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Biomedical subjects

P Nelson

Publications and source records attributed to P Nelson.

At least 145 records · Page 8Linked to original sources
PubMed1979

Magnitude of pollution indicator organisms in rural potable water.

A total of 460 water samples were randomly drawn from the potable water supply sources of rural communities in three counties of South Carolina. About 10% of the population, not incorporated in municipalities, was sampled. The samples were tested for total coliforms, Escherichia coli, and fecal streptococci. Significant levels of these pollution indicator organisms were detected in almost all the water supplies. Total coliforms were the most common, and only 7.5% of the water supplies were uncontaminated. E. coli, considered a reliable indicator of recent and dangerous pollution, was observed in 43% of the water supplies. Statistical analyses indicated that the bacterial populations, especially E. coli, were associated with the supply source depth and its distance from the septic tank. Total coliform counts were also weakly correlated to the pH of the water.

Enterococcus faecalis↗
PubMed1978

Regulation of acetylcholine release from neuroblastoma x glioma hybrid cells.

Neuroblastoma x glioma NG108-15 hybrid cells exposed to N6, O2'-dibutyryladenosine 3':5'-cyclic monophosphate for several days release [3H]acetylcholine in response to serotonin, prostaglandin F2alpha, KCl, or veratridine. NG108-15 cells grown in the absence of dibutyrul cyclic AMP do not respond to an excitatory stimulus by releasing [3H]acetylcholine but can be shifted to a responsive state by treatment with dibutyryl cyclic AMP. Thus, the reactions that are required for acetylcholine release can be regulated in NG108-15 cells, thereby regulating the ability of cells to form synapses and the efficiency of synaptic communication.

Acetylcholine↗
PubMed1976

Synapse formation between clonal neuroblastoma X glioma hybrid cells and striated muscle cells.

Clonal neuroblastoma X glioma hybrid cells were shown to form synapses with cultured, striated muscle cells. The properties of the synapses between hybrid and muscle cells were similar to those of the normal, neuromuscular synapse at an early stage of development. The number of synapses formed and the efficiency of transmission across synapses were found to be regulated, apparently independently, by components in the culture medium. Under appropriate conditions synapses were found with 20% of the hybrid-muscle cell pairs examined; thus, the hybrid cells form synapses with relatively high frequency.

Action Potentials↗
PubMed1975

Potable water quality in rural Georgetown County.

Drinking water supplies of 161 rural communities, in Georgetown County, South Carolina, were randomly selected for sample collection. The analysis showed that most of the waters were slightly acidic. Low, but acceptable concentrations of chloride, copper, fluoride, sodium, cadmium, nitrate and phosphate were found. A few water samples showed higher then recommended levels of arsenic, mercury, zinc and lead. Although only 2% of the samples exceeded the mandatory limit of 0.05 ppm for arsenic, 72% exceeded the recommended level of 0.01 ppm. The mandatory limit for manganese was exceeded in 37% of the waters while 88% exceeded the limit for iron. The high iron content was generally responsible for the high turbidity found in 45% of the samples. The well depth and the consumer income had some bearing on water quality. Statistical evidence suggested that septic tank seepage was partially responsible for nitrate, phosphate, iron and arsenic contamination of shallow water supplies. Lead concentrations appear to vary according to the plumbing used and the pH of the waters.

Hydrogen-Ion Concentration↗
PubMed1971

Genes for neuronal properties expressed in neuroblastoma x L cell hybrids.

Neuroblastoma cells with electrically excitable membranes were fused with electrically passive L cells having a hitherto undescribed electrical marker. Hybrid cells, examined 10-40 generations after fusion, were found to be electrically excitable. The results show that at least a part of the genetic information for neuron differentiation can be functionally expressed in N x L hybrid cells. Evidence for the regulation of action potential components was also found.

Action Potentials↗