Cytogenetic monitoring of fishermen with environmental mercury exposure

Due to high mercury levels in many Mediterranean aquatic organisms, people who live in this area and consume large amounts of seafood are exposed to a toxicological hazard. A group of 51 fishermen exposed to mercury through eating contaminated seafood from the northern Tyrrhenian Sea underwent cytogenetic monitoring. This work is part of a research project consisting of the evaluation of micronuclei (MN), chromosomal aberrations (CA) and sister-chromatid exchanges (SCE) in peripheral blood lymphocytes. Here we present data on mercury levels in blood and on micronucleus frequencies in peripheral blood lymphocytes of fishermen. The range of mercury concentrations in blood was 10.08–304.11 ng/g fresh weight, the average was 88.97±54.09 ng/g. Micronucleus frequency was defined with at least 2000 binucleated cells scored for each person; the average was 8.74 ± 2.56 expressed on 1000 binucleated cells. A statistical correlation was found between MN frequency and total mercury concentration in blood (p = 0.00041, r = 0.674), as well as between MN frequency and age (p = 0.017). No other parameters taken into account correlated with MN frequency.     

Persistence of Escherichia coli O157 on farm surfaces under different environmental conditions

AIMS: To compare the persistence of Escherichia coli O157 on a variety of common faecally contaminated farmyard material surfaces (wood and steel) under different moisture and temperature regimes. METHODS AND RESULTS: Samples of field-conditioned farmyard materials (galvanized steel and wood) were cut into pieces and contaminated with fresh cattle faeces inoculated with nontoxigenic E. coli O157 (strain 3704). Thereafter, they were stored at four different environmental conditions; with temperature (5 and 20 degrees C) and moisture (moist or dry) as variables. Transfer of the pathogen to hands from the surfaces was also evaluated. Escherichia coli O157 numbers declined over time on all surfaces albeit at different rates according to the sample material and environmental conditions. Persistence was greatest on moist wood samples under cooler temperatures with large population numbers remaining after 28 days. Desiccation of surfaces resulted in a more rapid decline in E. coli O157 populations under both temperature regimes. Substantial numbers of colonies may also potentially be transferred to human hands from the surfaces during brief contact. CONCLUSIONS: When environmental conditions are favourable, E. coli O157 may persist for considerable times on a range of surfaces. However, when exposed to higher temperatures and dehydration, survival is notably decreased. Overall, bacterial persistence was significantly greater on wood samples relative to steel. SIGNIFICANCE AND IMPACT OF THE STUDY: Escherichia coli O157 is a prevalent pathogen, common in ruminant faeces. Contact with contaminated faeces may lead to human infection, resulting in possible severe illness. Although our study used only one strain of bacteria, our findings indicates that E. coli O157 has the potential to persist for long periods of time on gates, stiles and other farmyard surfaces under a range of environmental conditions. These farmyard surfaces therefore pose a potential infection pathway particularly where there is a high risk of direct human contact (e.g. child petting zoos, open farms).     

Bio-indicators in the monitoring of environmental pollution

Summary Surveying the chemical pollution status of a given area is increasingly becoming the task of biological indicators, ie animal and plant organisms capable of providing us with the necessary data. For example, in the wake of certain contaminations, they may increase or decrease in number, vary population proportions in relation to given traits, become vectors of certain toxic molecules or heavy metals, or accumulate them in their bodies or in their «products». The advantage of bioindicators over chemical or physical detectors is their ability to supply extensive — both spatially and temporally —rather than limited and instantaneous data, thus making such information more representative. In many instances the bioindicator takes samples for us-a service that is undoubtedly valuable even though it must be linked to a sound knowledge of the organism's ethogram and biology so as to arrive at a scientifically legitimate interpretation of the data provided.     

Abnormalities of embryonal development of vertebrates under the conditions of technogenic environmental pollution

The performed investigations have revealed 21 kinds of pathologies in the embryonal development of amphibia and more than 30 kinds in small mammals in the territories with radiation-chemical environmental pollution. Differences in embryonal mortality and pathologies of embryogenesis have been demonstrated for both the representatives of amphibia and mammals and within one class in the regions with different technogenic load. Embryonàl death and pathologies of embryonal development are considered as important reasons of reproductive losses for different species.     

