NPE after SAH.
Ana Claudia Paradella
Full Text Available Intravesical botulinum toxin A (BoNTA injection has been widely used for the treatment of detrusor overactivity in patients with neurogenic bladder due to spinal cord injury who do not respond to conventional treatment. There is no consensus about antibiotic prophylaxis for this procedure. We conducted a retrospective analysis of medical records of adult patients with spinal cord injury who underwent detrusor BoNTA injection between January of 2007 and December of 2013 in a rehabilitation hospital. Occurrence of symptomatic urinary tract infection (UTI was assessed in 3 groups in accordance with their use of antibiotics (prophylactic dosage, 3 days, more than 3 days for the treatment of asymptomatic bacteriuria. All patients were performing self or assisted clean intermittent bladder catheterization and underwent a rigid cystoscopy, under general or regional anesthesia with sedation, and the drug used was Botox®. A total of 616 procedures were performed during the study period. There were 11 identified cases of UTI (1.8% with a trend to a higher rate in the group that used antibiotics for longer time. This report shows that a single dose of antibiotics before the detrusor BoNTA injection is enough to prevent UTI. Randomized clinical trial should be conducted for definitive conclusions.
Paradella, Ana Claudia; Musegante, André Ferraz de Arruda; Brites, Carlos
Intravesical botulinum toxin A (BoNTA) injection has been widely used for the treatment of detrusor overactivity in patients with neurogenic bladder due to spinal cord injury who do not respond to conventional treatment. There is no consensus about antibiotic prophylaxis for this procedure. We conducted a retrospective analysis of medical records of adult patients with spinal cord injury who underwent detrusor BoNTA injection between January of 2007 and December of 2013 in a rehabilitation hospital. Occurrence of symptomatic urinary tract infection (UTI) was assessed in 3 groups in accordance with their use of antibiotics (prophylactic dosage, 3 days, more than 3 days) for the treatment of asymptomatic bacteriuria. All patients were performing self or assisted clean intermittent bladder catheterization and underwent a rigid cystoscopy, under general or regional anesthesia with sedation, and the drug used was Botox ® . A total of 616 procedures were performed during the study period. There were 11 identified cases of UTI (1.8%) with a trend to a higher rate in the group that used antibiotics for longer time. This report shows that a single dose of antibiotics before the detrusor BoNTA injection is enough to prevent UTI. Randomized clinical trial should be conducted for definitive conclusions. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.
Wenger, Y; Buzgariu, W; Galliot, B
Hydra continuously differentiates a sophisticated nervous system made of mechanosensory cells (nematocytes) and sensory-motor and ganglionic neurons from interstitial stem cells. However, this dynamic adult neurogenesis is dispensable for morphogenesis. Indeed animals depleted of their interstitial stem cells and interstitial progenitors lose their active behaviours but maintain their developmental fitness, and regenerate and bud when force-fed. To characterize the impact of the loss of neurogenesis in Hydra, we first performed transcriptomic profiling at five positions along the body axis. We found neurogenic genes predominantly expressed along the central body column, which contains stem cells and progenitors, and neurotransmission genes predominantly expressed at the extremities, where the nervous system is dense. Next, we performed transcriptomics on animals depleted of their interstitial cells by hydroxyurea, colchicine or heat-shock treatment. By crossing these results with cell-type-specific transcriptomics, we identified epithelial genes up-regulated upon loss of neurogenesis: transcription factors (Dlx, Dlx1, DMBX1/Manacle, Ets1, Gli3, KLF11, LMX1A, ZNF436, Shox1), epitheliopeptides (Arminins, PW peptide), neurosignalling components (CAMK1D, DDCl2, Inx1), ligand-ion channel receptors (CHRNA1, NaC7), G-Protein Coupled Receptors and FMRFRL. Hence epitheliomuscular cells seemingly enhance their sensing ability when neurogenesis is compromised. This unsuspected plasticity might reflect the extended multifunctionality of epithelial-like cells in early eumetazoan evolution. © 2015 The Authors.
de Vocht, T. F.; Chrzan, R.; Dik, P.; Klijn, A. J.; de Jong, T. P. V. M.
PURPOSE: We evaluated the effectiveness of bladder neck injection as a supplementary treatment for persistent low pressure incontinence after unsatisfactory fascial sling procedures in patients with neurogenic lower urinary tract dysfunction. MATERIALS AND METHODS: A total of 89 patients with
It is widely accepted that tumors contain cancer stem cells (CSC) possessing self-renewal potential as well as the ability to generate numerous cancer cells. Cancer stem cells are resistant to conventional cancer therapy and have greater invasive and metastatic behavior. It has been suggested that blood vessels provide a niche that maintains stemness in normal organs. This role also extends to the field of cancer biology. Cancer stem cells have been isolated from leukemias and solid cancers. Identification of these cells and their niche is critical for identifying molecular targets in order to inhibit their growth and to destroy their niche. For this purpose, sorting of living CSC is required to monitor their presence in the presumptive niche to establish whether a CSC candidate actually shows malignant features. Based on and referring to analyses in normal tissues, molecules including nitric oxide, Wnt, neuropilin-1, hepatocyte growth factor and others involved in the maintenance of CSC have been isolated. Stem cells might affect niche cells and niche cells produce stemness factors on such stimulation. Therefore, the niche might be flexible to support self-renewal or differentiation of stem cells even in the same niche cells. © 2012 Japanese Cancer Association.
Niche marketing can be a form of diversification and a means to achieving business success in all economic climates-boom, recession and depression. There are several niche marketing potentials farm entrepreneurs can exploit in start-up and existing small and large farm businesses. Dynamic entrepreneurism, and ...
Hayduk, Allan W.
Examines barriers to conventional education and explains how distance education can fill the niche markets created by these barriers. Curriculum barriers and economic barriers are discussed; core attributes of distance education are described; and planning for niche markets is addressed based on the core attributes. (Contains five references.)…
Bakker, S.; Lente, H. van; Engels, R.
The notion of ‘niche’has proved to be useful to account for the emergence of radical innovations. Most studies, however, deal with the development of single emerging technologies. In this paper we address the competition between multiple niche technologies.Within the niche of the ‘car of the future’
Bruggeman, J.P.; Carnabuci, G.; Carnabuci, Gianluca; Vermeulen, Ivar
Diffuse competition due to niche overlap between actors without (direct) ties with each other, constrains their structural autonomy. This is not dealt with in Burt’s mathematical model of his well-known structural holes theory. We fix his model by introducing a network measure of niche overlap.
Pie, Marcio R; Campos, Leonardo L F; Meyer, Andreas L S; Duran, Andressa
Despite the remarkable diversity found in squamate reptiles, most of their species tend to be found in warm/dry environments, suggesting that climatic requirements played a crucial role in their diversification, yet little is known about the evolution of their climatic niches. In this study, we integrate climatic information associated with the geographical distribution of 1882 squamate species and their phylogenetic relationships to investigate the tempo and mode of climatic niche evolution in squamates, both over time and among lineages. We found that changes in climatic niche dynamics were pronounced over their recent squamate evolutionary history, and we identified extensive evidence for rate heterogeneity in squamate climatic niche evolution. Most rate shifts involved accelerations, particularly over the past 50 Myr. Most squamates occupy similar regions of the climatic niche space, with only a few lineages diversifying into colder and humid climatic conditions. The changes from arid to mesic conditions in some regions of the globe may have provided opportunities for climatic niche evolution, although most lineages tended to remain near their ancestral niche. Variation in rates of climatic niche evolution seems common, particularly in response to the availability of new climatic conditions over evolutionary time. © 2017 The Author(s).
Schwisow, C R
While niche marketing is not a new strategy, an increasing number of competitors are pursuing the same niches, resulting in stiff competition within the health care industry, writes C. Ronald Schwisow. This means marketers need to be resourceful to maximize their communications efforts. One such approach is specialty advertising.
Hut, Roelof A.; Kronfeld-Schor, Noga; van der Vinne, Vincent; De la Iglesia, Horacio
Time as an ecological niche variable or "temporal niche" can be defined in the context of the most prominent environmental cycles, including the tidal cycle, the lunar day and month, the solar day, and the earth year. For the current review, we focus on the 24-h domain generated through the earth's
Young, Tamara V.
Drawing on niche theory, I describe the resource dimensions that compose teachers unions' niche and explain how aspects of the current political landscape buttress or undermine teachers unions' realization of those resources. I also discuss teachers unions' strategies to oppose any threats that undermine the realization of the resource arrays that…
Agashe, Deepa; Bolnick, Daniel I
Theory and empirical evidence show that intraspecific competition can drive selection favouring the use of novel resources (i.e. niche expansion). The evolutionary response to such selection depends on genetic variation for resource use. However, while genetic variation might facilitate niche expansion, genetically diverse groups may also experience weaker competition, reducing density-dependent selection on resource use. Therefore, genetic variation for fitness on different resources could directly facilitate, or indirectly retard, niche expansion. To test these alternatives, we factorially manipulated both the degree of genetic variation and population density in flour beetles (Tribolium castaneum) exposed to both novel and familiar food resources. Using stable carbon isotope analysis, we measured temporal change and individual variation in beetle diet across eight generations. Intraspecific competition and genetic variation acted on different components of niche evolution: competition facilitated niche expansion, while genetic variation increased individual variation in niche use. In addition, genetic variation and competition together facilitated niche expansion, but all these impacts were temporally variable. Thus, we show that the interaction between genetic variation and competition can also determine niche evolution at different time scales.
Jeffrey M. Diez; Itamar Giladi; Robert Warren; H. Ronald. Pulliam
Summary 1. Mismatches between species distributions and habitat suitability are predicted by niche theory and have important implications for forecasting how species may respond to environmental changes. Quantifying these mismatches is challenging, however, due to the high dimensionality of species niches and the large spatial and temporal variability in population...
Elizabeth A. Flaherty; Merav Ben-David
Recently, it was proposed that stable isotope patterns can be used to quantify the width of the ecological niche of animals. However, the potential effects of habitat use on isotopic patterns of consumers have not been fully explored and consequently isotopic patterns may yield deceptive estimates of niche width. Here, we simulated four different scenarios of a...
tissue and improve gas exchange in trauma patients with blunt chest trauma and severe adult respiratory distress syndrome (Voggenreiter et al., 1999...dementia. Dement. Geriatr. Cogn. Disord. 27, 465–473. Wilson, M.A., Molliver, M.E., 1994. Microglial response to degeneration of serotonergic axon
Stauffer, Craig E; Snyder, Elizabeth; Ngo, Tin C; Elliott, Christopher S
To characterize the rate of febrile urinary tract infections (UTIs) after ureteroscopy in patients with neurogenic bladder compared with those with physiologically normal bladders. Although generally considered safe and effective, there is a growing body of evidence suggesting that patients with neurogenic bladder are at an increased risk of infectious complications following ureteroscopy. We performed a retrospective chart review of those undergoing ureteroscopy in a single academically affiliated hospital system between June 2013 and May 2016. Information regarding neurogenic bladder status, culture results, bladder management, and the presence of upper tract decompression was collected. Postoperative febrile UTI was defined as a hospital admission within 1 week of surgery because of fever not attributable to another source. Of 467 ureteroscopies, 44 (9.5%) were performed in the setting of neurogenic bladder. Febrile UTI rates were higher in patients with neurogenic bladder compared with control patients (9% vs 1.4%, P = .01) with significantly higher rates in those dependent on bladder catheterization. Interestingly, the presence of a nephrostomy tube in patients with physiologically normal bladders increased the risk of postoperative febrile UTI to levels comparable with patients with neurogenic bladder who were catheter dependent (10.5% vs 12.5%, respectively). Although infectious complications in the neurogenic population are likely multifactorial, the reliance on catheterization and thus colonization appears to be a significant factor and extends to non-neurogenic patients. These data suggest that bacterial colonization may be the significant underlying risk factor for febrile UTI after ureteroscopy. Copyright © 2017 Elsevier Inc. All rights reserved.
Jen-Bin Wang; Chin-Su Liu; Shin-Lin Tsai; Chou-Fu Wei; Tai-Wai Chin
Background: To compare the incidence of residual high-grade vesicoureteral reflux (HVUR) (≥Grade III) in neurogenic bladder patients receiving augmentation cystoplasty alone or with simultaneous ureteral reimplantation. Furthermore, we also tried to find the risk factors of residual VUR and febrile urinary tract infection. Methods: Between 1999 and 2009, urinary bladder augmentation was performed in 21 children with neurogenic bladder. Seventeen of these patients had VUR on preoperative vo...
Hu, Junhua; Jiang, Zhigang; Chen, Jing; Qiao, Huijie
Ecological niche divergence and adaptation to new environments are thought to play important roles in driving speciation. Whether recently evolved species show evidence for niche divergence or conservation is vital towards understanding the role of ecology in the process of speciation. The genus Procapra is an ancient, monophyletic lineage endemic to Asia that contains three extant species (P. gutturosa, P. przewalskii and P. picticaudata). These species mainly inhabit the Qinghai-Tibetan and Mongolian Plateaus, and today have primarily allopatric distributions. We applied a series of geographic information system-based analyses to test for environmental variation and niche divergence among these three species. We found substantial evidence for niche divergence in species' bioclimatic preferences, which supports the hypothesis that niche divergence accelerates diversification in Procapra. Our results provide important insight into the evolutionary history of ungulates in Asia and help to elucidate how environmental changes accelerate lineage diversification.
Broennimann, O; Treier, U A; Müller-Schärer, H; Thuiller, W; Peterson, A T; Guisan, A
Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species' invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of the observed climatic niche occurred between native and non-native ranges, providing the first empirical evidence that an invasive species can occupy climatically distinct niche spaces following its introduction into a new area. The models fail to predict the current invaded distribution, but correctly predict areas of introduction. Climate matching is thus a useful approach to identify areas at risk of introduction and establishment of newly or not-yet-introduced neophytes, but may not predict the full extent of invasions.
Broennimann, O.; Treier, Urs; Müller-Schärer, H.
Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species' invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche...... in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of the observed climatic niche occurred between native and non-native ranges, providing the first empirical...... evidence that an invasive species can occupy climatically distinct niche spaces following its introduction into a new area. The models fail to predict the current invaded distribution, but correctly predict areas of introduction. Climate matching is thus a useful approach to identify areas at risk...
Hof, Christian; Rahbek, Carsten; Araújo, Miguel B.
The question of whether closely related species share similar ecological requirements has attracted increasing attention, because of its importance for understanding global diversity gradients and the impacts of climate change on species distributions. In fact, the assumption that related species...... in the realised climatic niches is explained on higher taxonomic levels, and whether the climatic niches of species within a given taxonomic group are more similar than between taxonomic groups. We found evidence for phylogenetic signals in realised climatic niches although the strength of the signal varied among...... amphibian orders and across biogeographical regions. To our knowledge, this is the first study providing a comprehensive analysis of the phylogenetic signal in species climatic niches for an entire clade across the world. Even though our results do not provide a strong test of the niche conservatism...
Kiefer, Julie C
A stem cell niche is a microenvironment that supports self-renewal of a population of stem cells, and their production of differentiated cells. While the definition evokes images of a stem cell Shangri-La-where a serene stem cell pool nestles within a niche that shelters and sustains it-the reality is much more tumultuous. Niches are subject to an ever-changing maelstrom of environmental factors, the ravages of old age, and the sly tactics of disease. Presented here is a basic overview of the different ways in which stem cell niches respond to local and systemic environments, and their impact on stem cell behavior. The primer culminates with a discussion of the topic with stem cell and niche biologists D. Leanne Jones, Ph.D., and Tudorita Tumbar, Ph.D. Copyright © 2011 Wiley-Liss, Inc.
Embodied agents use bodily actions and environmental interventions to make the world a better place to think in. Where does language fit into this emerging picture of the embodied, ecologically efficient agent? One useful way to approach this question is to consider language itself as a cognition-enhancing animal-built structure. To take this perspective is to view language as a kind of self-constructed cognitive niche: a persisting but never stationary material scaffolding whose crucial role in promoting thought and reason remains surprisingly poorly understood. It is the very materiality of this linguistic scaffolding, I suggest, that gives it some key benefits. By materializing thought in words, we create structures that are themselves proper objects of perception, manipulation, and (further) thought.
Tsang, B; Stothers, L; Macnab, A; Lazare, D; Nigro, M
Validated questionnaires are increasingly the preferred method used to obtain historical information. Specialized questionnaires exist validated for patients with neurogenic disease including neurogenic bladder. Those currently available are systematically reviewed and their potential for clinical and research use are described. A systematic search via Medline and PubMed using the key terms questionnaire(s) crossed with Multiple Sclerosis (MS) and Spinal Cord Injury (SCI) for the years 1946 to January 22, 2014 inclusive. Additional articles were selected from review of references in the publications identified. Only peer reviewed articles published in English were included. 18 questionnaires exist validated for patients with neurogenic bladder; 14 related to MS, 3 for SCI, and 1 for neurogenic bladder in general; with 4 cross-validated in both MS and SCI. All 18 are validated for both male and female patients; 59% are available only in English. The domains of psychological impact and physical function are represented in 71% and 76% of questionnaires, respectively. None for the female population included elements to measure symptoms of prolapse. The last decade has seen an expansion of validated questionnaires to document bladder symptoms in neurogenic disease. Disease specific instruments are available for incorporation into the clinical setting for MS and SCI patients with neurogenic bladder. The availability of caregiver and interview options enhances suitability in clinical practice as they can be adapted to various extents of disability. Future developments should include expanded language validation to the top 10 global languages reported by the World Health Organization. © 2015 Wiley Periodicals, Inc.
Drew, Liam J.; Fusi, Stefano; Hen, René
In the adult mammalian brain, newly generated neurons are continuously incorporated into two networks: interneurons born in the subventricular zone migrate to the olfactory bulb, whereas the dentate gyrus (DG) of the hippocampus integrates locally born principal neurons. That the rest of the mammalian brain loses significant neurogenic capacity…
Full Text Available Neurogenic bladder (NB or neurogenic lower urinary tract dysfunction (NLUTD, a dysfunction of the urinary bladder and urethra due to disease of the central nervous system or peripheral nerves, is a major global medical and social problem. Numerous nervous system abnormalities, such as: stroke, Alzheimer’s and Parkinson’s diseases, traumatic spinal cord injury, spinal cord tumors, congenital spina bifida, and diabetes, can cause NB/NLUTD. There are two major types of bladder control problems associated with NB/NLUTD: the bladder becomes either overactive or underactive depending on the nature, level, and extent of nerve damage. This review specifically focuses on the diagnosis and management of NB/NLUTD in China as well as on recent efforts to treat this disease.
Andersen, Rikke K; Widmer, Hans R; Zimmer, Jens
There is a lot of excitement about the potential use of multipotent neural stem cells for the treatment of neurodegenerative diseases. However, the strategy is compromised by the general loss of multipotency and ability to generate neurons after long-term in vitro propagation. In the present study......-term propagated, our study also suggests that LIF favours neurogenic differentiation of human VM precursor cells....
Guichet, Pierre-Olivier; Bieche, Ivan; Teigell, Marisa; Serguera, Ché; Rothhut, Bernard; Rigau, Valérie; Scamps, Frédérique; Ripoll, Chantal; Vacher, Sophie; Taviaux, Sylvie; Chevassus, Hugues; Duffau, Hugues; Mallet, Jacques; Susini, Aurélie; Joubert, Dominique; Bauchet, Luc; Hugnot, Jean-Philippe
Glioblastoma multiform (GBM) are devastating brain tumors containing a fraction of multipotent stem-like cells which are highly tumorigenic. These cells are resistant to treatments and are likely to be responsible for tumor recurrence. One approach to eliminate GBM stem-like cells would be to force their terminal differentiation. During development, neurons formation is controlled by neurogenic transcription factors such as Ngn1/2 and NeuroD1. We found that in comparison with oligodendrogenic genes, the expression of these neurogenic genes is low or absent in GBM tumors and derived cultures. We thus explored the effect of overexpressing these neurogenic genes in three CD133(+) Sox2(+) GBM stem-like cell cultures and the U87 glioma line. Introduction of Ngn2 in CD133(+) cultures induced massive cell death, proliferation arrest and a drastic reduction of neurosphere formation. Similar effects were observed with NeuroD1. Importantly, Ngn2 effects were accompanied by the downregulation of Olig2, Myc, Shh and upregulation of Dcx and NeuroD1 expression. The few surviving cells adopted a typical neuronal morphology and some of them generated action potentials. These cells appeared to be produced at the expense of GFAP(+) cells which were radically reduced after differentiation with Ngn2. In vivo, Ngn2-expressing cells were unable to form orthotopic tumors. In the U87 glioma line, Ngn2 could not induce neuronal differentiation although proliferation in vitro and tumoral growth in vivo were strongly reduced. By inducing cell death, cell cycle arrest or differentiation, this work supports further exploration of neurogenic proteins to oppose GBM stem-like and non-stem-like cell growth. Copyright © 2012 Wiley Periodicals, Inc.
McMaster Marianne E
Abstract Background In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. Presentation of the hy...
Šedý, Jiří; Kuneš, Jaroslav; Zicha, Josef
Roč. 60, č. 6 (2011), s. 975-979 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/09/0336; GA AV ČR(CZ) IAA500110902 Institutional research plan: CEZ:AV0Z50110509 Keywords : hypertension * neurogenic pulmonary edema * Dahl salt-sensitive rats * SHR Subject RIV: ED - Physiology Impact factor: 1.555, year: 2011
Zhang, Han-Chao; Yang, Jin; Ye, Xin; Hu, Hai-Feng
The objective of this study was to assess the clinical outcome of vesicoureteral reflux (VUR) after augmentation cystoplasty alone in patients with a hypocompliant neurogenic bladder. Between January 2009 and December 2014, 29 patients with a hypocompliant bladder associated with VUR confirmed by videourodynamics (VUD) preoperatively were recruited in this study. All patients had undergone bladder augmentation with a generous detubularized segment of bowel at our institution. No effort had be...
Nandi, K.N.; Beal, J.A.; Knight, D.S.
Although the neurogenic period for neurons in the lumbar spinal cord has been clearly established (Days 12 through 16 of gestation), it is not known when the neurogenesis of ascending tract neurons is completed within this period. The purpose of the present study was to determine the duration of the neurogenic period for projection neurons of the ascending tracts. To label neurons undergoing mitosis during this period, tritiated thymidine was administered to fetal rats on Embryonic (E) Days E13 through E16 of gestation. Ascending tract neurons of the lumbar cord were later (Postnatal Days 40-50) labeled in each animal with a retrograde tracer, Fluoro-Gold, applied at the site of a hemisection at spinal cord segment C3. Ascending tract neurons which were undergoing mitosis in the upper lumbar cord were double labeled, i.e., labeled with both tritiated thymidine and Fluoro-Gold. On Day E13, 89-92% of the ascending tract neurons were double labeled; on Day E14, 35-37%; and on Day E15, 1-4%. Results showed, then, that some ascending tract neurons were double labeled through Day E15 and were, therefore, proliferating in the final one-third of the neurogenic period. Ascending tract neurons proliferating on Day E15 were confined to laminae III, IV, V, and X and the nucleus dorsalis. Long tract neurons in the superficial dorsal horn (laminae I and II), on the other hand, were found to have completed neurogenesis on Day E14 of gestation. Results of the present study show that spinal neurogenesis of ascending projection neurons continues throughout most of the neurogenic period and does not completely follow the well-established ventral to dorsal gradient
滝内, 秀和; 桜井, 勗; 辻本, 幸夫; 菅尾, 英木; 中村, 正広
A case of solitary pelvic kidney with neurogenic bladder dysfunction with vesicoureteral reflux is presented. The patient was a 15-year-old boy with sacral vertebral dysplasia and hare-lip, and he has been complaining of recurrent fever episodes and urinary incontinence since 11 years old. Renal anomaly was confirmed by DIP, CT and angiography, and grade IV vesicoureteral reflux was demonstrated by voiding cystourethrography. On cystometrography, low compliance bladder which had a 70 ml capac...
Noordhoff, Toscane C; Groen, Jan; Scheepe, Jeroen R; Blok, Bertil F M
Surgical treatment of anatomic bladder outlet obstruction (BOO) may be indicated in males with neurogenic bladder dysfunction. A bothersome complication after surgery is urinary incontinence. To identify the optimal practice in the surgical treatment of anatomic BOO in males with neurogenic bladder dysfunction, due to multiple sclerosis, Parkinson disease, spinal cord injury (SCI), spina bifida, or cerebrovascular accident (CVA). A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Medline, Embase, Cochrane controlled trial databases, Web of Science, and Google Scholar were searched for publications until January 2017. A total of 930 abstracts were screened. Eight studies were included. The types of anatomic BOO discussed were benign prostate obstruction, urethral stricture, and bladder neck sclerosis. The identified surgical treatments were transurethral resection of the prostate (TURP) in patients with Parkinson, CVA or SCI, endoscopic treatment of urethral stricture by laser ablation or urethrotomy (mainly in SCI patients), and bladder neck resection (BNR) in SCI patients. The outcome of TURP may be highly variable, and includes persistent or de novo urinary incontinence, regained normal micturition control, and urinary continence. Good results were seen in BNR and endoscopic urethrotomy studies. Laser ablation and cold knife urethrotomy resulted in restarting intermittent catheterization or adequate voiding. Overall, a high risk of bias was found. This systematic review provides an overview of the current literature on the outcome of several surgical approaches of different types of anatomic BOO in males with neurogenic bladder dysfunction. Identifying the optimal practice was impossible due to limited availability of high-quality studies. The outcome of several surgical approaches in males with neurogenic bladder dysfunction with benign prostate obstruction, urethral stricture
Snippert, H.J.G.; Clevers, H.
