Selective effect of thiazides on the human osteoblast-like cell line MG-63

Selective effect of thiazides on the human osteoblast-like cell line MG-63. Thiazide diuretics have been shown to decrease bone-loss rate and to improve bone mineral density in patients using this medication. However, the exact role of thiazides on bone cells is still debated. In the present work, we studied whether thiazides could affect the normal features of osteoblasts using the human model cell line MG-63. Hydrochlorothiazide (HCTZ) did not affect cell growth nor DNA synthesis in these cells, yet slightly increased alkaline phosphatase activity in these cells at pharmacologically relevant concentrations. Under similar conditions, HCTZ dose-dependently inhibited 1,25(OH)2D3-induced osteocalcin secretion by these cells (maximal effect, -40 to 50%, P < 0.005). However, HCTZ did not inhibit the basal production of osteocalcin in MG-63 cells (without 1,25(OH)2D3 induction), which was very low to undectable. Two different thiazide derivatives, chlorothiazide and cyclothiazide, and two structurally related sulfonamides with selective inhibition of carbonic anhydrase (Acetazolamide) or hyperglycemic effects (Diazoxide) were also tested. Chlorothiazide (1000 µm) inhibited osteocalcin secretion (-42 ± 12.7%) at doses 10-fold higher than HCTZ (100 µm) while cyclothiazide was effective at doses of 1 µm(-27 ± 3.6%), and hence 100-fold lower than HCTZ, compatible with the relative natriuretic effect in vivo of these compounds. Acetazolamide (10 µm) poorly affected osteocalcin secretion at doses 100-fold higher than those needed in vivo to inhibit carbonic anhydrase. Likewise, Diazoxide (100 µm) poorly affected osteocalcin secretion at doses known to promote its biological effect. Higher doses of acetazolamide and diazoxide induced cell death. Neither Acetazolamide nor Diazoxide affected alkaline phosphatase, whereas chlorothiazide had a weak positive effect on this enzymatic activity. The production of macrophage colony-stimulating factor (M-CSF) was stimulated in the presence of 1,25(OH)2D3 (50nm), TNF-α (2 ng/ml) both in MG-63 cells. HCTZ (25 µm, 24hr of preincubation) did not modify basal M-CSF production and did not reduce the response to 1,25(OH)2D3 alone. In contrast, HCTZ inhibited the response to TNF-α alone (P < 0,05), and also reduced the response to a combination of 1,25(OH)2D3 and TNF-α (P < 0.01). In conclusion, these results indicate that thiazide diuretics show a selective inhibion of osteocalcin secretion and M-CSF production by MG-63 cells unlike structurally related drugs. Therefore, these features may explain, in part, the positive effect of thiazides on bone mineral density

Flow rule, self-channelization and levees in unconfined granular flows

Unconfined granular flows along an inclined plane are investigated experimentally. During a long transient, the flow gets confined by quasistatic banks but still spreads laterally towards a well-defined asymptotic state following a nontrivial process. Far enough from the banks a scaling for the depth averaged velocity is obtained, which extends the one obtained for homogeneous steady flows. Close to jamming it exhibits a crossover towards a nonlocal rheology. We show that the levees, commonly observed along the sides of the deposit upon interruption of the flow, disappear for long flow durations. We demonstrate that the morphology of the deposit builds up during the flow, in the form of an underlying static layer, which can be deduced from surface velocity profiles, by imposing the same flow rule everywhere in the flow.Comment: 4 pages, 5 figure

Improved Resolution of Reef-Coral Endosymbiont (Symbiodinium) Species Diversity, Ecology, and Evolution through psbA Non-Coding Region Genotyping

Ribosomal DNA sequence data abounds from numerous studies on the dinoflagellate endosymbionts of corals, and yet the multi-copy nature and intragenomic variability of rRNA genes and spacers confound interpretations of symbiont diversity and ecology. Making consistent sense of extensive sequence variation in a meaningful ecological and evolutionary context would benefit from the application of additional genetic markers. Sequences of the non-coding region of the plastid psbA minicircle (psbAncr) were used to independently examine symbiont genotypic and species diversity found within and between colonies of Hawaiian reef corals in the genus Montipora. A single psbAncr haplotype was recovered in most samples through direct sequencing (∼80–90%) and members of the same internal transcribed spacer region 2 (ITS2) type were phylogenetically differentiated from other ITS2 types by substantial psbAncr sequence divergence. The repeated sequencing of bacterially-cloned fragments of psbAncr from samples and clonal cultures often recovered a single numerically common haplotype accompanied by rare, highly-similar, sequence variants. When sequence artifacts of cloning and intragenomic variation are factored out, these data indicate that most colonies harbored one dominant Symbiodinium genotype. The cloning and sequencing of ITS2 DNA amplified from these same samples recovered numerically abundant variants (that are diagnostic of distinct Symbiodinium lineages), but also generated a large amount of sequences comprising PCR/cloning artifacts combined with ancestral and/or rare variants that, if incorporated into phylogenetic reconstructions, confound how small sequence differences are interpreted. Finally, psbAncr sequence data from a broad sampling of Symbiodinium diversity obtained from various corals throughout the Indo-Pacific were concordant with ITS lineage membership (defined by denaturing gradient gel electrophoresis screening), yet exhibited substantially greater sequence divergence and revealed strong phylogeographic structure corresponding to major biogeographic provinces. The detailed genetic resolution provided by psbAncr data brings further clarity to the ecology, evolution, and systematics of symbiotic dinoflagellates

