Review and evaluation of a chiral enrichment model for chlordane enantiomers in the environment

2016 ◽  
Vol 24 (4) ◽  
pp. 363-376 ◽  
Author(s):  
Kavita Singh ◽  
Wim J.M. Hegeman ◽  
Remi W.P.M. Laane ◽  
Hing Man Chan

Chlordane is an organochlorine pesticide that contains a mixture of components, some of which are chiral. Analysis of enantiomers can provide insights into the mechanisms of their sources, pathway, and fate. The objectives of this work were: (i) to review the published literature that reported chlordane enantiomer concentrations in various environmental compartments; (ii) to evaluate the applicability of a model developed by Hegeman and Laane (2002) for predicting the relative distribution of various chiral pesticides in the environment. This model predicts that enantiomer deviation increases in the following order: air, water, soil, molluscs, fish/birds, marine mammals, specific tissues, and enzymes; (iii) to determine the relative ranking of plants within the model. All data were converted into an enantiomer fraction and aggregated by environmental compartment using bootstrap averaging to compare to model predictions. Enantiomer distributions of cis-chlordane, trans-chlordane, oxychlordane, and heptachlor exo-epoxide were reported in soil, air, water/sediments, plants, and animals. Based on aggregated average estimates for enantiomer fraction, the deviation from racemic increased in the following order for cis-chlordane: water/sediments = lower trophic aquatic organisms < air < fish < soil < plants (all combined) < seal < polar bear < bird < whale; for trans-chlordane: fish < water/sediments < lower trophic aquatic organisms < air < soil < plants (all combined) < seal < whales < bird < polar bear; and for heptachlor exo-epoxide: plants (all combined) < fish < soil = whale < water/sediments < bird < air < seal < polar bear. Depending on the species used to represent marine mammals, the Spearman’s rank-order correlation coefficients of observed data against model predictions were + 0.75 or + 0.84 for cis-chlordane, + 0.41 or + 0.49 for trans-chlordane, and −0.59 or + 0.12 for heptachlor exo-epoxide. This suggests that the model is applicable for cis- and trans-chlordane, but not for heptachlor exo-epoxide. The fundamental mechanisms behind the observed enantiomeric enrichment are of eminent importance in understanding the enantioselective deviations.

Author(s):  
Gabriel Núñez-Nogueira ◽  
Andres Arturo Granados-Berber

Coronaviruses are pathogens recognized for having an animal origin, commonly associated with terrestrial environments. However, although in a few cases, there are reports of their presence in aquatic organisms like fish, frogs, waterfowls and marine mammals. None of these cases has led to human health effects when contact with these infected organisms has taken place, whether they are alive or dead. Aquatic birds seem to be the main group carrying and circulating these types of viruses among healthy bird populations. Although the route of infection for CoVID-19 by water or aquatic organisms has not yet been observed in the wild, the relevance of its study is highlighted because there are cases of other viral infections known to have been transferred to humans by aquatic biota. It is encouraging to know that aquatic species, such as fish, marine mammals, and amphibians, shows very few cases of coronaviruses and that some other aquatic animals may also be a possible source of cure or treatment against then, as some evidence with algae and marine sponges suggest.


Author(s):  
GABRIEL NÚÑEZ-NOGUEIRA ◽  
Andres Arturo Granados-Berber

Coronaviruses are pathogens recognized for having an animal origin and commonly associated with terrestrial environments. However, although in few cases, there are reports of their presence in aquatic organisms like fish, crustaceans, waterfowls and marine mammals. None of these cases have even led to human health effects, when contact with these infected organisms, whether they are alive or dead. Aquatic birds seem to be the main group in carrying and circulating these types of viruses in healthy bird populations and play an important role in these environments. Although the route of infection for CoVID-19 (Coronavirus disease 2019) by water or aquatic organisms, has not yet been observed in the wild, the relevance of its study is highlighted , because there are cases of other viral infections (no coronavirus), which are known to have been transferred to the human by aquatic biota. What is even better, it becomes encouraging to know that aquatic species shows very few cases in fishes, marine mammals, and crustaceans, and some other aquatic animals may also be a possible source of cure or treatment against coronaviruses, as some evidence with algae and marine sponges suggests.


