Route of exposure influences pesticide body burden and the hepatic metabolome in post-metamorphic leopard frogs

2021 ◽  
Vol 779 ◽  
pp. 146358
Author(s):  
Donna A. Glinski ◽  
Robin J. Van Meter ◽  
S. Thomas Purucker ◽  
W. Matthew Henderson
Keyword(s):  
Body Burden ◽  
Leopard Frogs ◽  
Route Of Exposure

Oncogenesis and the Lucké Virus

1968 ◽  
Vol 26 ◽  
pp. 200-201
Author(s):  
A. E. Vatter ◽  
J. Zambernard
Keyword(s):  
Rna Viruses ◽  
Vegetative State ◽  
Temperature Sensitive ◽  
Structural Level ◽  
Oncogenic Viruses ◽  
Dna Viruses ◽  
Leopard Frogs ◽  
Renal Adenocarcinoma ◽  
Induced Tumors ◽  
Northern Leopard Frogs

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.

Carcinogenic risk assessment in population living in the ecologically problematic areas of Irkutsk region

2019 ◽  
pp. 117-121
Author(s):  
N. V. Yefi mova ◽  
I. V. Myl’nikova ◽  
M. V. Kuz’mina ◽  
L. G. Lisetskaya ◽  
Ye. Ye. Loznevaya
Keyword(s):  
Rural Area ◽  
Industrial Development ◽  
Ambient Air ◽  
Carcinogenic Risk ◽  
Environmental Objects ◽  
Irkutsk Region ◽  
Regional Population ◽  
Drinkable Water ◽  
Route Of Exposure ◽  
Risk Parameters

Irkutsk region is among territories of intense industrial development. Considerable part of the regional population is long exposed to chemical pollutants of environmental objects. Th e authors evaluated carcinogenic risk for the population of industrial centers and rural area. Findings are that maximal carcinogenic risk is carried by the urban population. Aggregated carcinogenic risk parameters evaluation proved inhalation to be a priority route of exposure. Irkutsk region appeared to have territories with high carcinogenic risk for public health. Among a list of chemicals in the ambient air are priority carcinogens: six-valent chromium and lead. The evidences necessitate measures on the risks minimization. Due to absent data on carcinogens content of drinkable water in some rural area, the necessity is to evaluate risk for the rural population by studies of drinkable water quality that does not match hygienic regulations, because oral one is a main route of carcinogens intake.

Effects of Dihydroquercetin on Behavior of Albino Rat Offspring with Transgenerational Chemical Body Burden

2020 ◽  
pp. 38-41
Author(s):  
E.A. Kapustina ◽  
L.G. Lisetskaya
Keyword(s):  
Physical Activity ◽  
Open Field ◽  
Antioxidant Properties ◽  
Body Burden ◽  
Statistical Processing ◽  
Lead Toxicity ◽  
Absorption Spectrometry ◽  
Albino Rats ◽  
Albino Rat ◽  
Rat Offspring

Introduction. Lead pollution is a common environmental problem. Having no physiological functions, this toxicant has a negative polytropic impact on a body, including neurotoxic, reproductive, and transgenerational effects. The mechanism of lead toxicity is oxidative stress. Flavonoids have active antioxidant properties. They are widely represented in plant foods, are able to restore protective capabilities of cells and have chelating properties with respect to lead. One of the representatives of this group of substances is dihydroquercetin. The objective was to study the effect of dihydroquercetin on behavior of rats with hereditary chemical body burden exposed to lead at 60 mg/kg during 25 days. Materials and methods. We studied the behavior of rat offspring in an open field and established their blood lead levels by electrothermal atomization atomic absorption spectrometry. For statistical processing the U-Mann – Whitney test was used. Results. In the present experiment, the effect of lead on the offspring of male albino rats exposed to 60 mg/kg of lead for 25 days caused changes in the activity of animals in the open field. The severity of changes was more pronounced in animals with a hereditary chemical body burden. These animals showed a decrease in orientation and physical activity and increased anxiety. In rats with a hereditary burden, changes in behavior were detected when administering dihydroquercetin. The activity of animals demonstrated a positive dynamics: we observed a statistically significant increase in physical activity and orientation. The number and duration of behavioral acts approached control values. Conclusions. The revealed effects of lead on the offspring of albino rats with a transgenerational chemical body burden require further study to understand the mechanism of the phenomenon.

