Tricia Coakley | University of Kentucky (original) (raw)
Papers by Tricia Coakley
A 1998 study of interstitial fluid geochemistry within Charonis Cascade in the Echo River/River S... more A 1998 study of interstitial fluid geochemistry within Charonis Cascade in the Echo River/River Styx area of the Mammoth Cave System found carbon dioxide pressures higher than that of the fluids of the cave stream itself. This was confirmed by a limestone weight loss experiment in which samples dissolved at various levels below the streambed despite the low fluid velocities. The high CO2 pressures appear to influence both conduit dissolution rates and geometry and presumably result from the microbial degradation of organics within the sediments. To explore the relationship between the geochemical environment of fluids and microbial ecology, additional samples were collected from the same location. Eight Coliform bacteria were identified to species level and inoculated in 65 milliliters of thioglycollate broth along with a calcite crystal of known weight and incubated at 12°C for 92 days. In the presence of five of the bacterial species, calcite dissolved more than the control, rangi...
The field of molecular fecal source tracking in the water environment has developed rapidly since... more The field of molecular fecal source tracking in the water environment has developed rapidly since the first PCR assays for general and host-‐specific Bacteroides 16s rRNA markers were published. Numerous host-‐specific molecular markers and PCR assays have been developed, adding greater specificity, sensitivity and quantitative methods to the array of options. The public demand for readying methods for transfer to the commercial lab, so that they may be used to generate data for public utilities, citizen action groups and regulatory agencies, has fueled the development of an entire new research community. These methods, however plentiful, have not found community agreement and there is no consensus concerning the appropriate implementation of molecular fecal source tracking in the field. Some issues plaguing the implementation include imperfect marker specificity, environmental variability, DNA extraction variability, PCR inhibition and high cost of molecular analysis. This thesis...
Journal of Controlled Release, 2004
The purpose of these studies was to compare the cell uptake, biodistribution and tumor retention ... more The purpose of these studies was to compare the cell uptake, biodistribution and tumor retention of folate-coated and PEG-coated gadolinium (Gd) nanoparticles. Gd is a potential agent for neutron capture therapy (NCT) of tumors. Gd nanoparticles were engineered from oil-in-water microemulsion templates. To obtain folate-coated nanoparticles, a folate ligand [folic acid chemically linked to distearoylphosphatidylethanolamine (DSPE) via a PEG spacer MW 3350] was included in nanoparticle preparations. Similarly, control nanoparticles were coated with DSPE-PEG-MW 3350 (PEG-coated). Nanoparticles were characterized based on size, size distribution, morphology, biocompatibility and tumor cell uptake. In vivo studies were carried out in KB (human nasopharyngeal carcinoma) tumor-bearing athymic mice. Biodistribution and tumor retention studies were carried out at pre-determined time intervals after injection of nanoparticles (10 mg/kg). Gd nanoparticles did not aggregate platelets or activate neutrophils. The retention of nanoparticles in the blood 8, 16 and 24 h post-injection was 60%, 13% and 11% of the injected dose (ID), respectively. A maximum Gd tumor localization of 33+/-7 microg Gd/g was achieved. Both folate-coated and PEG-coated nanoparticles had comparable tumor accumulation. However, the cell uptake and tumor retention of folate-coated nanoparticles was significantly enhanced over PEG-coated nanoparticles. Thus, the benefits of folate ligand coating were to facilitate tumor cell internalization and retention of Gd-nanoparticles in the tumor tissue. The engineered nanoparticles may have potential in tumor-targeted delivery of Gd thereby enhancing the therapeutic success of NCT.
Environmental Science & Technology, 2013
Water in Kentucky, 2017
Tracking the sources of fecal pollution in Kentucky streams is an important task to allow for rem... more Tracking the sources of fecal pollution in Kentucky streams is an important task to allow for removal of the associated pollution. Modern molecular biology techniques, analyzing the DNA of fecal bacteria, provide cost effective methods and make fecal source tracking possible for municipalities and non-profit organizations. This is a story of the use of these methods by a collaboration of stakeholders to solve a real world fecal pollution problem in Lexington, Kentucky.
Journal of Environment Quality, 2015
Human-associated fecal biomarkers offer potent tools for the detection and control of human fecal... more Human-associated fecal biomarkers offer potent tools for the detection and control of human fecal pollution in watersheds. In some cases, the probability of false-negative findings may call for using a less specific biomarker that is present in higher quantities as long as it can be related to the more specific indicator. The objective of this study is to investigate the relationship between two previously published human-associated biomarkers for Bacteroidales bacteria in an urban watershed influenced by human fecal pollution and to determine if the less specific marker may be used to identify the locations of broken or leaking sewer lines. Samples were collected from 19 stream locations on 10 dates. Sample DNA was extracted and qPCR analysis was conducted for the HuBac and qHF183 biomarkers. The HuBac biomarker was detected more frequently than the qHF183 biomarker and in greater quantities when both were detected. A strong linear relationship ( = 0.91) between the two markers was observed in 219 samples taken from both the watershed and inlet sewage. The relationship between the two biomarkers showed less variance at higher concentrations. However, even when the inlet sewage samples were excluded from the dataset, a clear linear relationship remained ( = 0.74). The results indicate that use of a less specific, but more sensitive, biomarker may provide greater utility when the prevention of false negatives is necessary and the primary fecal source is known, as in spatial distribution studies of human fecal pollution in an urban watershed.
