Layered CeSO and LiCeSO Oxide Chalcogenides Obtained via Topotactic Oxidative and Reductive Transformations.

The chemical accessibility of the CeIV oxidation state enables redox chemistry to be performed on the naturally coinage-metal-deficient phases CeM1- xSO (M = Cu, Ag). A metastable black compound with the PbFCl structure type (space group P4/ nmm: a = 3.8396(1) Å, c = 6.607(4) Å, V = 97.40(6) Å3) and a composition approaching CeSO is obtained by deintercalation of Ag from CeAg0.8SO. High-resolution transmission electron microscopy reveals the presence of large defect-free regions in CeSO, but stacking faults are also evident which can be incorporated into a quantitative model to account for the severe peak anisotropy evident in all the high-resolution X-ray and neutron diffractograms of bulk CeSO samples; these suggest that a few percent of residual Ag remains. A straw-colored compound with the filled PbFCl (i.e., ZrSiCuAs- or HfCuSi2-type) structure (space group P4/ nmm: a = 3.98171(1) Å, c = 8.70913(5) Å, V = 138.075(1) Å3) and a composition close to LiCeSO, but with small amounts of residual Ag, is obtained by direct reductive lithiation of CeAg0.8SO or by insertion of Li into CeSO using chemical or electrochemical means. Computation of the band structure of pure, stoichiometric CeSO predicts it to be a Ce4+ compound with the 4f-states lying approximately 1 eV above the sulfide-dominated valence band maximum. Accordingly, the effective magnetic moment per Ce ion measured in the CeSO samples is much reduced from the value found for the Ce3+-containing LiCeSO, and the residual paramagnetism corresponds to the Ce3+ ions remaining due to the presence of residual Ag, which presumably reflects the difficulty of stabilizing Ce4+ in the presence of sulfide (S2-). Comparison of the behavior of CeCu0.8SO with that of CeAg0.8SO reveals much slower reaction kinetics associated with the Cu1- xS layers, and this enables intermediate CeCu1- xLi xSO phases to be isolated.

Low load for disruptive mutations in autism genes and their biased transmission.

We previously computed that genes with de novo (DN) likely gene-disruptive (LGD) mutations in children with autism spectrum disorders (ASD) have high vulnerability: disruptive mutations in many of these genes, the vulnerable autism genes, will have a high likelihood of resulting in ASD. Because individuals with ASD have lower fecundity, such mutations in autism genes would be under strong negative selection pressure. An immediate prediction is that these genes will have a lower LGD load than typical genes in the human gene pool. We confirm this hypothesis in an explicit test by measuring the load of disruptive mutations in whole-exome sequence databases from two cohorts. We use information about mutational load to show that lower and higher intelligence quotients (IQ) affected individuals can be distinguished by the mutational load in their respective gene targets, as well as to help prioritize gene targets by their likelihood of being autism genes. Moreover, we demonstrate that transmission of rare disruptions in genes with a lower LGD load occurs more often to affected offspring; we show transmission originates most often from the mother, and transmission of such variants is seen more often in offspring with lower IQ. A surprising proportion of transmission of these rare events comes from genes expressed in the embryonic brain that show sharply reduced expression shortly after birth.

Derived variants at six genes explain nearly half of size reduction in dog breeds.

Selective breeding of dogs by humans has generated extraordinary diversity in body size. A number of multibreed analyses have been undertaken to identify the genetic basis of this diversity. We analyzed four loci discovered in a previous genome-wide association study that used 60,968 SNPs to identify size-associated genomic intervals, which were too large to assign causative roles to genes. First, we performed fine-mapping to define critical intervals that included the candidate genes GHR, HMGA2, SMAD2, and STC2, identifying five highly associated markers at the four loci. We hypothesize that three of the variants are likely to be causative. We then genotyped each marker, together with previously reported size-associated variants in the IGF1 and IGF1R genes, on a panel of 500 domestic dogs from 93 breeds, and identified the ancestral allele by genotyping the same markers on 30 wild canids. We observed that the derived alleles at all markers correlated with reduced body size, and smaller dogs are more likely to carry derived alleles at multiple markers. However, breeds are not generally fixed at all markers; multiple combinations of genotypes are found within most breeds. Finally, we show that 46%-52.5% of the variance in body size of dog breeds can be explained by seven markers in proximity to exceptional candidate genes. Among breeds with standard weights <41 kg (90 lb), the genotypes accounted for 64.3% of variance in weight. This work advances our understanding of mammalian growth by describing genetic contributions to canine size determination in non-giant dog breeds.