1999 ◽  
Vol 8 (4) ◽  
pp. 254-261 ◽  
Author(s):  
J Powers ◽  
SJ Bennett

BACKGROUND: Dyspnea, or difficult breathing, is common in patients receiving mechanical ventilation; however, dyspnea is not routinely or systematically measured. OBJECTIVE: The primary purpose of this methodological study was to evaluate the test-retest reliability of 5 dyspnea rating scales and the criterion validity of 4 dyspnea rating scales in patients receiving mechanical ventilation. The secondary purpose was to examine the correlations between each of these 5 rating scales and physiological measures of respiratory function. METHODS: The convenience sample consisted of 28 patients on mechanical ventilation during their hospitalization in the intensive care units of a large, inner-city hospital. Patients rated their dyspnea twice at 30-minute intervals on the visual analogue scale, the vertical analogue dyspnea scale, the modified Borg scale, the numerical scale, and the faces scale. Test-retest reliability was computed by using the intraclass correlation coefficient. Criterion validity was evaluated by using the Spearman rank-order correlation coefficient. RESULTS: The 5 rating scales had acceptable test-retest reliabilities, with intraclass correlation coefficients ranging from 0.81 to 0.97. Criterion validity of the 4 scales also was acceptable, with Spearman rank-order correlation coefficients from 0.76 to 0.96. The rating scales were not correlated with most of the physiological variables. At least half of the patients reported moderate to severe dyspnea. CONCLUSION: The scales showed acceptable reliability and validity, and they will be useful in quantifying dyspnea experienced by patients receiving mechanical ventilation. Further work is needed to evaluate the extent and the severity of dyspnea in such patients in order to evaluate the effectiveness of interventions.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Xueyan Fu ◽  
Will Patterson ◽  
Gregory Dolnikowski ◽  
Bess Dawson-Hughes ◽  
Martha Morris ◽  
...  

Abstract Objectives Very little is known about the forms of vitamin D and vitamin K in the human brain. The objective of this study is to evaluate concentrations of vitamin D and vitamin K forms in human brain and their correlations across four human brain regions. Methods Vitamin D [D3, 25(OH)D and 1,25(OH)2D] and vitamin K [phylloquinone and menaquinone-4 (MK4)] concentrations were measured by LC/MS/MS and HPLC, respectively, in four brain regions from post-mortem samples obtained from participants in the Rush Memory and Aging Project (n = 130, mean age 82 yrs, 81% female). The brain regions analyzed were the mid-frontal cortex (MF) and mid-temporal cortex (MT) [two regions important for memory in Alzheimer's Disease (AD)], the cerebellum (CR, a region not affected by AD), and the anterior watershed white matter (AWS, a region associated with vascular disease). The correlations among the vitamin forms across brain regions were calculated using Spearman rank order correlation coefficients. Significance was set at P < 0.001. Results The average concentrations of vitamin D3, 25(OH)D and MK4 were 604 pg/g, 535 pg/g, and 3.4 pmol/g, respectively. 25(OH)D and MK4 were detected in >95% of the brain samples. Nearly 92% of 1,25(OH)2D and 80% of phylloquinone samples had concentrations below the limit of assay detection (LOD) 1,25(OH)2D = 20 ng/g, phylloquinone = 0.1 pmol/g). Vitamin D3 and 25(OH)D concentrations were positively correlated across all four regions (all Spearman r ≥ 0.78, P < 0.0001). The 1,25(OH)2D was significantly correlated between the MF and CR regions only (Spearman r = 0.30, P < 0.001, all other P ≥ 0.002). MK4 and PK were positively correlated across the four regions studied (MK4 all Spearman r ≥ 0.78, phylloquinone r ≥ 0.49, all P < 0.001). Conclusions To the best of our knowledge, this study is the first evaluation of the concentrations of vitamin D and vitamin K forms in multiple regions of the human brain. Overall, the vitamin D and vitamin K forms were each positively correlated across the four brain regions studied. Future studies are needed to clarify the roles of these nutrients in AD and dementia. Funding Sources National Institute of Aging.


