A method for purifying enteric glia from rat myenteric plexus

The enteric nervous system is a large and complex division of the peripheral nervous system. The glia associated with it share some characteristics with the olfactory-ensheathing glia, astrocytes and Schwann cells. To facilitate studies of rat enteric glia, we have developed a method for preparing them in large quantities with a high degree of homogeneity. The enteric glia were isolated from the small intestine of Wistar rats by enzymatic digestion with dispase. The cell isolate was added to a mitotically arrested layer of 3T3 cells. Subsequent separation of the enteric glia from the 3T3 cells was done enzymatically, with unavoidable loss of many enteric glia and potential contamination of enteric glia cultures with the 3T3 cells. Therefore, 3T3 cells were cultured in Nunc 0.2-microm tissue culture inserts that could be readily removed from the wells when no longer needed. There was no loss of the enteric glia. The cultures consisted entirely of GFAP-labeled cells, presumptive enteric glia. This method permits the culturing of large numbers of highly purified enteric glia without the use of expensive growth factors and complement-mediated cytolysis.     

Seasonal occurrence of yeasts and yeast-like organisms in the river Danube

One hundred and seventy yeast strains belonging to 14 genera and 29 species were isolated from 112 water samples of the river Danube in the area of Bratislava. The samples were collected through the year from April to March.Saccharomyces cerevisiae, Candida maltosa, Aureobasidium pullulans, Cystofilobasidium capitatum, Rhodotorula glutinis, Geotrichum candidum, and Candida krusei were the most frequent. The basidiomycetous yeasts and yeast-like organisms with oxidative metabolism were present in approximately equal numbers to those with fermentative metabolism. Saccharomyces cerevisiae was the dominant yeast and was isolated from 50% of all samples examined and represented approximately one quarter of the yeast community.Yeast densities ranged from 100 to 21,100 CFU per litre. The highest population density was observed in October. Cryptococcus albidus, Saccharomyces cerevisiae, Rhodotorula glutinis, and Aureobasidium pullulans formed the main part of the yeast population in this month.     

THE INFLUENCE OF P-RETENTION BY SOILS AND SEDIMENTS ON THE WATER QUALITY OF THE LIONS RIVER

SUMMARY

The soils of Midmar dam catchment and the sediments of the Lions river are shown to have high P-retention properties. Present conditions result in little leaching of PO₄ ^?4 from the soils and favour a net transport of P from overlying water to the sediments. P levels in the water are likely to remain low even if the loading rate of P were increased substantially. It is postulated however that other factors may induce a release of P from the sediments and adversely affect the load carried by the water.     

Distribution of Enteric Pathogens in Wastewater Secondary Effluent and Safety Analysis for Urban Water Reuse

Through a 1-year monitoring of enteroviruses and pathogenic bacteria in the secondary effluent using real-time polymerase chain reaction (real-time PCR), the pathogen removal requirement was evaluated for safeguarding the reclaimed water quality for urban reuse. The distribution of each pathogen in the secondary effluent was found to follow a log-normal relationship, although 50% cumulative concentrations differed much from each other (1.4 GEC/L of infectious enteroviruses, 3.1 × 10² CFU/L of Salmonella typhi, 1.0 × 10³ CFU/L of Shigella, and 3.3 × 10⁵ CFU/L of Escherichia coli). By exposure analysis regarding two reuse scenarios (golf course irrigation and recreational impoundment), risks were analyzed for pathogens in reused water based on monitoring data and dose–response relation. For enteroviruses and pathogenic bacteria, there were obvious differences in the relationship between the reliability and removal efficiency. Under an acceptable annual risk level (10^–4/a), the pathogen removal requirement depends on the manner of water reuse. In the golf course irrigation, the removal efficiency of enteroviruses, Salmonella typhi, Shigella, and Escherichia coli reach to 3.8～4.0-log, 1.4-log, 3.3-log, and 2.0-log, respectively, in order to ensure 95% reliability. However, if wastewater is reused for recreational impoundment, only a further increase around 1.5-log removal efficiency of pathogens can meet the requirement for the same reliability.     

Temporal changes in the bacterioplankton of a Northeast Ohio [2pt] (USA) River

To examine temporal changes in a bacterial community, water samples were collected monthly for one year from five sites along a major use-reuse river, the Cuyahoga River, in northeastern Ohio (USA). Fluorescent in situ hybridization (FISH) was used to enumerate population sizes of two species of common bacteria, Pseudomonas putida and Acinetobacter calcoaceticus; FISH was also performed with a Domain Bacteria specific probe. In addition, the total bacteria (based on DAPI staining), colony forming units (on modified Nutrient agar) and coliforms were enumerated and supporting physical/chemical data were collected. Each variable examined exhibited a different seasonal pattern. Temporal changes in total number of bacteria and population size of P. putida were correlated with turbidity and precipitation suggesting that allochthonous sources and scouring of the benthos may be major contributors to these portions of the community. In contrast, the number of cells hybridizing the Domain Bacteria and A. calcoaceticus probes were correlated with temperature. Thus, different aspects of the bacterial community are potentially controlled by different factors and the role of allochthonous and autochthonous sources may vary among species.     