A 1998 study of interstitial fluid geochemistry within Charonis Cascade in the Echo River/River S... more A 1998 study of interstitial fluid geochemistry within Charonis Cascade in the Echo River/River Styx area of the Mammoth Cave System found carbon dioxide pressures higher than that of the fluids of the cave stream itself. This was confirmed by a limestone weight loss experiment in which samples dissolved at various levels below the streambed despite the low fluid velocities. The high CO2 pressures appear to influence both conduit dissolution rates and geometry and presumably result from the microbial degradation of organics within the sediments. To explore the relationship between the geochemical environment of fluids and microbial ecology, additional samples were collected from the same location. Eight Coliform bacteria were identified to species level and inoculated in 65 milliliters of thioglycollate broth along with a calcite crystal of known weight and incubated at 12°C for 92 days. In the presence of five of the bacterial species, calcite dissolved more than the control, rangi...
The field of molecular fecal source tracking in the water environment has developed rapidly since... more The field of molecular fecal source tracking in the water environment has developed rapidly since the first PCR assays for general and host-‐specific Bacteroides 16s rRNA markers were published. Numerous host-‐specific molecular markers and PCR assays have been developed, adding greater specificity, sensitivity and quantitative methods to the array of options. The public demand for readying methods for transfer to the commercial lab, so that they may be used to generate data for public utilities, citizen action groups and regulatory agencies, has fueled the development of an entire new research community. These methods, however plentiful, have not found community agreement and there is no consensus concerning the appropriate implementation of molecular fecal source tracking in the field. Some issues plaguing the implementation include imperfect marker specificity, environmental variability, DNA extraction variability, PCR inhibition and high cost of molecular analysis. This thesis...
Journal of Controlled Release, 2004
The purpose of these studies was to compare the cell uptake, biodistribution and tumor retention ... more The purpose of these studies was to compare the cell uptake, biodistribution and tumor retention of folate-coated and PEG-coated gadolinium (Gd) nanoparticles. Gd is a potential agent for neutron capture therapy (NCT) of tumors. Gd nanoparticles were engineered from oil-in-water microemulsion templates. To obtain folate-coated nanoparticles, a folate ligand [folic acid chemically linked to distearoylphosphatidylethanolamine (DSPE) via a PEG spacer MW 3350] was included in nanoparticle preparations. Similarly, control nanoparticles were coated with DSPE-PEG-MW 3350 (PEG-coated). Nanoparticles were characterized based on size, size distribution, morphology, biocompatibility and tumor cell uptake. In vivo studies were carried out in KB (human nasopharyngeal carcinoma) tumor-bearing athymic mice. Biodistribution and tumor retention studies were carried out at pre-determined time intervals after injection of nanoparticles (10 mg/kg). Gd nanoparticles did not aggregate platelets or activate neutrophils. The retention of nanoparticles in the blood 8, 16 and 24 h post-injection was 60%, 13% and 11% of the injected dose (ID), respectively. A maximum Gd tumor localization of 33+/-7 microg Gd/g was achieved. Both folate-coated and PEG-coated nanoparticles had comparable tumor accumulation. However, the cell uptake and tumor retention of folate-coated nanoparticles was significantly enhanced over PEG-coated nanoparticles. Thus, the benefits of folate ligand coating were to facilitate tumor cell internalization and retention of Gd-nanoparticles in the tumor tissue. The engineered nanoparticles may have potential in tumor-targeted delivery of Gd thereby enhancing the therapeutic success of NCT.
Environmental Science & Technology, 2013
Water in Kentucky, 2017
Tracking the sources of fecal pollution in Kentucky streams is an important task to allow for rem... more Tracking the sources of fecal pollution in Kentucky streams is an important task to allow for removal of the associated pollution. Modern molecular biology techniques, analyzing the DNA of fecal bacteria, provide cost effective methods and make fecal source tracking possible for municipalities and non-profit organizations. This is a story of the use of these methods by a collaboration of stakeholders to solve a real world fecal pollution problem in Lexington, Kentucky.
Journal of Environment Quality, 2015
Human-associated fecal biomarkers offer potent tools for the detection and control of human fecal... more Human-associated fecal biomarkers offer potent tools for the detection and control of human fecal pollution in watersheds. In some cases, the probability of false-negative findings may call for using a less specific biomarker that is present in higher quantities as long as it can be related to the more specific indicator. The objective of this study is to investigate the relationship between two previously published human-associated biomarkers for Bacteroidales bacteria in an urban watershed influenced by human fecal pollution and to determine if the less specific marker may be used to identify the locations of broken or leaking sewer lines. Samples were collected from 19 stream locations on 10 dates. Sample DNA was extracted and qPCR analysis was conducted for the HuBac and qHF183 biomarkers. The HuBac biomarker was detected more frequently than the qHF183 biomarker and in greater quantities when both were detected. A strong linear relationship ( = 0.91) between the two markers was observed in 219 samples taken from both the watershed and inlet sewage. The relationship between the two biomarkers showed less variance at higher concentrations. However, even when the inlet sewage samples were excluded from the dataset, a clear linear relationship remained ( = 0.74). The results indicate that use of a less specific, but more sensitive, biomarker may provide greater utility when the prevention of false negatives is necessary and the primary fecal source is known, as in spatial distribution studies of human fecal pollution in an urban watershed.