scholarly journals Depuration Kinetics and Growth Dilution of Caribbean Ciguatoxin in the Omnivore Lagodon rhomboides: Implications for Trophic Transfer and Ciguatera Risk

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 774
Author(s):  
Clayton T. Bennett ◽  
Alison Robertson
Keyword(s):  
Food Web ◽  
Half Life ◽  
Total Concentration ◽  
Body Burden ◽  
Trophic Transfer ◽  
The Body ◽  
Human Consumption ◽  
Two Phase ◽  
Lagodon Rhomboides ◽  
Benthic Dinoflagellates

Modeling ciguatoxin (CTX) trophic transfer in marine food webs has significant implications for the management of ciguatera poisoning, a circumtropical disease caused by human consumption of CTX-contaminated seafood. Current models associated with CP risk rely on modeling abundance/presence of CTX-producing epi-benthic dinoflagellates, e.g., Gambierdiscus spp., and are based on studies showing that toxin production is site specific and occurs in pulses driven by environmental factors. However, food web models are not yet developed and require parameterizing the CTX exposure cascade in fish which has been traditionally approached through top-down assessment of CTX loads in wild-caught fish. The primary goal of this study was to provide critical knowledge on the kinetics of C-CTX-1 bioaccumulation and depuration in the marine omnivore Lagodon rhomboides. We performed a two-phase, 17 week CTX feeding trial in L. rhomboides where fish were given either a formulated C-CTX-1 (n = 40) or control feed (n = 37) for 20 days, and then switched to a non-toxic diet for up to 14 weeks. Fish were randomly sampled through time with whole muscle, liver, and other pooled viscera dissected for toxin analysis by a sodium channel-dependent MTT-based mouse neuroblastoma (N2a) assay. The CTX levels measured in all tissues increased with time during the exposure period (days 1 to 20), but a decrease in CTX-specific toxicity with depuration time only occurred in viscera extracts. By the end of the depuration, muscle, liver, and viscera samples had mean toxin concentrations of 189%, 128%, and 42%, respectively, compared to fish sampled at the start of the depuration phase. However, a one-compartment model analysis of combined tissues showed total concentration declined to 56%, resulting in an approximate half-life of 97 d (R2 = 0.43). Further, applying growth dilution correction models to the overall concentration found that growth was a major factor reducing C-CTX concentrations, and that the body burden was largely unchanged, causing pseudo-elimination and a half-life of 143–148 days (R2 = 0.36). These data have important implications for food web CTX models and management of ciguatera poisoning in endemic regions where the frequency of environmental algal toxin pulses may be greater than the growth-corrected half-life of C-CTX in intermediate-trophic-level fish with high site fidelity.

The metabolism of caesium-137 in dairy cows

1966 ◽  
Vol 66 (3) ◽  
pp. 389-393 ◽  
Author(s):  
B. F. Sansom
Keyword(s):  
Dairy Cows ◽  
Half Life ◽  
Daily Intake ◽  
Body Burden ◽  
The Body ◽  
Daily Dose ◽  
Continuous Feeding ◽  
The Mean ◽  
Oral Doses ◽  
Mean Concentration

1. The metabolism of 137Cs in dairy cows has been studied after single oral and intravenous doses and during twice daily oral dosing for 28 days.2. Gastrointestinal absorption of 137Cs was about 70-80% of the oral doses.3. After 28 days continuous feeding the mean concentration of 137Cs in milk was 0.84% daily dose/1. and the body burden of the isotope varied between 5.7 and 8.2 times the daily intake.4. When feeding of 137Cs stopped the concentration of the isotope in milk fell by a factor of five in 8 days, by a factor of ten in 16 days, by a factor of twenty in 32 days, and thereafter exponentially with a half-life of 30 days. The concentrations of the isotope in muscle decreased at first rather slowly but finally also exponentially with a half-life of approximately 30 days.

Effect of Sample Storage Conditions on Body Burden Analysis of Organic Contaminants in Unionid Mussels

1992 ◽  
Vol 27 (4) ◽  
pp. 833-844 ◽  
Author(s):  
Micheline Hanna
Keyword(s):  
Organic Contaminants ◽  
Body Burden ◽  
Storage Conditions ◽  
The Body ◽  
Sample Storage ◽  
Pcb Congeners ◽  
Unionid Mussels ◽  
Group A ◽  
The Difference ◽  
Group B

