Biomedical subjects

C Dodson

Publications and source records attributed to C Dodson.

3 recordsLinked to original sources

PubMed1998

Mass-sensing, multianalyte microarray immunoassay with imaging detection.

Miniaturization of ligand binding assays may reduce costs by decreasing reagent consumption, but it is less apparent that miniaturized assays can simultaneously exceed the sensitivity of macroscopic techniques by analyte "harvesting" to exploit the total analyte mass available in a sample. Capture reagents (avidin or antibodies) immobilized in 200-microm diameter zones are shown to substantially deplete analyte from a liquid sample during a 1-3-h incubation, and the assays that result sense the total analyte mass in a sample rather than its concentration. Detection of as few as 10(5) molecules of analyte per zone is possible by fluorescence imaging in situ on the solid phase using a near-infrared dye label. Single and multianalyte mass-sensing sandwich array assays of the IgG subclasses show the sensitivity and specificity of ELISA methods but use less than 1/100 the capture antibody required by the 96-well plate format.

Avidin↗

PubMed1997

Lead Exposure among Adult Temporary Residents in Eastern Europe: Should Blood Lead Levels Be Monitored?

Background: The risk of lead exposure among temporary residents in Eastern Europe is unknown. We monitored blood lead levels (BLLs) of Peace Corps Volunteers serving in Albania, Bulgaria, the Czech Republic, Hungary, Poland, Romania, and Slovakia from June 1991 through June 1994. Methods: BLLs were analyzed before the Volunteers left the United States (Sample 1), at mid-service (median of 15 months in-country, Sample 2), and at end-of-service (median of 22 months in-country, Sample 3). Results: Among 425 study participants who provided at least one follow-up blood sample, BLLs were significantly higher at Samples 2 and 3 compared to the U.S. baseline (paired t-test, p<.0001); however, the mean increase in BLL was only 1.0 ug/dL (range = -9.6 to 10.7). Overall, 74% of Volunteers experienced an increase in BLLs, 24% a decrease in BLLs, and 2% no change in BLLs at Sample 3 compared to their U.S. baseline. The highest increases in BLLs were among Volunteers in Albania, Bulgaria, and Romania (analysis of variance, p<.0001). In addition, men had higher mean increases in BLLs at Samples 2 and 3 compared to women (t-test, p=.017 and.029). Conclusions: The risk of significant lead exposure among our study population was low, and monitoring of BLLs among adult short-term residents in Eastern Europe does not seem to be indicated.

Journal Article↗

PubMed1977

Submaxillary secretion in rats treated with guanethidine.

The composition of final submaxillary saliva and of whole gland homogenates were compared in rats treated with 14 daily doses of guanethidine (20 mg/kg body weight) and in untreated controls after stimulation with pilocarpine (10 mg/kg) or carbamylcholine (50-100 mg/kg). A 44% reduction in the volume of saliva and elevations in the salivary concentrations of K+, Ca2+ and protein were found in the treated animals after pilocarpine stimulation. Similarly, a 25% reduction in salivary volume and elevations in salivary Ca2+ and protein concentrations were observed following stimulation with carbamylcholine. A less significant elevation in salivary K+ was seen after this secretagogue. The Na+ and protein contents, but not the K+ and Ca2+ contents, were found to be elevated in the glands of the treated animals in the resting (unstimulated) state. After stimulation with the two secretagogues, however, similar changes in glandular Na+ and K+ contents were found in the glands of control and treated animals. The glandular water content was also similar in both types of glands in the resting and stimulated states. It is concluded that a reduced salivary secretion, rather than supersensitivity, is observed in the rat submaxillary gland following chronic guanethidine administration. The drug treatment does not impair the glandular electrolyte changes that occur upon stimulation, but most likely impairs the release of protein from the gland and also transductal K+ transport. Both these effects may result from the depletion of sympathetic neurotransmitter caused by the guanethidine administration.

Animals↗