Occupation matrix control of d- and f-electron localisations using DFT + U.

The use of a density functional theory methodology with on-site corrections (DFT + U) has been repeatedly shown to give an improved description of localised d and f states over those predicted with a standard DFT approach. However, the localisation of electrons also carries with it the problem of metastability, due to the possible occupation of different orbitals and different locations. This study details the use of an occupation matrix control methodology for simulating localised d and f states with a plane-wave DFT + U approach which allows the user to control both the site and orbital localisation. This approach is tested for orbital occupation using octahedral and tetrahedral Ti(iii) and Ce(iii) carbonyl clusters and for orbital and site location using the periodic systems anatase-TiO2 and CeO2. The periodic cells are tested by the addition of an electron and through the formation of a neutral oxygen vacancy (leaving two electrons to localise). These test systems allow the successful study of orbital degeneracies, the presence of metastable states and the importance of controlling the site of localisation within the cell, and it highlights the use an occupation matrix control methodology can have in electronic structure calculations.

Production of the alkaloid swainsonine by a fungal endophyte in the host Swainsona canescens.

Legumes belonging to the Astragalus, Oxytropis, and Swainsona genera have been noted by ranchers in the Americas, Asia, and Australia to cause a neurologic disease often referred to as locoism or peastruck. The toxin in these legumes is swainsonine, an α-mannosidase and mannosidase II inhibitor. Recent research has shown that in Astragalus and Oxytropis species swainsonine is produced by a fungal endophyte belonging to the Undifilum genus. Here Swainsona canescens is shown to harbor an endophyte that is closely related to Undifilum species previously cultured from locoweeds of North America and Asia. The endophyte produces swainsonine in vitro and was detected by PCR and culturing in S. canescens. The endophyte isolated from S. canescens was characterized as an Undifilum species using morphological and phylogenetic analyses.

Medicaid coverage practices for approved gene and cell therapies: Existing barriers and proposed policy solutions.

The current Medicaid system is ill equipped to handle the anticipated approvals of new gene and cell therapy products. These advanced therapies tend to be single-dose, potentially durable options for a variety of indications spanning oncology, rare disease, and more. The up-front cost of these therapies contrasts with chronic care treatment, which may incur cost over the life of a patient. The cost of these innovative treatments, along with the anticipated larger patient pools, can limit patient access as Medicaid programs operate on limited or fixed budgets. Given the value of these therapies for diseases that may have large Medicaid populations, the system will need to grapple with the existing barriers to access to ensure equitable patient care. This review focuses on one such barrier, discrepancies between product indications and state Medicaid and Medicaid Managed Care Organization coverage policies, and it proposes federal policy solutions to this barrier to better accommodate the exponential growth of the gene and cell therapy pipeline.

Extreme plasticity of reproductive state in a female rodent.

Successful sexual reproduction relies on the coordination of multiple biological systems, yet traditional concepts of biological sex often ignore the natural plasticity in morphology and physiology underlying sex. Most female mammals develop a patent (i.e., opened) vaginal entrance (introitus) prenatally or postnatally before or during puberty, usually under the influence of estrogens, and remain patent for the remainder of their lifespan1. An exception is the southern African giant pouched rat (Cricetomys ansorgei), whose vaginal introitus remains sealed well into adulthood2. Here, we explore this phenomenon and report that the reproductive organs and the vaginal introitus can undergo astounding and reversible transformation. Non-patency is characterized by reduced uterine size and the presence of a sealed vaginal introitus. Furthermore, the female urine metabolome shows that patent and non-patent females profoundly differ in their urine content, a reflection of differences in physiology and metabolism. Surprisingly, patency state did not predict fecal estradiol or progesterone metabolite concentrations. Exploring the plasticity that exists in reproductive anatomy and physiology can uncover that traits long considered 'fixed' in adulthood can become plastic under specific evolutionary pressures. Moreover, the barriers to reproduction that such plasticity creates present unique challenges to maximizing reproductive potential.