CJEM ◽  
2019 ◽  
Vol 21 (S1) ◽  
pp. S50
Author(s):  
Q. Paterson ◽  
R. Hartmann ◽  
R. Woods ◽  
L. Martin ◽  
B. Thoma

Innovation Concept: The fairness of the Canadian Residency Matching Service (CaRMS) selection process has been called into question by rising rates of unmatched medical students and reports of bias and subjectivity. We outline how the University of Saskatchewan Royal College emergency medicine program evaluates CaRMS applications in a standardized, rigorous, equitable and defensible manner. Methods: Our CaRMS applicant evaluation methods were first utilized in the 2017 CaRMS cycle, based on published Best Practices, and have been refined yearly to ensure validity, standardization, defensibility, rigour, and to improve the speed and flow of data processing. To determine the reliability of the total application scores for each rater, single measures intraclass correlation coefficients (ICCs) were calculated using a random effects model in 2017 and 2018. Curriculum, Tool or Material: A secure, online spreadsheet was created that includes applicant names, reviewer assignments, data entry boxes, and formulas. Each file reviewer entered data in a dedicated sheet within the document. Each application was reviewed by two staff physicians and two to four residents. File reviewers used a standardized, criterion-based scoring rubric for each application component. The file score for each reviewer-applicant pair was converted into a z-score based on each reviewer's distribution of scores. Z-scores of all reviewers for a single applicant were then combined by weighted average, with the group of staff and group of residents each being weighted to represent half of the final file score. The ICC for the total raw scores improved from 0.38 (poor) in 2017 to 0.52 (moderate) in 2018. The data from each reviewer was amalgamated into a master sheet where applicants were sorted by final file score and heat-mapped to offer a visual aid regarding differences in ratings. Conclusion: Our innovation uses heat-mapped and formula-populated spreadsheets, scoring rubrics, and z-scores to normalize variation in scoring trends between reviewers. We believe this approach provides a rigorous, defensible, and reproducible process by which Canadian residency programs can appraise applicants and create a rank order list.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 749-749
Author(s):  
Alexa Evenson ◽  
Emily Heying ◽  
Joleen Barnett ◽  
Annaliese Widmer

Abstract Objectives To investigate sensory attributes of carbonated, flavored, and sweetened beverage consumption, and relationship to the hunger hormone, acylated ghrelin. Methods In a randomized single-blinded crossover design, males (n = 14) and females (n = 15); aged 23–65; BMI &lt; 30 kg/m2; with no reported chronic disease consumed six different beverages (water, carbonated no flavor [CNF], carbonated lime flavor [CL], degassed lime flavor [DL], carbonated lime flavor with aspartame [CLS], and degassed lime flavor with aspartame [DLS]) at separate time points. Participants were asked to consume a breakfast meal (approximately 400 kcals) and then fast for approximately 4 hours. Blood was collected via finger-stick at baseline; and 10 and 45 minutes after consumption of the beverage. ELISA was used to determine acylated ghrelin concentration. A 7-pt likert scale was used to determine acceptability of the treatment beverages. ANOVA and spearman rank-order correlation coefficients were used to determine differences in liking of sensory attributes between beverages and correlations between variables, respectively. Results The CNF, CL, and water beverages were well liked by participants with mean overall liking scores of greater than 5. The overall liking scores were not significantly different between these three beverages (P &gt; 0.05). There were significant differences between CNF, CL, and water and the remaining 3 beverages – DL, CLS, and DLS. Degassed and sweetened beverages (DL, CLS, and DLS) were least liked with mean liking scores ranging from 3.69–4.28. There were no significant correlations (P &gt; 0.05) found between change in acylated ghrelin concentration and overall liking or liking of beverage attributes. Conclusions Acceptability of sensory attributes, including carbonation, flavor, and sweetness, was not related to change in acylated ghrelin concentrations after the consumption of six different beverages. Funding Sources This work was funded by the College of Saint Benedict/Saint John's University Faculty Research/Development Grant.