The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context,
Moss, Jonathan; Gebara, Elias; Bushong, Eric A; Sánchez-Pascual, Irene; O'Laoi, Ruadhan; El M'Ghari, Imane; Kocher-Braissant, Jacqueline; Ellisman, Mark H; Toni, Nicolas
Adult hippocampal neurogenesis relies on the activation of neural stem cells in the dentate gyrus, their division, and differentiation of their progeny into mature granule neurons. The complex morphology of radial glia-like (RGL) stem cells suggests that these cells establish numerous contacts with the cellular components of the neurogenic niche that may play a crucial role in the regulation of RGL stem cell activity. However, the morphology of RGL stem cells remains poorly described. Here, we used light microscopy and electron microscopy to examine Nestin-GFP transgenic mice and provide a detailed ultrastructural reconstruction analysis of Nestin-GFP-positive RGL cells of the dentate gyrus. We show that their primary processes follow a tortuous path from the subgranular zone through the granule cell layer and ensheathe local synapses and vasculature in the inner molecular layer. They share the ensheathing of synapses and vasculature with astrocytic processes and adhere to the adjacent processes of astrocytes. This extensive interaction of processes with their local environment could allow them to be uniquely receptive to signals from local neurons, glia, and vasculature, which may regulate their fate.
Moss, Jonathan; Gebara, Elias; Sánchez-Pascual, Irene; O’Laoi, Ruadhan; El M’Ghari, Imane; Kocher-Braissant, Jacqueline; Ellisman, Mark H.; Toni, Nicolas
Adult hippocampal neurogenesis relies on the activation of neural stem cells in the dentate gyrus, their division, and differentiation of their progeny into mature granule neurons. The complex morphology of radial glia-like (RGL) stem cells suggests that these cells establish numerous contacts with the cellular components of the neurogenic niche that may play a crucial role in the regulation of RGL stem cell activity. However, the morphology of RGL stem cells remains poorly described. Here, we used light microscopy and electron microscopy to examine Nestin-GFP transgenic mice and provide a detailed ultrastructural reconstruction analysis of Nestin-GFP–positive RGL cells of the dentate gyrus. We show that their primary processes follow a tortuous path from the subgranular zone through the granule cell layer and ensheathe local synapses and vasculature in the inner molecular layer. They share the ensheathing of synapses and vasculature with astrocytic processes and adhere to the adjacent processes of astrocytes. This extensive interaction of processes with their local environment could allow them to be uniquely receptive to signals from local neurons, glia, and vasculature, which may regulate their fate. PMID:27091993
Puschina, E V; Varaksin, A A; Obukhov, D K
Reparative proliferation and neurogenesis in the brain integrative centers after mechanical eye injury in an adult trout Oncorhynchus mykiss have been studied. We have found that proliferation and neurogenesis in proliferative brain regions, the cerebellum, and the optic tectum were significantly enhanced after the eye injury. The cerebellum showed a significant increase in the proliferative activity of the cells of the dorsal proliferative zone and parenchymal cells of the molecular and granular layers. One week after the injury, PCNA-positive radial glia cells have been identified in the tectum. We have found for the first time that the eye trauma resulted in the development of local clusters of undifferentiated cells forming so called neurogenic niches in the tectum and cerebellum. The differentiation of neuronal cells detected by labeling cells with antibodies against the protein HuC/D occurred in the proliferative zones of the telencephalon, the optic tectum, cerebellum, and medulla of a trout within 2 days after the injury. We have shown that the HuC/D expression is higher in the proliferative brain regions than in the definitive neurons of a trout. In addition, we have examined cell proliferation, migration, and apoptosis caused by the eye injury in the contra- and ipsilateral optic nerves and adjacent muscle fibers 2 days after the trauma. The qualitative and quantitative assessment of proliferation and apoptosis in the cells of the optic nerve of a trout has been made using antibodies against PCNA and the TUNEL method.
Reinchisi, Gisela; Limaye, Pallavi V; Singh, Mandakini B; Antic, Srdjan D; Zecevic, Nada
The efficient production of human neocortical neurons from human embryonic stem cells (hESC) is the primary requirement for studying early stages of human cortical development. We used hESC to obtain radial glial cells (hESC-RG) and then compared them with RG cells isolated from human fetal forebrain. Fate of hESC-RG cells critically depends on intrinsic and extrinsic factors. The expression of Pax6 (intrinsic factor) has a similar neurogenic effect on hESC-RG differentiation as reported for human fetal RG cells. Factors from the microenvironment also play a significant role in determining hESC-RG cell fate. In contrast to control cultures, wherein hESC-RG generate mainly astroglia and far fewer neurons, in co-cultures with human fetal forebrain cells, the reverse was found to be true. This neurogenic effect was partly due to soluble factors from human fetal brain cultures. The detected shift towards neurogenesis has significance for developing future efficient neuro-differentiation protocols. Importantly, we established that hESC-RG cells are similar in many respects to human fetal RG cells, including their proliferative capacity, neurogenic potential, and ability to generate various cortical neuronal sub-types. Unlike fetal RG cells, the hESC-RG cells are readily available and can be standardized, features that have considerable practical advantages in research and clinics. Published by Elsevier B.V.
Eric J. Neuberger
Full Text Available Hippocampal dentate gyrus is a focus of enhanced neurogenesis and excitability after traumatic brain injury. Increased neurogenesis has been proposed to aid repair of the injured network. Our data show that an early increase in neurogenesis after fluid percussion concussive brain injury is transient and is followed by a persistent decrease compared with age-matched controls. Post-injury changes in neurogenesis paralleled changes in neural precursor cell proliferation and resulted in a long-term decline in neurogenic capacity. Targeted pharmacology to restore post-injury neurogenesis to control levels reversed the long-term decline in neurogenic capacity. Limiting post-injury neurogenesis reduced early increases in dentate excitability and seizure susceptibility. Our results challenge the assumption that increased neurogenesis after brain injury is beneficial and show that early post-traumatic increases in neurogenesis adversely affect long-term outcomes by exhausting neurogenic potential and enhancing epileptogenesis. Treatments aimed at limiting excessive neurogenesis can potentially restore neuroproliferative capacity and limit epilepsy after brain injury.
Castro-Gago, Manuel; Dacruz-Alvarez, David; Pintos-Martínez, Elena; Beiras-Iglesias, Andrés; Arenas, Joaquín; Martín, Miguel Ángel; Martínez-Azorín, Francisco
Choline kinase beta gene (CHKB) mutations have been identified in Megaconial Congenital Muscular Dystrophy (MDCMC) patients, a very rare inborn error of metabolism with 21 cases reported worldwide. We report the case of a Spanish boy of Caucasian origin who presented a generalized congenital muscular hypotonia, more intense at lower limb muscles, mildly elevated creatine kinase (CK), serum aspartate transaminase (AST) and lactate. Electromyography (EMG) showed neurogenic potentials in the proximal muscles. Histological studies of a muscle biopsy showed neurogenic atrophy with enlarged mitochondria in the periphery of the fibers, and complex I deficiency. Finally, genetic analysis showed the presence of a homozygous mutation in the gene for choline kinase beta (CHKB: NM_005198.4:c.810T>A, p.Tyr270(∗)). We describe here the second Spanish patient whit mutation in CHKB gene, who despite having the same mutation, presented an atypical aspect: congenital neurogenic muscular atrophy progressing to a combined neuropathic and myopathic phenotype (mixed pattern). Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
McNamara, Erin R; Sullivan, Jennifer; Nagaraj, Shashi K; Wiener, John S; Kishnani, Priya S
Neuronopathic Gaucher disease can present as a continuum of clinical findings, including somatic symptoms of anemia, thrombocytopenia, hepatosplenomegaly, and bone disease as well as neurologic sequelae. There is a spectrum of neurologic symptoms ranging from oculomotor apraxia to severe convulsions. The heterozygosity of phenotypes makes it difficult to predict the disease course. We describe an 8-year-old male with neuronopathic type III Gaucher disease who developed bladder dysfunction and was unable to completely void. He also presented with hypertension and acute renal insufficiency, most likely secondary to urinary retention. A complete evaluation was done for causes of urinary retention and bladder dysfunction. A renal bladder ultrasound demonstrated marked hydroureteronephrosis. There was no clinical evidence of infection and cystoscopy revealed no anatomic obstruction. In addition, MRI showed no spinal abnormalities. His bladder dysfunction was managed operatively by creating a catheterizable stoma, using his appendix, to empty his bladder, and surgical findings were consistent with neurogenic bladder. He continues to be managed for his Gaucher disease and neurogenic bladder by genetics, nephrology and urology. This is the first clinical report of neurogenic bladder dysfunction in neuronopathic Gaucher disease.
Benabdallah, Justin O; Collins, Clinton W; Carucci, Laura R; Moores, Kenneth E; Gater, David R; Klausner, Adam P
Patients with neurogenic bladder secondary to spinal cord injury who are managed long term with an indwelling catheter are known to be at increased risk for transitional cell carcinoma of the bladder. Immunosuppression is a known risk factor for malignancies that often are more aggresSive than those seen in normal populations. Case report and discussion of management recommendations. We summarize the case of a 44-year-old HIV-positive C5-C6 incomplete tetraplegic male (date of injury 1980), who was diagnosed with transitional cell carcinoma of the bladder and succumbed to disease within 6 months of diagnosis. The patient was a non-smoker who was never managed with an indwelling catheter. There has been no such case reported in the literature. HIV infection in the presence of a neurogenic bladder may carry an increased risk of aggressive bladder malignancy. More studies are warranted to determine whether routine annual screening with cystoscopy in all patients with HIV and neurogenic bladder is indicated.
Wei, Zheng; Yaguchi, Junko; Yaguchi, Shunsuke; Angerer, Robert C; Angerer, Lynne M
Two major signaling centers have been shown to control patterning of sea urchin embryos. Canonical Wnt signaling in vegetal blastomeres and Nodal signaling in presumptive oral ectoderm are necessary and sufficient to initiate patterning along the primary and secondary axes, respectively. Here we define and characterize a third patterning center, the animal pole domain (APD), which contains neurogenic ectoderm, and can oppose Wnt and Nodal signaling. The regulatory influence of the APD is normally restricted to the animal pole region, but can operate in most cells of the embryo because, in the absence of Wnt and Nodal, the APD expands throughout the embryo. We have identified many constituent APD regulatory genes expressed in the early blastula and have shown that expression of most of them requires Six3 function. Furthermore, Six3 is necessary for the differentiation of diverse cell types in the APD, including the neurogenic animal plate and immediately flanking ectoderm, indicating that it functions at or near the top of several APD gene regulatory networks. Remarkably, it is also sufficient to respecify the fates of cells in the rest of the embryo, generating an embryo consisting of a greatly expanded, but correctly patterned, APD. A fraction of the large group of Six3-dependent regulatory proteins are orthologous to those expressed in the vertebrate forebrain, suggesting that they controlled formation of the early neurogenic domain in the common deuterostome ancestor of echinoderms and vertebrates.
Yang, Hanseul; Adam, Rene C; Ge, Yejing; Hua, Zhong L; Fuchs, Elaine
Adult tissue stem cells (SCs) reside in niches, which, through intercellular contacts and signaling, influence SC behavior. Once activated, SCs typically give rise to short-lived transit-amplifying cells (TACs), which then progress to differentiate into their lineages. Here, using single-cell RNA-seq, we unearth unexpected heterogeneity among SCs and TACs of hair follicles. We trace the roots of this heterogeneity to micro-niches along epithelial-mesenchymal interfaces, where progenitors display molecular signatures reflective of spatially distinct local signals and intercellular interactions. Using lineage tracing, temporal single-cell analyses, and chromatin landscaping, we show that SC plasticity becomes restricted in a sequentially and spatially choreographed program, culminating in seven spatially arranged unilineage progenitors within TACs of mature follicles. By compartmentalizing SCs into micro-niches, tissues gain precise control over morphogenesis and regeneration: some progenitors specify lineages immediately, whereas others retain potency, preserving self-renewing features established early while progressively restricting lineages as they experience dynamic changes in microenvironment. Copyright © 2017 Elsevier Inc. All rights reserved.
Costa, Marta H G; de Soure, António M; Cabral, Joaquim M S; Ferreira, Frederico Castelo; da Silva, Cláudia L
The adult bone marrow (BM) niche is a complex entity where a homeostatic hematopoietic system is maintained through a dynamic crosstalk between different cellular and non-cellular players. Signaling mechanisms triggered by cell-cell, cell-extracellular matrix (ECM), cell-cytokine interactions, and local microenvironment parameters are involved in controlling quiescence, self-renewal, differentiation, and migration of hematopoietic stem/progenitor cells (HSPC). A promising strategy to more efficiently expand HSPC numbers and tune their properties ex vivo is to mimic the hematopoietic niche through integration of adjuvant stromal cells, soluble cues, and/or biomaterial-based approaches in HSPC culture systems. Particularly, mesenchymal stem/stromal cells (MSC), through their paracrine activity or direct contact with HSPC, are thought to be a relevant niche player, positioning HSPC-MSC co-culture as a valuable platform to support the ex vivo expansion of hematopoietic progenitors. To improve the clinical outcome of hematopoietic cell transplantation (HCT), namely when the available HSPC are present in a limited number such is the case of HSPC collected from umbilical cord blood (UCB), ex vivo expansion of HSPC is required without eliminating the long-term repopulating capacity of more primitive HSC. Here, we will focus on depicting the characteristics of co-culture systems, as well as other bioengineering approaches to improve the functionality of HSPC ex vivo. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Zhu, Guo; Rankin, Sherri L; Larson, Jon D; Zhu, Xiaoyan; Chow, Lionel M L; Qu, Chunxu; Zhang, Jinghui; Ellison, David W; Baker, Suzanne J
Loss of the tumor suppressor gene PTEN exerts diverse outcomes on cancer in different developmental contexts. To gain insight into the effect of its loss on outcomes in the brain, we conditionally inactivated the murine Pten gene in neonatal neural stem/progenitor cells. Pten inactivation created an abnormal perivascular proliferative niche in the cerebellum that persisted in adult animals but did not progress to malignancy. Proliferating cells showed undifferentiated morphology and expressed the progenitor marker Nestin but not Math1, a marker of committed granule neuron progenitors. Codeletion of Pten and Trp53 resulted in fully penetrant medulloblastoma originating from the perivascular niche, which exhibited abnormal blood vessel networks and advanced neuronal differentiation of tumor cells. EdU pulse-chase experiments demonstrated a perivascular cancer stem cell population in Pten/Trp53 double mutant medulloblastomas. Genetic analyses revealed recurrent somatic inactivations of the tumor suppressor gene Ptch1 and a recapitulation of the sonic hedgehog subgroup of human medulloblastomas. Overall, our results showed that PTEN acts to prevent the proliferation of a progenitor niche in postnatal cerebellum predisposed to oncogenic induction of medulloblastoma. Cancer Res; 77(1); 123-33. ©2016 AACR. ©2016 American Association for Cancer Research.
Duran, Andressa; Pie, Marcio R
Climatic niches have increasingly become a nexus in our understanding of a variety of ecological and evolutionary phenomena, from species distributions to latitudinal diversity gradients. Despite the increasing availability of comprehensive datasets on species ranges, phylogenetic histories, and georeferenced environmental conditions, studies on the evolution of climate niches have only begun to understand how niches evolve over evolutionary timescales. Here, using primates as a model system, we integrate recently developed phylogenetic comparative methods, species distribution patterns, and climatic data to explore primate climatic niche evolution, both among clades and over time. In general, we found that simple, constant-rate models provide a poor representation of how climatic niches evolve. For instance, there have been shifts in the rate of climatic niche evolution in several independent clades, particularly in response to the increasingly cooler climates of the past 10 My. Interestingly, rate accelerations greatly outnumbered rate decelerations. These results highlight the importance of considering more realistic evolutionary models that allow for the detection of heterogeneity in the tempo and mode of climatic niche evolution, as well as to infer possible constraining factors for species distributions in geographical space. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.
van der Voet, Lucy Lucet F; Limperg, Tobias; Veersema, Sebastiaan; Timmermans, Anne; Bij de Vaate, A Marjolein J; Brölmann, Hans A M; Huirne, Judith A F
To study the prevalence of hysteroscopically evaluated disruptions of the integrity of the uterine wall ('niches') in women with and without a previous cesarean section. A prospective cohort study was performed in a teaching hospital in the Netherlands. Women seeking hysteroscopic sterilization were included. A hysteroscopic evaluation of the anterior wall of the uterus and cervix to identify the existence of disruptions (niches) was performed in a standard manner. Primary outcome was the presence of a uterine niche, defined as any visible defect, disruption, or concavity (gap) in the anterior wall. Secondary outcome was to develop a registration form of niche features for hysteroscopic evaluation. In total, 713 women were included, 603 without and 110 with a previous cesarean section. In women with a previous cesarean Section 83 (75%) niches were observed using hysteroscopy. Anterior wall disruptions were not observed in women without a cesarean section. The following niche features were identified and incorporated in a registration form: polyps, cysts, myometrium defect, fibrotic tissue, (abnormal) vascular pattern, lateral branches, mucus production inside the defect, and bleeding. In a prospective cohort study among women undergoing hysteroscopic sterilization, a uterine niche could be detected by hysteroscopy in 75% of women with a previous cesarean section. Copyright © 2017 Elsevier B.V. All rights reserved.
Parent, Christine E; Agashe, Deepa; Bolnick, Daniel I
Intraspecific competition is believed to drive niche expansion, because otherwise suboptimal resources can provide a refuge from competition for preferred resources. Competitive niche expansion is well supported by empirical observations, experiments, and theory, and is often invoked to explain phenotypic diversification within populations, some forms of speciation, and adaptive radiation. However, some foraging models predict the opposite outcome, and it therefore remains unclear whether competition will promote or inhibit niche expansion. We conducted experiments to test whether competition changes the fitness landscape to favor niche expansion, and if competition indeed drives niche expansion as expected. Using Tribolium castaneum flour beetles fed either wheat (their ancestral resource), corn (a novel resource) or mixtures of both resources, we show that fitness is maximized on a mixed diet. Next, we show that at higher population density, the optimal diet shifts toward greater use of corn, favoring niche expansion. In stark contrast, when beetles were given a choice of resources, we found that competition caused niche contraction onto the ancestral resource. This presents a puzzling mismatch between how competition alters the fitness landscape, versus competition's effects on resource use. We discuss several explanations for this mismatch, highlighting potential reasons why optimality models might be misleading.
Chalvet, Fabienne; Netter, Sophie; Dos Santos, Nicolas; Poisot, Emilie; Paces-Fessy, Mélanie; Cumenal, Delphine; Peronnet, Frédérique; Pret, Anne-Marie; Théodore, Laurent
The potential to produce new cells during adult life depends on the number of stem cell niches and the capacity of stem cells to divide, and is therefore under the control of programs ensuring developmental homeostasis. However, it remains generally unknown how the number of stem cell niches is controlled. In the insect ovary, each germline stem cell (GSC) niche is embedded in a functional unit called an ovariole. The number of ovarioles, and thus the number of GSC niches, varies widely among species. In Drosophila, morphogenesis of ovarioles starts in larvae with the formation of terminal filaments (TFs), each made of 8–10 cells that pile up and sort in stacks. TFs constitute organizers of individual germline stem cell niches during larval and early pupal development. In the Drosophila melanogaster subgroup, the number of ovarioles varies interspecifically from 8 to 20. Here we show that pipsqueak, Trithorax-like, batman and the bric-à-brac (bab) locus, all encoding nuclear BTB/POZ factors of the Tramtrack Group, are involved in limiting the number of ovarioles in D. melanogaster. At least two different processes are differentially perturbed by reducing the function of these genes. We found that when the bab dose is reduced, sorting of TF cells into TFs was affected such that each TF contains fewer cells and more TFs are formed. In contrast, psq mutants exhibited a greater number of TF cells per ovary, with a normal number of cells per TF, thereby leading to formation of more TFs per ovary than in the wild type. Our results indicate that two parallel genetic pathways under the control of a network of nuclear BTB factors are combined in order to negatively control the number of germline stem cell niches. PMID:23185495
Bonetti, Maria Fernanda; Wiens, John J
The evolution of climatic niche specialization has important implications for many topics in ecology, evolution and conservation. The climatic niche reflects the set of temperature and precipitation conditions where a species can occur. Thus, specialization to a limited set of climatic conditions can be important for understanding patterns of biogeography, species richness, community structure, allopatric speciation, spread of invasive species and responses to climate change. Nevertheless, the factors that determine climatic niche width (level of specialization) remain poorly explored. Here, we test whether species that occur in more extreme climates are more highly specialized for those conditions, and whether there are trade-offs between niche widths on different climatic niche axes (e.g. do species that tolerate a broad range of temperatures tolerate only a limited range of precipitation regimes?). We test these hypotheses in amphibians, using phylogenetic comparative methods and global-scale datasets, including 2712 species with both climatic and phylogenetic data. Our results do not support either hypothesis. Rather than finding narrower niches in more extreme environments, niches tend to be narrower on one end of a climatic gradient but wider on the other. We also find that temperature and precipitation niche breadths are positively related, rather than showing trade-offs. Finally, our results suggest that most amphibian species occur in relatively warm and dry environments and have relatively narrow climatic niche widths on both of these axes. Thus, they may be especially imperilled by anthropogenic climate change. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Dueñas, Fernando; Becerra, Víctor; Cortes, Yennifer; Vidal, Sonia; Sáenz, Leonardo; Palomino, Jaime; De Los Reyes, Mónica; Peralta, Oscar A
Mesenchymal stem cells (MSC) are multipotent progenitor cells characterized by their ability to both self-renew and differentiate into tissues of mesodermal origin. The plasticity or transdifferentiation potential of MSC is not limited to mesodermal derivatives, since under appropriate cell culture conditions and stimulation by bioactive factors, MSC have also been differentiated into endodermal (hepatocytes) and neuroectodermal (neurons) cells. The potential of MSC for hepatogenic and neurogenic differentiation has been well documented in different animal models; however, few reports are currently available on large animal models. In the present study we sought to characterize the hepatogenic and neurogenic differentiation and multipotent potential of bovine MSC (bMSC) isolated from bone marrow (BM) of abattoir-derived fetuses. Plastic-adherent bMSC isolated from fetal BM maintained a fibroblast-like morphology under monolayer culture conditions. Flow cytometric analysis demonstrated that bMSC populations were positive for MSC markers CD29 and CD73 and pluripotency markers OCT4 and NANOG; whereas, were negative for hematopoietic markers CD34 and CD45. Levels of mRNA of hepatic genes α-fetoprotein (AFP), albumin (ALB), alpha1 antitrypsin (α1AT), connexin 32 (CNX32), tyrosine aminotransferase (TAT) and cytochrome P450 (CYP3A4) were up-regulated in bMSC during a 28-Day period of hepatogenic differentiation. Functional analyses in differentiated bMSC cultures evidenced an increase (P < 0.05) in albumin and urea production and glycogen storage. bMSC cultured under neurogenic conditions expressed NESTIN and MAP2 proteins at 24 h of culture; whereas, at 144 h also expressed TRKA and PrPC. Levels of MAP2 and TRKA mRNA were up-regulated at the end of the differentiation period. Conversely, bMSC expressed lower levels of NANOG mRNA during both hepatogenic and neurogenic differentiation processes. The expression patterns of linage-specific markers and the production of
Nogues, David Bravo
Predicting past distributions of species climatic niches, hindcasting, by using climate envelope models (CEMs) is emerging as an exciting research area. CEMs are used to examine veiled evolutionary questions about extinctions, locations of past refugia and migration pathways, or to propose...... the theoretical assumptions behind niche modelling and using inadequate methods for hindcasting CEMs may well entail a cascade of errors and naïve ecological and evolutionary inferences. We should also push integrative research lines linking macroecology, physiology, population biology, palaeontology......, evolutionary biology and CEMs for a better understanding of niche dynamics across space and time....
We use the Hotelling's model allowing for a "gap" in the consumers' preferences. As a result, the characteristics space is divided in two separate intervals. The largest one represents the main market, and the smallest represents a niche. We find that in this set up the principle of maximum differentiation may not hold. We also, examine the incentives of a firm to adopt a niche marketing strategy. That is, to relocate and price its product so that to maximize its profits from the niche market...
