Samuel H. Sandifer

Polychlorinated biphenyl (Aroclor 1242): effects of uptake on growth, nucleic acids, and chlorophyll of a marine diatom.

ConclusionCylindrotheca closterium absorbed and concentrated the polychlorinated biphenyl (Aroclor 1242) 900 to 1000 times above the level in sea water. At.1 ppm concentration in sea water, PCBs inhibited growth and diminished levels of RNA and chlorophyll of this marine diatom.

DDT and polychlorinated biphenyl (Aroclor 1242). Effects of uptake on E. coli growth

Abstract DDT at 0.01 and PCB at 0.01 and 0.1 ppm consistently stimulated E. coli growth in vitro . Differences between treatments and controls were statistically significant at the 95 per cent confidence level. E. coli uniformly converted DDT to DDD (75 per cent) and DDE (25 per cent). There was no difference in nucleic acids content between treatments and controls at the conclusion of 24 hours incubation although increased uridine uptake was noted in all DDT and PCB cultures after 5 h of incubation.

Effect of DDT on Antibody Response to Typhoid Vaccine in Rabbits and Man

DDT-dosed humans and animals injected with Salmonella typhi vaccine produced O, H and Vi agglutinin titers somewhat higher than controls (no DDT). This is In contrast to an earlier report that DDT-fed animals injected with this vaccine experienced a 30% decrease in antibody titre to whole organisms. Immunoglobulin levels in human volunteers were unaffected by DDT ingestion.

Serum vitamin a elevation in DDT exposed volunteers

ConclusionTwenty-one pesticide-exposed participants had significantly higher serum vitamin A and plasma DDT, DDD and DDE levels than their age, race, and sex matched controls. There was also a significant positive correlation of vitamin A with DDT and its principal metabolites, which may be a natural biological event since both compounds are lipid soluble.

The effect of DDT and PCB on lipid metabolism inE. coli andB. fragilis

SummaryEscherichia coli andBacteroides fragilis, principal human enteric aerobic and anaerobic bacteria, were cultured with suitable controls in the presence of.01 and.1 ppm of DDT and PCB. The bacteria were assayed for dry weight and total lipids. DDT increased the growth ofE. coli at the.01 ppm level but had no detectable effect at.1 ppm. Total lipid content was not significantly altered by either DDT or PCB.DDT at. 01 ppm depressedB. fragilis growth, but had no significant effect on lipid levels. PCB increased the growth ofB. fragilis significantly at the 1 ppm level, but significantly depressed lipid synthesis at both concentrations. The effect was apparently dose dependent. All cultures metabolized DDT to DDD. Trace amounts of DDE were also found in several replicates.DDT/PCB are statistically associated with cardiovascular disease risk factors, but the mechanism does not appear to be that of increased lipid anabolism by enteric bacteria.

Urinary protein excretion in workers exposed to low doses of cadmium

ConclusionsThere was evidence of mild renal dysfunction in three of the cadmium-exposed individuals out of the total of 39. However, in none of them did we find a fully developed tubular proteinuria in which moderate increases of total proteinuria, increased lysozymuria and beta-2 microglobulinuria, and excretion of low molecular weight proteins by SDS-PAGE would also be found.Out of the four parameters determined, only one patient had three of them in the abnormal range, but this patient showed predominant elimination of high molecular weight proteins, compatible with glomerular damage, an unexpected finding in cadmium poisoning. Renal dysfunction was detected in one control subject who had increased total protein classified as tubular. There were two abnormal SDS-PAGE patterns found in the control group in which the other parameters measured were normal as was the case in the cadmium exposed patients.

Pesticide Exposure Index (PEI)

Pesticide exposure indices may be of value and serve several purposes : 1. In selecting study groups, a. Prior to blood or other precise determinations, b. When precise analytical methods are not available, 2. Providing reference for data evaluation, e,g, exposure versus reaction, 3. Corroboration of laboratory determinations, 4. Establishing thresholds of permissibility (safety),