Characteristic Changes in Decidual Gene Expression Signature in Spontaneous Term Parturition

Background: The decidua has been implicated in the "terminal pathway" of human term parturition, which is characterized by the activation of pro-inflammatory pathways in gestational tissues. However, the transcriptomic changes in the decidua leading to terminal pathway activation have not been systematically explored. This study aimed to compare the decidual expression of developmental signaling and inflammation-related genes before and after spontaneous term labor in order to reveal their involvement in this process. Materials and Methods: Chorioamniotic membranes were obtained from normal pregnant women who delivered at term with spontaneous labor (TIL, n=14) or without labor (TNL, n=15). Decidual cells were isolated from snap-frozen chorioamniotic membranes with laser microdissection. The expression of 46 genes involved in decidual development, sex steroid and prostaglandin signaling, as well as pro- and anti-inflammatory pathways was analyzed using high-throughput quantitative real-time polymerase chain reaction (qRT-PCR). Chorioamniotic membrane sections were immunostained and then semi-quantified for five proteins, and immunoassays for three chemokines were performed on maternal plasma samples. Results: The genes with the highest expression in the decidua at term gestation included insulin-like growth factor-binding protein 1 (IGFBP1), galectin-1 (LGALS1), and progestogen-associated endometrial protein (PAEP); the expression of estrogen receptor 1 (ESR1), homeobox A11 (HOXA11), interleukin 1beta (IL1B), IL8, progesterone receptor membrane component 2 (PGRMC2), and prostaglandin E synthase (PTGES) was higher in TIL than in TNL cases; the expression of chemokine C-C motif ligand 2 (CCL2), CCL5, LGALS1, LGALS3, and PAEP was lower in TIL than in TNL cases; immunostaining confirmed qRT-PCR data for IL-8, CCL2, galectin-1, galectin-3, and PAEP; and no correlations between the decidual gene expression and the maternal plasma protein concentrations of CCL2, CCL5, and IL-8 were found. Conclusion: Our data suggests that with the initiation of parturition, the decidual expression of anti-inflammatory mediators decreases, while the expression of pro-inflammatory mediators and steroid receptors increases. This shift may affect downstream signaling pathways that can lead to parturition

Solid state synthesis of silver nanowires by biopolymer thin films

In this paper, we describe a novel method of silver nanowire (AgNW) synthesis. Silver nanoparticles (AgNPs) were synthesized under ambient conditions by a chitosan/chitin-based method. These crystalline AgNPs then served as seeds for the solid-state formation of AgNWs within a drop-cast chitosan/chitin thin film. To the best of our knowledge, this is the first report of AgNW growth on a bio-polymer thin film. Chemical analysis demonstrated that AgNPs and AgNWs produced by this synthetic process have distinct interactions with polysaccharide polymers, and unlike AgNWs produced by other methods, the AgNWs formed in the chitin/chitosan matrix display an irregular twisted morphology. The flexible AgNW/chitosan nanocomposite material is conductive, and we incorporate this new material into a peroxide sensor to demonstrate of its potential applications in chemical sensing devices

Diversity and Distribution of Symbiodinium Associated with Seven Common Coral Species in the Chagos Archipelago, Central Indian Ocean