Lowrey, B; Garrott, R A; McWhirter, D E; White, P J; DeCesare, N J; Stewart, S T
The niche concept provides a strong foundation for theoretical and applied research among a broad range of disciplines. When two ecologically similar species are sympatric, theory predicts they will occupy distinct ecological niches to reduce competition. Capitalizing on the increasing availability of spatial data, we built from single species habitat suitability models to a multispecies evaluation of the niche partitioning hypothesis with sympatric mountain ungulates - native bighorn sheep (BHS; Ovis canadensis) and introduced mountain goats (MTG; Oreamnos americanus) in the northeast Greater Yellowstone Area. We characterized seasonal niches using two-stage resource selection functions with a used-available design and descriptive summaries of the niche attributes associated with used GPS locations. We evaluated seasonal similarity in niche space according to confidence interval overlap of model coefficients and similarity in geographic space by comparing model predicted values with Schoener's D metric. Our sample contained 37,962 summer locations from 53 individuals (BHS = 31, MTG = 22), and 79,984 winter locations from 57 individuals (BHS = 35, MTG = 22). Slope was the most influential niche component for both species and seasons, and showed the strongest evidence of niche partitioning. Bighorn sheep occurred on steeper slopes than mountain goats in summer and mountain goats occurred on steeper slopes in winter. The pattern of differential selection among species was less prevalent for the remaining covariates, indicating similarity in niche space. Model predictions in geographic space showed broad seasonal similarity (summer D = 0.88, winter D = 0.87), as did niche characterizations from used GPS locations. The striking similarities in seasonal niches suggest that introduced mountain goats will continue to increase their spatial overlap with native bighorn. Our results suggest that reducing densities of mountain goats in hunted areas where they are sympatric
Dorn, David C; Dorn, August
The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon
Dorn, David C; Dorn, August
The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon
This paper is about the evolution of hominin intelligence. I agree with defenders of the social intelligence hypothesis in thinking that externalist models of hominin intelligence are not plausible: such models cannot explain the unique cognition and cooperation explosion in our lineage, for changes in the external environment (e.g. increasing environmental unpredictability) affect many lineages. Both the social intelligence hypothesis and the social intelligence-ecological complexity hybrid I outline here are niche construction models. Hominin evolution is hominin response to selective environments that earlier hominins have made. In contrast to social intelligence models, I argue that hominins have both created and responded to a unique foraging mode; a mode that is both social in itself and which has further effects on hominin social environments. In contrast to some social intelligence models, on this view, hominin encounters with their ecological environments continue to have profound selective effects. However, though the ecological environment selects, it does not select on its own. Accidents and their consequences, differential success and failure, result from the combination of the ecological environment an agent faces and the social features that enhance some opportunities and suppress others and that exacerbate some dangers and lessen others. Individuals do not face the ecological filters on their environment alone, but with others, and with the technology, information and misinformation that their social world provides.
Higgins, Steven I; Richardson, David M
Invasive species cost the global economy billions of dollars each year, but ecologists have struggled to predict the risk of an introduced species naturalizing and invading. Although carefully designed experiments are needed to fully elucidate what makes some species invasive, much can be learned from unintentional experiments involving the introduction of species beyond their native ranges. Here, we assess invasion risk by linking a physiologically based species distribution model with data on the invasive success of 749 Australian acacia and eucalypt tree species that have, over more than a century, been introduced around the world. The model correctly predicts 92% of occurrences observed outside of Australia from an independent dataset. We found that invasiveness is positively associated with the projection of physiological niche volume in geographic space, thereby illustrating that species tolerant of a broader range of environmental conditions are more likely to be invasive. Species achieve this broader tolerance in different ways, meaning that the traits that define invasive success are context-specific. Hence, our study reconciles studies that have failed to identify the traits that define invasive success with the urgent and pragmatic need to predict invasive success.
Mann, Ethan E.; Wozniak, Daniel J.
Biofilms are a predominant form of growth for bacteria in the environment and in the clinic. Critical for biofilm development are adherence, proliferation, and dispersion phases. Each of these stages includes reinforcement by, or modulation of, the extracellular matrix. Pseudomonas aeruginosa has been a model organism for the study of biofilm formation. Additionally, other Pseudomonas species utilize biofilm formation during plant colonization and environmental persistence. Pseudomonads produce several biofilm matrix molecules, including polysaccharides, nucleic acids, and proteins. Accessory matrix components shown to aid biofilm formation and adaptability under varying conditions are also produced by pseudomonads. Adaptation facilitated by biofilm formation allows for selection of genetic variants with unique and distinguishable colony morphology. Examples include rugose small-colony variants and wrinkly spreaders (WS), which over produce Psl/Pel or cellulose, respectively, and mucoid bacteria that over produce alginate. The well-documented emergence of these variants suggests that pseudomonads take advantage of matrix-building subpopulations conferring specific benefits for the entire population. This review will focus on various polysaccharides as well as additional Pseudomonas biofilm matrix components. Discussions will center on structure–function relationships, regulation, and the role of individual matrix molecules in niche biology. PMID:22212072
Litsios, Glenn; Kostikova, Anna; Salamin, Nicolas
Why generalist and specialist species coexist in nature is a question that has interested evolutionary biologists for a long time. While the coexistence of specialists and generalists exploiting resources on a single ecological dimension has been theoretically and empirically explored, biological systems with multiple resource dimensions (e.g. trophic, ecological) are less well understood. Yet, such systems may provide an alternative to the classical theory of stable evolutionary coexistence of generalist and specialist species on a single resource dimension. We explore such systems and the potential trade-offs between different resource dimensions in clownfishes. All species of this iconic clade are obligate mutualists with sea anemones yet show interspecific variation in anemone host specificity. Moreover, clownfishes developed variable environmental specialization across their distribution. In this study, we test for the existence of a relationship between host-specificity (number of anemones associated with a clownfish species) and environmental-specificity (expressed as the size of the ecological niche breadth across climatic gradients). We find a negative correlation between host range and environmental specificities in temperature, salinity and pH, probably indicating a trade-off between both types of specialization forcing species to specialize only in a single direction. Trade-offs in a multi-dimensional resource space could be a novel way of explaining the coexistence of generalist and specialists. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Soley-Guardia, Mariano; Gutiérrez, Eliécer E; Thomas, Darla M; Ochoa-G, José; Aguilera, Marisol; Anderson, Robert P
Correlative ecological niche models (ENMs) estimate species niches using occurrence records and environmental data. These tools are valuable to the field of biogeography, where they are commonly used to infer potential connectivity among populations. However, a recent study showed that when locally relevant environmental data are not available, records from patches of suitable habitat protruding into otherwise unsuitable regions (e.g., gallery forests within dry areas) can lead to overestimations of species niches and their potential distributions. Here, we test whether this issue obfuscates detection of an obvious environmental barrier existing in northern Venezuela - that of the hot and xeric lowlands separating the Península de Paraguaná from mainland South America. These conditions most likely promote isolation between mainland and peninsular populations of three rodent lineages occurring in mesic habitat in this region. For each lineage, we calibrated optimally parameterized ENMs using mainland records only, and leveraged existing habitat descriptions to assess whether those assigned low suitability values corresponded to instances where the species was collected within locally mesic conditions amidst otherwise hot dry areas. When this was the case, we built an additional model excluding these records. We projected both models onto the peninsula and assessed whether they differed in their ability to detect the environmental barrier. For the two lineages in which we detected such problematic records, only the models built excluding them detected the barrier, while providing additional insights regarding peninsular populations. Overall, the study reveals how a simple procedure like the one applied here can deal with records problematic for ENMs, leading to better predictions regarding the potential effects of the environment on lineage divergence.
Laland, Kevin N; Odling-Smee, John; Gilbert, Scott F
Evolutionary developmental biology and niche-construction theory have much in common, despite independent intellectual origins. Both place emphasis on the role of ontogenetic processes in evolution. The same historical events shaped them, and similar philosophical and sociological barriers hindered their respective advances. Both perspectives maintain that neo-Darwinism needs a theory of macroevolutionary variation and that such a theory can now be adduced from developmental biology. Some proponents of both EvoDevo and niche construction propose additional evolutionary mechanisms, and specify a key role for stable extra-genetic forms of inheritance. Similarly, proponents of each lay emphasis on "reciprocal causation" in the relationship between organism and environment. We illustrate here how EvoDevo and niche construction could gain "added value" from each other, and demonstrate how the niche-construction perspective potentially provides a useful conduit to integrate evolutionary and developmental biology. Copyright 2008 Wiley-Liss, Inc.
Rompolas, Panteleimon; Greco, Valentina
Hair follicles are skin appendages of the mammalian skin that have the ability to periodically and stereotypically regenerate in order to continuously produce new hair over our lifetime. The ability of the hair follicle to regenerate is due to the presence of stem cells that along with other cell populations and non-cellular components, including molecular signals and extracellular material, make up a niche microenvironment. Mounting evidence suggests that the niche is critical for regulating stem cell behavior and thus the process of regeneration. Here we review the literature concerning past and current studies that have utilized mouse genetic models, combined with other approaches to dissect the molecular and cellular composition of the hair follicle niche. We also discuss our current understanding of how stem cells operate within the niche during the process of tissue regeneration and the factors that regulate their behavior. PMID:24361866
Ugarte, Fernando; Forsberg, E Camilla
Haematopoietic stem cell (HSC) niches provide an environment essential for life-long HSC function. Intense investigation of HSC niches both feed off and drive technology development to increase our capability to assay functionally defined cells with high resolution. A major driving force behind the desire to understand the basic biology of HSC niches is the clear implications for clinical therapies. Here, with particular emphasis on cell type-specific deletion of SCL and CXCL12, we focus on unresolved issues on HSC niches, framed around some very recent advances and novel discoveries on the extrinsic regulation of HSC maintenance. We also provide ideas for possible paths forward, some of which are clearly within reach while others will require both novel tools and vision. PMID:24022369
HOWARD VAN AUKEN; SHAWN CARRAHER
This paper examines the flow of funds from providers of capital to niche agricultural users of capital. Various programs through the US government, state/local economic development and private agencies work to improve the flow of capital to the niche agricultural sector. However, despite the expansion of programs aimed at providing financial resources to the agricultural sector, many sectors remain poorly served. Previous studies have suggested that agencies need to facilitate the flow of cap...
Theys, Catherine; De Nil, Luc; Thijs, Vincent; van Wieringen, Astrid; Sunaert, Stefan
Neurogenic stuttering is an acquired speech disorder characterized by the occurrence of stuttering-like dysfluencies following brain damage. Because the onset of stuttering in these patients is associated with brain lesions, this condition provides a unique opportunity to study the neural processes underlying speech dysfluencies. Lesion localizations of 20 stroke subjects with neurogenic stuttering and 17 control subjects were compared using voxel-based lesion symptom mapping. The results showed nine left-hemisphere areas associated with the presence of neurogenic stuttering. These areas were largely overlapping with the cortico-basal ganglia-cortical network comprising the inferior frontal cortex, superior temporal cortex, intraparietal cortex, basal ganglia, and their white matter interconnections through the superior longitudinal fasciculus and internal capsule. These results indicated that stroke-induced neurogenic stuttering is not associated with neural dysfunction in one specific brain area but can occur following one or more lesion throughout the cortico-basal ganglia-cortical network. It is suggested that the onset of neurogenic stuttering in stroke subjects results from a disintegration of neural functions necessary for fluent speech. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.
Aguilée, Robin; Shaw, Frank H; Rousset, François; Shaw, Ruth G; Ronce, Ophélie
In heterogeneous landscapes, the genetic and demographic consequences of dispersal influence the evolution of niche width. Unless pollen is limiting, pollen dispersal does not contribute directly to population growth. However, by disrupting local adaptation, it indirectly affects population dynamics. We compare the effect of pollen versus seed dispersal on the evolution of niche width in heterogeneous habitats, explicitly considering the feedback between maladaptation and demography. We consider two scenarios: the secondary contact of two subpopulations, in distinct, formerly isolated habitats, and the colonization of an empty habitat with dispersal between the new and ancestral habitat. With an analytical model, we identify critical levels of genetic variance leading to niche contraction (secondary contact scenario), or expansion (new habitat scenario). We confront these predictions with simulations where the genetic variance freely evolves. Niche contraction occurs when habitats are very different. It is faster as total gene flow increases or as pollen predominates in overall gene flow. Niche expansion occurs when habitat heterogeneity is not too high. Seed dispersal accelerates it, whereas pollen dispersal tends to retard it. In both scenarios very high seed dispersal leads to extinction. Overall, our results predict a wider niche for species dispersing seeds more than pollen. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Lane, Steven W; Williams, David A; Watt, Fiona M
The field of regenerative medicine holds considerable promise for treating diseases that are currently intractable. Although many researchers are adopting the strategy of cell transplantation for tissue repair, an alternative approach to therapy is to manipulate the stem cell microenvironment, or niche, to facilitate repair by endogenous stem cells. The niche is highly dynamic, with multiple opportunities for intervention. These include administration of small molecules, biologics or biomaterials that target specific aspects of the niche, such as cell-cell and cell–extracellular matrix interactions, to stimulate expansion or differentiation of stem cells, or to cause reversion of differentiated cells to stem cells. Nevertheless, there are several challenges in targeting the niche therapeutically, not least that of achieving specificity of delivery and responses. We envisage that successful treatments in regenerative medicine will involve different combinations of factors to target stem cells and niche cells, applied at different times to effect recovery according to the dynamics of stem cell–niche interactions. PMID:25093887
Escobar, Luis E; Craft, Meggan E
Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches for disease mapping can fail to generate robust study designs, producing incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables), identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks.
Chen, Yang; Song, Feifei; Lu, Guoping; Lu, Zhujin
Neurogenic pulmonary edema (NPE ) was indicative of poor prognosis in the epidemic of enterovirus 71 infections. The pathogenesis of NPE remains poorly understood. The objectives of this experimental study were to explore whether RAS is activated during NPE in rabbit models induced by fibrin and the effects of an angiotensin converting enzyme inhibitor (enalaprilat) on NPE. NPE models were induced by intracisternal injection of fibrinogen and thrombin. According to random number table method, 18 healthy adult New Zealand rabbits were assigned to three groups (with 6 in each) : normal control group (Con group), NPE group and enalaprilat treated (Ena) group. After establishment of NPE models, rabbits in Ena group were given intravenous enalaprilat 0.5 mg/kg. Expression of ACE,ACE2,AT1R mRNA of the lung tissue were evaluated by real-time polymerise chain reaction; and Ang II of the lung tissue was determined by enzyme linked immunosorbent assay ( ELISA ). Meanwhile, histopathological lung injury scores were evaluated. ACE mRNA expression level in NPE group ( 17.2 ± 3.3) appeared an increasing trend in contrast to Con group ( 12.6 ± 5.2 ) and Ena group ( 11.5 ± 2.4, both P > 0.05 ). Compared with Con group (81 ± 22 ), ACE2 mRNA expression levels of NPE group ( 52 ± 6 ) and Ena group ( 45 ± 13 ) both decreased ( both P 0.05). Lung AngII level of NPE group [(540 ± 147) pg/ml] was significantly higher than that of Con group [(253 ± 37 ) pg/ml] and Ena group [(309 ± 35 ) pg/ml, both P edema fluid appeared in the tracheal tubes in NPE group, but spontaneously appeared in neither Con group nor Ena group; and the level of pulmonary subpleural bleeding in Con group, 12 graded 0; in NPE group, 2 graded II, 10 graded III; in Ena group, 2 graded, 8 grade II, 2 grade III. The histopathologic lung injury scores in Ena group was decreased in contrast to NPE group (1.36 ± 0.26 vs.2.32 ± 0.49, P edema. The present study showed that when NPE occurs, a high lung Ang
Flamini, Valentina; Ghadiali, Rachel S; Antczak, Philipp; Rothwell, Amy; Turnbull, Jeremy E; Pisconti, Addolorata
Satellite cells are adult muscle stem cells residing in a specialized niche that regulates their homeostasis. How niche-generated signals integrate to regulate gene expression in satellite cell-derived myoblasts is poorly understood. We undertook an unbiased approach to study the effect of the satellite cell niche on satellite cell-derived myoblast transcriptional regulation and identified the tumor suppressor p53 as a key player in the regulation of myoblast quiescence. After activation and proliferation, a subpopulation of myoblasts cultured in the presence of the niche upregulates p53 and fails to differentiate. When satellite cell self-renewal is modeled ex vivo in a reserve cell assay, myoblasts treated with Nutlin-3, which increases p53 levels in the cell, fail to differentiate and instead become quiescent. Since both these Nutlin-3 effects are rescued by small interfering RNA-mediated p53 knockdown, we conclude that a tight control of p53 levels in myoblasts regulates the balance between differentiation and return to quiescence. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.
Schewe, Matthias; Sacchetti, Andrea; Schmitt, Mark; Fodde, Riccardo
The intestinal epithelium is characterized by an extremely rapid turnover rate. In mammals, the entire epithelial lining is renewed within 4 - 5 days. Adult intestinal stem cells reside at the bottom of the crypts of Lieberkühn, are earmarked by expression of the Lgr5 gene, and preserve homeostasis through their characteristic high proliferative rate 1 . Throughout the small intestine, Lgr5 + stem cells are intermingled with specialized secretory cells called Paneth cells. Paneth cells secrete antibacterial compounds (i.e., lysozyme and cryptdins/defensins) and exert a controlling role on the intestinal flora. More recently, a novel function has been discovered for Paneth cells, namely their capacity to provide niche support to Lgr5 + stem cells through several key ligands as Wnt3, EGF, and Dll1 2 . When isolated ex vivo and cultured in the presence of specific growth factors and extracellular matrix components, whole intestinal crypts give rise to long-lived and self-renewing 3D structures called organoids that highly resemble the crypt-villus epithelial architecture of the adult small intestine 3 . Organoid cultures, when established from whole crypts, allow the study of self-renewal and differentiation of the intestinal stem cell niche, though without addressing the contribution of its individual components, namely the Lgr5 + and Paneth cells. Here, we describe a novel approach to the organoid assay that takes advantage of the ability of Paneth and Lgr5 + cells to associate and form organoids when co-cultured. This approach, here referred to as "organoid reconstitution assay" (ORA), allows the genetic and biochemical modification of Paneth or Lgr5 + stem cells, followed by reconstitution into organoids. As such, it allows the functional analysis of the two main components of the intestinal stem cell niche.
Ni, Jianshu; Wang, Xiaohu; Cao, Nailong; Si, Jiemin; Gu, Baojun
To investigate the value of repeat botulinum toxin A (BTX-A) injections in patients with neurogenic detrusor overactivity (NDO). We searched the PubMed, EMBASE, and EBSCO databases for articles published until June 2016. Studies that reported the efficacy and safety of repeat BTX-A injections for adult patients with NDO were eligible. The effect size for each outcome was calculated as the standardized mean difference ± standard error and 95% confidence interval, and was graded as small, >0.2; moderate, >0.5; or large, >0.8. The outcomes included maximum cystometric capacity (MCC), maximum detrusor pressure (MDP), reflex volume (RV), bladder compliance (BC), quality of life (QOL), and injection interval. Descriptive reviews were performed for urinary incontinence (UI) and adverse events (AEs). Eighteen studies involving 1533 patients whose level of evidence ranged from 3 to 4 were included in this study. We noted non-significant changes in MCC, MDP, RV, and BC between the first and last injections. Patients who had received ≤4 injections were found to have stable QOL improvements after the first and last injections, whereas patients who had received ≥5 injections were found to have a significant decrease in QOL after the last injection. No significant differences in injection intervals were noted after repeat BTX-A injections, and the repeat injection failure rate was low. Our study demonstrated that repeat BTX-A injections allow sustained improvements in patients with NDO. The rate of AEs was stable and low. However, additional high-quality, large-scale, and long-term trials are necessary to establish the efficacy and safety of ≥5 repeat BTX-A injections. © 2017 Wiley Periodicals, Inc.
Darouiche, Rabih O; Green, Bruce G; Donovan, William H; Chen, David; Schwartz, Michael; Merritt, John; Mendez, Michelle; Hull, Richard A
To compare the effectiveness of bacterial interference versus placebo in preventing urinary tract infection (UTI). The main outcome measure was the numbers of episodes of UTI/patient-year. Randomization was computer generated, with allocation concealment by visibly indistinguishable products distributed from a core facility. The healthcare providers and those assessing the outcomes were unaware of the group allocation. Adult patients (n = 65) with neurogenic bladder after spinal cord injury and a history of recurrent UTI were randomized in a 3:1 ratio to receive either Escherichia coli HU2117 or sterile saline. Urine cultures were obtained weekly during the first month and then monthly for 1 year. The patients were evaluable if they remained colonized with E. coli HU2117 for >4 weeks (experimental group). The trial is closed to follow-up. Of the 59 patients who received bladder inoculations, 27 were evaluable (17 in the experimental group and 10 in the placebo group). The 2 study groups had comparable clinical characteristics. Of 17 patients colonized with E. coli HU2117 and the 10 control patients, 5 (29%, 95% confidence interval 0.11-0.56) and 7 (70%, 95% confidence interval 0.35-0.92) developed >1 episode of UTI (P = .049; 1-sided Fisher's exact test), respectively. The average number of episodes of UTI/patient-year was also lower (P = .02, Wilcoxon rank sum test) in the experimental (0.50) than in the control group (1.68). E. coli HU2117 did not cause symptomatic UTI. Bladder colonization with E. coli HU2117 safely reduces the risk of symptomatic UTI in patients with spinal cord injury. Effective, but less complex, methods for achieving bladder colonization with E. coli HU2117 are under investigation. Published by Elsevier Inc.
Wang, Jianhuo; Hou, Chunlin; Zheng, Xianyou; Xu, Zhen; Wang, Wanhong; Lin, Haodong
To study major influential factors of the micturition alert device dedicated to neurogenic bladders for the product design and clinical application of the device. One ferrite permanent magnet with thickness and diameter of 3 mm and 10 mm, respectively, and three NdFeB permanent magnets with the thickness of 3 mm and diameter of 10, 15 and 20 mm, respectively, were used. The effects of thickness of the abdominal wall as well as the position and type of permanent magnets on the micturition alert device dedicated to neurogenic bladders were measured in vitro simulated test, when the abdominal wall was set to 2, 3, 4, 5, 6, 7, 8 and 9 cm, respectively, and the position of permanent magnets was 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 cm, respectively. The effect of the geomagnetic field on the device was measured under the condition that the thickness of the simulated abdominal wall was set to 2, 3, 4 and 5 cm, respectively, and the position of permanent magnets was 2, 3, 4, 5, 6, 7, 8, 9 and 10 cm, respectively. The value showed in the warning unit was positively correlated with the position of the ferrite permanent magnet only when the thickness of the simulated abdominal wall was 2 cm (r=0.632, P NdFeB permanent magnets was significant (r > 0.622, P NdFeB permanent magnets, but weakened with the increasing thickness of the simulated abdominal wall. The effect of the geomagnetic field was correlated with the exposition of the body, the position of the permanent magnet and the thickness of the abdominal wall. The major influential factors of the micturition alert device dedicated to neurogenic bladder include the magnetism and location of the permanent magnet, the thickness of the abdominal wall and the geomagnetic field. These factors are correlated with and affect each other. Reasonable allocation of these factors may optimize the device.
Zaragoza Torres, Raúl Ignacio; Galarza-Flores, Mario Eduardo; Gómez-Castellanos, Julio Cesar; Barrera-de León, Juan Carlos
Augmentation cystoplasty is a successful surgical procedure for the management of neurogenic bladder in children in order to improve urodynamic parameters. The aim of this article is to describe urodynamic changes after augmentation cystoplasty in children with myelomeningocele. A descriptive cross-sectional study including children aged 8-16 years with a myelomeningocele operated on for augmentation cystoplasty surgery with sigmoid colon segments due to a neurogenic bladder from the years 2003-2013. A urodynamic study was conducted before and after the surgical procedure. Non-probabilistic sample of consecutive cases. Descriptive statistics with frequencies and percentages, medians, and ranges. Inferential intra-group comparison with the Wilcoxon test and inter-group with Mann-Whitney U. SPSS 20.0 statistical package. The study included 50 patients, of whom 25 were male and 25 were female, with a median age of 12 years (range, 6-15 years). Bladder capacity improved from 52.8% to 95.9% (p<0.001), uninhibited contractions 1.4-1.8, contraction intensity 47-8.5 (p<0.001), mean pre-surgical and post-surgical filling pressure 40.8cm H2O and 11.0cm H2O, respectively (p<0.001), mean emptying pressure 48.5 vs. 3.6cm H2O (p<0.001), and bladder accommodation 4.6 vs. 41.3cm H2O (p<0.001). Augmentation cystoplasty with sigmoid colon significantly improved urodynamic parameters, such as bladder accommodation and filling pressure in children with myelomeningocele-associated neurogenic bladder. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Henriet, B; Roumeguère, T
OAB is common with a potential negative impact on quality of life. Anticholinergics and β3-mimetics are the first-line medical treatment. This treatment meets only 50% of patients given a lack of efficacy and adverse effects. Used in the treatment of neurogenic overactive bladder, botulinum toxin is now evaluated for the treatment of refractory non-neurogenic overactive bladder. The objective of this work is to review the literature data concerning the efficacy and safety of intradetrusor botulinum toxin injections to treat refractory idiopathic overactive bladder. A systematic literature review was conducted to identify articles published between May 1988 and April 2013 in Medline for the treatment of refractory idiopathic overactive bladder with botulinum toxin. 37 studies with original samples were selected including 8 randomized controlled trials against placebo. The effectiveness of intra- detrusor injections is demonstrated to reduce the frequency, urgency, nighttime urination, incontinence episodes and to improve bladder capacity and quality of life. The most common side effects are incomplete bladder emptying, intermittent catheterization and increased risk of urinary tract infection. A dose of 100 to 150 U of onabotulinumtoxinA allows the best compromise between efficiency and tolerance. Duration of the effects varies between 3 to 12 months and repeating the injections did not seem to affect the efficiency. Injections including the trigone zone do not cause vesicoureteral reflux. The absence of detrusor hyperactivity does not alter the clinical response. The detrusor injections of botulinum toxin can be considered as an effective second-line treatment for refractory non-neurogenic overactive bladder. Information on intermittent catheterization risk must be provided. The very long-term effectiveness and the absence of urothelium alterations are still outstanding issues.