Impaired defense mechanism against inflammation, hyperalgesia, and airway hyperreactivity in somatostatin 4 receptor gene-deleted mice.

We have shown that somatostatin released from activated capsaicin-sensitive nociceptive nerve endings during inflammatory processes elicits systemic anti-inflammatory and analgesic effects. With the help of somatostatin receptor subtype 4 gene-deleted mice (sst(4)(-/-)), we provide here several lines of evidence that this receptor has a protective role in a variety of inflammatory disease models; several symptoms are more severe in the sst(4) knockout animals than in their wild-type counterparts. Acute carrageenan-induced paw edema and mechanical hyperalgesia, inflammatory pain in the early phase of adjuvant-evoked chronic arthritis, and oxazolone-induced delayed-type hypersensitivity reaction in the skin are much greater in mice lacking the sst(4) receptor. Airway inflammation and consequent bronchial hyperreactivity elicited by intranasal lipopolysaccharide administration are also markedly enhanced in sst(4) knockouts, including increased perivascular/peribronchial edema, neutrophil/macrophage infiltration, mucus-producing goblet cell hyperplasia, myeloperoxidase activity, and IL-1beta, TNF-alpha, and IFN-gamma expression in the inflamed lung. It is concluded that during these inflammatory conditions the released somatostatin has pronounced counterregulatory effects through sst(4) receptor activation. Thus, this receptor is a promising novel target for developing anti-inflammatory, analgesic, and anti-asthmatic drugs.

The structure and dynamics of hydrated and hydroxylated magnesium oxide nanoparticles.

An understanding of the structure of water on metal oxide nanoparticles is important due to its involvement in a number of surface processes, such as in the modification of transport near surfaces and the resulting impact on crystal growth and dissolution. However, as direct experimental measurements probing the metal oxide-water interface of nanoparticles are not easily performed, we use atomistic simulations using experimentally derived potential parameters to determine the structure and dynamics of the interface between magnesium oxide nanoparticles and water. We use a simple strategy to generate mineral nanoparticles, which can be applied to any shape, size, or composition. Molecular dynamics simulations were then used to examine the structure of water around the nanoparticles, and highly ordered layers of water were found at the interface. The structure of water is strongly influenced by the crystal structure and morphology of the mineral and the extent of hydroxylation of the surface. Comparison of the structure and dynamics of water around the nanoparticles with their two-dimensional flat surface counterparts revealed that the size, shape, and surface composition also affects properties such as water residence times and coordination number.

Schistosoma mansoni: egg-induced downregulation of hepatic stellate cell activation and fibrogenesis.

Eggs of Schistosoma mansoni trapped in human liver can lead to fibrosis. Since liver fibrosis requires activation of hepatic stellate cells (HSC) from a quiescent to a myofibroblastic phenotype, we investigated the effects of S. mansoni eggs on this process using in vitro co-cultures with human HSC and evaluated established biomarkers for activation and fibrosis. HSC demonstrate significantly reduced expression of alpha-smooth muscle actin (p<0.001), connective tissue growth factor (p<0.01) and type I collagen (p<0.001) but significantly increased expression of peroxisome proliferator-activated receptor-gamma (p<0.01). Morphologically, HSC exhibited elongated fine cellular processes and reduced size, increased accumulation of lipid droplets and reduced expression and organization of alpha-smooth muscle actin and F-actin stress fibres. Additionally, schistosome eggs prevented the HSC fibrogenic response to exogenous transforming growth factor-beta. In summary, schistosome eggs blocked fibrogenesis in HSC, a finding which may have implications for our understanding of the fibrotic pathology in S. mansoni infections.