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.

The effects of contaminated sediments of the Blesbok Spruit near Witbank on water quality and the toxicity thereof to Daphnia pulex

1999 ◽  
Vol 39 (10-11) ◽  
pp. 173-176 ◽  
Author(s):  
Liesl Hill ◽  
Sebastian Jooste
Keyword(s):  
Surface Water ◽  
Mine Drainage ◽  
Interstitial Water ◽  
Stream Water ◽  
Daphnia Pulex ◽  
Contaminated Sediments ◽  
Toxicity Tests ◽  
Major Route ◽  
Acute Toxicity Tests ◽  
Route Of Exposure

With the increasing focus on environmental issues, the objective of this study is to evaluate the potential impact of contaminated sediments of the Blesbok Spruit near Witbank - which receives acid mine drainage (AMD) inter alia - on biota. Direct transfer of chemicals from sediments to organisms is considered to be a major route of exposure for many species, and therefore focusing attention on sediment contamination and highlighting the fact that sediments are an important resource. Acute toxicity tests were performed on Daphnia pulex using both extracted sediment interstitial water and surface water. Chemical analyses were also performed on the sediment, interstitial water and surface water samples. The toxicity results suggest that metal toxicity adds significantly to the toxicity of the stream water which is enhanced by the effect of pH. The pH of the stream and interstitial water was consistently below 4.5.

Phthalate Esters, Cystic Kidney Disease in Animals and Possible Effects on Human Health: A Review

1990 ◽  
Vol 9 (6) ◽  
pp. 397-401 ◽  
Author(s):  
K.N. Woodward
Keyword(s):  
Kidney Disease ◽  
Human Health ◽  
Phthalate Esters ◽  
Renal Cysts ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Peroxisome Proliferation ◽  
Peroxisome Proliferators ◽  
Prolonged Administration ◽  
Route Of Exposure

1 Phthalate esters are known to cause hepatic peroxisome proliferation in rodents and, after prolonged administration, hepatocarcinogenesis. Peroxisome proliferators as a group are hepatocarcinogenic. The mechanism is not known but it does not appear to involve a direct genotoxic element. 2 DEHP and DBP have been shown to cause renal cysts in rodents and they also produce renal peroxisome proliferation. There are no data to causally link the two phenomena. 3 Although renal cysts have been noted in haemodialysis patients and haemodialysis is a route of exposure to DEHP, there are no data to suggest a cause and effect relationship. 4 More studies are needed on the mechanism of renal cystogenesis.

Use of Toxicokinetics in Risk Assessment Based on In Vitro Data

1993 ◽  
Vol 21 (2) ◽  
pp. 173-180
Author(s):  
Gunnar Johanson
Keyword(s):  
Risk Assessment ◽  
Whole Body ◽  
External Exposure ◽  
Target Dose ◽  
Toxic Response ◽  
Route Of Exposure ◽  
Vitro Data ◽  
In Vitro Data

This presentation addresses some aspects of the methodology, advantages and problems associated with toxicokinetic modelling based on in vitro data. By using toxicokinetic models, particularly physiologically-based ones, it is possible, in principle, to describe whole body toxicokinetics, target doses and toxic effects from in vitro data. Modelling can be divided into three major steps: 1) to relate external exposure (applied dose) of xenobiotic to target dose; 2) to establish the relationship between target dose and effect (in vitro data, e.g. metabolism in microsomes, partitioning in tissue homogenates, and toxicity in cell cultures, are useful in both steps); and 3) to relate external exposure to toxic effect by combining the first two steps. Extrapolations from in vitro to in vivo, between animal and man, and between high and low doses, can easily be carried out by toxicokinetic simulations. In addition, several factors that may affect the toxic response by changing the target dose, such as route of exposure and physical activity, can be studied. New insights concerning the processes involved in toxicity often emerge during the design, refinement and validation of the model. The modelling approach is illustrated by two examples: 1) the carcinogenicity of 1,3-butadiene; and 2) the haematotoxicity of 2-butoxyethanol. Toxicokinetic modelling is an important tool in toxicological risk assessment based on in vitro data. Many factors, some of which can, and should be, studied in vitro, are involved in the expression of toxicity. Successful modelling depends on the identification and quantification of these factors.

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.

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