Thomas Keefe | Colorado State University (original) (raw)

Papers by Thomas Keefe

Preventive Veterinary Medicine, Mar 1, 2003

Factor analysis was used to assess relationships in the minimum-inhibitory concentration among 17... more Factor analysis was used to assess relationships in the minimum-inhibitory concentration among 17 antimicrobials tested on isolates of Escherichia coli isolated from 360 faecal samples obtained from feedlot cattle. Six factors were extracted using maximum-likelihood factor analysis. The factors were interpretable antimicrobial groupings based on class of antimicrobial and previously described associations. New-generation cephalosporins, older-generation beta-lactams, fluoroquinolones and aminoglycosides grouped separately as classes of antimicrobials on four of the six factors. One of the remaining factors was a grouping of antimicrobials that had been identified as being related in previous feedlot studies. The last factor was a grouping of three of the five antimicrobials that comprise the antimicrobials found in penta-resistant strains of Salmonella Typhimurium. The factor analysis described patterns in the MIC data that would not have been apparent if only antimicrobial-resistance data categorized as susceptible-resistance had been analysed.

American Journal of Epidemiology, 1987

The relation between various risk factors and adenocarcinoma of the lung was evaluated in a case-... more The relation between various risk factors and adenocarcinoma of the lung was evaluated in a case-control study. Subjects were selected from the Colorado Central Cancer Registry from 1979-1982 in the Denver metropolitan area. A total of 102 (50 males and 52 females) adenocarcinoma case interviews and 131 (65 males and 66 females) control interviews were completed. The control group consisted of persons with cancers of the colon and bone marrow. The risk estimates associated with cigarette smoking were significantly elevated among males (odds ratio (OR) = 4.49) and females (OR = 3.95) and were found to increase significantly (p less than 0.01) with increasing levels of cigarette smoking for both males and females. For adenocarcinoma in females, the age- and smoking-adjusted odds ratios at different levels of passive smoke exposure followed an increasing overall trend (p = 0.05). After additional adjustment for potential confounders, prior cigarette use remained the most significant predictor of risk of adenocarcinoma among males and females. Analysis restricted to nonsmoking females revealed a risk of adenocarcinoma of 1.68 (95% confidence interval (Cl) = 0.39-2.97) for passive smoke exposure of four or more hours per day. Neither sex showed significantly elevated risk for occupational exposures, although males bordered on significance (OR = 2.23, 95% Cl = 0.97-5.12). The results suggest the need to develop cell type-specific etiologic hypotheses.

$Research paper thumbnail of {"__content__"=>"The Use of Insecticide-Treated Curtains for Control of and Dengue Virus Transmission in \"Fraccionamiento\" Style Houses in México.", "i"=>{"__content__"=>"Aedes aegypti"}}$

Journal of tropical medicine, 2018

Dengue, chikungunya, yellow fever, and Zika viruses transmitted by mosquitoes are major public he... more Dengue, chikungunya, yellow fever, and Zika viruses transmitted by mosquitoes are major public health threats in the tropical and subtropical world. In México, construction of large tracts of "fraccionamientos" high density housing to accommodate population growth and urbanization has provided fertile ground for -transmitted viruses. We investigated the utility of pyrethroid-treated window curtains to reduce both the abundance of and to prevent dengue virus (DENV) transmission in fraccionamiento housing. Windows and doors of fraccionamiento homes in urban/suburban areas, where pyrethroid resistance associated with the Ile1016 knock down resistance (kdr) mutation in the voltage gated sodium channel gene was high, and in rural areas, where kdr resistance was low, were fitted with either insecticide-treated curtains (ITCs) or non-treated curtains (NTCs). The homes were monitored for mosquito abundance and DENV infection. ITCs reduced the indoor abundance of and the number of ...

Journal of Toxicology and Environmental Health, 1993

ABSTRACT Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, ... more ABSTRACT Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, were studied in order to determine whether exposures to mercury were greater among persons who resided there than among residents of a comparison area 12-15 miles distant. From a census-based stratified random sample, 469 persons were interviewed and urine samples were obtained for biomonitoring. Mercury was detected in urine from 32 (6.8%) of the 469 persons sample at a detection limit of 5 ppb. Trace levels of mercury (detectable, but nonquantifiable) were found in 80 (17.1%) of the persons sampled. Neither the frequency of detection, the arithmetic mean, nor the geometric mean value for urine mercury was found to be statistically different when persons living near the site were compared to persons from the more distant comparison area. The risk of mercury exposure associated with demographic variables, residence, occupation, hobbies, dietary habits, water supply, housing, and activity patterns was evaluated. In the second stage of the evaluation, the Neurobehavioral Core Test Battery (NCTB) is being used to assess individual functional deficits and nervous system disorders associated with exposure to mercury and other neurotoxic chemicals.