Assessing the risk of residues of the toxin indospicine in bovine muscle and liver from north-west Australia.

Indospicine is a natural toxin occurring only in Indigofera plant species, including the Australian native species I. linnaei. These perennial legumes are resistant to drought and palatable to grazing livestock including cattle. Indospicine accumulates in the tissues (including muscle) of animals grazing Indigofera and these residues persist for several months after exposure. Dogs are particularly sensitive to indospicine with reports in past decades of hepatotoxicosis and mortalities in dogs after dietary exposure to indospicine-contaminated horse and camel meat. The risk for human consumption is not known, and the current study was undertaken to assess indospicine levels in cattle going to slaughter from divergent regions of Western Australia, and to predict the likelihood of significant residues being present. Muscle and corresponding liver samples from 776 cattle originating from the Kimberley and Pilbara Regions in the tropical north of the state, where I. linnaei is prevalent, and 640 cattle from the South West and South Coast Regions in the temperate south west of the state, where the plant is not known to occur, were collected at abattoirs over four seasons in 2015-2017. Indospicine levels were measured by LC-MS/MS and ranged from below detection to 3.63 mg/kg. No indospicine residues were detected in any of the animals originating from the South West and South Coast Regions. Prevalence of indospicine residues in cattle from the Kimberley Region was as high as 33% in spring and 91% in autumn, with positive animals being present in most consignments and on most properties. The average prevalence of indospicine residues from the Kimberley and Pilbara Regions throughout the survey period was 63%. @Risk best fit probability distributions showed ninety-fifth percentile (P95) indospicine concentrations of 0.54 mg/kg for muscle and 0.77 mg/kg for liver in cattle originating from the Kimberley and Pilbara Regions during the survey period. When considered with average Australian meat consumption data, the estimated consumer exposure from this P95 muscle was 0.32 µg indospicine/kg bw/day, which compared favourably with our calculated provisional tolerable daily intake (PTDI) of 1.3 µg indospicine/kg bw/day. However canine exposure is of potential concern, with active working dog exposure calculated to exceed this PTDI by a factor of 25, based on a P95 indospicine concentration of 0.54 mg/kg in muscle.

The omega-3 fatty acid, eicosapentaenoic acid (EPA), prevents the damaging effects of tumour necrosis factor (TNF)-alpha during murine skeletal muscle cell differentiation.

BACKGROUND: Eicosapentaenoic acid (EPA) is a omega-3 polyunsaturated fatty acid with anti-inflammatory and anti-cachetic properties that may have potential benefits with regards to skeletal muscle atrophy conditions where inflammation is present. It is also reported that pathologic levels of the pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha are associated with muscle wasting, exerted through inhibition of myogenic differentiation and enhanced apoptosis. These findings led us to hypothesize that EPA may have a protective effect against skeletal muscle damage induced by the actions of TNF-alpha. RESULTS: The deleterious effects of TNF-alpha on C2C12 myogenesis were completely inhibited by co-treatment with EPA. Thus, EPA prevented the TNF-mediated loss of MyHC expression and significantly increased myogenic fusion (p < 0.05) and myotube diameter (p < 0.05) indices back to control levels. EPA protective activity was associated with blocking cell death pathways as EPA completely attenuated TNF-mediated increases in caspase-8 activity (p < 0.05) and cellular necrosis (p < 0.05) back to their respective control levels. EPA alone significantly reduced spontaneous apoptosis and necrosis of differentiating myotubes (p < 0.001 and p < 0.05, respectively). A 2 hour pre-treatment with EPA, prior to treatment with TNF alone, gave similar results. CONCLUSION: In conclusion, EPA has a protective action against the damaging effects of TNF-alpha on C2C12 myogenesis. These findings support further investigations of EPA as a potential therapeutic agent during skeletal muscle regeneration following injury.

Disruption of ephrin signaling associates with disordered axophilic migration of the gonadotropin-releasing hormone neurons.