Balsara, Zarine R; Ross, Sherry S; Dolber, Paul C; Wiener, John S; Tang, Yuping; Seed, Patrick C
Neurogenic bladder predisposes to recurrent urinary tract infections (UTI) and renal failure, and susceptibility is commonly ascribed to urinary stasis from elevated residual urine volumes. Escherichia coli UTI was modeled in the spinal cord-injured (SCI) rat with the hypothesis that SCI animals would require fewer bacteria to establish infection, have an exaggerated inflammatory response, and have delayed clearance of infection compared to normal-voiding controls. T10 SCI rats and controls had median infectious doses (ID50) of 10(2) and 10(5) CFU, respectively. Mean residual volumes in the SCI animals did not correlate with susceptibility to initiation of UTI or outcome. In the acute infection, control and SCI rats developed acute cystitis and pyelitis without acute differences in histopathological scores of inflammation. However, in vivo imaging of infected animals revealed persistently higher levels of bacteria in the SCI urine and bladders than were seen for controls over 2 weeks. Likewise, at 2 weeks, acute and chronic inflammatory infiltrates persisted in the bladders and kidneys of SCI rats, whereas inflammation largely resolved within the controls. Together these data demonstrate that SCI rats exhibit delayed clearance of infection and exaggerated inflammatory responses in bladders and kidneys; however, the severity of residual volumes does not predict increased susceptibility to UTI. These studies suggest that host-dependent mechanisms that are discrete from alterations in bladder physiology influence UTI susceptibility with the SCI-neurogenic bladder. This model will allow elucidation of SCI-neurogenic bladder-mediated changes in host response that yield UTI susceptibility and may lead to new preventative and therapeutic options.
Madersbacher, H; Mürtz, G
Propiverine hydrochloride (propiverine) is a compound that has neurotropic and musculotropic effects on the urinary bladder smooth muscle. Controlled clinical trials have shown its effectiveness in treating detrusor hyperreflexia and in treating patients with symptoms of an overactive bladder: this is true not only for adults but in children and the elderly as well. European and Japanese studies have also documented that propiverine is well tolerated. It is better tolerated than oxybutynin (particularly in regard to frequency and severity of dryness of the mouth). In several Japanese studies authors demonstrated that propiverine is well tolerated on a long-term basis. Voigt reported an adverse event incidence rate of 13% in a follow-up investigation during 10 years of treatment. A post-marketing drug surveillance consisting of 4390 patients provided additional data concerning efficacy and safety of propiverine. It is one of the few drugs recommended for the treatment of detrusor overactivity by the Committee on Pharmacological Treatment during the First International Consultation on Incontinence.
Šedý, Jiří; Urdzíková, Lucia; Likavčanová, Katarína; Hejčl, A.; Jendelová, Pavla; Syková, Eva
Roč. 423, - (2007), s. 167-171 ISSN 0304-3940 R&D Projects: GA MŠk 1M0538; GA MŠk(CZ) LC554; GA ČR GA309/06/1246 Grant - others:EU(FR) 518233; GA MZd(CZ) 1A8697 Institutional research plan: CEZ:AV0Z50390703 Source of funding: R - rámcový projekt EK Keywords : Isoflurane * Neurogenic pulmonary edema * Spinal cord injury Subject RIV: FH - Neurology Impact factor: 2.085, year: 2007
Denard, Patrick J.; Holton, Kathleen F.; Miller, Jessica; Fink, Howard A.; Kado, Deborah M.; Marshall, Lynn M.; Yoo, Jung U.
Background Context Degenerative spondylolisthesis is a presumed cause of back pain. Previous studies of spondylolisthesis and back pain included only women or combined results for men and women. Comparisons of the frequency of back pain, neurogenic symptoms, and functional limitations specifically among elderly men with and without spondylolisthesis are needed. Purpose To determine associations of prevalent spondylolisthesis with back pain symptoms, neurogenic symptoms, and functional limitations among elderly men. Study Design/ Setting: Cross-sectional epidemiologic study conducted within the Osteoporotic Fractures in Men (MrOS) cohort. The MrOS cohort is comprised of 5,995 community dwelling men ages ≥65 years who were recruited at 6 US academic medical centers. Extensive self-reported data and lumbar spine radiographs were obtained for all MrOS participants at baseline. Patient Sample For this study, 300 men were selected at random specifically for the evaluation of spondylolisthesis on the baseline spine radiographs. Outcome Measures Standardized questionnaires were used to assess self-reported back pain, leg pain (radiculopathy), lower extremity numbness (paresthesias) and lower extremity weakness occurring in the past 12 months, and to ascertain current difficulty with activities of daily living. Methods In the present study, radiographic spondylolisthesis was classified as forward slip of ≥5%. Prevalence of back pain, neurogenic symptoms and difficulty with activities of daily living were compared between men with and without spondylolisthesis using chisquare or Fisher’s exact tests. Results Spondylolisthesis was present among 92 (31%) men. Among men with and without spondylolisthesis, back pain (63% vs. 67%, p=0.46) and moderate/severe back pain (41% vs. 38%, p=0.76) were reported with similar frequency. Men with spondylolisthesis more often reported radiculopathy (33% vs. 22%, p=0.06), paresthesias (18% vs. 11%, p= 0.10) and weakness (18% vs. 9%, p=0
Fode, Mikkel; Ohl, Dana A; Sønksen, Jens
is most commonly associated with spinal cord injury. This aetiology is especially relevant because most men with spinal cord injuries are injured at reproductive age. Assisted ejaculation in the form of penile vibratory stimulation is the first choice for sperm retrieval in such patients because......Normal fertility is dependent on intravaginal delivery of semen through ejaculation. This process is highly dependent on an intact ejaculatory reflex arc, which can be disrupted through any type of trauma or disease causing damage to the CNS and/or peripheral nerves. Neurogenic anejaculation...
A.J.M.W. Vervoort; L.F. Van der Voet; M. Witmer; A.L. Thurkow; C.M. Radder; P.J.M. van Kesteren; H.W.P. Quartero; W.K.H. Kuchenbecker (Walter); M.Y. Bongers; P.M.A.J. Geomini; L.H.M. de Vleeschouwer (Marloes); M.H.A. van Hooff (Marcel); H.A. van Vliet; S. Veersema (S.); W.B. Renes; H.S. van Meurs (Hannah); J. Bosmans (Johan); K.O. Rengerink (Katrien Oude); H.A.M. Brölmann (H. A M); B.W.J. Mol (Ben W.J.); J.A.F. Huirne (Judith)
textabstractBackground: A caesarean section (CS) can cause a defect or disruption of the myometrium at the site of the uterine scar, called a niche. In recent years, an association between a niche and postmenstrual spotting after a CS has been demonstrated. Hysteroscopic resection of these niches is
Vervoort, A. J. M. W.; van der Voet, L. F.; Witmer, M.; Thurkow, A. L.; Radder, C. M.; van Kesteren, P. J. M.; Quartero, H. W. P.; Kuchenbecker, W. K. H.; Bongers, M. Y.; Geomini, P. M. A. J.; de Vleeschouwer, L. H. M.; van Hooff, M. H. A.; van Vliet, H. A. A. M.; Veersema, S.; Renes, W. B.; van Meurs, H. S.; Bosmans, J.; Oude Rengerink, K.; Brölmann, H. A. M.; Mol, B. W. J.; Huirne, J. A. F.
A caesarean section (CS) can cause a defect or disruption of the myometrium at the site of the uterine scar, called a niche. In recent years, an association between a niche and postmenstrual spotting after a CS has been demonstrated. Hysteroscopic resection of these niches is thought to reduce
religious concerns, convenience, food safety, and food quality issues. Opportunities exist to develop niche marketing opportunities for fresh goat with local ethnic or faith based populations.
Full Text Available BACKGROUND: The adult endocrine pituitary is known to host several hormone-producing cells regulating major physiological processes during life. Some candidates to progenitor/stem cells have been proposed. However, not much is known about pituitary cell renewal throughout life and its homeostatic regulation during specific physiological changes, such as puberty or pregnancy, or in pathological conditions such as tumor development. PRINCIPAL FINDINGS: We have identified in rodents and humans a niche of non-endocrine cells characterized by the expression of GFRa2, a Ret co-receptor for Neurturin. These cells also express b-Catenin and E-cadherin in an oriented manner suggesting a planar polarity organization for the niche. In addition, cells in the niche uniquely express the pituitary-specific transcription factor Prop1, as well as known progenitor/stem markers such as Sox2, Sox9 and Oct4. Half of these GPS (GFRa2/Prop1/Stem cells express S-100 whereas surrounding elongated cells in contact with GPS cells express Vimentin. GFRa2+-cells form non-endocrine spheroids in culture. These spheroids can be differentiated to hormone-producing cells or neurons outlining the neuroectoderm potential of these progenitors. In vivo, GPSs cells display slow proliferation after birth, retain BrdU label and show long telomeres in its nuclei, indicating progenitor/stem cell properties in vivo. SIGNIFICANCE: Our results suggest the presence in the adult pituitary of a specific niche of cells characterized by the expression of GFRa2, the pituitary-specific protein Prop1 and stem cell markers. These GPS cells are able to produce different hormone-producing and neuron-like cells and they may therefore contribute to postnatal pituitary homeostasis. Indeed, the relative abundance of GPS numbers is altered in Cdk4-deficient mice, a model of hypopituitarism induced by the lack of this cyclin-dependent kinase. Thus, GPS cells may display functional relevance in the
Laland, Kevin; Odling-Smee, John; Endler, John
Organisms modify and choose components of their local environments. This 'niche construction' can alter ecological processes, modify natural selection and contribute to inheritance through ecological legacies. Here, we propose that niche construction initiates and modifies the selection directly affecting the constructor, and on other species, in an orderly, directed and sustained manner. By dependably generating specific environmental states, niche construction co-directs adaptive evolution by imposing a consistent statistical bias on selection. We illustrate how niche construction can generate this evolutionary bias by comparing it with artificial selection. We suggest that it occupies the middle ground between artificial and natural selection. We show how the perspective leads to testable predictions related to: (i) reduced variance in measures of responses to natural selection in the wild; (ii) multiple trait coevolution, including the evolution of sequences of traits and patterns of parallel evolution; and (iii) a positive association between niche construction and biodiversity. More generally, we submit that evolutionary biology would benefit from greater attention to the diverse properties of all sources of selection.
Eckstein, Susan; Nguyen, Thanh-Nghi
The article addresses how Vietnamese immigrant women developed an urban employment niche in the beauty industry, in manicuring. They are shown to have done so by creating a market for professional nail care, through the transformation of nailwork into what might be called McNails, entailing inexpensive, walk-in, impersonal service, in stand-alone salons, nationwide, and by making manicures and pedicures de riguer across class and racial strata. Vietnamese are shown to have simultaneously gained access to institutional means to surmount professional manicure credentializing barriers, and to have developed formal and informal ethnic networks that fueled their growing monopolization of jobs in the sector, to the exclusion of non-Vietnamese. The article also elucidates conditions contributing to the Vietnamese build-up and transformation of the niche, to the nation-wide formation of the niche and, most recently, to the transnationalization of the niche. It also extrapolates from the Vietnamese manicure experience propositions concerning the development, expansion, maintenance, and transnationalization of immigrant-formed labor market niches.
Nikkels, C; Vervoort, Anke J M W; Mol, Ben Willem; Hehenkamp, Wouter J K; Huirne, Judith A F; Brölmann, Hans A M
The research objective of the current systematic literature review is to classify the laparoscopic niche repair according to the IDEAL framework of 'innovation stages' and to recommend the required research setting to facilitate safe and properly timed implementation of the technique. In doing so, we are also able to evaluate the practical applicability of the IDEAL framework. A systematic search of the available literature on laparoscopic niche repair was performed in PubMed, Embase, and the Wiley/Cochrane library. Articles were classified according to the IDEAL framework and recommendations were given on additional required research before the technique can be safely implemented. Practical applicability of the IDEAL framework was also evaluated. Introduction of laparoscopic niche repair matches Idea (1) and Development (2a), according to the stages of IDEAL framework, although most studies are retrospective and complications have not been registered structurally in a considerable number of the articles. As feasibility and safety have been more or less established and surgery has been further developed we enter stage 2b (Exploration) and need prospective trials preferably comparing the effectiveness of laparoscopic niche repair to expectant management, the current standard care. Available studies were classified with the use of the IDEAL framework, achieving an overall IDEAL stage to be 2a Development. As clinical outcomes, though poorly registered, have been substantially improved, laparoscopic niche repair needs to be carried forward by more advanced study designs. Copyright © 2017 Elsevier B.V. All rights reserved.
Mak, Sunny; Klinkenberg, Brian; Bartlett, Karen; Fyfe, Murray
Cryptococcus gattii emerged on Vancouver Island, British Columbia (BC), Canada, in 1999, causing human and animal illness. Environmental sampling for C.gattii in southwestern BC has isolated the fungal organism from native vegetation, soil, air, and water. Our aim was to help public health officials in BC delineate where C.gattii is currently established and forecast areas that could support C.gattii in the future. We also examined the utility of ecological niche modeling (ENM) based on human and animal C.gattii disease surveillance data. We performed ENM using the Genetic Algorithm for Rule-set Prediction (GARP) to predict the optimal and potential ecological niche areas of C.gattii in BC. Human and animal surveillance and environmental sampling data were used to build and test the models based on 15 predictor environmental data layers. ENM provided very accurate predictions (> 98% accuracy, p-value models identified optimal C.gattii ecological niche areas along the central and south eastern coast of Vancouver Island and within the Vancouver Lower Mainland. Elevation, biogeoclimatic zone, and January temperature were good predictors for identifying the ecological niche of C.gattii in BC. The use of human and animal case data for ENM proved useful and effective in identifying the ecological niche of C.gattii in BC. These results are shared with public health to increase public and physician awareness of cryptococcal disease in regions at risk of environmental colonization of C.gattii.
Balás, I; Llumiguano, C; Horvath, Z; Kovér, F; Dóczi, T P
Medial thalamotomy is one of the first stereotactic operations to have been used for neurogenic pain, has a low complication rate and no risk of the development of iatrogenic neurogenic pain. It represents selective local relief for all types of pain, without causing somatosensorial deficit. We did 39 posteromedial thalamotomies in patients with persistent intractable pain due to various disorders. The pain was assessed pre- and postoperatively on the VAS (Visual Analogic Scale). Half of the patients operated on had relief of pain after thalamotomy. In 84% (n = 39) of our cases this relief occurred on the second day, in 70% (n = 35) after three months, in 63% (n = 27) after six months, in 64% (n = 25) after nine months, in 62% (n = 23) of the patients after 12 months, and in 62% (n = 22) after 24 months. Three patients had temporary complications and one a permanent complication, but this did not make him an invalid. Posteromedial stereotactic thalamotomy under MR guidance can provide safe, effective treatment for persistent, intractable pain.
Liu, Yanli; Yang, Fen; Liang, Shengying; Liu, Qing; Fu, Sulei; Wang, Zhenyu; Yang, Ciqing; Lin, Juntang
Peripheral nerve injuries are typically caused by either trauma or medical disorders, and recently, stem cell-based therapies have provided a promising treatment approach. Menstrual blood-derived endometrial stem cells (MenSCs) are considered an ideal therapeutic option for peripheral nerve repair due to a noninvasive collection procedure and their high proliferation rate and immunological tolerance. Here, we successfully isolated MenSCs and examined their biological characteristics including their morphology, multipotency, and immunophenotype. Subsequent in vitro studies demonstrated that MenSCs express high levels of neurotrophic factors, such as NT3, NT4, BDNF, and NGF, and are capable of transdifferentiating into glial-like cells under conventional induction conditions. Moreover, upregulation of N-cadherin (N-cad) mRNA and protein expression was observed after neurogenic differentiation. In vivo studies clearly showed that N-cad knockdown via in utero electroporation perturbed the migration and maturation of mouse neural precursor cells (NPCs). Finally, a further transfection assay also confirmed that N-cad upregulation in MenSCs results in the expression of S100. Collectively, our results confirmed the paracrine effect of MenSCs on neuroprotection as well as their potential for transdifferentiation into glial-like cells and demonstrated that N-cad upregulation promotes the neurogenic differentiation of MenSCs, thereby providing support for transgenic MenSC-based therapy for peripheral nerve injury.
Full Text Available ABSTRACT Erectile dysfunction (ED is a common complication of pelvic fractures. To identify the vascular and neurogenic factors associated with ED, 120 patients admitted with ED after traumatic pelvic fracture between January 2009 and June 2013 were enrolled in this study. All patients answered the International Index of Erectile Function (IIEF-5 questionnaire. Nocturnal penile tumescence (NPT testing confirmed the occurrence of ED in 96 (80% patients on whom penile duplex ultrasound and neurophysiological testing were further performed. Of these ED patients 29 (30% were demonstrated only with vascular abnormality, 41 (42.7% were detected only with neural abnormality, 26 (27.1% revealed mixed abnormalities. Of the 55 patients (29+26 with vascular problems, 7 patients (12.7% with abnormal arterial response to intracavernous injection of Bimix (15mg papaverine and 1mg phentolamine, 31 (56.4% with corporal veno-occlusive dysfunction and 17 (30.9% had both problems. Of the 67 (41+26 patients with abnormal neurophysiological outcomes, 51 (76.1% with abnormal bulbocavernosus reflex (BCR, 20 (29.9% with pathological pudendal nerve evoked potentials (PDEPs and 25 (37.3% with abnormal posterior tibial somatosensory nerve evoked potentials (PTSSEPs. Our observation indicated that neurogenic factors are important for the generation of ED in patients with pelvic fracture; venous impotence is more common than arteriogenic ED.
Cruz, Francisco; Nitti, Victor
Following use of botulinum toxin in the 1980s for the treatment of detrusor sphincter dyssynergia in patients with spinal cord injury (SCI), the potential therapeutic value of this neurotoxin in urology has been the subject of much interest. The DIGNITY (Double-blind InvestiGation of purified Neurotoxin complex In neurogenic deTrusor overactivitY) clinical research program aimed to compare onabotulinumtoxinA with placebo in terms of efficacy and safety in patients with neurogenic detrusor overactivity (NDO) due to SCI or multiple sclerosis. The EMBARK clinical research program mirrored these aims in patients with overactive bladder with urinary incontinence (UI). Each program comprised two phase III, randomized, placebo-controlled studies. In all four trials, primary efficacy endpoints were met, and significant benefits of onabotulinumtoxinA versus placebo were demonstrated across a range of secondary endpoints, including measures of health-related quality of life. The most common adverse event across both programs was urinary tract infection. Interim analyses of data from ongoing long-term extensions to these phase III trials have provided promising evidence for the efficacy of repeated injections. While further investigation is recommended to enrich the dataset, the available evidence indicates that onabotulinumtoxinA provides an effective treatment option for these two populations, which were previously considered very difficult to treat. © 2014 Wiley Periodicals, Inc.
Weglinski, L; Rouzaud, C; Even, A; Bouchand, F; Davido, B; Duran, C; Salomon, J; Perronne, C; Denys, P; Chartier-Kastler, E; Dinh, A
Patients presenting with neurogenic bladder often require urological procedures (urodynamic testing and botulinum toxin injections) and a preventive antibiotic therapy. We aimed to assess the efficacy of this little known strategy in a cohort of patients. All patients presenting with neurogenic bladder who underwent urological procedure were included in the study. They received an antibiotic therapy in accordance with the urine cytobacteriological examination results. The antibiotic therapy was initiated two days before the procedure and prolonged up until two days after the procedure if the culture was positive. Patients were treated with a single dose of fosfomycin-trometamol in case of a negative culture. The main study outcome was the occurrence of urinary tract infection (UTI), defined by a positive urine culture and symptoms, up until 14 days after the procedure. A total of 80 urological procedures were performed. Mean patient age was 47±13.1 years (sex ratio 1.22); 59 (73.8%) presented with asymptomatic bacteriuria before the procedure. Nine (11.1%) UTIs were recorded on Day 14, of which one (1.2%) was febrile. Two patients required an additional curative antibiotic therapy. No patient was hospitalized. Overall, 77.8% of UTIs were cured without antibiotic therapy. Screening and treating asymptomatic bacteriuria before urological procedures seems unnecessary and vainly exposes this population at high risk of infectious diseases to antibiotic therapies. This data should be confirmed by a randomized clinical trial. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Hansen, Eva Lund; Hvistendahl, Gitte Møller; Rawashdeh, Yazan F H; Olsen, L Henning
We evaluated the long-term outcome of bladder autoaugmentation in children with neurogenic bladder dysfunction. Data were compiled from the records of 25 children with a median age of 9.3 years (range 0.9 to 14.2) who underwent detrusor myotomy between 1992 and 2008. All patients were diagnosed with small bladder capacity, low compliance and high end filling pressures, and were unresponsive to clean intermittent catheterization and anticholinergics. Median followup was 6.8 years (range 0.1 to 15.6). Median postoperative bladder capacity was unchanged or decreased to 95 ml (range 25 to 274) during the first 3 months compared to a median preoperative capacity of 103 ml (14 to 250). At 5 months postoperatively median bladder capacity increased significantly to 176 ml (range 70 to 420, pbladder compliance doubled after 1 year to 10 ml/cm H2O (range 1 to 31, pBladder autoaugmentation in children with neurogenic bladder dysfunction offers, after a transient decrease in bladder capacity, a long lasting increase in capacity and compliance, while the end filling pressure decreases. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Full Text Available Domenico A Restivo,1 Shaheen Hamdy2 1Neurological Unit, Garibaldi Hospital, Catania, Italy; 2School of Translational Medicine—Inflammation Sciences, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK Abstract: Neurogenic dysphagia (ND can occur in patients with nervous system diseases of varying etiologies. Moreover, recovery from ND is not guaranteed. The therapeutic approaches for oropharyngeal ND have drastically changed over the last decade, mainly due to a better knowledge of the neurophysiology of swallowing along with the progress of neuroimaging and neurophysiological studies. For this reason, it is a priority to develop a treatment that is repeatable, safe, and can be carried out at the bedside as well as for outpatients. Pharyngeal electrical stimulation (PES is a novel rehabilitation treatment for ND. PES is carried out via location-specific intraluminal catheters that are introduced transnasally and enable clinicians to stimulate the pharynx directly. This technique has demonstrated increasingly promising evidence in improving swallowing performance in patients with ND associated with stroke and multiple sclerosis, probably by increasing the corticobulbar excitability and inducing cortical reorganization of swallowing motor cortex. In this article, we update the reader as to both the physiologic background and past and current studies of PES in an effort to highlight the clinical progress of this important technique. Keywords: pharyngeal electrical stimulation, swallowing, neurogenic dysphagia, swallowing motor cortex, pharynx, catheter
Ji Hee Kim
Full Text Available Objective. To investigate the effects and safety of the aqueous extract of the dried, immature fruit of Poncirus trifoliata (L. Raf., known as Poncirus fructus (PF, in spinal cord injury (SCI patients with neurogenic bowel. Methods. Thirty-one SCI patients with neurogenic bowel were recruited. Patients were evaluated based on clinical information, constipation score, Bristol Stool Form Scale, stool retention score using plain abdominal radiograph, and colon transit time. PF was administered in dosages of 800 mg each prior to breakfast and lunch for 14 days. Results. The morphological feature of the stool before and after administration indicated a statistically significant difference from 3.52 ± 1.33 to 4.32 ± 1.44 points (p<0.05. Stool retention score before and after administration of PF was represented with low significance (7.25 ± 1.60 to 6.46 ± 1.53 points in the whole colon (p<0.05, and the colon transit time was significantly shortened (57.41 ± 20.7 to 41.2 ± 25.5 hours in terms of the whole transit time (p<0.05. Side effects were observed in 7 people (28.0% consisting of 2 people with soft stools and 5 people with diarrhea. Conclusion. For SCI patients, PF administration significantly improved defecation patterns, defecation retention, and colon transit time. PF could be an effective aid to improve colonic motility and constipation.
Queenborough, Simon A; Burslem, David F R P; Garwood, Nancy C; Valencia, Renato
In order to differentiate between mechanisms of species coexistence, we examined the relative importance of local biotic neighbourhood, abiotic habitat factors and species differences as factors influencing the survival of 2330 spatially mapped tropical tree seedlings of 15 species of Myristicaceae in two separate analyses in which individuals were identified first to species and then to genus. Using likelihood methods, we selected the most parsimonious candidate models as predictors of 3 year seedling survival in both sets of analyses. We found evidence for differential effects of abiotic niche and neighbourhood processes on individual survival between analyses at the genus and species levels. Niche partitioning (defined as an interaction of taxonomic identity and abiotic neighbourhood) was significant in analyses at the genus level, but did not differentiate among species in models of individual seedling survival. By contrast, conspecific and congeneric seedling and adult density were retained in the minimum adequate models of seedling survival at species and genus levels, respectively. We conclude that abiotic niche effects express differences in seedling survival among genera but not among species, and that, within genera, community and/or local variation in adult and seedling abundance drives variation in seedling survival. These data suggest that different mechanisms of coexistence among tropical tree taxa may function at different taxonomic or phylogenetic scales. This perspective helps to reconcile perceived differences of importance in the various non-mutually exclusive mechanisms of species coexistence in hyper-diverse tropical forests.