Identifying and monitoring pain in farm animals: a review

One important objective for animal welfare is to maintain animals free from pain, injury or disease. Therefore, detecting and evaluating the intensity of animal pain is crucial. As animals cannot directly communicate their feelings, it is necessary to identify sensitive and specific indicators that can be easily used. The aim of the present paper is to review relevant indicators to assess pain in several farm species. The term pain is used for mammals, birds and fish, even though the abilities of the various species to experience the emotional component of pain may be different. Numerous behavioural changes are associated with pain and many of them could be used on farms to assess the degree of pain being experienced by an animal. Pain, as a stressor, is associated with variations in the hypothalamic–pituitary–adrenal axis as well as in the sympathetic and immune systems that can be used to identify the presence of pain rapidly after it started. However, most of these measures need sophisticated equipment for their assessment. Therefore, they are mainly adapted to experimental situations. Injuries and other lesional indicators give information on the sources of pain and are convenient to use in all types of situations. Histopathological analyses can identify sources of pain in experimental studies. When pronounced and/or long lasting, the pain-induced behavioural and physiological changes can decrease production performance. Some indicators are very specific and sensitive to pain, whereas others are more generally related to stressful situations. The latter can be used to indicate that animals are suffering from something, which may be pain. Overall, this literature review shows that several indicators exist to assess pain in mammals, a few in birds and very few in fish. Even if in some cases, a single indicator, usually a behavioural indicator, may be sufficient to detect pain, combining various types of indicators increases sensitivity and specificity of pain assessment. Research is needed to build and validate new indicators and to develop systems of pain assessment adapted to each type of situation and each species.     

Comparative mapping in farm animals.

This paper summarises the current status of comparative mapping in farm animals. For most of the major farm animal species, a wide range of genomic tools are now available to create high-resolution genetic and physical maps of the genome. For many farm animals, the use of radiation hybrid panels and sequence data from expressed sequence tag (EST) projects has accelerated the development of high-resolution comparative maps, with human--the model species for farm animals. These tools and comparative maps are being used to map and identify the genes at the loci for simple and complex traits. The development of detailed physical maps in farm animals based on radiation hybrid panels and bacterial artificial chromosome (BAC) contigs provides a direct link between the 'information-poor' maps of farm animals and the 'information-rich' genomes of human and other model organisms.     

新型吡唑类化合物DL-1的硝化抑制效应初探

以国内外应用较为广泛的硝化抑制剂双氰胺（DCD）为参比对象,采用室内培养方法,对新型吡唑类化合物DL-1的硝化抑制效应进行初步探讨.结果表明,DL-1对土壤中铵的氧化过程具有显著的抑制效应,前3周的硝化抑制率可达70％以上,且硝化抑制能力在第14天至28天最强.与等量DCD相比,施用量为(NH₄)₂SO₄氮量1.0%的DL-1在14、21和28 d使土壤中的NO₃^--N含量分别下降 26.23%、33.27%和23.31%;与不加抑制剂的对照处理相比,土壤NO₃^--N含量则分别下降了71.12%、69.10%和55.14%.当DL-1用量为(NH₄)₂SO₄氮量的2。0%时,土壤的硝化作用受到了更强烈的抑制,到培养第90天试验结束,土壤中的NO₃^--N含量始终维持在较低水平.     

Characteristics of acute respiratory viral infections in children under conditions of technogenic environmental pollution

The results of observations on children with acute virus respiratory infections (ARVI) and who had long been residents of zones with different levels of technogenic pollution of the atmospheric air are presented. The technogenic pollution of the environment has been found to exert influence on the spread and clinical course of ARVI in children, this influence being the more pronounced, the higher is the level of xenobiotics in the atmospheric air. The severity of the disease is noted to depend on the development of a number of syndromes, aggravating the course of ARVI, such as the neurotoxic and bronchoobstructive syndromes. Bronchical and ENT lesions are the most frequent complication of the main disease. The child population residing under the conditions of high technogenic environmental pollution should be regarded as a group of risk subject to the aggravated course of ARVI, and the examination of sick children should be made with due regard to this circumstance.     

Survey of aflatoxicosis in farm animals.

Over a 22-month period, 278 submissions of farm animals were made to the North Carolina Diagnostic Laboratory for suspected aflatoxicosis, and 94 cases were confirmed on the basis of finding aflatoxin in the feed and the occurrence of bile ductule proliferation. There was an annual variation in the incidence of aflatoxicosis, as well as a seasonal variation: the peak incidence occurred in the winter, and the minimum incidence occurred during the summer. The annual increase coincided with the corn harvest. All confirmed cases occurred on farms that raised and stored their own corn, and 88% were in swine. The cases were geographically localized in the eastern section of North Carolina (94% of the total cases) where 82% of the swine and 79% of the corn are produced. Mean concentration of aflatoxin in feed samples from the confirmed cases was 3,890 mug/kg, and the mean value for corn used in making the feed was 5,180 mug/kg. Only aflatoxin B1 was found in the samples. These data were interpreted to mean that the incidence and severity of aflatoxicosis is greater than previously suspected, that poor on-farm storage of corn is a primary contributing factor, that aflatoxin formation continues during and after the milling process, and that mycotoxicoses other than aflatoxicosis may cause equal or greater problems.     