The Chagos Archipelago designated as a no-take marine protected area in 2010, lying about 500 km south of the Maldives in the Indian Ocean, has a high conservation priority, particularly because of its fast recovery from the ocean-wide massive coral mortality following the 1998 coral bleaching event. The aims of this study were to examine Symbiodinium diversity and distribution associated with scleractinian corals in five atolls of the Chagos Archipelago, spread over 10,000 km 2. Symbiodinium clade diversity in 262 samples of seven common coral species, Acropora muricata, Isopora palifera, Pocillopora damicornis, P. verrucosa, P. eydouxi, Seriatopora hystrix, and Stylophora pistillata were determined using PCR-SSCP of the ribosomal internal transcribed spacer 1 (ITS1), PCR-DDGE of ITS2, and phylogenetic analyses. The results indicated that Symbiodinium in clade C were the dominant symbiont group in the seven coral species. Our analysis revealed types of Symbiodinium clade C specific to coral species. Types C1 and C3 (with C3z and C3i variants) were dominant in Acroporidae and C1 and C1c were the dominant types in Pocilloporidae. We also found 2 novel ITS2 types in S. hystrix and 1 novel ITS2 type of Symbiodinium in A. muricata. Some colonies of A. muricata and I. palifera were also associated with Symbiodinium A1. These results suggest that corals in the Chagos Archipelago host different assemblages of Symbiodinium types then their conspecifics from other locations in the Indian Ocean; and that future research will show whether these patterns in Symbiodinium genotypes may be due to local adaptation to specific conditions in the Chagos

An examination of semantic impairment in amnestic MCI and AD : What can we learn from verbal fluency?

Introduction The Verbal Fluency Test (VF) is commonly used in neuropsychology. Some studies have demonstrated a marked impairment of semantic VF compared to phonemic VF in Alzheimer’s disease (AD). Since amnestic Mild Cognitive Impairment (aMCI) is associated with increased risk of conversion to incident AD, it is relevant to examine whether a similar impairment is observed in this population. The objective of the present empirical study is to compare VF performance of aMCI patients to those of AD and elderly controls matched one-to-one for age and education. Method Ninety-six participants divided into three equal groups (N = 32: AD, aMCI and Controls) were included in this study. Participants in each group were, on average, 76 years of age and had 13 years of education. A repeated measures ANOVA with the Group (AD, aMCI, NC) as between-subject factor and the Fluency condition (“P” and “animals”) as within-subject factor was performed. T-tests and simple ANOVAs were also conducted to examine the interaction. Results There was a significant interaction between the groups and the verbal fluency condition. In AD, significantly fewer words were produced in both conditions. In contrast, participants with aMCI demonstrated a pattern similar to controls in the phonemic condition, but generated significantly fewer words in the semantic condition. Conclusion These results indicate a semantic memory impairment in aMCI revealed by a simple, commonly-used neuropsychological test. Future studies are needed to investigate if semantic fluency deficits can help predict future conversion to AD

Assessing Symbiodinium diversity in scleractinian corals via next-generation sequencing-based genotyping of the ITS2 rDNA region.

The persistence of coral reef ecosystems relies on the symbiotic relationship between scleractinian corals and intracellular, photosynthetic dinoflagellates in the genus Symbiodinium. Genetic evidence indicates that these symbionts are biologically diverse and exhibit discrete patterns of environmental and host distribution. This makes the assessment of Symbiodinium diversity critical to understanding the symbiosis ecology of corals. Here, we applied pyrosequencing to the elucidation of Symbiodinium diversity via analysis of the internal transcribed spacer 2 (ITS2) region, a multicopy genetic marker commonly used to analyse Symbiodinium diversity. Replicated data generated from isoclonal Symbiodinium cultures showed that all genomes contained numerous, yet mostly rare, ITS2 sequence variants. Pyrosequencing data were consistent with more traditional denaturing gradient gel electrophoresis (DGGE) approaches to the screening of ITS2 PCR amplifications, where the most common sequences appeared as the most intense bands. Further, we developed an operational taxonomic unit (OTU)-based pipeline for Symbiodinium ITS2 diversity typing to provisionally resolve ecologically discrete entities from intragenomic variation. A genetic distance cut-off of 0.03 collapsed intragenomic ITS2 variants of isoclonal cultures into single OTUs. When applied to the analysis of field-collected coral samples, our analyses confirm that much of the commonly observed Symbiodinium ITS2 diversity can be attributed to intragenomic variation. We conclude that by analysing Symbiodinium populations in an OTU-based framework, we can improve objectivity, comparability and simplicity when assessing ITS2 diversity in field-based studies.We would like to thank the KAUST BioScience Core Lab and S. Neelamegam for 454 library generation and sequencing. We would also like to thank Y. Sawall and A. Al-Sofyani for provision and collection of coral samples, and three anonymous reviewers for helpful comments. This project was funded by a KAUST Academic Excellence Alliance (AEA) Award to CRV and CJH, baseline research funds to CRV and a National Science Foundation grant to TCL (OCE-09287664).This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/mec.12869/abstract