Ji, Jiang; Ho, Bryan Siu-Yin; Qian, Ge; Xie, Xiao-Ming; Bigliardi, Paul Lorenz; Bigliardi-Qi, Mei
Hair graying and hair loss are prominent and common characteristics of the elderly population. In some individuals these processes can significantly impact their quality of life, leading to depression, anxiety and other serious mental health problems. Accordingly, there has been much interest in understanding the complex physiological changes within the hair follicle in the aging individual. It is now known that hair follicles represent a prototypical stem cell niche, where both micro- and macroenvironmental influences are integrated alongside stem cell-stem cell and stem cell-stem niche interactions to determine hair growth or hair follicle senescence. Recent studies have identified imbalanced stem cell differentiation and altered stem cell activity as important factors during hair loss, indicating new avenues for the development of therapeutic agents to stimulate hair growth. Here, we pull together the latest findings on the hair follicle stem cell niche and the multifactorial interactions underlying the various forms of hair loss. © 2017 Japanese Dermatological Association.
Asada, Noboru; Takeishi, Shoichiro; Frenette, Paul S
Hematopoietic stem cells (HSCs) that produce a variety of hematopoietic lineage cells throughout the life reside in specialized microenvironment called "niche" in the bone marrow (BM) where they are tightly regulated. With the recent advances in experimental technologies enabling the selective deletion of molecules, various types of cells in the BM have been proposed to contribute to HSC niche activity. Among these are stromal cells closely associated with the vasculature. In this review, we provide an overview of recent advances in HSC niche research, and focus on the studies describing the functional roles of perivascular cells for HSC maintenance and mobilization. Not only for physiologic state, we also discuss the recent evidences suggesting the importance of microenvironment for emergence of malignant hematopoietic diseases.
Beniamin G. BOŞCAI
Full Text Available Based on technological evolution and a very large number of users, the Internet plays a key role in attracting talented employees which can generate competitive advantage for the organization. Therefore nowadays niche websites, specialised recruitment sites, become increasingly important. With the creation of such sites also appeared several applications for recruiting. The purpose of this paper is to analyze these sites and applications in order to determine the advantages and disadvantages of specialised recruitment websites (1, career sites of organizations (2 social professional sites (3 . Using these online recruitment tools lead to the development of e-recruitment. Our conclusion is that these websites do not represent yet a universal solution for organizations although the number of users is growing. For being successful in the recruitment process, recruiters have to combine niche websites in recruiting and not use only one type of niche websites.
Full Text Available The intestinal epithelium comprises a monolayer of polarised columnar cells organised along the crypt-villus axis. Intestinal stem cells reside at the base of crypts and are constantly nourished by their surrounding niche for maintenance, self-renewal, and differentiation. The cellular microenvironment including the adjacent Paneth cells, stromal cells, smooth muscle cells, and neural cells as well as the extracellular matrix together constitute the intestinal stem cell niche. A dynamic regulatory network exists among the epithelium, stromal cells, and the matrix via complex signal transduction to maintain tissue homeostasis. Dysregulation of these biological or mechanical signals could potentially lead to intestinal injury and disease. In this review, we discuss the role of different intestinal stem cell niche components and dissect the interaction between dynamic matrix factors and regulatory signalling during intestinal stem cell homeostasis.
Full Text Available Abstract Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases.
Godoy, Oscar; Bartomeus, Ignasi; Rohr, Rudolf P; Saavedra, Serguei
The quest for understanding how species interactions modulate diversity has progressed by theoretical and empirical advances following niche and network theories. Yet, niche studies have been limited to describe coexistence within tropic levels despite incorporating information about multi-trophic interactions. Network approaches could address this limitation, but they have ignored the structure of species interactions within trophic levels. Here we call for the integration of niche and network theories to reach new frontiers of knowledge exploring how interactions within and across trophic levels promote species coexistence. This integration is possible due to the strong parallelisms in the historical development, ecological concepts, and associated mathematical tools of both theories. We provide a guideline to integrate this framework with observational and experimental studies. Copyright © 2018 Elsevier Ltd. All rights reserved.
Full Text Available Sporadic mitochondrial DNA mutations serve as clonal marks providing access to the identity and lineage potential of stem cells within human tissues. By combining quantitative clonal mapping with 3D reconstruction of adult human prostates, we show that multipotent basal stem cells, confined to discrete niches in juxta-urethral ducts, generate bipotent basal progenitors in directed epithelial migration streams. Basal progenitors are then dispersed throughout the entire glandular network, dividing and differentiating to replenish the loss of apoptotic luminal cells. Rare lineage-restricted luminal stem cells, and their progeny, are confined to proximal ducts and provide only minor contribution to epithelial homeostasis. In situ cell capture from clonal maps identified delta homolog 1 (DLK1 enrichment of basal stem cells, which was validated in functional spheroid assays. This study establishes significant insights into niche organization and function of prostate stem and progenitor cells, with implications for disease.
Marco A.L. Zuffi
Full Text Available Trophic niche of the Italian wall lizard was studied at three different sites in Tuscany (central northern Italy, two along the Mediterranean sea, one inland. Fecal pellet analysis was carried out on 71 pellets (37 of male and 34 of female adult lizards, accounting on the whole for 184 prey items. Coleoptera, Hymenoptera (ants, Araneae and Gastropoda were the most represented taxa (numerical abundance of ca 22, 7, 7, 6% respectively. We found Brillouin diversity index similar in females and in males, with a marked overlap between sexes, but differences in niche overlapping among localities. Diet spectrum was quite different with that found in other central Italy localities, in the Tuscan Archipelago, or in areas where P. siculus has recently introduced. Our study confirms the opportunistic pattern and adaptability of this lizard species, and increases the range of sampled localities within the species’ range.
Latchney, Sarah E; Calvi, Laura M
The hematopoietic system has the remarkable ability to provide a lifelong supply of mature cells that make up the entire blood and immune system. However, similar to other adult stem cell niches, the hematopoietic system is vulnerable to the detrimental effects of aging. This is a substantial health concern as the trend for population aging continues to increase. Identifying mechanisms that underlie hematopoietic aging is vital for understanding hematopoietic-related diseases. In this review, we first discuss the cellular hierarchy of the hematopoietic system and the components that make up the surrounding hematopoietic niche. We then provide an overview of the major phenotypes associated with hematopoietic aging and discuss recent research investigating cell-intrinsic and cell-extrinsic mechanisms of hematopoietic stem cell (HSCs) aging. We end by discussing the exciting new concept of possibly reversing the HSC aging process along with outstanding questions that remain to be answered. Copyright © 2017 Elsevier Inc. All rights reserved.
Wald, Heidi L; Bandle, Brian; Richard, Angela A; Min, Sung-Joon; Capezuti, Elizabeth
Catheter-associated urinary tract infection (CAUTI) risk is directly related to duration of indwelling urinary catheters (IUCs), rising beyond 2 days of catheterization. We conducted a cluster randomized study in nonintensive care units of Nurses Improving Care for Healthsystem Elders (NICHE) hospitals. Electronic surveillance data were used in an audit and feedback intervention for frontline nurses to reduce IUC duration. Multivariable methods were used to identify the difference in average IUC duration and proportion of patients with IUC duration hospital characteristics. A total of 24 units at 19 NICHE hospitals reported 13,499 adult patients with IUCs over 18 months. Early and delayed intervention groups had important baseline differences in IUC utilization. Use of evidence-based CAUTI prevention measures increased during study participation. In multivariable analysis, the average IUC duration and proportion of patients with IUC duration Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Karlson, Agnes M L; Reutgard, Martin; Garbaras, Andrius; Gorokhova, Elena
The isotopic niche has become an established concept in trophic ecology. However, the assumptions behind this approach have rarely been evaluated. Evidence is accumulating that physiological stress can affect both magnitude and inter-individual variability of the isotopic signature in consumers via alterations in metabolic pathways. We hypothesized that stress factors (inadequate nutrition, parasite infestations, and exposure to toxic substances or varying oxygen conditions) might lead to suboptimal physiological performance and altered stable isotope signatures. The latter can be misinterpreted as alterations in isotopic niche. This hypothesis was tested by inducing physiological stress in the deposit-feeding amphipod Monoporeia affinis exposed to either different feeding regimes or contaminated sediments. In the amphipods, we measured body condition indices or reproductive output to assess growth status and δ 13 C and δ 15 N values to derive isotope niche metrics. As hypothesized, greater isotopic niche estimates were derived for the stressed animals compared to the control groups. Moreover, the δ 15 N values were influenced by body size, reproductive status and parasite infestations, while δ 13 C values were influenced by body size, oxygen conditions and survival. Using regression analysis with isotope composition and growth variables as predictors, we were able to discriminate between the amphipods exposed to nutritionally or chemically stressful conditions and those in the control groups. Thus, interpretation of isotopic niche can be confounded by natural or anthropogenic stressors that may induce an apparent change in isotopic niche. These findings stress the importance of including measures of growth and health status when evaluating stable isotope data in food web studies.
Høye, Anette M; Erler, Janine T
The aim of this review is to give an overview of the extracellular matrix (ECM) components that are important for creating structural changes in the premetastatic and metastatic niche. The successful arrival and survival of cancer cells that have left the primary tumor and colonized distant sites...... depends on the new microenvironment they encounter. The primary tumor itself releases factors into the circulation that travel to distant organs and then initiate structural changes, both non-enzymatic and enzymatic, to create a favorable niche for the disseminating tumor cells. Therapeutic strategies...
Nygaard, Ivan; Bolwig, Simon
, reduced access to locally specific technical and managerial information. The report presents an example of non-evolutionary niche development, which goes beyond the European experience of industrial niche development on which the MLP framework was first established. The importance of investors and policy...... attributes, including chain structure, governance, ownership, and access to land and capital. The study identifies significant entry barriers to establishing new agriculture-based value chains for global biofuel markets, especially high volume requirements, high capital needs and international market risks...
Vrijenhoek, Robert C.; Parker, Dave
hypotheses concerning the evolution of niche breadth in asexual species - the "general-purpose genotype" (GPG) and "frozen niche-variation" (FNV) models. The two models are often portrayed as mutually exclusive, respectively viewing clonal lineages as generalists versus specialists. Nonetheless......Clonally reproducing all-female lineages of plants and animals are often more frequent at higher latitudes and altitudes, on islands, and in disturbed habitats. Attempts to explain this pattern, known as geographical parthenogenesis, generally treat the parthenogens as fugitive species that occupy...
Bhattacharyya, Subhes C.
Renewable energies are considered as an essential element of any strategy for sustainable energy development. The poor in the developing world without access to modern energies are regarded as a major market for renewable energies. This short paper attempts to analyse whether such a niche is backed by any economic logic and whether renewable energy and the poor nexus could be a strategy for success. The paper suggests that contrary to the common belief, the economic logic behind the niche is unsound and that the nexus is not a recipe for success
Maitines, Gennaro; Ugenti, Ippazio; Memeo, Riccardo; Clemente, Nicola; Iambrenghi, Onofrio Caputi
Enteral nutrition can be administered via a nasogastric tube or, in selected patients, via a percutaneous endoscopic gastrostomy. In patients with neurogenic dysphagia, the choice of nutritional administration, and above all the timing, are crucial. Our aim was to retrospectively assess the impact of new guidelines for percutaneous endoscopic gastrostomy insertion adopted since January 2002 and compare them with our previous experience. From January 1992 to June 2007, 285 gastrostomies (168 M, 117 F) were positioned in our institute. We analysed 232 patients (139 M, 93 F) in whom a percutaneous endoscopic gastrostomy was applied for neurogenic dysphagia: Group A (from January 1992 to December 2001) consisting of 174 patients; Group B (from January 2002 to June 2007) consisting of 58 patients. The percutaneous endoscopic gastrostomy was positioned in all the cases with neurogenic dysphagia after a period of not less than 3 weeks of nutrition by nasogastric tube. A total of 6 major complications (2.3 %) occurred, almost all in group A. The mortality rate (3 patients, 2%) correlated with the complications in group A. In cases of neurogenic dysphagia we believe that greater methodological rigour in the multidisciplinary decision-making process, and a period of about 6-8 weeks' nutrition by nasogastric tube after the acute neurological damage may be useful to ensure a better prognostic evaluation of the patient and hence of the indications for percutaneous endoscopic gastrostomy.
Moojen, Wouter A.; Arts, Mark P.; Bartels, Ronald H. M. A.; Jacobs, Wilco C. H.; Peul, Wilco C.
Despite an increasing implantation rate of interspinous process distraction (IPD) devices in the treatment of intermittent neurogenic claudication (INC), definitive evidence on the clinical effectiveness of implants is lacking. The main objective of this review was to perform a meta-analysis of all
Vasudeva, Pawan; Madersbacher, Helmut
To comprehensively review factors implicated in the pathogenesis of urinary tract infection in patients with neurogenic bladders, and to stimulate research, especially in the somewhat ignored and forgotten areas of this important clinical subject. In addition to reviewing relevant articles on pubmed, some important articles from previous times which were not available online were also procured and reviewed. Intrinsic defence mechanisms including protective flora, anti-adherence mechanisms, urothelial, and immunological responses to bacterial binding and the blood supply to the urinary bladder may be impaired in patients with neurogenic bladders. Further, bacterial washout mechanisms may be compromised as a result of inefficient voiding, reflux, and altered hydrokinetics. Finally, catheterization itself contributes to urinary tract infection in patients with neurogenic bladders. In order to address the issue of urinary tract infection in patients with neurogenic bladders, multiple factors need to be looked into and corrected. Further research is required, especially in the area of compromised host defence mechanisms. An individualized approach, which attempts to optimize each factor is recommended. © 2013 Wiley Periodicals, Inc.
Blochin, Elen B; Park, Kay J; Tickoo, Satish K; Reuter, Victor E; Al-Ahmadie, Hikmat
Squamous cell carcinomas of the urinary bladder are rare in the Western world; the majority of cases are reported in countries endemic to Schistosoma parasitic infections. Unlike squamous tumors of the uterine cervix or oropharynx, the human papillomavirus (HPV) is not commonly associated with bladder squamous cell carcinomas. We report on two cases of HPV-positive urothelial carcinomas of the urinary bladder with extensive squamous differentiation showing the typical basaloid, poorly differentiated morphology of HPV-associated tumors. These occurred in patients with neurogenic bladders who had long-standing histories of self-catheterization with tumors that tested positive for HPV by in situ hybridization. A retrospective review of our institutional database revealed four additional patients with bladder tumors showing squamous differentiation arising in the setting of neurogenic bladder. Review of these cases showed the more common well-differentiated keratinizing appearance of squamous cell carcinomas of the bladder. These tumors showed only patchy positivity for p16 immunohistochemical stain (not the diffuse strong staining seen in HPV-positive tumors), and the one tested case was negative for HPV by in situ hybridization. HPV infection and neurogenic bladder have been independently associated with increased risk of developing carcinoma in the urinary bladder; however, this is the first report of squamous tumors arising in the setting of concurrent neurogenic bladder and HPV infection. The morphology of these tumors is similar to that of other high-risk HPV-associated squamous carcinomas with a basaloid, poorly differentiated appearance and little to no keratin formation.
Conclusions: For most patients and with close long-term follow-up, early treatment of neurogenic bladder using CIC in children born with myelomeningocele yields better results than late treatment. In our experience, treatment is recommended as soon as possible, especially during the first year of life.
Li, Xiao-Shi; Quan, Chang-Yi; Li, Gang; Cai, Qi-Liang; Hu, Bin; Wang, Jiu-Wei; Niu, Yuan-Jie
To study the etiology, clinical manifestation, diagnosis and treatment of giant prostatic calculus with neurogenic bladder disease and prostate diverticulum. We retrospectively analyzed the clinical data of a case of giant prostatic calculus with neurogenic bladder disease and prostate diverticulum and reviewed the relevant literature. The patient was a 37-year-old man, with urinary incontinence for 22 years and intermittent dysuria with frequent micturition for 9 years, aggravated in the past 3 months. He had received surgery for spina bifida and giant vesico-prostatic calculus. The results of preoperative routine urinary examination were as follows: WBC 17 -20/HPF, RBC 12 - 15/HPF. KUB, IVU and pelvic CT revealed spina bifida occulta, neurogenic bladder and giant prostatic calculus. The patient underwent TURP and transurethral lithotripsy with holmium-YAG laser. The prostatic calculus was carbonate apatite in composition. Urinary dynamic images at 2 weeks after surgery exhibited significant improvement in the highest urine flow rate and residual urine volume. Seventeen months of postoperative follow-up showed dramatically improved urinary incontinence and thicker urine stream. Prostate diverticulum with prostatic giant calculus is very rare, and neurogenic bladder may play a role in its etiology. Cystoscopy is an accurate screening method for its diagnosis. For the young patients and those who wish to retain sexual function, TURP combined with holmium laser lithotripsy can be employed, and intraoperative rectal examination should be taken to ensure complete removal of calculi.
Erdem, D.; Hava, D.; Keskinoglu, P.
Study design: Psychometrics study. Objectives: The aim of this study is to investigate the validity, reliability and sensitivity to change of neurogenic bowel dysfunction (NBD) score. Setting: Dokuz Eylul University Faculty of Medicine, Turkey. Methods: The study included 42 patients with spinal ...
... fluency disorders. Some communication disorders such as dysarthria, apraxia of speech, palilalia, and aphasia may impair the speaker’s ability ... that affect the intelligibility of the individuals speech Apraxia of speech—irregularities in the timing and inaccuracies in the ...
Yıldız, N; Akkoç, Y; Erhan, B; Gündüz, B; Yılmaz, B; Alaca, R; Gök, H; Köklü, K; Ersöz, M; Cınar, E; Karapolat, H; Catalbaş, N; Bardak, A N; Turna, I; Demir, Y; Güneş, S; Alemdaroğlu, E; Tunç, H
Multi-center, cross-sectional study. Our aim was to evaluate the treatment methods and follow-up of neurogenic bladder in patients with traumatic spinal cord injury retrospectively using a questionnaire. Turkey. Three hundred and thirty-seven patients who had spinal cord injury for at least 2 years were enrolled from six centers in the neurogenic bladder study group. They were asked to fill-out a questionnaire about treatments they received and techniques they used for bladder management. The study included 246 male and 91 female patients with a mean age of 42±14 years. Intermittent catheterization (IC) was performed in 77.9% of the patients, 3.8% had indwelling catheters, 13.8% had normal spontaneous micturition, 2.6% performed voiding maneuvers, 1.3% used diapers and 0.6% used condom catheters. No gender difference was found regarding the techniques used in bladder rehabilitation (P>0.05). Overall, 63.2% of patients used anticholinergic drugs; anticholinergic drug use was similar between genders (P>0.05). The most common anticholinergic drug used was oxybutynin (40.3%), followed by trospium (32.6%), tolterodine (19.3%) darifenacin (3.3%), propiverine (3.3%) and solifenacin (1.1%). The specialties of the physicians who first prescribed the anticholinergic drug were physiatrists (76.2%), urologists (22.1%) and neurologists (1.7%). Only four patients had previously received injections of botulinum-toxin-A into the detrusor muscle and three of them stated that their symptoms showed improvement. Most of the patients (77%) had regular follow-up examinations, including urine cultures, urinary system ultrasound and urodynamic tests, when necessary; the reasons for not having regular control visits were living distant from hospital (15.3%) and monetary problems (7.7%). Of the patients, 42.7% did not experience urinary tract infections (UTI), 36.4% had bacteriuria but no UTI episodes with fever, 15.9% had 1-2 clinical UTI episodes per year and 5% had ⩾3 clinical UTIs
Blok, Bertil F M; Karsenty, Gilles; Corcos, Jacques
To determine current trends in management and surveillance of the neurogenic bladder population by Canadian urologists who routinely work with and provide care for these patients. A questionnaire was mailed to members of the Canadian Urological Association. The assessment and follow-up of upper and lower urinary tract function in neurogenic bladder patients, their optimal frequency and management of related infections were the topics of inquiry. One hundred and five of 602 urologists responded, for a response rate of 18%. Twenty-three (22%) of the respondents did not treat neurogenic bladder patients. Four out of five urologists who treated these patients favored a yearly renal ultrasound for routine surveillance of the upper urinary tract and routinely performed urodynamic studies for evaluation of the lower tract. Only a relatively small percentage used videourodynamics. Clean intermittent catheterization (CIC) was preferred for the management of neurogenic bladder in patients with emptying difficulties. Asymptomatic urinary tract infection (UTI) was preferably not treated. Symptomatic UTI was treated with antibiotics for 7 to 10 days by about 75% of the responding urologists, while 23% of female patients and 9% of male patients were treated for less than 7 days. Although most of the urologists had access to established treatment modalities, like CIC education and bladder augmentation, only 30% made use of botulinum toxin injections. This study confirms that most urologists in Canada, working with neurogenic bladder patients, follow principles reported in the literature regarding the need for evaluation, surveillance, and management of the urinary tract. However, there is no consensus on the specific methods used for surveillance of the urinary system. The results emphasize the need for clear guidelines in this field of urology in Canada.
Righton, David A.; Andersen, Ken Haste; Neat, Francis
in those cod with a mean thermal history of between 8 and 10°C. Our direct observations of habitat occupation suggest that adult cod will be able to tolerate warming seas, but that climate change will affect cod populations at earlier life-history stages as well as exerting effects on cod prey species........ The data demonstrate that cod is an adaptable and tolerant species capable of surviving and growing in a wide range of temperate marine climates. The total thermal niche ranged from –1.5 to 19°C; this range was narrower (1 to 8°C) during the spawning season. Cod in each of the stocks studied had a thermal...... niche of approximately 12°C, but latitudinal differences in water temperature meant that cod in the warmer, southern regions experienced 3 times the degree days (DD; ~4000 DD yr–1) than individuals from northern regions (~1200 DD yr–1). Growth rates increased with temperature, reaching a maximum...
Full Text Available The spontaneous return of fertility after bone marrow transplantation or heterotopic grafting of cryopreserved ovarian cortical tissue has surprised many, and a possible link with stem cells has been proposed. We have reviewed the available literature on ovarian stem cells in adult mammalian ovaries and presented a model that proposes that the ovary harbors two distinct populations of stem cells, namely, pluripotent, quiescent, very small embryonic-like stem cells (VSELs, and slightly larger “progenitor” ovarian germ stem cells (OGSCs. Besides compromising the somatic niche, oncotherapy destroys OGSCs since, like tumor cells, they are actively dividing; however VSELs persist since they are relatively quiescent. BMT or transplanted ovarian cortical tissue may help rejuvenate the ovarian niche, which possibly supports differentiation of persisting VSELs resulting in neo-oogenesis and follicular development responsible for successful pregnancies. Postnatal oogenesis in mammalian ovary from VSELs may be exploited for fertility restoration in cancer survivors including those who were earlier deprived of gametes and/or gonadal tissue cryopreservation options.
Chiarini-Garcia, Hélio; Alves-Freitas, Daniel; Barbosa, Ivan S; Almeida, Fernanda R L C
Kinetics of spermatogonia as well as localization in niches have been described in rodents, but rarely in large animals or in species of economical interest. In this regard, and envisioning the possibility of spermatogonial transplantation from donkeys (Equus asinus) to mules (Equus mulus mulus), many variables that may contribute for an enhanced understanding of the spermatogonial biology in donkeys were investigated. Testes from five adult donkeys were routinely processed for high-resolution light microscopy. Donkey seminiferous epithelium can be divided in XII stages based on the development of the acrosomal system. In addition, spermatogonial morphology and morphometric analysis were performed allowing the characterization of two groups of spermatogonia: undifferentiated (A(und)) and differentiating (A(1), A(2), A(3), B(1) and B(2)). A(und) spermatogonia were present along all XII stages of the seminiferous epithelium cycle of this species, whereas differentiating spermatogonia were only at specific stages. Number of differentiating spermatogonia gradually increased as the cycle progressed, despite the apparent rigid regulation of the balance between mitosis and apoptosis throughout the spermatogenic process. Understanding of spermatogonial biology and kinetics in donkeys, revealed that type A(und) spermatogonia are located in specific microenvironments, the spermatogonial niches. The present results enhance understanding of spermatogonial biology in donkeys providing information about subtypes, morphology, number and mitosis/apoptosis along the seminiferous epithelium cycle.
Ramalingam, Pradeep; Poulos, Michael G; Butler, Jason M
Hematopoietic stem cells (HSCs) predominantly reside either in direct contact or in close proximity to the vascular endothelium throughout their lifespan. From the moment of HSC embryonic specification from hemogenic endothelium, endothelial cells (ECs) act as a critical cellular-hub that regulates a vast repertoire of biological processes crucial for HSC maintenance throughout its lifespan. In this review, we will discuss recent findings in endothelial niche-mediated regulation of HSC function during development, aging and regenerative conditions. Studies employing genetic vascular models have unequivocally confirmed that ECs provide the essential instructive cues for HSC emergence during embryonic development as well as adult HSC maintenance during homeostasis and regeneration. Aging of ECs may impair their ability to maintain HSC function contributing to the development of aging-associated hematopoietic deficiencies. These findings have opened up new avenues to explore the therapeutic application of ECs. ECs can be adapted to serve as an instructive platform to expand bona fide HSCs and also utilized as a cellular therapy to promote regeneration of the hematopoietic system following myelosuppressive and myeloablative injuries. ECs provide a fertile niche for maintenance of functional HSCs throughout their lifecycle. An improved understanding of the EC-HSC cross-talk will pave the way for development of EC-directed strategies for improving HSC function during aging.
