Okadaic Acid Meet and Greet: An Insight into Detection Methods, Response Strategies and Genotoxic Effects in Marine Invertebrates

Harmful Algal Blooms (HABs) constitute one of the most important sources of contamination in the oceans, producing high concentrations of potentially harmful biotoxins that are accumulated across the food chains. One such biotoxin, Okadaic Acid (OA), is produced by marine dinoflagellates and subsequently accumulated within the tissues of filtering marine organisms feeding on HABs, rapidly spreading to their predators in the food chain and eventually reaching human consumers causing Diarrhetic Shellfish Poisoning (DSP) syndrome. While numerous studies have thoroughly evaluated the effects of OA in mammals, the attention drawn to marine organisms in this regard has been scarce, even though they constitute primary targets for this biotoxin. With this in mind, the present work aimed to provide a timely and comprehensive insight into the current literature on the effect of OA in marine invertebrates, along with the strategies developed by these organisms to respond to its toxic effect together with the most important methods and techniques used for OA detection and evaluation

Leveraging Geologic CO2 Storage Technology for CO2-EOR Management

Enhanced oil recovery (EOR) through CO2 injection has evolved from the laboratory testing and field piloting phases in the early 1970s to the widespread and refined operations of today. Over the last 20 years, geological CO2 storage (GCS) has emerged as a promising approach to dispose of large volumes of CO2. Much of the early advances in the operational aspects of GCS were learned from CO2-EOR. However, given its “newness� and the health, safety, and environment (HSE) concerns related to CO2 emissions, considerable fundamental and applied research with heavily instrumented GCS field projects, from pilot to commercial scale, has produced data not ordinarily available from conventional CO2-EOR studies. A key exception is the Weyburn-Midale CO2-EOR project in Saskatchewan, Canada, which has had a dedicated characterization, reservoir dynamics and surveillance program in operation since 2000. Even though many of the processes and workflows for these two operations are similar, significant differences do exist primarily because of the different objectives and regulatory environments that exist for CO2-EOR and CO2 storage projects. Fundamentally, CO2 storage tools and processes are geared toward developing a much more detailed understanding of the storage system and the physical and chemical processes accompanying CO2 injection, with monitoring and surveillance being conducted during the pre-operational, operational, and post-operational stages of a project. Pre-operational monitoring for a CO2-EOR project is primarily focused on understanding the reservoir physical and petrophysical properties as well as the properties of the reservoir and injected fluids. Surveillance in the operational phase of an EOR flood is limited, with emphasis being placed on monitoring injection pressures and rates as well as the volumes and properties of the injected and produced fluids. Lessons learned from GCS research and field tests will likely benefit CO2-EOR project performance by employing aspects of characterization, simulation and surveillance. This study reviews the predictive and diagnostic tools currently applied to GCS projects and infers how their deployment might improve CO2-EOR projects. These improvements might include project conformance, CO2 utilization / oil produced, field management, and containment risks.Bureau of Economic Geolog

L-DOPA Is an Endogenous Ligand for OA1

Albinism is a genetic defect characterized by a loss of pigmentation. The neurosensory retina, which is not pigmented, exhibits pathologic changes secondary to the loss of pigmentation in the retina pigment epithelium (RPE). How the loss of pigmentation in the RPE causes developmental defects in the adjacent neurosensory retina has not been determined, but offers a unique opportunity to investigate the interactions between these two important tissues. One of the genes that causes albinism encodes for an orphan GPCR (OA1) expressed only in pigmented cells, including the RPE. We investigated the function and signaling of OA1 in RPE and transfected cell lines. Our results indicate that OA1 is a selective L-DOPA receptor, with no measurable second messenger activity from two closely related compounds, tyrosine and dopamine. Radiolabeled ligand binding confirmed that OA1 exhibited a single, saturable binding site for L-DOPA. Dopamine competed with L-DOPA for the single OA1 binding site, suggesting it could function as an OA1 antagonist. OA1 response to L-DOPA was defined by several common measures of G-protein coupled receptor (GPCR) activation, including influx of intracellular calcium and recruitment of β-arrestin. Further, inhibition of tyrosinase, the enzyme that makes L-DOPA, resulted in decreased PEDF secretion by RPE. Further, stimulation of OA1 in RPE with L-DOPA resulted in increased PEDF secretion. Taken together, our results illustrate an autocrine loop between OA1 and tyrosinase linked through L-DOPA, and this loop includes the secretion of at least one very potent retinal neurotrophic factor. OA1 is a selective L-DOPA receptor whose downstream effects govern spatial patterning of the developing retina. Our results suggest that the retinal consequences of albinism caused by changes in melanin synthetic machinery may be treated by L-DOPA supplementation

The CHROMEVALOA Database: A Resource for the Evaluation of Okadaic Acid Contamination in the Marine Environment Based on the Chromatin-Associated Transcriptome of the Mussel Mytilus galloprovincialis

Okadaic Acid (OA) constitutes the main active principle in Diarrhetic Shellfish Poisoning (DSP) toxins produced during Harmful Algal Blooms (HABs), representing a serious threat for human consumers of edible shellfish. Furthermore, OA conveys critical deleterious effects for marine organisms due to its genotoxic potential. Many efforts have been dedicated to OA biomonitoring during the last three decades. However, it is only now with the current availability of detailed molecular information on DNA organization and the mechanisms involved in the maintenance of genome integrity, that a new arena starts opening up for the study of OA contamination. In the present work we address the links between OA genotoxicity and chromatin by combining Next Generation Sequencing (NGS) technologies and bioinformatics. To this end, we introduce CHROMEVALOAdb, a public database containing the chromatin-associated transcriptome of the mussel Mytilus galloprovincialis (a sentinel model organism) in response to OA exposure. This resource constitutes a leap forward for the development of chromatin-based biomarkers, paving the road towards the generation of powerful and sensitive tests for the detection and evaluation of the genotoxic effects of OA in coastal areas

