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Biomedical subjects

I Nestor

Publications and source records attributed to I Nestor.

At least 19 recordsLinked to original sources

Virus isolation data from water of some European rivers: an overview.

The present overview is the result of our scrutiny of data concerning the presence of viruses in the water of diverse European rivers. These data were assembled from the published literature--articles, doctoral theses and reports from investigations conducted by environmental virologists beginning during the final years of the sixth decenium of the twentieth century, first in France, Czechoslovakia, Romania, Ukraine, U.S.A. then in other European and countries worldwide. The overview covers the methodology referring both to water sampling (by gauze pads or by grab procedures), and to virus detection methods, including virus concentration from large volumes of water and the inoculation of virus concentrates on cell cultures and/or into suckling mice. Other more recently elaborated methods of virus detection and identification, consisting of immunological tests, as the enzyme immunoassay (EIA), immunofluorescence (IF), or the genetic techniques, as the molecular hybridization and flow cytometry (FC), were also applied. The obtained results refer to the virus positivity with the specification of virus types and various virus contamination levels of these waters. Finally, the ways by which the viral contamination of the searched river waters might be demonstrated and, ways by which the human body can be contaminated by the virus polluted river waters are discussed, and some conclusions and recommendations are formulated.

England↗

Human viruses possibly present in the environment.

This paper deals with some aspects of human viruses in the environment. Thus, a systematization of these viruses was made on the basis of their elimination from the human body and also with regard to their detection in various segments of the environment. The data compiled lead to the conclusion that virtually any human virus, of any taxonomic group known, may be present, in one or another segment of the environment, at one or another time.

DNA Viruses↗

Viral contamination of some drinking waters in Romania: a twenty years survey.

A synthesis is made on the 20 years virological survey of the drinking water from some towns of Romania. The sampling of the water was made by the gauze-pad method. The virus concentration method by adsorption-elution with the yeast cells was applied concomitantly, at first with the PE60 method, then, during the last years, either with aluminum hydroxide or with the polymer PV methods, and the concentrates were inoculated both into suckling mice and into cell cultures. Various types of coxsackievirus A and B, poliovirus and adenovirus were detected. The proportions of positive samples varied between 0 and 25% annually, in diverse towns, the mean proportion being 2.1%. These proportions are relative low, although two concentrating and two detecting methods were applied concomitantly.

Adenoviridae↗

[Detection of enteroviruses in seawater and beach sand].

In the years from 1975 to 1978 investigations were carried out to detect enteroviruses in the sea-water and in the sand of the beaches of the Rumanian Black Sea coast, in zones with and without waste water discharge. The quantities of enteroviruses found in the seawater and in the sand of the beaches were lower than those verified in other countries. For the identification of viruses we used two concentration methods simultaneously (polyelectrolyte PE60 Monsanto USA and brewer's yeast cells) as well as two methods of isolation (in cell cultures and with newborn mice). The incidence of enteroviruses depended on the season, with no viruses present in the sea-water and in the sand of the beaches during the periods considered to be outside the holidaying season. The discharge of purified sewage into the sea was not attended by considerable viral contamination of the sea-water and of the beaches.

Animals↗

[Methodology for detecting enteric viruses in sea water].

Within the set of measures to protect the marine environment against ever greater viral pollution, the methodology for the detection of human virus in seawater is of primary importance as a means of evaluating the efficiency of protective measures. So far only a limited number of methods have been applied to determine the presence of enteritis virus in sea-water. These methods are the ones already used to study soft water. However, the specific characteristics of sea-water require certain modifications to these methods. Experimental research or on site examinations have to date made significant contribution to the methodology. The importance of the problems posed to hygienists and to health policy makers calls for efforts to perfect these methodologies. The results obtained in this respect, both in the laboratory and in the field, are encouraging. They confirm that the techniques developed are suitable, in the majority of cases, for the detection of enteritis virus in the marine environment, but they still remain to be perfected. The present work takes as its basis both data from the literature and the results of personal experiments.