Steinbauer, Manuel; Field, Richard; Fernández-Palacios, José María
Aim: Ecological niche concepts, in combination with biogeographic history, underlie our understanding of biogeographic ranges. Two pillars of this understanding are competitive displacement and niche conservatism. The competitive displacement hypothesis holds that very similar (e.g. closely relat...
Chepko, Gloria; Hilakivi-Clarke, Leena
Develop an immunohistochemical method for identifying stem cells and stem cell niches, and to use this to determine if in utero estrogenic overstimulation causes changes in the number of stem cells or their niches...
Auffret, Alistair G.; Meineri, Eric; Bruun, Hans Henrik
Background: Climate warming in arctic and alpine regions is expected to result in the altitudinal migration of plant species, but current predictions neglect differences between species' regeneration niche and established niche. Aims: To examine potential recruitment of Vaccinium myrtillus, V...
Individual variation and fitness are cornerstones of evolution by natural selection. The niche variation hypothesis (NVH) posits that when interspecific competition is relaxed, intraspecific competition should drive niche expansion by selection favoring use of novel resources. Po...
Birdwatching is a subsector of wildlife tourism that focuses explicitly on looking at bird populations. Over the past decade there has emerged a growing international literature about the role of birdwatching as a recreational activity and increasingly as a niche form of tourism. Recognition of the potential opportunities ...
Creanza, Nicole; Fogarty, Laurel; Feldman, Marcus W
Niche construction is a process through which organisms modify their environment and, as a result, alter the selection pressures on themselves and other species. In cultural niche construction, one or more cultural traits can influence the evolution of other cultural or biological traits by affecting the social environment in which the latter traits may evolve. Cultural niche construction may include either gene-culture or culture-culture interactions. Here we develop a model of this process and suggest some applications of this model. We examine the interactions between cultural transmission, selection, and assorting, paying particular attention to the complexities that arise when selection and assorting are both present, in which case stable polymorphisms of all cultural phenotypes are possible. We compare our model to a recent model for the joint evolution of religion and fertility and discuss other potential applications of cultural niche construction theory, including the evolution and maintenance of large-scale human conflict and the relationship between sex ratio bias and marriage customs. The evolutionary framework we introduce begins to address complexities that arise in the quantitative analysis of multiple interacting cultural traits.
The aim of the studies presented in this thesis was the search for niche differentiation between the ammonia-oxidizing bacteria in aquatic environments. Ammonia-oxidizing bacteria are chemolitho-autotrophic microorganisms responsible for the first, mostly rate-limiting step of the nitrification
Yu, Yang; Makowski, David; Stomph, Tjeerd Jan; Werf, van der Wopke
Intercropping has been shown to be land use efficient, but there is a large variation in the land equivalent ratio (LER) among studies. We used quantile regression to estimate the effect of temporal niche differentiation and its interaction with other key characteristics of intercropping, i.e.,
Jul 6, 2017 ... Keywords. niche construction; standard evolutionary theory; coevolution; natural selection; philosophy of biology; post-truth. In recent years, fairly ...... that the proximate cause of the architect's design has far greater explanatory power in ... general principle rather than a phenomenon that exists as a specific ...
Roets, F; Wingfield, M J; Crous, P W; Dreyer, L L
The floral heads (infructescences) of South African Protea L. represent a most unusual niche for fungi of the economically important genus Ophiostoma Syd. and P. Syd. emend. Z.W. de Beer et al. Current consensus holds that most members of Ophiostoma are vectored by tree-infesting bark beetles.
Symbiosis is a process that can generate evolutionary novelties and can extend the phenotypic niche space of organisms. Symbionts can act together with their hosts to co-construct host organs, within which symbionts are housed. Once established within hosts, symbionts can also influence various aspects of host ...
Lee, Jennifer C.
The increase in high-skilled immigrants to the United States coincided with the expansion of the high-technology sector, and now a large share of Asian immigrants concentrate in high-tech industries. Despite much research on the relationship between ethnic concentration and labor market outcomes, the association between ethnic niche employment and…
The data analysis was carried out using logistic regression models to evaluate the determinants of adoption of forages and production niches. Land tenure, access to formal education and experience in livestock farming positively and significantly (p < 0.1) influenced the adoption of forages. In contrast, distance to market, ...
A lucrative niche remains in a market increasingly dominated by managed care and cost containment. Many infertile women are willing to pay just about any price for infertility products, usually not covered by their insurers, writes Pamela Moore, managing editor of Healthcare Advertising Review.
Charles B. Yackulic; James D. Nichols; Janice Reid; Ricky Der
Ecologists frequently try to predict the future geographic distributions of species. Most studies assume that the current distribution of a species reflects its environmental requirements (i.e., the speciesâ niche). However, the current distributions of many species are unlikely to be at equilibrium with the current distribution of environmental conditions, both...
The differences and similarities between buffalo, zebra, wildebeest and white rhino, with respect to the variables characterizing their feeding localities, were determined using a discriminant function analysis. The dimensions of the community niche are described using the Latent Roots and their associated vectors extracted ...
Švandová, Eva; Veselá, Barbora; Šmarda, J.; Hampl, A.; Radlanski, R.J.; Matalová, Eva
Roč. 44, č. 5 (2015), s. 338-344 ISSN 0340-2096 R&D Projects: GA ČR GAP304/11/1418; GA ČR GCP302/12/J059 Institutional support: RVO:67985904 Keywords : c-Myb * stem cell niches Subject RIV: EA - Cell Biology Impact factor: 0.615, year: 2015
Bergamino, Leandro; Martínez, Ana; Han, Eunah; Lercari, Diego; Defeo, Omar
Stable isotopes (δ13C and δ15N) together with chlorophyll a and densities of surf diatoms were used to analyze changes in trophic niches of species in two sandy beaches of Uruguay with contrasting morphodynamics (i.e. dissipative vs. reflective). Consumers and food sources were collected over four seasons, including sediment organic matter (SOM), suspended particulate organic matter (POM) and the surf zone diatom Asterionellopsis guyunusae. Circular statistics and a Bayesian isotope mixing model were used to quantify food web differences between beaches. Consumers changed their trophic niche between beaches in the same direction of the food web space towards higher reliance on surf diatoms in the dissipative beach. Mixing models indicated that A. guyunusae was the primary nutrition source for suspension feeders in the dissipative beach, explaining their change in dietary niche compared to the reflective beach where the proportional contribution of surf diatoms was low. The high C/N ratios in A. guyunusae indicated its high nutritional value and N content, and may help to explain the high assimilation by suspension feeders at the dissipative beach. Furthermore, density of A. guyunusae was higher in the dissipative than in the reflective beach, and cell density was positively correlated with chlorophyll a only in the dissipative beach. Therefore, surf diatoms are important drivers in the dynamics of sandy beach food webs, determining the trophic niche space and productivity. Our study provides valuable insights on shifting foraging behavior by beach fauna in response to changes in resource availability.
Jul 6, 2017 ... Keywords. niche construction; standard evolutionary theory; coevolution; natural selection; philosophy of biology; post-truth. In recent years, fairly ... process in its own right, almost at par with natural selec- tion. Claims have .... depletion of available resources by an increasing popu- lation eventually has a ...
Van de Vliert, Evert
This commentary seeks to refine Kashima’s (2016) timely and topical but too-general call for embedding culture within the planetary ecosystem. My starting point is that cultures are to an underestimated extent ongoing niche constructions within the merry-go-round of the Sun’s radiation, the Earth’s
Full Text Available Niche construction is a process through which organisms modify their environment and, as a result, alter the selection pressures on themselves and other species. In cultural niche construction, one or more cultural traits can influence the evolution of other cultural or biological traits by affecting the social environment in which the latter traits may evolve. Cultural niche construction may include either gene-culture or culture-culture interactions. Here we develop a model of this process and suggest some applications of this model. We examine the interactions between cultural transmission, selection, and assorting, paying particular attention to the complexities that arise when selection and assorting are both present, in which case stable polymorphisms of all cultural phenotypes are possible. We compare our model to a recent model for the joint evolution of religion and fertility and discuss other potential applications of cultural niche construction theory, including the evolution and maintenance of large-scale human conflict and the relationship between sex ratio bias and marriage customs. The evolutionary framework we introduce begins to address complexities that arise in the quantitative analysis of multiple interacting cultural traits.
van der Voet, Lucy Lucet F.; Limperg, Tobias; Veersema, Sebastiaan; Timmermans, Anne; Bij de Vaate, A. Marjolein J.; Brölmann, Hans A. M.; Huirne, Judith A. F.
Objective: To study the prevalence of hysteroscopically evaluated disruptions of the integrity of the uterine wall ('niches') in women with and without a previous cesarean section. Study design: A prospective cohort study was performed in a teaching hospital in the Netherlands. Women seeking
D.A. Loorbach (Derk); R. van Raak (Ronald)
textabstractThis discussion paper sets out to compare two different, yet related, approaches to achieve sustainable development and (technological) innovation. Strategic Niche Management (SNM) (Kemp, Schot et al. 1998; Weber 1999) emerged as a novel concept by the end of the 1990’s and is presented
de Rooij, Dirk G.; Repping, S.; van Pelt, Ans M. M.
In this issue of Cell Stem Cell, Kanatsu-Shinohara et al. (2008) show that beta 1-integrin participates in normal spermatogenesis and is required for spermatogonial stem cell (SSC) homing to the basal membrane niche. The methodology used provides a powerful tool to study the role of other factors in
Altmann, Eduardo G; Pierrehumbert, Janet B; Motter, Adilson E
Patterns of word use both reflect and influence a myriad of human activities and interactions. Like other entities that are reproduced and evolve, words rise or decline depending upon a complex interplay between their intrinsic properties and the environments in which they function. Using Internet discussion communities as model systems, we define the concept of a word niche as the relationship between the word and the characteristic features of the environments in which it is used. We develop a method to quantify two important aspects of the size of the word niche: the range of individuals using the word and the range of topics it is used to discuss. Controlling for word frequency, we show that these aspects of the word niche are strong determinants of changes in word frequency. Previous studies have already indicated that word frequency itself is a correlate of word success at historical time scales. Our analysis of changes in word frequencies over time reveals that the relative sizes of word niches are far more important than word frequencies in the dynamics of the entire vocabulary at shorter time scales, as the language adapts to new concepts and social groupings. We also distinguish endogenous versus exogenous factors as additional contributors to the fates of words, and demonstrate the force of this distinction in the rise of novel words. Our results indicate that short-term nonstationarity in word statistics is strongly driven by individual proclivities, including inclinations to provide novel information and to project a distinctive social identity.
Eduardo G Altmann
Full Text Available Patterns of word use both reflect and influence a myriad of human activities and interactions. Like other entities that are reproduced and evolve, words rise or decline depending upon a complex interplay between their intrinsic properties and the environments in which they function. Using Internet discussion communities as model systems, we define the concept of a word niche as the relationship between the word and the characteristic features of the environments in which it is used. We develop a method to quantify two important aspects of the size of the word niche: the range of individuals using the word and the range of topics it is used to discuss. Controlling for word frequency, we show that these aspects of the word niche are strong determinants of changes in word frequency. Previous studies have already indicated that word frequency itself is a correlate of word success at historical time scales. Our analysis of changes in word frequencies over time reveals that the relative sizes of word niches are far more important than word frequencies in the dynamics of the entire vocabulary at shorter time scales, as the language adapts to new concepts and social groupings. We also distinguish endogenous versus exogenous factors as additional contributors to the fates of words, and demonstrate the force of this distinction in the rise of novel words. Our results indicate that short-term nonstationarity in word statistics is strongly driven by individual proclivities, including inclinations to provide novel information and to project a distinctive social identity.
Purwandana, Deni; Ariefiandy, Achmad; Imansyah, M. Jeri; Seno, Aganto; Ciofi, Claudio; Letnic, Mike; Jessop, Tim S.
Ontogenetic allometries in ecological habits and niche use are key responses by which individuals maximize lifetime fitness. Moreover, such allometries have significant implications for how individuals influence population and community dynamics. Here, we examined how body size variation in Komodo dragons ( Varanus komodoensis) influenced ecological allometries in their: (1) prey size preference, (2) daily movement rates, (3) home range area, and (4) subsequent niche use across ontogeny. With increased body mass, Komodo dragons increased prey size with a dramatic switch from small (≤10 kg) to large prey (≥50 kg) in lizards heavier than 20 kg. Rates of foraging movement were described by a non-linear concave down response with lizard increasing hourly movement rates up until ˜20 kg body mass before decreasing daily movement suggesting reduced foraging effort in larger lizards. In contrast, home range area exhibited a sigmoid response with increased body mass. Intrapopulation ecological niche use and overlap were also strongly structured by body size. Thus, ontogenetic allometries suggest Komodo dragon's transition from a highly active foraging mode exploiting small prey through to a less active sit and wait feeding strategy focused on killing large ungulates. Further, our results suggest that as body size increases across ontogeny, the Komodo dragon exhibited marked ontogenetic niche shifts that enabled it to function as an entire vertebrate predator guild by exploiting prey across multiple trophic levels.
Roč. 294, č. 8 (2011), s. 1284-1306 ISSN 1932-8486 Institutional research plan: CEZ:AV0Z50520701 Keywords : ovary * stem cell niche * neo-oogenesis Subject RIV: EA - Cell Biology Impact factor: 1.473, year: 2011
how well ‘back- casting ’ of ecological niche models can complement phylogeo- graphic approaches in identifying refugia. A clear advantage of the ENM...records: a test case using cryptic geckos in Madagascar. Journal of Biogeography 34: 102–117. 47. Araújo MB, Whittaker RJ, Ladle RJ, Erhard M (2005
Jul 5, 2017 ... Symbiosis is a process that can generate evolutionary novelties and can extend the phenotypic niche space of organisms. Symbionts can act together with their hosts to co-construct host organs, within which symbionts are housed. Once established within hosts, symbionts can also influence various ...
Niche marketing involves targetting a product or service to a small but specific well defined segment of the ... farm origin includes local products, organics, humanely treated livestock sought by specific consumer .... of such opportunities include creativity, innovativeness and calculated risk-taking (Maatman and Schrader,.
Caniels, Marjolein C. J.; Romijn, Henny A.
Purpose: The purpose of this paper is to contribute to the study of supply chain design from the perspective of complex dynamic systems. Unlike extant studies that use formal simulation modelling and associated methodologies rooted in the physical sciences, it adopts a framework rooted in the social sciences, strategic niche management, which…
Bekci, Tumay; Yucel, Serap; Turgut, Eser; Soylu, Aysegul Idil
Pelvic arteriovenous malformations (AVMs) are uncommon lesions and only a rare number of male cases have been reported. Their clinical presentations are variable and imaging modalities have an important place in diagnosis and treatment planning. We present the imaging findings of a giant congenital pelvic AVM that was diagnosed in a 30-year-old male patient eight years ago and which progressed despite follow-up and treatment, causing cardiac failure, diplegia, and neurogenic bladder. Pelvic AVMs are uncommon lesions and they can present with various symptoms based on their locations and sizes. Delays in the diagnosis and treatment can cause local and systemic complications. Imaging is very important in the diagnosis of pelvic AVM.
Schoeller, Thomas; Gurunluoglu, Raffi; Wechselberger, Gottfried; Hussl, Heribert; Huemer, Georg M
Neurogenic atrophy of the deltoid muscle due to brachial plexus injury will lead to a disfiguring deformity of the shoulder contour, apart from the functional deficit. When there is no possibility for functional restoration of the shoulder movement, this contour defect will become the patient's major concern. We present a new method in which the ipsilateral latissimus dorsi muscle was used as a pedicled musculocutaneous flap to augment the shoulder contour in 3 patients. In all patients, there was a concomitant lesion to the thoracodorsal nerve, with subsequent palsy of the latissimus dorsi muscle. Therefore, donor-site morbidity was minimal. The final esthetic appearance was pleasing, and the patient satisfaction was quite high.
Stein, R; Assion, C; Beetz, R; Bürst, M; Cremer, R; Ermert, A; Goepel, M; Kuwertz-Bröking, E; Ludwikowski, B; Michael, T; Pannek, J; Peters, H; Rohrmann, D; Rübben, I; Schröder, A; Trollmann, R; Thüroff, J W; Wagner, W
The treatment of children and adolescents with meningomyelocele has experienced a clear change in the last 30 years. The establishment of pharmacotherapy, clean intermittent catheterization (CIC) and infection prophylaxis have improved the prognosis for patients and have led to new therapeutic strategies. The interdisciplinary cooperation between neonatologists, neurosurgeons, pediatric neurologists, pediatric urologists, pediatric nephrologists, pediatric orthopedists and pediatric surgeons leads to optimization of individualized therapy. These guidelines present definitions and classifications, investigations and timing which are described in detail. The conservative and operative therapy options for neurogenic bladder function disorders are described and discussed with reference to the current literature. The brief overview provides in each case assistance for the treating physician in the care of this patient group and facilitates the interdisciplinary cooperation.
Šedý, Jiří; Zicha, Josef; Kuneš, Jaroslav; Jendelová, Pavla; Syková, Eva
Roč. 58, č. 2 (2009), s. 269-277 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA ČR GA309/06/1246 Grant - others:EC FP6 projekt RESCUE(FR) LSHB-CT-2005-518233; GA MZd(CZ) 1A8697; GA MZd(CZ) NR8339; GA MŠk(CZ) 1M0538; GA MŠk(CZ) 1M0510 Program:1M; 1M Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50110509 Keywords : neurogenic pulmonary edema * rat * spinal cord injury Subject RIV: FH - Neurology Impact factor: 1.430, year: 2009
Meseguer, Victor; Alpizar, Yeranddy A.; Luis, Enoch; Tajada, Sendoa; Denlinger, Bristol; Fajardo, Otto; Manenschijn, Jan-Albert; Fernández-Peña, Carlos; Talavera, Arturo; Kichko, Tatiana; Navia, Belén; Sánchez, Alicia; Señarís, Rosa; Reeh, Peter; Pérez-García, María Teresa; López-López, José Ramón; Voets, Thomas; Belmonte, Carlos; Talavera, Karel; Viana, Félix
Gram-negative bacterial infections are accompanied by inflammation and somatic or visceral pain. These symptoms are generally attributed to sensitization of nociceptors by inflammatory mediators released by immune cells. Nociceptor sensitization during inflammation occurs through activation of the Toll-like receptor 4 (TLR4) signalling pathway by lipopolysaccharide (LPS), a toxic by-product of bacterial lysis. Here we show that LPS exerts fast, membrane delimited, excitatory actions via TRPA1, a transient receptor potential cation channel that is critical for transducing environmental irritant stimuli into nociceptor activity. Moreover, we find that pain and acute vascular reactions, including neurogenic inflammation (CGRP release) caused by LPS are primarily dependent on TRPA1 channel activation in nociceptive sensory neurons, and develop independently of TLR4 activation. The identification of TRPA1 as a molecular determinant of direct LPS effects on nociceptors offers new insights into the pathogenesis of pain and neurovascular responses during bacterial infections and opens novel avenues for their treatment.
Magill, Stephen T; Brus-Ramer, Marcel; Weinstein, Philip R; Chin, Cynthia T; Jacques, Line
Neurogenic thoracic outlet syndrome (nTOS) is caused by compression of the brachial plexus as it traverses from the thoracic outlet to the axilla. Diagnosing nTOS can be difficult because of overlap with other complex pain and entrapment syndromes. An nTOS diagnosis is made based on patient history, physical exam, electrodiagnostic studies, and, more recently, interpretation of MR neurograms with tractography. Advances in high-resolution MRI and tractography can confirm an nTOS diagnosis and identify the location of nerve compression, allowing tailored surgical decompression. In this report, the authors review the current diagnostic criteria, present an update on advances in MRI, and provide case examples demonstrating how MR neurography (MRN) can aid in diagnosing nTOS. The authors conclude that improved high-resolution MRN and tractography are valuable tools for identifying the source of nerve compression in patients with nTOS and can augment current diagnostic modalities for this syndrome.
Streit, Robin S
Neurogenic thoracic outlet syndrome (NTOS) is a neuromuscular condition affecting brachial plexus functionality. NTOS is characterized by paresthesia, pain, muscle fatigue, and restricted mobility in the upper extremity. This study quantified massage therapy's possible contribution to treatment of NTOS. A 24-year-old female with NTOS received eight treatments over 35 days. Treatment included myofascial release, trigger point therapy, cross fiber friction, muscle stripping, and gentle passive stretching. Abduction and lateral rotation at the glenohumeral (GH joint) assessments measured range of motion (ROM). A resisted muscle test evaluated upper extremity strength. The client rated symptoms daily via a visual analog scale (VAS). Findings showed improvement in ROM at the GH joint. VAS ratings revealed a reduction in muscle weakness, pain, numbness, and 'paresthesia'. Results suggest massage may be useful as part of a broad approach to managing NTOS symptoms and improving mobility. Copyright © 2013 Elsevier Ltd. All rights reserved.
Nitta, Masahiro; Tamaki, Tetsuro; Tono, Kayoko; Okada, Yoshinori; Masuda, Maki; Akatsuka, Akira; Hoshi, Akio; Usui, Yukio; Terachi, Toshiro
BACKGROUND.: Postoperative neurogenic bladder dysfunction is a major complication of radical hysterectomy for cervical cancer and is mainly caused by unavoidable damage to the bladder branch of the pelvic plexus (BBPP) associated with colateral blood vessels. Thus, we attempted to reconstitute disrupted BBPP and blood vessels using skeletal muscle-derived multipotent stem cells that show synchronized reconstitution capacity of vascular, muscular, and peripheral nervous systems. METHODS.: Under pentobarbital anesthesia, intravesical pressure by electrical stimulation of BBPP was measured as bladder function. The distal portion of BBPP with blood vessels was then cut unilaterally (experimental neurogenic bladder model). Measurements were performed before, immediately after, and at 4 weeks after transplantation as functional recovery. Stem cells were obtained from the right soleus and gastrocnemius muscles after enzymatic digestion and cell sorting as CD34/45 (Sk-34) and CD34/45 (Sk-DN). Suspended cells were autografted around the damaged region, whereas medium alone and CD45 cells were transplanted as control groups. To determine the morphological contribution of the transplanted cells, stem cells obtained from green fluorescent protein transgenic mouse muscles were transplanted into a nude rat model and were examined by immunohistochemistry and immunoelectron microscopy. RESULTS.: At 4 weeks after surgery, the transplantation group showed significantly higher functional recovery ( approximately 80%) than the two controls ( approximately 28% and 24%). The transplanted cells showed an incorporation into the damaged peripheral nerves and blood vessels after differentiation into Schwann cells, perineurial cells, vascular smooth muscle cells, pericytes, and fibroblasts around the bladder. CONCLUSION.: Transplantation of multipotent Sk-34 and Sk-DN cells is potentially useful for the reconstitution of damaged BBPP.
Full Text Available Antidromic stimulation of the rat trigeminal ganglion triggers the release of substance P (SP and calcitonin gene-related peptide (CGRP from sensory nerve terminals of the capsaicin sensitive C-fibers. These pro-inflammatory neuropeptides produce a marked hyperemia in the anterior segment of the eye, accompanied by increased intraocular pressure, breakdown of the blood-aqueous barrier and myosis. To assess the effects of neurogenic inflammation on the retina, specifically on the immunostaining of neurotransmitters and neurotrophins, as well as on the expression of neurotrophin receptors in the retina. RT-PCR was also accomplished in control and stimulated animals to confirm the immunohistochemical results. In the electrically stimulated eyes, immunostaining for SP, CGRP, VIP and nNOS demonstrated a marked increase in the RPE/POS (Retinal Pigment Epithelium/Photoreceptor Outer Segments, in the inner and outer granular layers and in the ganglion cells in comparison to the control eyes. CGRP and SP were found increased in stimulated animals and this result has been confirmed by RT- PCR. Changes in neurotrophin immunostaining and in receptor expression were also observed after electric stimulation of trigeminal ganglia. Decrease of BDNF and NT4 in the outer and inner layers and in ganglion cells was particularly marked. In stimulated rat retinas immunostaining and RT-PCR showed a NGF expression increase. Neurotrophin receptors remained substantially unchanged. These studies demonstrated, for the first time, that antidromic stimulation of the trigeminal ganglion and subsequent neurogenic inflammation affect immunostaining of retinal cell neurotransmitter/ neuropeptides and neurotrophins as well as the expression of neurotrophin receptors.
