Insect and rodent samples were collected from suspected VSV-NJ enzootic areas over 2 consecutive field seasons (1996-1997) and from southern Arizona only during 1998. Insect samples were screened for arboviruses, and rodent sera were tested for the presence of VSV-NJ and VSV-IN neutralizing antibodies. Vesicular stomatitis virus New Jersey serotype was isolated from a pool of Culicoides sp. collected in 1997 near Belen, New Mexico. All rodent sera were negative for specific VSV-NJ and VSV-IN antibodies. Genetic analysis of the hypervariable region of the phosphoprotein gene demonstrated that the 1997 Belen VSV-NJ isolate was more closely related to viruses isolated from livestock during the 1982-83 western U.S. epizootic than to other VSV-NJ isolates. This suggests that VSV-NJ may be enzootic in the western U.S. Simulium vittatum was shown to be a competent vector of VSV-NJ. Virus-infected females were allowed to feed on laboratory mice and on deer mice. All laboratory mice seroconverted by day 21 post-exposure. Neutralizing antibody titers increased from an average of 1:4 at baseline to >1:1,024 on day 21. An age-related effect on viral pathogenesis was evident in Peromyscus maniculatus following VSV-NJ exposure by black fly bite. Lethal encephalomyelitis was evident in all 6-week-old mice, but in only one 6-month-old mouse. Peromyscus maniculatus did not meet the standard definition of a reservoir host for VSV-NJ because a viremia, was not detected. Nonetheless, P. maniculatus may play a role in virus maintenance since non-infected black flies became infected while co-feeding with infected black flies on the same non-viremic host. These results represent the first example of a western U.S. insect species becoming infected with VSV-NJ by feeding on a host. Simulium vinatum and S. notatum were shown to be competent laboratory vectors of VSV-IN. Saliva from experimentally infected Simulium vittatum and S. notatum was collected and tested for the presence of infectious virus. Virus was detected in the saliva of both species following oral infection. Independent experiments were conducted to determine if transovarial transmission of VSV-NJ and VSV-IN occurs in black flies. Transovarial transmission was not detected. Transstadial transmission of both virus serotypes was detected.

<p> Feline oral squamous cell carcinoma (SCC) is a devastating disease that responds poorly to traditional treatment modalities. The tumor location directly impacts the patient's ability to eat and drink, and immediate intervention to alleviate clinical signs is important. To design better treatment strategies it is paramount to understand the underlying biological behavior of this poorly defined tumor. This research takes a comprehensive approach in attempt to understand this disease. A number of assays have been developed and applied to elucidate underlying biology. New imaging modalities have been used to better stage the disease and define tumor location. Finally, patients were treated with a new radiation therapy modality, stereotactic radiation therapy (SRT), and outcome was correlated with the biological assays for potential predictive value. </p><p> The goal of the prospective study described in Chapter 2 was to compare gross tumor volume measurements using ¹⁸F-FDG PET vs. those using computed tomography (CT) for SRT planning in cats with oral SCC. Twelve cats with confirmed oral SCC underwent pretreatment ¹⁸F-FDG PET/CT. Gross tumor volumes based on contrast-enhanced CT and ¹⁸F-FDG PET were measured and compared between cats. Mean PET gross tumor volume was significantly smaller than mean CT gross tumor volume in the mandibular/maxillary SCC group (n=8, <i>P</i>=0.002) and for all cats (n=12, <i> P</i>=0.006), but not for cats with lingual/laryngeal SCC (n=4, <i> P</i>=0.57). Mismatch fraction analysis revealed that most of the lingual/laryngeal patients had a large region of high-¹⁸F-FDG activity outside of the CT gross tumor volume. This mismatch fraction was significantly greater in the lingual/laryngeal group than the mandibular/maxillary group (<i> P</i>=0.028). The effect of poor spatial resolution of PET imaging was greater when the absolute tumor volume was small. Findings from this study indicated that ¹⁸F-FDG PET warrants further investigation as a supplemental imaging modality in cats with oral SCC because it detected presumed regions of primary tumor that were not detected on CT images.</p><p> For canine and feline patients with tumors in the head region, simultaneous irradiation of the primary tumor and mandibular and retropharyngeal lymph nodes (LNs) is often indicated. The purpose of this study described in Chapter 3 was to assess the reliability of a planning target volume (PTV) expansion protocol for secondary targets (LNs). </p><p> Information about the molecular biology of feline oral SCC is still limited. In Chapter 4, 22 archived tumor samples of feline oral SCC were evaluated to develop immunohistochemical assays and to determine if there was correlation to clinical parameters. Immunohistochemistry for Ki67, MVD, and EGFR was performed and scored. Patient survival information was obtained from the medical records. These molecular markers as well as MI were correlated with tumor locations and patient survival time. The 22 tumors showed wide variation in Ki67, MI, MVD, and EGFR. Tongue SCC expressed higher MVD than mandibular/maxillary SCC (<i>P</i>=0.088). </p><p> Cancer stem cell or tumor initiating cell (TIC) theory and telomere biology are actively studied fields in human head and neck (H&amp;N) cancer. In feline oral SCC, which has been advocated as a feline model for human H&amp;N cancer, our knowledge about the TIC and telomere/telomerase biology is limited. Protein expression levels of putative TIC markers of human H&amp;N cancer, CD44 and Bmi-1, were immunohistochemically evaluated for their possible role as prognostic markers in 20 patients with feline oral SCC who underwent SRT. This patient population was part of a clinical trial and information relevant to PFI and ST was available. A combined technique of fluorescent in-situ hybridization and immunofluorescent staining was used to determine telomere length ratio (fractions of very short telomere/average length telomere in the putative cancer stem cells) in the putative TICs that were positive for CD44 and Bmi-1. This was also correlated with treatment outcome. (Abstract shortened by UMI.) </p>