Hepatitis E virus‐based evaluation of a virion concentration method and detection of enteric viruses in environmental samples by multiplex nested RT‐PCR

Aims: The prevalence of enteric viruses in drinking and river water samples collected from Pune, India was assessed. During an outbreak of HEV in a small town near pune, water samples were screened for enteric viruses. Methods and Results: The water samples were subjected to adsorption–elution‐based virus concentration protocol followed by multiplex nested PCR. Among 64 Mutha river samples, 49 (76·56%) were positive for Hepatitis A Virus, 36 (56·25%) were positive for Rotavirus, 33 (51·56%) were positive for Enterovirus and 16 (25%) were positive for Hepatitis E Virus RNA. Only enterovirus RNA was detected in 2/662 (0·3%) drinking water samples, and the samples from the city’s water reservoir tested negative for all four viruses. HEV RNA was detected in three out of four river water samples during HEV outbreak and partial sequences from patients and water sample were identical. Conclusions: The study suggests absence of enteric viruses both in the source and in the purified water samples from Pune city, not allowing evaluation of the purification system and documents high prevalence of enteric viruses in river water, posing threat to the community. Significance and Impact of the Study: The rapid, sensitive and relatively inexpensive protocol developed for virological evaluation of water seems extremely useful and should be adapted for evaluating viral contamination of water for human consumption. This will lead to development of adequate control measures thereby reducing disease burden because of enteric viruses.     

Surnames in Argentina: a population study through isonymy

In order to study the isonymic structure of Argentina, the surname distributions of 22.6 million electors registered for the year 2001 were analyzed in the 24 districts (distritos) and 541 municipalities (municipios) of the country. The number of different surnames found was 414,441. Matrices of isonymic distances between districts were constructed and tested for correlation with the geographic distance between the capital towns of the districts. We found that, for the whole of Argentina, Euclidean distance was correlated with the log of geographic distance (r=0.480+/- 0.067). A dendrogram of the 24 regions was built from the matrix of Euclidean distances, using the UPGMA method. The clusters identified by the dendrogram are coincident with conterminous geographical regions of the country. Random inbreeding calculated from isonymy, F(ST), was highest in La Rioja, Corrientes, and Santiago del Estero. It was lowest in the area of Buenos Aires and in the north-central region of Santa Fé. Average Fisher's alpha for municipalities was 358; for districts, it was 422; and for Argentina as a unit, it was 602. The geographical distribution of alpha in 541 municipalities, high in the east and lower in the west of the country, is compatible with the settlement in the 20th century of subsequent waves of immigrants moving from the North Atlantic coast toward the foot of the Andes and toward the south. The present structure of Argentina indicates that migration dominates over drift.     

Enteric viruses evoke broad host immune responses resembling those elicited by the bacterial microbiome

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Drastically lowering the titer of waterborne bacteriophage PRD1 by exposure to immobilized hydrophobic polycations

Decrease in the titer of bacteriophage PRD1 (a model of animal adenoviruses) in aqueous solutions caused by the presence of systematically chemically derivatized surfaces was kinetically investigated. The greatest loss of infectivity – up to a 4-log reduction in the titer – was observed with immobilized hydrophobic polyethylenimine-based and dendrimer-based polycations.     

Inbreeding levels in Northeast Brazil: Strategies for the prospecting of new genetic disorders

A new autosomal recessive genetic condition, the SPOAN syndrome (an acronym for spastic paraplegia, optic atrophy and neuropathy syndrome), was recently discovered in an isolated region of the State of Rio Grande do Norte in Northeast Brazil, in a population that was identified by the IBGE (Brazilian Institute of Geography and Statistics) as belonging to the Brazilian communities with the highest rates of "deficiencies" (Neri, 2003), a term used to describe diseases, malformations, and handicaps in general. This prompted us to conduct a study of consanguinity levels in five of its municipal districts by directly interviewing their inhabitants. Information on 7,639 couples (corresponding to about 40% of the whole population of the studied districts) was obtained. The research disclosed the existence of very high frequencies of consanguineous marriages, which varied from about 9% to 32%, suggesting the presence of a direct association between genetic diseases such as the SPOAN syndrome, genetic drift and inbreeding levels. This fact calls for the introduction of educational programs for the local populations, as well as for further studies aiming to identify and characterize other genetic conditions. Epidemiological strategies developed to collect inbreeding data, with the collaboration of health systems available in the region, might be very successful in the prospecting of genetic disorders.     

Seasonal distribution of live births in a rural community in the southern United States

Births in Greene County, Alabama for the years 1980–1984 were examined and an overall seasonal trend was found with a peak from August through November. This trend was found to be most pronounced among women greater than 24 yeas old, and among multiparous women, and to be negatively correlated with seasonal variations in temperature and daylight. The phenomenon is likely multifactorial in origin, with sociocultural factors playing a considerable role. The influence of increasing maternal age and parity in the expression of the seasonal trend may be a function of age-related changes in families, with nuclear families acting as the most powerful potentiators of seasonality.     

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.     

Incipient allochronic speciation by climatic disruption of the reproductive period

Disruptive selection of life-cycle timing may cause temporal isolation directly and, ultimately, allochronic speciation. Despite the fact that segregation of the reproductive period among related species has been broadly observed across taxa, it remains controversial whether temporal isolation can function as the primary process of speciation. In the Japanese winter geometrid moth Inurois punctigera, allochronic divergence has resulted from climatic disruption of the reproductive period. In habitats with severe midwinter, two sympatric groups of moth reproduce allochronically in early and late winter. These groups are genetically diverging sister lineages and now co-occur allochronically throughout Japan. By contrast, in habitats with milder midwinter these lineages form a continuous adult period and gene flow has been facilitated between the lineages. These results, together with the fact that there is no difference in larval host use, indicate that temporal isolation has been the sole mechanism for allochronic isolation in colder habitats and that allochrony is not a by-product of other adaptations. Thus, the allochronic divergence of sympatric I. punctigera populations represents an incipient speciation process driven by midwinter disruption of the reproductive period.     

Abiotic vs. Biotic Factors: Lessons Drawn From Rotifers in the Middle Loire,a Meandering River Monitored From 1995 to 2002, During Low Flow Periods

The numbers of rotifers in large rivers never achieve the abundances observed in eutrophic lakes. The adverse conditions of the current have conduct biologists to establish links between particular geomorphologies and biological processes in the plankton of rivers. Recent attempts to examine specific adaptations of rotifers have shown that among several planktonic forms, the loricate species appeared to be better adapted to the current than soft-bodied or littoral-epibenthic species. The eutrophic Middle Loire provides rotifers with more edible biomass than that necessary for their production so, the aim of this study was to determine which other factors were responsible for the origins, growth and survival of rotifer populations in the river. Samples were taken bi-monthly in the current, from end-June to early-October during 8 years, in two sections of the River Loire situated at 550 and 640 km from the source. Flow rate, temperature, dissolved oxygen, suspended matter, biological oxygen demand and algal densities were examined in parallel, and among the 61 rotifer species collected at each site, the 30 dominant species were retained for the analysis. Planktonic loricate species were dominant in the Middle Loire, followed by epibenthic species, soft-bodied species being least abundant. The densities of rotifers and algae changed in parallel and in relation to temperature; flow was clearly unfavourable to algae, represented by the Chlorophytes and to rotifers, whatever the sites. Co-inertia analysis revealed that the assemblage of species was closely grouped at Dam where the immediate environment was dominated by numerous scattered islands. This analysis also illustrated that the consequence of eutrophication in the water quality was more marked downstream. Lessons drawn from this experience of the Middle Loire, which ranks among the richest rivers in terms of species, allowed to highlight that dominance of the Brachionidae is a rule in numerous rivers and may be explained by the capacity of several species to continue growing in a current of 0.2 m s⁻¹. Trichocercids may be relevant indicators of sandy rivers. The flexibility of rotifers in the face of hydraulic conditions, the question of the rotifers’ origin, the respective roles of downstream transfer and processes, as well as the role of the rotifers in the river food-web are discussed.     

Quantitative analysis of human enteric adenoviruses in aquatic environments

AIMS: The aim of this study was to determine human adenoviruses (HuAdVs) in aquatic environments by real-time polymerase chain reaction (PCR). METHODS AND RESULTS: In order to describe the ratio of enteric serotypes to the total HuAdVs, the primer set specific for the enteric serotypes 40 and 41 was used in parallel with the universal primer set for all 51 serotypes of HuAdVs. The enteric serotypes of HuAdVs were detected at the concentration of 7.3-1500 PCR-detection units (PDU) per ml in raw sewage (n = 17), 0.00060-4.1 PDU ml(-1) in secondary-treated sewage before chlorination (n = 17), 0.0018-7.0 PDU ml(-1) in river water (n = 36), and 0.032-6.1 PDU ml(-1) in seawater (n = 18). The concentration of HuAdVs, determined by the universal primer set, was equivalent to that of enteric serotypes in almost all the samples tested. CONCLUSIONS: Enteric serotypes were predominant among all serotypes of HuAdVs in the aquatic environments. SIGNIFICANCE AND IMPACT OF THE STUDY: The abundance of enteric serotypes of HuAdVs should be more emphasized than other serotypes in order to assess the risk of their infection via water.