Manach, Q; Dommergues, M; Denys, P; Loiseau, K; Idiard-Chamois, B; Chartier-Kastler, E; Phé, V
Data are scarce regarding pregnancy and delivery among women with a neurogenic bladder due to congenital spinal cord defects. To report the obstetrical and urological outcomes of women with congenital spinal cord defects and vesico-sphincteric disorders. A retrospective multicentric study included all consecutive women with a neurogenic bladder due to congenital spinal defects, who delivered between January 2005 and December 2014. The following data were collected: demographics, neuro-urological disease characteristics, urological and obstetrical history, complications during pregnancy, neonatal outcomes, and changes in urological symptoms. Overall, sixteen women, median age 29,4 years old (IQR 22-36), had a total of 20 pregnancies and 21 births (15 caesareans, 5 vaginal deliveries). Prior to the beginning of their first pregnancy, 12 patients were under intermittent self-catheterization. Symptomatic urinary tract infections during pregnancy occurred in 11 pregnancies, including 4 pyelonephritis. In 4 women, stress urinary incontinence had worsened but recovered post-partum. In 3 women, de novo clean intermittent catheterization became necessary and had to be continued post-partum. During 3 pregnancies, anticholinergic treatment had been started or increased because of urge urinary incontinence worsened. These changes were maintained after delivery. The median gestational age at birth was 39.0 weeks (IQR 37.8-39.5). There were 15 caesarean sections, of which 9 were indicated to prevent a potential aggravation of vesico-sphincteric disorders. Among the 5 pregnancies with vaginal delivery, there was no post-partum alteration of the sphincter function. Successful pregnancy outcome is possible in women with congenital spinal cord defects and vesico-sphincteric disorders but it requires managing an increased risk of urinary tract infections, caesarean section, and occasionally worsened urinary incontinence. 5. Copyright © 2017 Elsevier Masson SAS. All
Kim, Soo Han; Yu, Yun Jeong; Shin, Hyun Ja [Korea Veterans Hospital, Seoul (Korea, Republic of)
We evaluated 104 patients of neurogenic bladder secondary to traumatic spinal cord injury. Those were diagnosed by I. V. P. and V. C. U. at Korea Veterans Hospital during 9 years from January, 1978 to May, 1987. The type of neurogenic bladder, complications and urethral configuration, according to the level of spinal cord injury were discusses. The result were as follows: 1. The incidence of patient according to the level of spinal cord injury was 49 out of 104 in those with vertebral level T7 or above, 15 out of 104 in those with T8-T10 level, and 40 in those with vertebral level T11 or below. The incidence of UMNB was 67.3% in those with vertebral T7 or above, 53.3% in T8-T10. The incidence of LMNB was 62.5% in those with vertebral level T11 or below. 2. Overall incidence of urinary tract calculus was 32.7%. Highest incidence of calculus was 46.7% in those with vertebral level T8-T10. 3. Overall incidence of vesicoureteral reflux was 23.1%. Highest incidence of reflux was 46.7% in those with vertebral level T11 or below. 4. Overall incidence of pyelonephritis was 26.9%. 5. Overall incidence of hydronephrosis was 20.2%. Highest incidence of hydronephrosis was 27.5% in those with vertebral level T11 or below. 6. Almost entire urethra was shown funnel type in 66 out of 73 cases. Saccular dilatation of posterior urethra was 7 cases. Saccular dilatation of posterior urethra with LMNB was 4 cases, which were occurred only in those with vertebral level T11 or below.
Sriramula, Srinivas; Lazartigues, Eric
Hypertension is associated with increased activity of the kallikrein-kinin system. Kinin B1 receptor (B1R) activation leads to vasoconstriction and inflammation. Despite evidence supporting a role for the B1R in blood pressure regulation, the mechanisms by which B1R could alter autonomic function and participate in the pathogenesis of hypertension remain unidentified. We sought to explore whether B1R-mediated inflammation contributes to hypertension and investigate the molecular mechanisms involved. In this study, we tested the hypothesis that activation of B1R in the brain is involved in the pathogenesis of hypertension, using the deoxycorticosterone acetate-salt model of neurogenic hypertension in wild-type and B1R knockout mice. Deoxycorticosterone acetate-salt treatment in wild-type mice led to significant increases in B1R mRNA and protein levels and bradykinin levels, enhanced gene expression of carboxypeptidase N supporting an increase in the B1R ligand, associated with enhanced blood pressure, inflammation, sympathoexcitation, autonomic dysfunction, and impaired baroreflex sensitivity, whereas these changes were blunted or prevented in B1R knockout mice. B1R stimulation was further shown to involve activation of the ASK1-JNK-ERK1/2 and NF-κB pathways in the brain. To dismiss potential developmental alterations in knockout mice, we further used B1R blockade selectively in the brain of wild-type mice. Supporting the central origin of this mechanism, intracerebroventricular infusion of a specific B1R antagonist, attenuated the deoxycorticosterone acetate-salt-induced increase in blood pressure in wild-type mice. Our data provide the first evidence of a central role for B1R-mediated inflammatory pathways in the pathogenesis of deoxycorticosterone acetate-salt hypertension and offer novel insights into possible B1R-targeted therapies for the treatment of neurogenic hypertension. © 2017 American Heart Association, Inc.
Kim, Soo Han; Yu, Yun Jeong; Shin, Hyun Ja
We evaluated 104 patients of neurogenic bladder secondary to traumatic spinal cord injury. Those were diagnosed by I. V. P. and V. C. U. at Korea Veterans Hospital during 9 years from January, 1978 to May, 1987. The type of neurogenic bladder, complications and urethral configuration, according to the level of spinal cord injury were discusses. The result were as follows: 1. The incidence of patient according to the level of spinal cord injury was 49 out of 104 in those with vertebral level T7 or above, 15 out of 104 in those with T8-T10 level, and 40 in those with vertebral level T11 or below. The incidence of UMNB was 67.3% in those with vertebral T7 or above, 53.3% in T8-T10. The incidence of LMNB was 62.5% in those with vertebral level T11 or below. 2. Overall incidence of urinary tract calculus was 32.7%. Highest incidence of calculus was 46.7% in those with vertebral level T8-T10. 3. Overall incidence of vesicoureteral reflux was 23.1%. Highest incidence of reflux was 46.7% in those with vertebral level T11 or below. 4. Overall incidence of pyelonephritis was 26.9%. 5. Overall incidence of hydronephrosis was 20.2%. Highest incidence of hydronephrosis was 27.5% in those with vertebral level T11 or below. 6. Almost entire urethra was shown funnel type in 66 out of 73 cases. Saccular dilatation of posterior urethra was 7 cases. Saccular dilatation of posterior urethra with LMNB was 4 cases, which were occurred only in those with vertebral level T11 or below
Full Text Available Introduction: Vision loss can be a consequence of numerous disorders of eye and neural pathway conveying visual input to brain. A variety of conditions can affect visual pathway producing neurogenic vision loss. The presentation and course of vision loss depends on the site of involvement and underlying etiology. We conducted this unprecedented study to evaluate the characteristics and outcome of various diseases of the visual pathway. Materials and Methods: In this prospective cohort study, we evaluated 64 patients with neurogenic visual impairment. Ophthalmological causes were excluded in all of them. Their presentation, ophthalmological characteristics and investigation findings were recorded. These patients were followed up till 6 months. Results: Out of 69 patients evaluated, 5 were excluded as they had ophthalmological abnormalities. The remaining 64 cases (113 eyes were enrolled. 54 cases were due to diseases of anterior visual pathway and rest 10 had cortical vision loss. The etiologic distribution is as follows: Isolated optic neuritis- 12 (19%, multiple sclerosis- 4 (6.3%, neuromyelitis optica- 5 (7.9%, tubercular meningitis- 15 (23.8%, non-arteritic ischemic optic neuropathy, ischemic optic neuropathy complicating cavernous sinus thrombosis, cryptococcal meningitis, malignant infiltration of optic nerve, Crouzon′s syndrome, calvarial thickening and traumatic occipital gliosis- 1 (1.6% case each, idiopathic intracranial hypertension, pituitary adenoma, acute disseminated encephalomyelitis, posterior reversible leukoencephalopathy- 3 (4.8% cases each, cortical venous thrombosis 5 (7.9%, subacute scleroing panencephalitis- 4 (6.3% cases. Conclusions: The diseases of anterior visual pathway were much more common than cortical vision loss. A majority of our patients had severe impairment of vision at presentation.
Full Text Available Introduction:Neurogenic mediastinal tumors comprise a wide range of benign and malignant diseases. A group of these tumors, located at thoracic apex, sometimes spread to cervical spaces causing numerous surgical difficulties. In thoracotomy approaches, due to proximity of the tumors to major blood vessels, complete removal of these tumors from cervical spaces is impossible or may cause intraoperative severe bleeding or other dangerous incidents Because of the adjacent major vessels that are not visible.The aim of this study is to report cases of surgical treatment of such tumors using Anterior Trans Cervicothoracic Approach (ATCA. Materials and Methods:All patients with neurogenic tumors and cervicomediastinal (CM spread who underwent surgey with ATCA technique during 2005-2011 were included in our study. Then they were evaluated in terms of age, sex, clinical symptoms, radiological and pathological findings, technical success rate of the surgery, surgical complications and first-year relapse rate after the surgery. Results:Our study included 10 patients from whom 9 were female and 1 was male (M/F= 1/9 and the mean age was 27 years. The most common symptoms were pain and feeling of a lump. All patients were operated by this technique successfully. The most common pathological finding was neurofibroma (in 5 patients and surgical complications occurred in 2 patients (20% (Wound infection in 1 patient and brachial plexus injury in another patient. There was no mortality. Disease relapse was reported in 1 patient ganglioneuroblastoma who underwent surgical resection for the second time. Conclusion: Considering the successful removal of the tumors and favorable exposure of major vessels in cervicomediastinal spaces, this technique is recommended to resect mediastinal tumors with spread to cervical spaces. However, a more definite conclusion requires further studies.
Koff, Stephen A; Gigax, Michael R; Jayanthi, Venkata R
In this preliminary study we sought to determine the effect of instituting nocturnal bladder emptying (NBE) in children with neurogenic (NGB) or nonneurogenic neurogenic bladder (NNGNGB) in whom urinary tract deterioration developed despite optimal daytime clean intermittent catheterization (CIC) and urotropic medications. We hypothesize that a syndrome of nocturnal overdistention of the bladder (SNOB) can cause urinary tract deterioration through increased nighttime storage pressures manifested by recurrent urinary tract infection (UTI), worsening incontinence, hydronephrosis and/or decreasing bladder compliance and capacity, and may be reversed by NBE. A total of 19 children with NGB (17) or NNGNGB (2) who displayed urinary tract deterioration while on CIC and urotropic medications were started on NBE. Of the patients 15 used a continuously draining nighttime catheter while 4 had scheduled awakenings during the night to perform CIC. The primary indications for NBE were recurrent symptomatic UTI in 5, new or progressive hydronephrosis in 7, and decreasing bladder capacity and compliance in 7. At a mean followup of 23 months 15 (79%) patients showed improvement or complete resolution of 1 or more signs or symptoms of hydronephrosis (7), increase in bladder capacity (5), recurrent UTI (6) and worsening incontinence (3). The remaining 4 patients had no response to NBE. No adverse effects were observed with 10 hours or less of nightly indwelling catheter time. Patients with NGB or NNGNGB on idealized daytime programs of CIC and urotropic drugs may have high intravesical pressures and experience urological deterioration because of an unrecognized SNOB. NBE is a simple technique for treating this condition and reversing the pathophysiological changes. The observation that NBE alone may increase bladder compliance and capacity sufficient to avoid bladder augmentation suggests that development of decreased bladder compliance and capacity in children with NGB may not
Zhang, Han-Chao; Yang, Jin; Ye, Xin; Hu, Hai-Feng
The objective of this study was to assess the clinical outcome of vesicoureteral reflux (VUR) after augmentation cystoplasty alone in patients with a hypocompliant neurogenic bladder. Between January 2009 and December 2014, 29 patients with a hypocompliant bladder associated with VUR confirmed by videourodynamics (VUD) preoperatively were recruited in this study. All patients had undergone bladder augmentation with a generous detubularized segment of bowel at our institution. No effort had been made to correct the existing reflux. Preoperative assessment included urinalysis, kidney function tests, ultrasonography, and videourodynamic evaluation. All patients had various degrees of VUR. The status of VUR and bladder function were studied by VUD. The mean follow-up period was 2.2 years (range 0.5-5.5 years). The VUD manifested a significant improvement of bladder capacity, diminution of intravesical pressure, and resolution of reflux after bladder augmentation. After the surgery, 24/29 (83%) no longer had reflux, 3/29 (10%) showed improvement in reflux, and 2/29 (7%) demonstrated no change in reflux. In addition, 16/21 (76%) patients had reflux Grades I-III; 100% patients with reflux Grades IV and V had complete cessation of reflux. Only one patient had symptomatic urinary infection after the surgery. Augmentation enterocystoplasty without ureteral reimplantation is thus effective and adequate for patients with high-pressure and hypocompliant neurogenic bladder. Therefore, ureteral reimplantation is not necessary when augmentation enterocystoplasty is recommended for patients with high-pressure, low-compliant bladder and VUR. Copyright © 2016. Published by Elsevier Taiwan.
Full Text Available Jürgen Pannek, Jens Wöllner Neuro-Urology, Swiss Paraplegic Center, Nottwil, Switzerland Introduction: Urinary tract infections (UTIs are one of the most common morbidities in persons with neurogenic lower urinary tract dysfunction (NLUTD. They are associated with a significant morbidity and mortality, and they affect the quality of life of the affected patients. Diagnosis and treatment of UTI in this group of patients are challenging. In this review, the current strategies regarding diagnosis, treatment, and prevention are summarized. Diagnostics: it is important to correctly diagnose a UTI, as treatment of bacteriuria should strictly be avoided. A UTI is defined as a combination of laboratory findings (leukocyturia and bacteriuria and symptoms. Laboratory findings without symptoms are classified as asymptomatic bacteriuria. Routine urine screening is not advised. Treatment: Only UTI should be treated; treatment of asymptomatic bacteriuria is not indicated. Prior to treatment, urine for a urine culture should be obtained. Antibiotic treatment for ~7 days is advised. Prevention: In recurrent UTI, bladder management should be optimized and morphologic causes for UTI should be excluded. If UTIs persist, medical prophylaxis should be considered. Currently, no prophylactic measure with evidence-based efficacy exists. Long-term antibiotic prophylaxis should be used merely as an ultimate measure. Among the various mentioned innovative approaches for UTI prevention, bacteriophages, intravesical instillations, complementary and alternative medicine techniques, and probiotics seem to be most promising. Conclusion: Recently, several promising innovative options for UTI prophylaxis have been developed which may help overcome the current therapeutic dilemma. However, further well designed studies are necessary to evaluate the safety and efficacy of these approaches. Keywords: neurogenic lower urinary tract dysfunction, spinal cord injury, prophylaxis
Roshanzamir, Fathollah; Rouzrokh, Mohsen; Mirshemirani, Alireza; Khaleghnejad, Ahmad; Mohajerzadeh, Leila; Dalirani, Reza
A neurogenic bladder is one which functions abnormally due to disorders of sacral nerves that control the bladder's ability to fill, store and empty urine. Abnormal bladder function can cause the bladder to be underactive or overactive. This study was planned to evaluate the treatment outcome of our patients with neurogenic bladder dysfunction (NGBD). Thirty three patients who have been treated for NGBD were evaluated. Diagnosis was confirmed by voiding-cysto-urethrography (VCUG) and urodynamic study. The patients were treated medically and all had clean intermittent catheterization (CIC). Data regarding age, sex, clinical and paraclinical findings, sonography, imagings, renal scan, associated anomalies, treatment and outcomes were collected and entered in SPSS software version18 and analyzed by descriptive statistical. Findings : Totally 33 patients aged three days to four years (mean 6.8 months) were included in this study. There were 20 (61%) males and 13 (39%) females. Mean follow-up period was 3.4±1.2 years (1.5 months to 5 years). Eighty two precent cases had bilatral and 18% unilatral hydronephrosis and bilatral vesicouretral reflux (VUR) existed in 67% and unilatral in 33% of the patients. Treatment consisted of antibiotherapy and CIC in all patients, which was only in 33% of the cases succesful. The most common associated anomaly was meningomyelocle in 8 patients. Vesicostomy was performed in 22 (67%) cases. Kidney scan showed scar in 10 patients at follow-up study. Complete continence on follow-up was achieved in 24 (71% ) patients, and it was improved in 6 (18% ) cases. Mortality rate was 9% (3 cases). Cure rate was 85% in urinary tract infection, 82.7% in hydronephrosis, 80% in VUR and 86.5% in kidney function. Anticholinergic medications was not effective in all our patients. We believe that permanent vesicostomy is an effective and acceptable surgical intervention for protection of upper urinary tract decompression, especially in those who do not
Full Text Available The objective of this study was to assess the clinical outcome of vesicoureteral reflux (VUR after augmentation cystoplasty alone in patients with a hypocompliant neurogenic bladder. Between January 2009 and December 2014, 29 patients with a hypocompliant bladder associated with VUR confirmed by videourodynamics (VUD preoperatively were recruited in this study. All patients had undergone bladder augmentation with a generous detubularized segment of bowel at our institution. No effort had been made to correct the existing reflux. Preoperative assessment included urinalysis, kidney function tests, ultrasonography, and videourodynamic evaluation. All patients had various degrees of VUR. The status of VUR and bladder function were studied by VUD. The mean follow-up period was 2.2 years (range 0.5–5.5 years. The VUD manifested a significant improvement of bladder capacity, diminution of intravesical pressure, and resolution of reflux after bladder augmentation. After the surgery, 24/29 (83% no longer had reflux, 3/29 (10% showed improvement in reflux, and 2/29 (7% demonstrated no change in reflux. In addition, 16/21 (76% patients had reflux Grades I-III; 100% patients with reflux Grades IV and V had complete cessation of reflux. Only one patient had symptomatic urinary infection after the surgery. Augmentation enterocystoplasty without ureteral reimplantation is thus effective and adequate for patients with high-pressure and hypocompliant neurogenic bladder. Therefore, ureteral reimplantation is not necessary when augmentation enterocystoplasty is recommended for patients with high-pressure, low-compliant bladder and VUR.
Romero-Cullerés, G; Planells-Romeo, I; Martinez de Salazar-Muñoz, P; Conejero-Sugrañes, J
To analyze the most frequent causes and resistances of the uropathogens in patients affected by neurogenic bladder. A total of 284 patients, in whom a total of 284 urinary cultures were performed, were included. Of these, 106 came from patients with neurological injuries, 28 from a non-neurogenic control group, 75 from patients admitted to the intensive care unit (ICU) of our Hospital and 75 patients who came into the emergency room with the symptoms of an acute urinary tract infection. A quantitative urine culture was performed in a chromogenic media and the resistances of all urine cultures that were positive for one or two micro-organisms were identified and studied. A total of 67% of the patients with neurological injuries had positive urine cultures compared to 25% of control group patients. The urine cultures of patients admitted into the ICU and those of the Emergency Room group were 100% positive, since the first 75 positive urine cultures were selected for the study. E.coli was the most-frequently microorganism isolated in the group of neurological patients, as well as among the patients from the Emergency Room and from the control group. In the ICU, the most-frequently isolated micro-organism was Enterococcus spp. (19.4%), followed by P. aeruginosa (16.5%). The study of resistances in general E. coli has high rates of resistance to ampicillin and co-trimoxazole and, although to a lesser degree to ciprofloxacin. E. coli is the micro-organism most frequently isolated among all of the groups except in the ICU, where it is surpassed by Enterococcus spp. and P. aeruginosa. The resistances among the four population groups studied have different features, overall showing a low rate of resistance to nitrofurantoin and especially to fosfomycin, observed in patients from the Emergency Room or admitted to the ICU and neurological patients. Copyright © 2011 AEU. Published by Elsevier Espana. All rights reserved.
Linsenmeyer, Todd A.
Background Botulinum neurotoxin (BoNT) injection into the bladder wall has been shown to be an effective alternative to anticholinergic (antimuscarinic) medications and more invasive surgery in those with multiple sclerosis and spinal cord injury with neurogenic detrusor overactivity (NDO) and urinary incontinence who are not tolerating anticholinergic medications. In August 2011, Botox® (onabotulinumtoxinA) received Food and Drug Administration (FDA) approval for this use. Clinically, intradetrusor injection of BoNT has been found to decrease urinary incontinence and improve quality of life. Its impact on urodynamic parameters is an increase in the maximum cystometric (bladder) capacity and decrease in the maximum detrusor pressures. The most common side effects are urinary tract infections and urinary retention. There have been rare reports and a black box warning of distant spread of BoNT. BoNT has gained popularity because of its effectiveness and long duration of action, relative ease of administration, easy learning curve, reproducibility of results on repeated administration, and low incidence of complications. Objective To discuss the structure and function, mechanisms of action, clinical and urodynamic studies, injection technique, potential beneficial and adverse effects, and potential areas of research of BoNT. Methods Literature search focused on botulinum toxin in MEDLINE/PubMed. Search terms included botulinum toxin, neurogenic bladder, NDO, botox bladder, botox spinal cord injury, botox, FDA, botox side effects. All papers identified were English language, full-text papers. In addition, English abstracts of non-English papers were noted. The reference list of identified articles was also searched for further papers. Conclusion Botulinum toxin is an alternative treatment for individuals with NDO who fail to tolerate anticholinergic medications. Its popularity has increased because of the literature, which has supported its effectiveness, safety, easy
Michel, Matt J; Knouft, Jason H
When species distribution models (SDMs) are used to predict how a species will respond to environmental change, an important assumption is that the environmental niche of the species is conserved over evolutionary time-scales. Empirical studies conducted at ecological time-scales, however, demonstrate that the niche of some species can vary in response to environmental change. We use habitat and locality data of five species of stream fishes collected across seasons to examine the effects of niche variability on the accuracy of projections from Maxent, a popular SDM. We then compare these predictions to those from an alternate method of creating SDM projections in which a transformation of the environmental data to similar scales is applied. The niche of each species varied to some degree in response to seasonal variation in environmental variables, with most species shifting habitat use in response to changes in canopy cover or flow rate. SDMs constructed from the original environmental data accurately predicted the occurrences of one species across all seasons and a subset of seasons for two other species. A similar result was found for SDMs constructed from the transformed environmental data. However, the transformed SDMs produced better models in ten of the 14 total SDMs, as judged by ratios of mean probability values at known presences to mean probability values at all other locations. Niche variability should be an important consideration when using SDMs to predict future distributions of species because of its prevalence among natural populations. The framework we present here may potentially improve these predictions by accounting for such variability.
Matt J Michel
Full Text Available When species distribution models (SDMs are used to predict how a species will respond to environmental change, an important assumption is that the environmental niche of the species is conserved over evolutionary time-scales. Empirical studies conducted at ecological time-scales, however, demonstrate that the niche of some species can vary in response to environmental change. We use habitat and locality data of five species of stream fishes collected across seasons to examine the effects of niche variability on the accuracy of projections from Maxent, a popular SDM. We then compare these predictions to those from an alternate method of creating SDM projections in which a transformation of the environmental data to similar scales is applied. The niche of each species varied to some degree in response to seasonal variation in environmental variables, with most species shifting habitat use in response to changes in canopy cover or flow rate. SDMs constructed from the original environmental data accurately predicted the occurrences of one species across all seasons and a subset of seasons for two other species. A similar result was found for SDMs constructed from the transformed environmental data. However, the transformed SDMs produced better models in ten of the 14 total SDMs, as judged by ratios of mean probability values at known presences to mean probability values at all other locations. Niche variability should be an important consideration when using SDMs to predict future distributions of species because of its prevalence among natural populations. The framework we present here may potentially improve these predictions by accounting for such variability.
Full Text Available The degree of phenotypic divergence and reproductive isolation between taxon pairs can vary quantitatively, and often increases as evolutionary divergence proceeds through various stages, from polymorphism to population differentiation, ecotype and race formation, speciation, and post-speciational divergence. Although divergent natural selection promotes divergence, it does not always result in strong differentiation. For example, divergent selection can fail to complete speciation, and distinct species pairs sometimes collapse ('speciation in reverse'. Widely-discussed explanations for this variability concern genetic architecture, and the geographic arrangement of populations. A less-explored possibility is that the degree of phenotypic and reproductive divergence between taxon pairs is positively related to the number of ecological niche dimensions (i.e., traits subject to divergent selection. Some data supporting this idea stem from laboratory experimental evolution studies using Drosophila, but tests from nature are lacking. Here we report results from manipulative field experiments in natural populations of herbivorous Timema stick insects that are consistent with this 'niche dimensionality' hypothesis. In such insects, divergent selection between host plants might occur for cryptic colouration (camouflage to evade visual predation, physiology (to detoxify plant chemicals, or both of these niche dimensions. We show that divergent selection on the single niche dimension of cryptic colouration can result in ecotype formation and intermediate levels of phenotypic and reproductive divergence between populations feeding on different hosts. However, greater divergence between a species pair involved divergent selection on both niche dimensions. Although further replication of the trends reported here is required, the results suggest that dimensionality of selection may complement genetic and geographic explanations for the degree of
Cedeno, Walter [Univ. of California, Davis, CA (United States)
The ability of organisms to evolve and adapt to the environment has provided mother nature with a rich and diverse set of species. Only organisms well adapted to their environment can survive from one generation to the next, transferring on the traits, that made them successful, to their offspring. Competition for resources and the ever changing environment drives some species to extinction and at the same time others evolve to maintain the delicate balance in nature. In this disertation we present the multi-niche crowding genetic algorithm, a computational metaphor to the survival of species in ecological niches in the face of competition. The multi-niche crowding genetic algorithm maintains stable subpopulations of solutions in multiple niches in multimodal landscapes. The algorithm introduces the concept of crowding selection to promote mating among members with qirnilar traits while allowing many members of the population to participate in mating. The algorithm uses worst among most similar replacement policy to promote competition among members with similar traits while allowing competition among members of different niches as well. We present empirical and theoretical results for the success of the multiniche crowding genetic algorithm for multimodal function optimization. The properties of the algorithm using different parameters are examined. We test the performance of the algorithm on problems of DNA Mapping, Aquifer Management, and the File Design Problem. Applications that combine the use of heuristics and special operators to solve problems in the areas of combinatorial optimization, grouping, and multi-objective optimization. We conclude by presenting the advantages and disadvantages of the algorithm and describing avenues for future investigation to answer other questions raised by this study.