Enzymatic and Molecular Identification of Meloidogyne Species in Tomato Orchards in Paraguay

Tomato is a major crop in Paraguay, where it provides a source of employment and income for households. Tomato production can be affected by root-knot nematodes, especially Meloidogyne spp. The unequivocal identification of Meloidogyne spp. in Paraguay has not been conducted yet. This study aims to identify Meloidogyne species in eight tomato production districts of this country by biochemical and molecular techniques. Females of Meloidogyne spp. were extracted from tomato roots and characterized using esterase isozyme phenotypes. In addition, DNA was extracted from nematode eggs, and species-specific SCARs (sequence-characterized amplified regions) were used to confirm the diagnosis. Nematodes were detected in 100% of studied samples (prevalence), of which M. incognita (Est: I2, Rm: 1.1;1.2) and M. javanica (Est: J3, Rm: 1.0, 1.20, 1.35) were present in 39.13% and 26.08% of samples, respectively. One population (8.69%) of Meloidogyne sp. presenting an atypical esterase profile (Rm: 1.0 and 1.3) was only detected in Julián Augusto Saldívar District. Mixed populations, mostly M. incognita and M. javanica, were observed in 26.08% of samples. The SCAR primers incK14F/incK14R amplified specific fragments for M. incognita (399 bp) and M. javanica (670 bp), confirming the enzymatic results. Here, we present the first study of root-knot nematode identification at the species level in Paraguay

Maternity care provider knowledge, attitudes, and practices regarding provision of postpartum intrauterine contraceptive devices at a tertiary center in Ghana

ObjectiveTo assess knowledge, attitudes, and practices of maternity care providers regarding the provision of postpartum intrauterine contraceptive devices (IUDs) in Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana.MethodsA descriptive, cross‐sectional study was conducted between June 28 and July 15, 2011. Specialists, residents, house officers, and nurse midwives who had been working in the Department of Obstetrics and Gynecology for at least 3 months were included. Self‐administered questionnaires assessed formal training, current proficiency in IUD insertion, and attitudes toward postpartum IUD provision.ResultsOf 91 providers surveyed, 70 (77%) reported previous training in contraceptive counseling. Fewer than one in three respondents had ever inserted an IUD: 17 (44%) of 39 physicians and 9 (17%) of 52 midwives reported ever having inserted an IUD. A total of 33 (36%) respondents reported that they would recommend an IUD in the immediate postpartum period.ConclusionAlthough most maternity care providers at KATH had received training in contraceptive counseling, few felt confident in their ability to insert an IUD. Further training in postpartum contraceptive management is needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135552/1/ijgo137.pd

Differential effect of sleep deprivation on place cell representations, sleep architecture, and memory in young and old mice

Poor sleep quality is associated with age-related cognitive decline, and whether reversal of these alterations is possible is unknown. In this study, we report how sleep deprivation (SD) affects hippocampal representations, sleep patterns, and memory in young and old mice. After training in a hippocampus-dependent object-place recognition (OPR) task, control animals sleep ad libitum, although experimental animals undergo 5 h of SD, followed by recovery sleep. Young controls and old SD mice exhibit successful OPR memory, whereas young SD and old control mice are impaired. Successful performance is associated with two cellular phenotypes: (1) context cells, which remain stable throughout training and testing, and (2) object configuration cells, which remap when objects are introduced to the context and during testing. Additionally, effective memory correlates with spindle counts during non-rapid eye movement (NREM)/rapid eye movement (REM) sigma transitions. These results suggest SD may serve to ameliorate age-related memory deficits and allow hippocampal representations to adapt to changing environments

Genome wide association study of fatty acid composition in Duroc swine

Objective Genome wide association study was conducted to identify and validate candidate genes associated with fatty acid composition of pork. Methods A total of 480 purebreed Duroc pigs were genotyped using IlluminaPorcine60k bead chips while the association test was implemented following genome-wide rapid association using Mixed Model and Regression-Genomic Control (GRAMMAR-GC) approach. Results A total of 25, 29, and 16 single nucleotide polymorphisms (SNPs) were significantly associated with stearic (18:0), oleic (18:1) and saturated fatty acids (SFA), respectively. Genome wide significant variants were located on the same region of swine chromosome 14 (SSC14) that spanned from 120 to 124 Mb. Top SNP ALGA008191 was located at 5 kb near the stearoyl-CoA desaturase (SCD) gene. This gene is directly involved in desaturation of stearic acid into oleic acid. General relationship of significant SNPs showed high linkage disequilibrium thus genome-wide signals was attributed to SCD gene. However, understanding the role of other genes like elongation of very long chain fatty acids-3 (ELOVL3) located on this chromosomal segment might help in further understanding of metabolism and biosynthesis of fatty acids. Conclusion Overall, this study provides evidence that validates SCD gene as strong candidate gene associated with fatty acid composition in Duroc pigs. Moreover, this study confirms significant SNPs near ELOVL3 gene

Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design.

Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)-many of which are refractory to current standard-of-care treatments-from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer