Browsing by Subject "sensitivity"
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Item Aging Confers an Increase in Sensitivity and Sensitization to Pain and Results in Shifts of Spinal NR1 expression(2009-05-01) Jenschke, Monica L; Ratka, Anna; Forster, Michael J.Purpose: Many elderly experience inadequate postoperative pain relief resulting in increased morbidity and mortality. Several experimental models of postoperative pain have been developed but none were adapted to study the effects of aging on the postoperative pain. Review of literature explored current knowledge of postoperative pain models and identified several models suitable for aging studies. A unique model of postoperative pain, the dorsal hairy skin incision model, was modified and adopted for aged rats. Using this model, we tested two hypotheses: a) aged rats will exhibit similar intensity but longer duration of postincision hyperalgesia compared to young rats and b) spinal cord NR1 expression will increase in response to nociceptive stimulation and that age-related differences in magnitude of NR1 expression will be evident. Methods: In study I, young (5-7 months old) and aged (22-23 months old) male Fischer 344 rats were exposed to nociceptive testing with von Frey filaments and the cutaneous trunci muscle reflex was measured. For each stimulation, a graded response of 0, 0.5, or 1, for no reflex, a small reflex, or vigorous reflex, respectively was recorded. After baseline testing, a 2 cm incision was made through the dorsal skin followed by skin closure and recovery. Subsequently, rats were tested at 3 hours, 6 hours, and on postoperative days (POD) 1, 3, 6, 10, and 14. In study II, young (4-6 months old) and aged (19-21 months old) male Fischer 344 rats were subjected to three sessions of mechanical nociceptive stimulus. After testing, spinal cords were harvested for western blot analysis of NR1 expression. Results: In study I, aged rats had greater baseline graded responses to nociceptive stimuli. After incision, young rats developed primary allodynia lasting until POD 3 and primary hyperalgesia until POD 8. Aged rats did not develop allodynia or primary hyperalgesia. Neither group developed secondary hyperalgesia. Aged rats demonstrated greater sensitivity to baseline nociceptive testing and greater maximal graded responses to repetitive testing sessions. In young rats, nociceptive stimulation resulted in a significant increase in NR1 expression. Increased NR1 expression in young tested rats positively correlated with an increase in graded response for one of 18 session/region/force categories tested. There was no increase in spinal cord NR1 expression in aged rats in response to nociceptive stimulation. Low NR1 expression in aged tested rats negatively correlated with an increase in graded response for 9 of 18 session/region/force categories tested. Conclusions: An experimental rat model to study effects of age on postoperative pain is presented. Age has a profound impact on the pre- and postoperative periods. Aged rats differ significantly from young rats in sensitivity and maximal graded response to acute incisional pain. Young rats exposed to mechanical punctate nociceptive stimuli experienced increased NR1 expression which positively correlated with an increase in graded response. In contrast, aged rats with decreased NR1 expression negatively correlated with an increased graded response. Lower sensitivity and maximal graded responses in the young rats reflect an intact endogenous modulatory pain pathway. Greater sensitivity and maximal graded responses in the aged rats reflect impairment of descending modulatory pain pathways.Item Epidemiology and Diagnostic Testing of Tuberculosis (Mycobacterium bovis) Infection in Ungulates in a Texas Zoo(1998-06-01) Hodges, Connie M.; Bidaut-Russell, Michelle; Licciardone, John C.; Murnane, ThomasTuberculosis infection among ungulates with Mycobacterium bovis (M. bovis) in a Texas zoo resulted in epidemiological assessment and testing of 161ungulates because of concerns about the validity of tuberculosis infection in the zoo. Three intradermal tests and one serological test were used to assess M.bovis infection : 1)the comparative cervical tuberculin test (CCT) consisting of biologically balanced bovine purified protein derivative (PPD) and avian PPD; 2) the single cervical bovine PPD tuberculin (BPDD); 3) the Tuberculin-Mammalian (MOT) intradermal tuberculin; and 4) the serological blood tuberculosis test (BTB). All four tests were evaluated. Validity (i.e. sensitivity and specificity), positive predictive value (PPV), and negative predictive value (NPV) were measured. The MOT followed by the BPPD were the most sensitive tests, correctly identifying 100% and 67%, respectively of tuberculosis infected/exposed ungulates. The BTB test was the third order of recommendation followed by the combined CCT and BTB (CCT+BTB) tests, where a positive result in either test denoted a positive response. The CCT test ranked last, as this test had the lowest sensitivity and would have allowed tuberculosis infection to remain in the zoo.Item Evaluation of Applied Biosystems' Real-Time Human Quantification Assays(2003-05-01) Hybki, Dixie Lee Peters; John Planz; Arthur Eisenberg; Joseph WarrenTo aid the forensic community with its quantification issues, Applied Biosystems is currently developing human specific and human male specific quantification assays using Real-Time PCR (RT-PCR) and TaqMan probes. The human specific assay amplifies an autosomal specific gene, located on chromosome five, while the human male specific assay amplifies a region on the Y chromosome. The purpose of this project was to evaluate the assays with forensic samples to determine if the use of these kits would be appropriate to the forensic community. These kits are not commercially available at the time of this writing. Therefore, several details have been omitted to protect the patent and legal issues that are still pending. It is expected that these assays will surpass the sensitivity and specificity of current methods. This will not only meet, but also exceed the standard set forth by the DAB. By providing additional information such as human male DNA quantification and PCR inhibitor detection, these kits can provide what the forensic community has been lacking. The human male DNA detection and quantification is valuable in providing proof that male DNA was present in an intimate sample from a sexual assault case. This would be especially important in a case in which the offender was a vasectomized male, and for resolving mixtures of the victim and offender’s genetic profiles. The detection of PCR inhibitors for the elimination of futile genetic analysis is a novel component that would provide additional advantages. These kits will offer means for proper quantification to allow for minimal space waste, and allow for successful multiplex PCR within its optimal range. Today, STR analysis will proceed, and is often successful, even if no quantification results are obtained with current methods. The legal system questions this approach. The ability of autosomal specific and Y-chromosome specific RT-PCR quantification assays to assess low level DNA would provide the justification for subsequent analysis that would quiet the legal system’s arguments concerning human quantification.Item Internal Validation of Applied Biosystems Quantifiler Duo DNA Quantitation Kit For Use in Fornesic Casework(2008-08-01) Klein, Cindi Leann; Arthur Eisenberg; Joseph Warren; John PlanzKlein, Cindi Leann. Internal Validation of Applied Biosystems Quantifiler Duo DNA Quantification Kit for Use in Forensic Casework. Master of Science (Forensic Genetics), August 2008, 48 pages, 19 figures, 4 tables, 10 references. Applied Biosystems (Foster City, CA) has recently developed a new DNA quantification kit, Quantifiler Duo, which simultaneously quantitates the total amount of amplifiable human and male DNA present in a sample. The kit is a multiplex real-time PCR system based on the 5’ nuclease assay and Taqman probe-based technology. An internal validation was performed at the Harris County Medical Examiner’s Office using Quantifiler Duo and was comprised of six studies: sensitivity, reproducibility, cross-contamination, precision, mixture, and stability. The preliminary results show an increased sensitivity from the currently used Quantifiler Human and Quantifiler Y Human Male DNA Quantification kits. The accuracy and precision of the Quantifiler Duo kit was also comparable or superior to that of the current kits.