Journal of exposure analysis and environmental epidemiology, 1993

Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, were stud... more Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, were studied in order to determine whether exposures to arsenic were greater among persons who resided there than among residents of a comparison area. A census was conducted in areas adjacent to the RMA and in a comparison area 12-15 miles distant. From a stratified random sample, 469 persons were interviewed and urine samples obtained. Arsenic was detected in urine from 43 (9.2%) of the 469 persons sampled at a detection limit of 10 ppb. Trace levels of arsenic (detectable, but non-quantifiable) were found in 184 (39.2%) of those persons sampled. Neither the frequency of detection, the arithmetic mean nor the geometric mean values for urine arsenic was found to be statistically different when persons living near the site were compared to persons from the more distant comparison area. Therefore, the data were pooled across the study areas to evaluate risk factors for exposure to arsenic in this ...

Preventive Veterinary Medicine, 1992

Journal of Veterinary Diagnostic Investigation, 1995

Immunoglobin G (IgG) quantitation was performed by a commercially available single radial immunod... more Immunoglobin G (IgG) quantitation was performed by a commercially available single radial immunodiffusion kit on 528 plasma samples obtained from llamas. Fifty samples encompassing the range of values obtained were selected for further evaluation. The IgG concentration of these samples was measured by a second commercially available single radial immunodiffusion kit and a sodium sulfite precipitation kit. γ-Globulins also were measured. IgG values predicted by the single radial immunodiffusion kits were not in agreement. Failure to appreciate this lack of agreement could result in misinterpretation of a llama's IgG level derived from one kit when clinical guidelines established using the other kit are followed.

Journal of Construction Engineering and Management, 2012

Applied and Environmental Microbiology, 2010

As a potent inflammatory agent, endotoxin is a key analyte of interest for studies of lung ailmen... more As a potent inflammatory agent, endotoxin is a key analyte of interest for studies of lung ailments in domestic environments and occupational settings with organic dust. A relatively unexplored advance in endotoxin exposure assessment is the use of recombinant factor C (rFC) from the Limulus pathway in a fluorometric assay. In this study, we compared airborne endotoxin concentrations in laboratory- and field-collected parallel air samples using the kinetic Limulus amebocyte lysate (LAL) assay and the rFC assay. Air sampling was performed using paired Institute of Occupational Medicine (IOM) samplers, Button samplers, closed-face cassettes, and cyclone samplers. Field sampling was performed in 10 livestock production facilities, including those housing swine, chicken, turkey, dairy cows, cattle, and horses. Laboratory sampling was performed in exposure chambers using resuspended airborne dust collected in five livestock facilities. Paired samples were extracted in pyrogen-free water ...

The Annals of Occupational Hygiene, 2009

American Journal of Epidemiology, 1999

Health Education Research, 2005

This guide brings together all of the freely-available study and exam preparation resources provi... more This guide brings together all of the freely-available study and exam preparation resources provided by the Loyola Law School Library for its students. The guide includes links to study aids for more than 30 Loyola courses. This page contains links to sample law school exams and links to Library resources on preparing for and improving performance on law school exams

Clinical and Experimental Dental Research, 2021

Journal of occupational and environmental hygiene, Jan 20, 2017

Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological... more Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological and chemical constituents, which have been tied to adverse health effects. A better understanding of the variation in the magnitude and composition of exposures by task is needed to inform worker protection strategies. To characterize the levels and types of exposures, 115 dairy workers grouped into three task categories on nine farms in the high plains western United States underwent personal monitoring for inhalable dust, endotoxin, 3-hydroxy fatty acids (3-OHFA), muramic acid, ergosterol, and ammonia over one work shift. Eighty nine percent of dairy workers were exposed to endotoxin at concentrations exceeding the recommended exposure guidelines (adjusted for a long workshift). The proportion of workers with exposures exceeding recommended guidelines was lower for inhalable dust (12%), and ammonia (1%). Ergosterol exposures were only measurable on 28% of samples, primarily among medi...

A pilot exposure study was undertaken in communities surrounding the RMA. The objectives of the s... more A pilot exposure study was undertaken in communities surrounding the RMA. The objectives of the study were: (1) To determine whether arsenic and mercury levels in urine were greater among residents of communities adjacent to the RMA than among residents of comparison communities located 12 to 15 miles from the RMA and presumed to be exposed. (2) To determine whether exposure to arsenic and mercury were associated with proximity to the RMA.