Abstract In order to quantitatively assess the effect of sample storage conditions on the body burden analysis of organic contaminants, a comparative analysis was carried out on the unionid mussel Elliptic complanata. The mussels were divided into two groups, each with distinct storage conditions, while Group A was kept in the freezer at −20°C, Group B was kept in the refrigerator for five days at 5°C. All the compounds present in the control were also present in Group B samples. Analysis of the organic contaminants in each of these two groups showed that for total PCB concentrations, the two treatments were not significantly different; however when compared individually 6 of the 13 PCB congeners showed significant differences. The observed differences were relatively small for individual PCB congeners (7.1 to 15.3%), higher for chlorobenzenes (10.5 to 36.4%), and yet higher for HCE (44.1%); the difference for HCE, although large is nevertheless not significant, even if only marginally so.

scholarly journals Decompression sickness risk in rats by microbial removal of dissolved gas

1998 ◽  
Vol 275 (3) ◽  
pp. R677-R682 ◽  
Author(s):  
Susan R. Kayar ◽  
Terry L. Miller ◽  
Meyer J. Wolin ◽  
Eugenia O. Aukhert ◽  
Milton J. Axley ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
High Pressures ◽  
Decompression Sickness ◽  
Body Burden ◽  
The Body ◽  
Dissolved Gas ◽  
Hyperbaric Chamber ◽  
Methanobrevibacter Smithii ◽  
Water Rate ◽  
Microbial Removal

We present a method for reducing the risk of decompression sickness (DCS) in rats exposed to high pressures of H2. Suspensions of the human colonic microbe Methanobrevibacter smithii were introduced via a colonic cannula into the large intestines of the rats. While the rats breathed H2in a hyperbaric chamber, the microbe metabolized some of the H2diffusing into the intestine, converting H2and CO2to methane and water. Rate of release of methane from the rats, which was monitored by gas chromatography, varied with chamber H2pressure. This rate was higher during decompression than during compression, suggesting that during decompression the microbe was metabolizing H2stored in the rats’ tissues. Rats treated with M. smithii had a 25% (5 of 20) incidence of DCS, which was significantly lower ( P < 0.01) than the 56% (28 of 50) incidence of untreated controls, brought on by a standardized compression and decompression sequence. Thus using a microbe in the intestine to remove an estimated 5% of the body burden of H2reduced DCS risk by more than one-half. This method of biochemical decompression may potentially facilitate human diving.

A Developed Numerical Method for Turbulent Unsteady Fluid Flow in Two-Phase Systems with Moving Interface

2017 ◽  
Vol 14 (06) ◽  
pp. 1750063 ◽  
Author(s):  
A. M. Hegab ◽  
S. A. Gutub ◽  
A. Balabel
Keyword(s):  
Numerical Model ◽  
Gas Phase ◽  
Level Set ◽  
The Body ◽  
Phase System ◽  
Computational Domain ◽  
Two Phase ◽  
Moving Interface ◽  
Level Set Function ◽  
Gas System

This paper presents the development of an accurate and robust numerical modeling of instability of an interface separating two-phase system, such as liquid–gas and/or solid–gas systems. The instability of the interface can be refereed to the buoyancy and capillary effects in liquid–gas system. The governing unsteady Navier–Stokes along with the stress balance and kinematic conditions at the interface are solved separately in each fluid using the finite-volume approach for the liquid–gas system and the Hamilton–Jacobi equation for the solid–gas phase. The developed numerical model represents the surface and the body forces as boundary value conditions on the interface. The adapted approaches enable accurate modeling of fluid flows driven by either body or surface forces. The moving interface is tracked and captured using the level set function that initially defined for both fluids in the computational domain. To asses the developed numerical model and its versatility, a selection of different unsteady test cases including oscillation of a capillary wave, sloshing in a rectangular tank, the broken-dam problem involving different density fluids, simulation of air/water flow, and finally the moving interface between the solid and gas phases of solid rocket propellant combustion were examined. The latter case model allowed for the complete coupling between the gas-phase physics, the condensed-phase physics, and the unsteady nonuniform regression of either liquid or the propellant solid surfaces. The propagation of the unsteady nonplanar regression surface is described, using the Essentially-Non-Oscillatory (ENO) scheme with the aid of the level set strategy. The computational results demonstrate a remarkable capability of the developed numerical model to predict the dynamical characteristics of the liquid–gas and solid–gas flows, which is of great importance in many civilian and military industrial and engineering applications.