Ephrin signaling is involved in repulsive and attractive interactions mediating axon guidance and cell-boundary formation in the developing nervous system. As a result of a fortuitous transgene integration event, we have identified here a potential role for EphA5 in the axophilic migration of gonadotropin-releasing hormone (GnRH) neurons from the nasal placode into the brain along ephrin-expressing vomeronasal axons. Transgene integration in the GNR23 mouse line resulted in a 26 kb deletion in chromosome 5, approximately 67 kb 3' to Epha5. This induced a profound, region-specific upregulation of EphA5 mRNA and protein expression in the developing mouse brain. The GnRH neurons in GNR23 mice overexpressed EphA5 from embryonic day 11, whereas ephrin A3 and A5 mRNA levels in olfactory neurons were unchanged. The GnRH neurons were found to be slow in commencing their migration from the olfactory placode and also to form abnormal clusters of cells on the olfactory axons, prohibiting their migration out of the nose. As a result, adult hemizygous mice had only 40% of the normal complement of GnRH neurons in the brain, whereas homozygous mice had <15%. This resulted in infertility in adult female homozygous GNR23 mice, suggesting that some cases of human hypogonadotropic hypogonadism may result from ephrin-related mutations. These data provide evidence for a role of EphA-ephrin signaling in the axophilic migration of the GnRH neurons during embryogenesis.

The Differential Hormonal Milieu of Morning versus Evening May Have an Impact on Muscle Hypertrophic Potential.

Substantial gains in muscle strength and hypertrophy are clearly associated with the routine performance of resistance training. What is less evident is the optimal timing of the resistance training stimulus to elicit these significant functional and structural skeletal muscle changes. Therefore, this investigation determined the impact of a single bout of resistance training performed either in the morning or evening upon acute anabolic signalling (insulin-like growth factor-binding protein-3 (IGFBP-3), myogenic index and differentiation) and catabolic processes (cortisol). Twenty-four male participants (age 21.4±1.9yrs, mass 83.7±13.7kg) with no sustained resistance training experience were allocated to a resistance exercise group (REP). Sixteen of the 24 participants were randomly selected to perform an additional non-exercising control group (CP) protocol. REP performed two bouts of resistance exercise (80% 1RM) in the morning (AM: 0800 hrs) and evening (PM: 1800 hrs), with the sessions separated by a minimum of 72 hours. Venous blood was collected immediately prior to, and 5 min after, each resistance exercise and control sessions. Serum cortisol and IGFBP-3 levels, myogenic index, myotube width, were determined at each sampling period. All data are reported as mean ± SEM, statistical significance was set at P≤0.05. As expected a significant reduction in evening cortisol concentration was observed at pre (AM: 98.4±10.5, PM: 49.8±4.4 ng/ml, P<0.001) and post (AM: 98.0±9.0, PM: 52.7±6.0 ng/ml, P<0.001) exercise. Interestingly, individual cortisol differences pre vs post exercise indicate a time-of-day effect (AM difference: -2±2.6%, PM difference: 14.0±6.7%, P = 0.03). A time-of-day related elevation in serum IGFBP-3 (AM: 3274.9 ± 345.2, PM: 3605.1 ± 367.5, p = 0.032) was also evident. Pre exercise myogenic index (AM: 8.0±0.6%, PM: 16.8±1.1%) and myotube width (AM: 48.0±3.0, PM: 71.6±1.9 µm) were significantly elevated (P<0.001) in the evening. Post exercise myogenic index was greater AM (11.5±1.6%) compared with PM (4.6±0.9%). No difference was observed in myotube width (AM: 48.5±1.5, PM: 47.8±1.8 µm) (P>0.05). Timing of resistance training regimen in the evening appears to augment some markers of hypertrophic potential, with elevated IGFBP-3, suppressed cortisol and a superior cellular environment. Further investigation, to further elucidate the time course of peak anabolic signalling in morning vs evening training conditions, are timely.

Somatostatin receptor 2 is activated in cortical neurons and contributes to neurodegeneration after focal ischemia.