2021 ◽  
Vol 22 (15) ◽  
pp. 8305
Author(s):  
Chisato Kataoka ◽  
Shosaku Kashiwada

The immunotoxic effects of some anthropogenic pollutants on aquatic organisms are among the causes of concern over the presence of these pollutants in the marine environment. The immune system is part of an organism’s biological defense necessarily for homeostasis. Thus, the immunotoxicological impacts on aquatic organisms are important to understand the effects of pollutant chemicals in the aquatic ecosystem. When aquatic organisms are exposed to pollutant chemicals with immunotoxicity, it results in poor health. In addition, aquatic organisms are exposed to pathogenic bacteria, viruses, parasites, and fungi. Exposure to pollutant chemicals has reportedly caused aquatic organisms to show various immunotoxic symptoms such as histological changes of lymphoid tissue, changes of immune functionality and the distribution of immune cells, and changes in the resistance of organisms to infection by pathogens. Alterations of immune systems by contaminants can therefore lead to the deaths of individual organisms, increase the general risk of infections by pathogens, and probably decrease the populations of some species. This review introduced the immunotoxicological impact of pollutant chemicals in aquatic organisms, including invertebrates, fish, amphibians, and marine mammals; described typical biomarkers used in aquatic immunotoxicological studies; and then, discussed the current issues on ecological risk assessment and how to address ecological risk assessment through immunotoxicology. Moreover, the usefulness of the population growth rate to estimate the immunotoxicological impact of pollution chemicals was proposed.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Qi Jia ◽  
Nana Xu ◽  
Pengqian Mu ◽  
Bo Wang ◽  
Shuming Yang ◽  
...  

Tau-fluvalinate (TFLV) is one of the most potent chiral synthetic pyrethroids to control a wide range of pests in agricultural fields, especially in apiary. In this study, two stereoisomers of TFLV were fully separated by high-performance liquid chromatography (HPLC) with a semipreparative chiral column using cellulose-tris(3,5-dimethylphenylcarbamate) as chiral stationary phase andn-hexane and 2-propanol (96/4, v/v) as mobile phase at a flow rate of 2.5 mL min−1. The (+)-stereoisomer was first eluted by detecting with an optical rotation detector. After obtaining pure single stereoisomer of TFLV, acute toxicities of each isomer and TFLV standard to zebrafish were evaluated. The results showed that the (+)-stereoisomer exhibited 273.4 times higher toxicity than the (−)-stereoisomer and 6.7 times higher than TFLV standard, according to their LC50values at 96 h after exposure. This indicates that the toxicity of TFLV mainly originates from (+)-stereoisomer. These results are very helpful to prepare single stereoisomer of chiral pesticides and evaluate their different toxicological effects to aquatic organisms.


Neurosurgery ◽  
2017 ◽  
Vol 82 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Bennet Omalu ◽  
Gary W Small ◽  
Julian Bailes ◽  
Linda M Ercoli ◽  
David A Merrill ◽  
...  

Abstract Currently, only presumptive diagnosis of chronic traumatic encephalopathy (CTE) can be made in living patients. We present a modality that may be instrumental to the definitive diagnosis of CTE in living patients based on brain autopsy confirmation of [F-18]FDDNP-PET findings in an American football player with CTE. [F-18]FDDNP-PET imaging was performed 52 mo before the subject's death. Relative distribution volume parametric images and binding values were determined for cortical and subcortical regions of interest. Upon death, the brain was examined to identify the topographic distribution of neurodegenerative changes. Correlation between neuropathology and [F-18]FDDNP-PET binding patterns was performed using Spearman rank-order correlation. Mood, behavioral, motor, and cognitive changes were consistent with chronic traumatic myeloencephalopathy with a 22-yr lifetime risk exposure to American football. There were tau, amyloid, and TDP-43 neuropathological substrates in the brain with a differential topographically selective distribution. [F-18]FDDNP-PET binding levels correlated with brain tau deposition (rs = 0.59, P = .02), with highest relative distribution volumes in the parasagittal and paraventricular regions of the brain and the brain stem. No correlation with amyloid or TDP-43 deposition was observed. [F-18]FDDNP-PET signals may be consistent with neuropathological patterns of tau deposition in CTE, involving areas that receive the maximal shearing, angular–rotational acceleration–deceleration forces in American football players, consistent with distinctive and differential topographic vulnerability and selectivity of CTE beyond brain cortices, also involving midbrain and limbic areas. Future studies are warranted to determine whether differential and selective [F-18]FDDNP-PET may be useful in establishing a diagnosis of CTE in at-risk patients.


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