Trophic transfer of heavy metals in the marine food web based on tissue residuals

2021 ◽  
Vol 772 ◽  
pp. 145064
Author(s):  
Yongfei Gao ◽  
Ruyue Wang ◽  
Yanyu Li ◽  
Xuebin Ding ◽  
Yueming Jiang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Food Web ◽  
Trophic Transfer ◽  
Web Based ◽  
Marine Food Web ◽  
Marine Food

Dothiepin for depression: single nightly dosage

1977 ◽  
Vol 15 (23) ◽  
pp. 92-92
Keyword(s):  
Single Dose ◽  
Depressed Patient ◽  
Large Dose ◽  
Half Life ◽  
Dosage Regimen ◽  
The Body ◽  
Dry Mouth ◽  
Blurred Vision ◽  
Depressed Patients ◽  
Single Large Dose

Depressed patients tend to be forgetful, and for them a simple dosage regimen is particularly appropriate. The use of a single daily dosage depends on the drug having a relatively long (over 36 hours) half-life in the body and being tolerated in a single large dose. Many tricyclic anti-depressives fulfil these requirements provided that the single dose is given before the patient goes to bed. Unwanted effects such as dry mouth and blurred vision, which are troublesome during the day, are not a problem during sleep. The sedative actions of many of these drugs can help the insomniac depressed patient who might otherwise need a separate hypnotic.

Textures of the Hot-Forged Ti6Al4V Alloy

2013 ◽  
Vol 203-204 ◽  
pp. 111-114
Author(s):  
Adam Bunsch ◽  
Wiktoria Ratuszek ◽  
Małgorzata Witkowska ◽  
Joanna Kowalska ◽  
Aneta Łukaszek-Sołek
Keyword(s):  
Deformation Temperature ◽  
Phase State ◽  
Hexagonal Phase ◽  
Ti6al4v Alloy ◽  
The Body ◽  
Cubic Phase ◽  
Body Centered Cubic ◽  
Two Phase ◽  
Different Temperatures

This paper presents the results of the texture investigation in the hexagonal phase and the body-centered cubic  phase of the Ti6Al4V alloy hot-deformed by forging. Forging was performed at two different temperatures on the occurrence of the single  and in the two-phase  +  state. It was found that after deformation both  and  phases are textured and their textures strongly depends on deformation temperature.

scholarly journals Perspectives on Sustainable Development in the Context of Public Health Issues

2015 ◽  
Vol 7 (1) ◽  
pp. 37-39
Author(s):  
Ioana-Codruta Racz
Keyword(s):  
Public Health ◽  
Sustainable Development ◽  
Iodine Deficiency ◽  
Central Africa ◽  
Public Health Problem ◽  
The Body ◽  
Human Consumption ◽  
Main Role ◽  
Northern Asia ◽  
Good Nutrition

Abstract Health is an integral part of sustainable development, a process that can’t be materialized if there is a high prevalence of diseases, a high percentage of those is due to environmental factors. An important component of health is the healthy nutrition, especially of children and pregnant women. Iodine is an essential micronutrient for a good nutrition that covers the physiological needs of the body, iodine deficiency having important consequences for mother and fetus, then for children, especially in the first years of life. The main role of iodine in the body is due to his importance for synthesis of thyroid hormones involved in growth and development of psychic and somatic body, starting with intrauterine life. Iodine deficiency was, and still is, a public health problem, globally the most affected countries are in Central Africa, central South America and northern Asia. Europe iodine deficiency is relatively lower. Multiple interventions were made to improve and even eradicate iodine deficiency disorders, in particular through the universal iodization of salt for human consumption, but must be supported in continuing efforts because this issue is not fully resolved to this day.

scholarly journals Human Body Burden of Heavy Metals and Health Consequences of Pb Exposure in Guiyu, an E-Waste Recycling Town in China

2021 ◽  
Vol 18 (23) ◽  
pp. 12428
Author(s):  
Wenlong Huang ◽  
Xiaoling Shi ◽  
Kusheng Wu
Keyword(s):  
Heavy Metals ◽  
Body Burden ◽  
Local Environment ◽  
Waste Recycling ◽  
The Body ◽  
Health Consequences ◽  
Long Term Effects ◽  
Adaptive Immune ◽  
Pb Exposure

Guiyu accommodates millions of tons of e-waste from overseas and domestic sources each year and is notorious for its e-waste dismantling industry. As a consequence, Guiyu has been described as “the world’s most toxic place” and “junk town”. Informal e-waste recycling activities have caused severe pollution to the local environment and are associated with extensive health problems to the residents. This review provides updated insights on the body burden of heavy metals derived from e-waste and health outcomes resulted from lead (Pb) exposure. The review identified that Guiyu has been highly contaminated by heavy metals, especially Pb. Excessive exposure to Pb has been associated with multi-system and long-term effects in neonates and children, covering nervous, cardiovascular, adaptive immune, and hematologic systems as well as chromosome and DNA damage. Our review indicates strong associations that emphasize the need to develop strong regulations for prevention of exposure and health consequences in Guiyu and similar sites around the world.

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