Somatostatin receptor 2 (SSTR2) mediates neuromodulatory signals of somatostatin and cortistatin in the cerebral cortex. Recently, SSTR2 has been shown to enhance conserved death ligand- and mitochondria-mediated apoptotic pathways in non-neuronal cells. Whether somatostatin receptors are activated in cerebrocortical neurons and contribute to neurodegeneration after experimental focal ischemia was unknown until now. Here we examined internalization of SSTR2 in a rat model of middle cerebral artery occlusion (MCAO) by confocal microscopy. At 3 and 6 hr after MCAO, SSTR2 was internalized excessively in cerebrocortical neurons adjacent to the infarct, which was prevented by intracerebroventricular application of the SSTR2-selective antagonist BIM-23627. SSTR2 internalization was associated with a transient depletion of somatostatin from axonal terminals and increased expression of SSTR2 mRNA. The initial loss of somatostatin was followed by an increase in somatostatin mRNA levels, whereas cortistatin mRNA expression was decreased. In SSTR2-deficient mice with lacZ under the control of the SSTR2 promoter, MCAO-induced upregulation of SSTR2 gene expression was less pronounced than in wild types. SSTR2-deficient mice exhibited a 40% reduction of infarct size after permanent distal MCAO and a 63% reduction after transient proximal MCAO. In summary, we provide direct evidence for activation of SSTR2 by an endogenous ligand after focal ischemia. Activation of functional SSTR2 receptors contributes to increased SSTR2 gene expression and postischemic neurodegeneration.

TGF-beta1 induces human alveolar epithelial to mesenchymal cell transition (EMT).

BACKGROUND: Fibroblastic foci are characteristic features in lung parenchyma of patients with idiopathic pulmonary fibrosis (IPF). They comprise aggregates of mesenchymal cells which underlie sites of unresolved epithelial injury and are associated with progression of fibrosis. However, the cellular origins of these mesenchymal phenotypes remain unclear. We examined whether the potent fibrogenic cytokine TGF-beta1 could induce epithelial mesenchymal transition (EMT) in the human alveolar epithelial cell line, A549, and investigated the signaling pathway of TGF-beta1-mediated EMT. METHODS: A549 cells were examined for evidence of EMT after treatment with TGF-beta1. EMT was assessed by: morphology under phase-contrast microscopy; Western analysis of cell lysates for expression of mesenchymal phenotypic markers including fibronectin EDA (Fn-EDA), and expression of epithelial phenotypic markers including E-cadherin (E-cad). Markers of fibrogenesis, including collagens and connective tissue growth factor (CTGF) were also evaluated by measuring mRNA level using RT-PCR, and protein by immunofluorescence or Western blotting. Signaling pathways for EMT were characterized by Western analysis of cell lysates using monoclonal antibodies to detect phosphorylated Erk1/2 and Smad2 after TGF-beta1 treatment in the presence or absence of MEK inhibitors. The role of Smad2 in TGF-beta1-mediated EMT was investigated using siRNA. RESULTS: The data showed that TGF-beta1, but not TNF-alpha or IL-1beta, induced A549 cells with an alveolar epithelial type II cell phenotype to undergo EMT in a time-and concentration-dependent manner. The process of EMT was accompanied by morphological alteration and expression of the fibroblast phenotypic markers Fn-EDA and vimentin, concomitant with a downregulation of the epithelial phenotype marker E-cad. Furthermore, cells that had undergone EMT showed enhanced expression of markers of fibrogenesis including collagens type I and III and CTGF. MMP-2 expression was also evidenced. TGF-beta1-induced EMT occurred through phosphorylation of Smad2 and was inhibited by Smad2 gene silencing; MEK inhibitors failed to attenuate either EMT-associated Smad2 phosphorylation or the observed phenotypic changes. CONCLUSION: Our study shows that TGF-beta1 induces A549 alveolar epithelial cells to undergo EMT via Smad2 activation. Our data support the concept of EMT in lung epithelial cells, and suggest the need for further studies to investigate the phenomenon.