On-line and in situ biosensors for monitoring environmental pollution

Efficient tools for on-line and in situ monitoring of environmental pollutants are required to provide early warning systems. In addition, such tools can contribute important information on the progress of various remediation treatments. One of the recently developed monitoring technologies involves the use of whole-cell biosensors. Such biosensors could be constructed to detect general toxicity or specific toxicity caused by one or more pollutants. Currently, a large spectrum of microbial biosensors have been developed that enable the monitoring of pollutants by measuring light, fluorescence, color or electric current. Electrochemical monitoring is of special interest for in situ measurements as it can be performed using simple, compact and mobile equipment and is easily adaptable for on-line measurements. Here we survey the potential application of electrochemical biosensors in monitoring of general toxicity as well as hydrocarbons and heavy metals.     

Relationship between environmental pollution and genetic monitoring of human populations

The basis of genetic monitoring is the knowledge of laws of the spontaneous mutation process. These laws are determined for human chromosome and genome mutations by cytogenetic examination of newborns, infants with congenital defects, and the material of spontaneous abortions. Confidence intervals and all the necessary sample sizes were calculated when registering the mutagenic effects of different intensity in the general population as well as to the groups of closer contact with mutagens. Such calculations were made for controlling the spontaneous mutation process in lymphocytes of human peripheral blood on the basis of registering chromosome aberrations.     

Survival of coxsackievirus B3 under diverse environmental conditions.

The survival of coxsackievirus B3 was studied under various conditions of incubation. The comparative study demonstrated that coxsackievirus B3 was stable for 24h (less than 0.4-log decrease in titer) when suspended at neutral pH (6 or 23 degrees C) in the presence of 0.25% bovine serum albumin in saline regardless of whether the preparations were subjected to evaporation. Bovine serum albumin provided increased stability to the virus for each of the conditions tested. At 37 degrees C, evaporation greatly reduced the virus infectivity between 6 and 20 h of incubation. Nevertheless, coxsackievirus B3 was found to be stable for at least 24 h under conditions similar to those of a household environment, and its presence represents a potential biohazard to nonimmune persons. These data provide a rationale for using coxsackievirus B3 as a model for investigating the role of environmental surfaces in the transmission of enteroviral diseases.     

Survival of coxsackievirus B3 under diverse environmental conditions.

The survival of coxsackievirus B3 was studied under various conditions of incubation. The comparative study demonstrated that coxsackievirus B3 was stable for 24h (less than 0.4-log decrease in titer) when suspended at neutral pH (6 or 23 degrees C) in the presence of 0.25% bovine serum albumin in saline regardless of whether the preparations were subjected to evaporation. Bovine serum albumin provided increased stability to the virus for each of the conditions tested. At 37 degrees C, evaporation greatly reduced the virus infectivity between 6 and 20 h of incubation. Nevertheless, coxsackievirus B3 was found to be stable for at least 24 h under conditions similar to those of a household environment, and its presence represents a potential biohazard to nonimmune persons. These data provide a rationale for using coxsackievirus B3 as a model for investigating the role of environmental surfaces in the transmission of enteroviral diseases.     

Persistence of human rhinovirus infectivity under diverse environmental conditions.

The persistence of human rhinovirus type 2 and type 14 infectivity was studied under various laboratory conditions designed to mimic those commonly found in the environment. The effects of temperature, ionic strength, protein content, and evaporation were compared. Both viruses were stable (less than 0.3-log decrease in titer) at 6 and 23 degrees c for 24 h in the liquid state regardless of salt or protein additives; a titer decrease of less than 1.0 log was noted at 37 degrees C. However, evaporation at 37 degrees C reduced virus infectivity by 3.2 to 4.5 logs in buffered water, an effect which could be significantly lessened by the addition of bovine serum albumin in saline (2.0- to 2.9-log decrease in titer). These studies support and extend observations by others that the human rhinoviruses retain sufficient infectivity after drying on hard surfaces to permit their transmission to susceptible persons upon contact.     

Psychophysiological monitoring under conditions of real and simulated microgravity.

Dynamics of indices characterizing the process of adaptation of operators to complicated conditions of vital activity was studied with psychophysiological monitoring. This technique is based on the complex analysis of subjective and objective estimations of the current psychoemotional state and physiological and biochemical indices. We analyzed the data obtained during the examination of three healthy volunteers, who participated in the HUBES experiment (135-day isolation in the ground-based model of the orbital station "Mir"), and during a biorhythmological study conducted by six Russian cosmonauts of the main expeditions on the station "Mir." It was shown that psychophysiological monitoring is an informative method for studying different parameters of the operator's state and regulatory processes, the dynamics of biological rhythms, and individual characteristics of adaptation. By means of the analysis of a population of the variation in the characteristics of the parameters under study the experimental period of isolation was divided into three stages. The first and third stages were characterized by a relatively high variability, which was minimized at the second stage. The phasic character of the adaptation processes with a phase duration of about 60 days was revealed and a correlation was shown between the dynamics of parameters obtained by means of psychophysiological monitoring and specific features of the system regulation in different phases of the space flight and its simulation. It is suggested that the phases of the minimal variability of the studied characteristics are related to the periods of the minimal reliability of an operator's work. [Translated from Fiziologiya Cheloveka, vol. 25, no. 5, 1999 Sep-Oct, p. 86-91]