Full Text Available Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N and carbon (δ13C isotopic mixing models, perch (Perca fluviatilis L. and rudd (Scardinius erythrophthalmus (L. showed larger individual variation (i.e., variance in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.. Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence
Amirpour Haredasht, Sara; Barrios, Miguel; Farifteh, Jamshid; Maes, Piet; Clement, Jan; Verstraeten, Willem W; Tersago, Katrien; Van Ranst, Marc; Coppin, Pol; Berckmans, Daniel; Aerts, Jean-Marie
The bank vole (Myodes glareolus) is the natural host of Puumala virus (PUUV) in vast areas of Europe. PUUV is one of the hantaviruses which are transmitted to humans by infected rodents. PUUV causes a general mild form of hemorrhagic fever with renal syndrome (HFRS) called nephropathia epidemica (NE). Vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. Land cover influences disease transmission by controlling both the spatial distribution of vectors or hosts, as well as by facilitating the human contact with them. In this study the use of ecological niche modelling (ENM) for predicting the geographical distribution of bank vole population on the basis of spatial climate information is tested. The Genetic Algorithm for Rule-set Prediction (GARP) is used to model the ecological niche of bank voles in Western Europe. The meteorological data, land cover types and geo-referenced points representing the locations of the bank voles (latitude/longitude) in the study area are used as the primary model input value. The predictive accuracy of the bank vole ecologic niche model was significant (training accuracy of 86%). The output of the GARP models based on the 50% subsets of points used for testing the model showed an accuracy of 75%. Compared with random models, the probability of such high predictivity was low (χ(2) tests, p < 10(-6)). As such, the GARP models were predictive and the used ecologic niche model indeed indicates the ecologic requirements of bank voles. This approach successfully identified the areas of infection risk across the study area. The result suggests that the niche modelling approach can be implemented in a next step towards the development of new tools for monitoring the bank vole's population.
Sara Amirpour Haredasht
Full Text Available The bank vole (Myodes glareolus is the natural host of Puumala virus (PUUV in vast areas of Europe. PUUV is one of the hantaviruses which are transmitted to humans by infected rodents. PUUV causes a general mild form of hemorrhagic fever with renal syndrome (HFRS called nephropathia epidemica (NE. Vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. Land cover influences disease transmission by controlling both the spatial distribution of vectors or hosts, as well as by facilitating the human contact with them. In this study the use of ecological niche modelling (ENM for predicting the geographical distribution of bank vole population on the basis of spatial climate information is tested. The Genetic Algorithm for Rule-set Prediction (GARP is used to model the ecological niche of bank voles in Western Europe. The meteorological data, land cover types and geo-referenced points representing the locations of the bank voles (latitude/longitude in the study area are used as the primary model input value. The predictive accuracy of the bank vole ecologic niche model was significant (training accuracy of 86%. The output of the GARP models based on the 50% subsets of points used for testing the model showed an accuracy of 75%. Compared with random models, the probability of such high predictivity was low (χ2 tests, p < 10−6. As such, the GARP models were predictive and the used ecologic niche model indeed indicates the ecologic requirements of bank voles. This approach successfully identified the areas of infection risk across the study area. The result suggests that the niche modelling approach can be implemented in a next step towards the development of new tools for monitoring the bank vole’s population.
Evgeniya V Pushchina
Full Text Available Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1-4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration.
Pushchina, Evgeniya V.; Shukla, Sachin; Varaksin, Anatoly A.; Obukhov, Dmitry K.
Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1–4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration. PMID:27212918
Strubbe, D.; Beauchard, O.; Matthysen, E.
Niche conservatism, the hypothesis that niches remain constant through time and space, is crucial for the study of biological invasions as it underlies native-range based predictions of invasion risk. Niche changes between native and non-native populations are increasingly reported. However, it has
Hegger, D.L.T.; Vliet, van J.M.; Vliet, van B.J.M.
Strategic niche management (SNM) implies that new technologies are applied in so-called niches, in which they are protected against mainstream market selection. A major question currently subject to debate is through which processes niches can bring about any wider changes at the level of
Foote, Andrew David; Newton, Jason; Avila Arcos, Maria del Carmen
Niche variation owing to individual differences in ecology has been hypothesized to be an early stage of sympatric speciation. Yet to date, no study has tracked niche width over more than a few generations. In this study, we show the presence of isotopic niche variation over millennial timescales...
Ingrid R. Cordeiro
Full Text Available Human adipose-derived stromal cells (hADSC are a heterogeneous cell population that contains adult multipotent stem cells. Although it is well established that hADSC have skeletal potential in vivo in adult organisms, in vitro assays suggest further differentiation capacity, such as into glia. Thus, we propose that grafting hADSC into the embryo can provide them with a much more instructive microenvironment, allowing the human cells to adopt diverse fates or niches. Here, hADSC spheroids were grafted into either the presumptive presomitic mesoderm or the first branchial arch (BA1 regions of chick embryos. Cells were identified without previous manipulations via human-specific Alu probes, which allows efficient long-term tracing of heterogeneous primary cultures. When grafted into the trunk, in contrast to previous studies, hADSC were not found in chondrogenic or osteogenic territories up to E8. Surprisingly, 82.5% of the hADSC were associated with HNK1+ tissues, such as peripheral nerves. Human skin fibroblasts showed a smaller tropism for nerves. In line with other studies, hADSC also adopted perivascular locations. When grafted into the presumptive BA1, 74.6% of the cells were in the outflow tract, the final goal of cardiac neural crest cells, and were also associated with peripheral nerves. This is the first study showing that hADSC could adopt a perineural niche in vivo and were able to recognize cues for neural crest cell migration of the host. Therefore, we propose that xenografts of human cells into chick embryos can reveal novel behaviors of heterogeneous cell populations, such as response to migration cues.
Ravichandran, Srikanth; Del Sol, Antonio
Understanding how the cellular niche controls the stem cell phenotype is often hampered due to the complexity of variegated niche composition, its dynamics, and nonlinear stem cell-niche interactions. Here, we propose a systems biology view that considers stem cell-niche interactions as a many-body problem amenable to simplification by the concept of mean field approximation. This enables approximation of the niche effect on stem cells as a constant field that induces sustained activation/inhibition of specific stem cell signaling pathways in all stem cells within heterogeneous populations exhibiting the same phenotype (niche determinants). This view offers a new basis for the development of single cell-based computational approaches for identifying niche determinants, which has potential applications in regenerative medicine and tissue engineering. © 2017 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.
Anjali P. Kusumbe
Full Text Available The vasculature of the skeletal system regulates osteogenesis and hematopoiesis, in addition to its primary function as a transportation network. Recent studies suggest that the vasculature in bone regulates multiple steps involved in the metastatic cascade. Matrix and growth factor abundant vascular microenvironments in bone not only provide a fertile soil for the metastatic growth but also support the dormancy of Disseminated Tumour Cells (DTCs. Interestingly, vasculature also seems to direct the reactivation of dormant DTCs. Targeting such early steps of bone metastasis by directing therapies against vascular niches can lead to the development of effective therapeutic strategies that delay or even prevent the metastatic relapse. However, this would require a detailed understanding of the regulatory mechanisms that govern the interaction between endothelial cells and DTCs in the early stages of bone metastasis. This review aims to highlight the importance of vascular niches and outline their newly identified roles during bone metastasis.
Genet, Nafiisha; Bhatt, Neha; Bourdieu, Antonin; Hirschi, Karen K
Considerable progress has been made in the field of stem cell research; nonetheless, the use of stem cells for regenerative medicine therapies, for either endogenous tissue repair or cellular grafts post injury, remains a challenge. To better understand how to maintain stem cell potential in vivo and promote differentiation ex vivo, it is fundamentally important to elucidate the interactions between stem cells and their surrounding partners within their distinct niches. Among the vast array of proteins depicted as mediators for cell-to-cell interactions, connexin-comprised gap junctions play pivotal roles in the regulation of stem cell fate both in vivo and in vitro. This review summarizes and illustrates the current knowledge regarding the multifaceted roles of Cx43, specifically, in various stem cell niches.
In the process of liberalization of the electricity market the customers are now in a position to participate in the decision on how their electricity is produced. In particular, many consumers have a preference for renewable energies. For the producers, marketing of 'eco-power' is an opportunity to achieve sustainable competitive advantage. However, the market share of these products is still quite small today, and 'eco-power' is usually marketed as an expensive niche product. From the perspective of sustainable development these niches are a necessary but not sufficient step. In this book, ways are discussed which could lead to a mass-market penetration of eco-power products. A theoretical analysis is combined with empirical evidence derived from the eco-power market in Germany, Switzerland, Great Britain and the U.S. as well as with a comparison with other market segments [de
Quiner, Claire A; Nakazawa, Yoshinori
Emerging and understudied pathogens often lack information that most commonly used analytical tools require, such as negative controls or baseline data; thus, new analytical strategies are needed to analyze transmission patterns and drivers of disease emergence. Zoonotic infections with Vaccinia virus (VACV) were first reported in Brazil in 1999, VACV is an emerging zoonotic Orthopoxvirus, which primarily infects dairy cattle and farmers in close contact with infected cows. Prospective studies of emerging pathogens could provide critical data that would inform public health planning and response to outbreaks. By using the location of 87-recorded outbreaks and publicly available bioclimatic data, we demonstrate one such approach. Using an ecological niche model (ENM) algorithm, we identify the environmental conditions under which VACV outbreaks have occurred, and determine additional locations in two affected countries that may be susceptible to transmission. Further, we show how suitability for the virus responds to different levels of various environmental factors and highlight the most important factors in determining its transmission. A literature review was performed and the geospatial coordinates of 87 molecularly confirmed VACV outbreaks in Brazil were identified. An ENM was generated using MaxENT software by combining principal component analysis results of 19 bioclim spatial layers, and 25 randomly selected subsets of the original list of 87 outbreaks. The final ENM predicted all areas where Brazilian outbreaks occurred, one out of five of the Colombian outbreak regions and identified new regions within Brazil that are suitable for transmission based on bioclimatic factors. Further, the most important factors in determining transmission suitability are precipitation of the wettest quarter, annual precipitation, mean temperature of the coldest quarter and mean diurnal range. The analyses here provide a means by which to study patterns of an emerging
Social media is becoming more and more important in our daily life as it influences the ways people live and how they think. For example, people no longer just rely on traditional travel agencies for travelling. Thus, how traditional travel agencies survive in such transformation is crucial. In order to find connections between social media and travel agencies marketing strategies, quantitative research was introduced to encourage and help the traditional travel agencies to find their niche m...
Klawonn, M.; Dow, E. M.
Ecological Niche Modeling (ENM) is a collection of techniques to find a "fundamental niche", the range of environmental conditions suitable for a species' survival in the absence of inter-species interactions, given a set of environmental parameters. Traditional approaches to ENM face a number of obstacles including limited data accessibility, data management problems, computational costs, interface usability, and model validation. The MERGANSER system, which stands for Modeling Ecological Residency Given A Normalized Set of Environmental Records, addresses these issues through powerful data persistence and flexible data access, coupled with a clear presentation of results and fine-tuned control over model parameters. MERGANSER leverages data measuring 72 weather related phenomena, land cover, soil type, population, species occurrence, general species information, and elevation, totaling over 1.5 TB of data. To the best of the authors' knowledge, MERGANSER uses higher-resolution spatial data sets than previously published models. Since MERGANSER stores data in an instance of Apache SOLR, layers generated in support of niche models are accessible to users via simplified Apache Lucene queries. This is made even simpler via an HTTP front end that generates Lucene queries automatically. Specifically, a user need only enter the name of a place and a species to run a model. Using this approach to synthesizing model layers, the MERGANSER system has successfully reproduced previously published niche model results with a simplified user experience. Input layers for the model are generated dynamically using OpenStreetMap and SOLR's spatial search functionality. Models are then run using either user-specified or automatically determined parameters after normalizing them into a common grid. Finally, results are visualized in the web interface, which allows for quick validation. Model results and all surrounding metadata are also accessible to the user for further study.
Kulkarni, Girish; Gohil, Kushal; Misra, Vatsala; Kakrani, Arjun L; Misra, Sri P; Patole, Milind; Shouche, Yogesh; Dharne, Mahesh
The human stomach is colonized by diverse bacterial species. The presence of non-Helicobacter pylori bacteria in urease-positive biopsies of individuals has been reported. Bacteria belonging to the Ochrobactrum genus have been documented in the human gastric niche. The co-occurrence of Ochrobactrum spp. with H. pylori was previously reported in an antral biopsy of a non-ulcer dyspeptic (NUD) subject from Northern India. There is no information on the genetic diversity of Ochrobactrum spp. isolated from the gastric niche in the stomach. We aimed to study the species distribution and diversity of Ochrobactrum spp. with and without H. pylori in urease-positive biopsies across three different geographical regions in India. Sixty-two Ochrobactrum isolates recovered from patients with an upper gastric disorder (n=218) were subjected to molecular identification and multilocus sequence typing. H. pylori DNA was found in the majority of biopsies, which had a variable degree of Ochrobactrum spp present. Interestingly, some of the urease-positive biopsies only had Ochrobactrum without any H. pylori DNA. Based on phylogenetic analysis, the Ochrobactrum isolates were distributed into the O. intermedium, O. anthropi and O. oryzae groups. This indicates there are multiple species in the gastric niche irrespective of the presence or absence of H. pylori. Antibiotyping based on colistin and polymyxin B could differentiate between O. intermedium and O. anthropi without revealing the resistance-driven diversity. Considering the prevalence of multiple Ochrobactrum spp. in the human gastric niche, it is important to evaluate the commensal and/or pathogenic nature of non-H. pylori bacteria with respect to their geographical distribution, lifestyle and nutrition needs. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
Liang, Jingjing; Zhou, Mo; Tobin, Patrick C; McGuire, A David; Reich, Peter B
The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity-ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche-efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche-efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species' inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.
Lush, L.; Ward, A. I.; Wheeler, P.
Coexistence of ecologically similar species is sustained by niche partitioning, a fundamental element of which is diet. Overlapping of resource requirements between sympatric species can create interspecific competitive or facilitative effects on the foraging behaviour of herbivores. Brown hares (Lepus europaeus) and European rabbits (Oryctolagus cuniculus) are similar in size, morphology, feeding type and occupy the same habitats, but direct evidence of competition for resources between them...
Meador, Jessica P.; Caldwell, Matthew E.; Cohen, Paul S.; Conway, Tyrrell
Since the first step of the infection process is colonization of the host, it is important to understand how Escherichia coli pathogens successfully colonize the intestine. We previously showed that enterohemorrhagic O157:H7 strain E. coli EDL933 colonizes a niche in the streptomycin-treated mouse intestine that is distinct from that of human commensal strains, which explains how E. coli EDL933 overcomes colonization resistance imparted by some, but not all, commensal E. coli strains. Here we...
Adam L. MacLean
Full Text Available Within populations of cells, fate decisions are controlled by an indeterminate combination of cell-intrinsic and cell-extrinsic factors. In the case of stem cells, the stem cell niche is believed to maintain ‘stemness’ through communication and interactions between the stem cells and one or more other cell-types that contribute to the niche conditions. To investigate the robustness of cell fate decisions in the stem cell hierarchy and the role that the niche plays, we introduce simple mathematical models of stem and progenitor cells, their progeny and their interplay in the niche. These models capture the fundamental processes of proliferation and differentiation and allow us to consider alternative possibilities regarding how niche-mediated signalling feedback regulates the niche dynamics. Generalised stability analysis of these stem cell niche systems enables us to describe the stability properties of each model. We find that although the number of feasible states depends on the model, their probabilities of stability in general do not: stem cell–niche models are stable across a wide range of parameters. We demonstrate that niche-mediated feedback increases the number of stable steady states, and show how distinct cell states have distinct branching characteristics. The ecological feedback and interactions mediated by the stem cell niche thus lend (surprisingly high levels of robustness to the stem and progenitor cell population dynamics. Furthermore, cell–cell interactions are sufficient for populations of stem cells and their progeny to achieve stability and maintain homeostasis. We show that the robustness of the niche – and hence of the stem cell pool in the niche – depends only weakly, if at all, on the complexity of the niche make-up: simple as well as complicated niche systems are capable of supporting robust and stable stem cell dynamics.
Waleed Al Taweel
Full Text Available Aim: The aim of this study is to determine the current trends in the management and surveillance of the NB population secondary to spinal cord injury (SCI or myelomeningocele by certified urologist working in Saudi Arabia and to compare it to the current guidelines. Materials and Methods: A cross-sectional study was conducted using a 12-points questionnaire distributed to urologists working in Saudi Arabia and registered at the Saudi medical association. The assessment and follow-up of upper and lower urinary tract function in neurogenic bladder patients, their optimal frequency and management of related infections were the topics of inquiry. Results: Of the 272 urologists surveyed, 105 responded, yielding a response rate of 38%. Eighty-nine percent of respondents said that ultrasound was their diagnostic tool of choice for upper tract evaluation. Sixty-one percent of respondents said that they would follow their patients with a multichannel urodynamic study. Forty percent of urologists stated that they would treat asymptomatic bacteriuria. Clean intermittent catheterization (CIC was the most common modality chosen for the management of neurogenic bladder in patients with emptying difficulties. Conclusion: This study confirms that most urologists in Saudi Arabia involved with neurogenic bladder management. However, more than one third of the urologists do not have urodynamic machine and only two of the reporting practitioners has a videourodynamic machine. The results emphasize the need for clear guidelines in this field of urology in Saudi Arabia. Highly specialized rehabilitation centers for neurogenic bladder secondary to SCI are required for optimal care and urologist teaching.
Ohnishi, A; Sato, Y; Nagara, H; Sakai, T; Iwashita, H; Kuroiwa, Y; Nakamura, T; Shida, K
In three cases of chorea-acanthocytosis (acanthocytosis and neurological disease, or familial degeneration of the basal ganglia with acanthocytosis), biopsies of short peroneal muscles and sural nerves were studied histologically. The muscles showed groups of atrophic fibres with clumping of sarcolemmal nuclei in all cases. It was concluded that neurogenic muscular atrophy should be included as one of the main pathological findings in chorea-acanthocytosis. The sural nerves showed a small num...
Šedý, Jiří; Zicha, Josef; Nedvídková, J.; Kuneš, Jaroslav
Roč. 112, č. 1 (2012), s. 1-8 ISSN 8750-7587 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/08/0139; GA AV ČR(CZ) IAA500110902 Institutional research plan: CEZ:AV0Z50110509 Keywords : neurogenic pulmonary edema * sympathetic nervous system * baroreflex Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 3.484, year: 2012
Johnson, Matthew G; Granath, Gustaf; Tahvanainen, Teemu; Pouliot, Remy; Stenøien, Hans K; Rochefort, Line; Rydin, Håkan; Shaw, A Jonathan
Peat mosses (Sphagnum) are ecosystem engineers-species in boreal peatlands simultaneously create and inhabit narrow habitat preferences along two microhabitat gradients: an ionic gradient and a hydrological hummock-hollow gradient. In this article, we demonstrate the connections between microhabitat preference and phylogeny in Sphagnum. Using a dataset of 39 species of Sphagnum, with an 18-locus DNA alignment and an ecological dataset encompassing three large published studies, we tested for phylogenetic signal and within-genus changes in evolutionary rate of eight niche descriptors and two multivariate niche gradients. We find little to no evidence for phylogenetic signal in most component descriptors of the ionic gradient, but interspecific variation along the hummock-hollow gradient shows considerable phylogenetic signal. We find support for a change in the rate of niche evolution within the genus-the hummock-forming subgenus Acutifolia has evolved along the multivariate hummock-hollow gradient faster than the hollow-inhabiting subgenus Cuspidata. Because peat mosses themselves create some of the ecological gradients constituting their own habitats, the classic microtopography of Sphagnum-dominated peatlands is maintained by evolutionary constraints and the biological properties of related Sphagnum species. The patterns of phylogenetic signal observed here will instruct future study on the role of functional traits in peatland growth and reconstruction. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Calvi, Laura M
Hematopoietic stem cells (HSC) are rare primitive cells capable of reconstituting all blood cell lineages throughout the life of an individual. The microenvironment in which stem cells reside is essential for their survival, self-renewal, and differentiation. This microenvironment, or HSC niche, has been difficult to define in bone and bone marrow, but recent studies from our laboratory and others have shown that osteoblasts, the bone-forming cells, are an essential regulatory component of this complex cellular network. We established that parathyroid hormone (PTH), through activation of the PTH/PTHrP receptor (PTH1R) in osteoblastic cells, could alter the HSC niche resulting in HSC expansion in vivo and in vitro and improving dramatically the survival of mice receiving bone marrow transplants. These findings are of great clinical appeal, because they suggest that a strategy aimed at modifying supportive cells in a stem cell niche can expand HSC. While a number of molecules have been found to be important for hematopoietic/osteoblastic interactions, we have focused on the Jagged1/Notch signaling pathway, which was necessary for the PTH-dependent HSC expansion. Since the Jagged1/Notch signaling pathway has been implicated in the microenvironmental control of stem cell self-renewal in several organ systems, definition of Jagged1 modulation, which is currently poorly understood, should provide additional molecular targets for stem cell regulation and advance the understanding of stem cell-microenvironmental interactions.
Domingues, Mélanie J; Cao, Huimin; Heazlewood, Shen Y; Cao, Benjamin; Nilsson, Susan K
Maintenance of hematopoietic stem cells (HSC) takes place in a highly specialized microenvironment within the bone marrow. Technological improvements, especially in the field of in vivo imaging, have helped unravel the complexity of the niche microenvironment and have completely changed the classical concept from what was previously believed to be a static supportive platform, to a dynamic microenvironment tightly regulating HSC homeostasis through the complex interplay between diverse cell types, secreted factors, extracellular matrix molecules, and the expression of different transmembrane receptors. To add to the complexity, non-protein based metabolites have also been recognized as a component of the bone marrow niche. The objective of this review is to discuss the current understanding on how the different extracellular matrix components of the niche regulate HSC fate, both during embryonic development and in adulthood. Special attention will be provided to the description of non-protein metabolites, such as lipids and metal ions, which contribute to the regulation of HSC behavior. J. Cell. Biochem. 118: 1984-1993, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Whiten, Andrew; Erdal, David
Hominin evolution took a remarkable pathway, as the foraging strategy extended to large mammalian prey already hunted by a guild of specialist carnivores. How was this possible for a moderately sized ape lacking the formidable anatomical adaptations of these competing ‘professional hunters’? The long-standing answer that this was achieved through the elaboration of a new ‘cognitive niche’ reliant on intelligence and technology is compelling, yet insufficient. Here we present evidence from a diversity of sources supporting the hypothesis that a fuller answer lies in the evolution of a new socio-cognitive niche, the principal components of which include forms of cooperation, egalitarianism, mindreading (also known as ‘theory of mind’), language and cultural transmission, that go far beyond the most comparable phenomena in other primates. This cognitive and behavioural complex allows a human hunter–gatherer band to function as a unique and highly competitive predatory organism. Each of these core components of the socio-cognitive niche is distinctive to humans, but primate research has increasingly identified related capacities that permit inferences about significant ancestral cognitive foundations to the five pillars of the human social cognitive niche listed earlier. The principal focus of the present study was to review and integrate this range of recent comparative discoveries. PMID:22734055
Mohammad Saiful Mansor
Full Text Available Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i how these babblers forage in the wild and use vegetation to obtain food, and ii how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause' law of competitive exclusion, which states two species occupying the same niche will not stably coexist.
Asada, Noboru; Kunisaki, Yuya; Pierce, Halley; Wang, Zichen; Fernandez, Nicolas F; Birbrair, Alexander; Ma'ayan, Avi; Frenette, Paul S
Arterioles and sinusoids of the bone marrow (BM) are accompanied by stromal cells that express nerve/glial antigen 2 (NG2) and leptin receptor (LepR), and constitute specialized niches that regulate quiescence and proliferation of haematopoietic stem cells (HSCs). However, how niche cells differentially regulate HSC functions remains unknown. Here, we show that the effects of cytokines regulating HSC functions are dependent on the producing cell sources. Deletion of chemokine C-X-C motif ligand 12 (Cxcl12) or stem cell factor (Scf) from all perivascular cells marked by nestin-GFP dramatically depleted BM HSCs. Selective Cxcl12 deletion from arteriolar NG2 + cells, but not from sinusoidal LepR + cells, caused HSC reductions and altered HSC localization in BM. By contrast, deletion of Scf in LepR + cells, but not NG2 + cells, led to reductions in BM HSC numbers. These results uncover distinct contributions of cytokines derived from perivascular cells in separate vascular niches to HSC maintenance.