Identification of cells expressing somatostatin receptor 2 in the gastrointestinal tract of Sstr2 knockout/lacZ knockin mice.

Somatostatin is found in neurons and endocrine cells in the gastrointestinal tract. The actions of somatostatin are mediated by a family of G-protein-coupled receptors that compose five subtypes (SSTR1-5), each of which is encoded by a separate gene. lacZ "knockin" mice, in which the reporter gene lacZ was engineered into the genomic locus of Sstr2 by gene targeting, were used to examine the expression pattern of Sstr2 and identify potential targets for neurally released and hormonal somatostatin in the gastrointestinal tract. In the body of the stomach, a large proportion of epithelial cells and subpopulations of myenteric neurons expressed Sstr2. Double- or triple-labeling with antisera to H(+)K(+)ATPase (to identify parietal cells) and/or histidine decarboxylase (to identify enterochromaffin-like [ECL] cells) combined with beta-galactosidase staining revealed that both parietal cells and ECL cells expressed Sstr2, and these two cell types accounted for almost all of the Sstr2-expressing epithelial cells. Somatostatin inhibits gastric acid secretion. The presence of SSTR2 on both parietal and ECL cells suggests that somatostatin acting on SSTR2 may reduce acid secretion by both acting directly on parietal cells and by reducing histamine release from ECL cells. In the small and large intestine, subpopulations of neurons in the myenteric and submucosal plexuses expressed Sstr2, and many of the Sstr2-expressing myenteric neurons also showed SSTR2(a) immunostaining. Most of Sstr2-expressing neurons in the myenteric plexus showed nitric oxide synthase (NOS) immunoreactivity. Previous studies have shown that NOS neurons are descending interneurons and anally projecting, inhibitory motor neurons. Thus, somatostatin acting at SSTR2 receptors on NOS neurons might modulate descending relaxation.

Growth factors in idiopathic pulmonary fibrosis: relative roles.

Treatment of idiopathic pulmonary fibrosis patients has evolved very slowly; the fundamental approach of corticosteroids alone or in combination with other immunosuppressive agents has had little impact on long-term survival. The continued use of corticosteroids is justified because of the lack of a more effective alternative. Current research indicates that the mechanisms driving idiopathic pulmonary fibrosis reflect abnormal, dysregulated wound healing within the lung, involving increased activity and possibly exaggerated responses by a spectrum of profibrogenic growth factors. An understanding of the roles of these growth factors, and the way in which they modulate events at cellular level, could lead to more targeted therapeutic strategies, improving patients' quality of life and survival.

Somatostatin inhibits potassium-evoked glutamate release by activation of the sst(2) somatostatin receptor in the mouse retina.

In the mammalian retina, somatostatin (SRIF-14) acts through distinct receptor subtypes (sst(1-5)). Among them, sst(2) has been localized to numerous retinal cells, including photoreceptors and rod bipolar cells (RBCs). The specific role of sst(2) in the retina is largely undetermined. In this study, we characterized retinas of mice with targeted deletion of sst(2) (sst(2) KO) and we investigated functions of sst(2) in respect to its possible modulation of glutamate (GLU) release, as measured by HPLC. In contrast with wild-type (WT) mice, sst(2) mRNA and sst(2A) immunoreactivity were no longer detectable in the retina of sst(2) KO mice. In retinal explants of WT mice, SRIF and its analogue octreotide that displays high selectivity for sst(2), similarly reduced the evoked release of GLU without affecting its basal level. In sst(2) KO retinas, SRIF or octreotide did not affect GLU release indicating that they act at sst(2). Unexpectedly, the compound CYN-154806, although introduced as the first potent sst(2) antagonist, reduced the evoked release of GLU with equipotency to SRIF and octreotide. Its inhibitory effect was no longer observed in sst(2) KO retinas, indicating that this substance acts at sst(2) receptors as an agonist. In conclusion, SRIF controls evoked release of GLU through sst(2) receptors and this control may represent part of a mechanism by which SRIF regulates GLU concentration in the retina.