Adsorption↗

Viral pollution of some artificial reservoirs in Romania.

Five reservoirs were investigated for the presence of enteroviruses by using simultaneously two methods for concentration (PE60 and yeast cells) and two techniques for isolation (inoculation into suckling mice and into cell cultures). The average rate of virus positive samples was lower in reservoir water than in the water of the adjoined rivers. The paper discusses the possibilities of viral self-purification in reservoir water and the advantages of its use for drinking purposes after adequate treatment.

Animals↗

Enteroviruses in drinking water correlated with the physical-chemical and bacteriological indicators of water quality.

A comparison between the presence of enteroviruses and the physical-chemical and bacteriological qualities of drinking water showed that the usual treatment procedures of surface water, though correctly applied to satisfy the standards of quality, yet failed to achieve complete removal of enteroviruses. Thus the results obtained in field conditions confirmed the data established experimentally in laboratory conditions, by other authors.

Enterovirus↗

Enteric viruses in the Danube river water and sludge.

A study of the viral pollution of the Roumanian course of the Danube river was carried out from 1972 to 1974. The presence of enteric viruses was investigated in 123 water samples, taken by the gauze swab method and in 116 sludge samples from the bottom of the river. The samples were collected from 20 sampling points along the river from Moldova Veche to Brăila, in accordance with the water use and the main pollution sources. Viruses were recovered from 17.5% of the samples. The frequency of virus isolations from water samples was similar to that observed in sludge samples. Therefore, the viral pollution of the Romanian course of the Danube showed a low level in comparison with other rivers, though two concentration techniques into suckling mice and into tissue cultures, were used for each sample.

Enterovirus↗

Presence of certain enteroviruses (Coxsackie) in sewage effluents and in river waters of Roumania.

The paper presents the results of research studies conducted during a 10-year period (1962-1971) with the view to detect certain enteroviruses (Coxsackie) from sewage, river and drinking water samples, and from the filter sand of drinking water-works supplied with river water. The method consisted first in preconcentrating the samples collected on immersed gauze pads, secondly in the concentration of the virus samples by the following methods-used either separately or in parallel: the Amberlite method, the yeast cell and the aluminium bydroxide concentration method. The isolation of A and B Coxackie viruses averaged 29.12% in the sewage samples and 14.66% in the river water samples. Lower values were found both in aqueduct water and in the filter sand (2 positive samples out of 65 and 3 positive samples out of 39, respectively). A seasonal distribution of the viral incidence was evidenced in the sewage samples with lower value in the river water, while the frequency decreased with the distance from the pollution source. For the lightly contaminated water (river and aqueduct waters) the yeast cell concentration method gave the best results, this method being also the single reliable method for Coxsackie virus isolation from the filter sand samples.

Enterovirus↗

Presence of certain enteroviruses (Coxsackie) in sewage effluents and in river waters of Roumania.

The paper presents the results of research studies conducted during a lo-year period (1962-1971) with the view to detect certain enteroviruses (Coxsackie) from sewage, river and drinking water samples, and from the filter sand of drinking water-works supplied with river water. The method consisted first in preconcentrating the samples collected on immersed gauze pads, secondly in the concentration of the virus samples by the following methods-used either separately or in parallel: the Amberlite method, the yeast cell and the aluminum hydroxide concentration method. The isolation of A and B Coxasackie viruses averaged 29.12% in the sewage samples and 14.66% in the river water samples. Lower values were found both in aqueduct water and in the filter sand (2 positive samples out of 65 and 3 positive samples out of 39, respectively). A seasonal distribution of the viral incidence was evidenced in the sewage samples with lower value in the river water, while the frequency decreased with the distance from the pollution source. For the lightly contamined waters (river and aqueduct waters) the yeast cell concentration method gave the best results, this method being also the single reliable method for Coxsackie virus isolation from the filter sand samples.

Animals↗