Thesis (Ph.D.)--University of California, Davis, 2006. / (UMI)AAI3236039. Adviser: Roberto Sainz. Source: Dissertation Abstracts International, Volume: 67-09, Section: B, page: 4768.

No description available.

Doctor of Philosophy / Department of Anatomy and Physiology / Frank Blecha / L Tonatiuh Melgarejo / Background - Cardiovascular disease (CVD) impacts the lives of millions, and ranks as the number one killer world-wide. Despite significant research efforts, CVD remains a major burden on the national health care system, and novel therapeutic modalities to effectively and curatively fight many debilitating diseases of the heart and vasculature are urgently needed. The role of inflammation in the development of CVD has been increasingly in focus through the past decade. Elucidating upon the plethora of innate immune mechanisms likely involved in CVD therefore becomes of immediate interest. Host defense peptides (HDPs) are central elements of innate immunity, encompassing molecules (including the defensin peptides) with wide-reaching biological effects, including immunomodulation and antimicrobial activity. Hypothesis & Specific Aims - The study's main hypothesis relies upon the basic concept that the heart possesses a local innate defense system, which actively aids in fighting off a variety of "danger signals", and that a disarray in this defense contributes to development of CVD. The heart expresses beta-defensin peptides (BDs), and we theorized that these HDPs act as a local defense system within the myocardium - or in other words as "guardians of heart health". The specific aims of the experimental studies were to 1) Evaluate expression of cardiac BDs in response to inflammatory mediators, and 2) Assess the functional properties (including antimicrobial activity and immunomodulation) of synthetic BD peptides in vitro. Design & Methods - To test our hypothesis, we studied myocardial beta-defensin expression (rBDs) in a rat model, comparing levels among two experimental and one control group. Animals were exposed to lipopolysaccharide (LPS) or high-fat diet (HFD) intake - representative of exposure to either an infectious (LPS) or non-infectious (HFD) inflammatory mediator. Serum samples were collected for measurement of cytokines, inflammatory and cardiac biomarkers and lipid-profiling. Beta-defensin levels were assessed using customized Superarray assays and qRT-PCR, and all amplicon sizes on the PCR products were subsequently confirmed using agarose gel electrophoresis. Serum levels were assessed on commercial ELISA kits. Functional assessment of select rBDs included computational modeling as well as in vitro antimicrobial and cell migration assays. Results & Conclusion - Exposure to high-fat diet feeding for a period of three weeks resulted in a multifold-increase in cardiac mRNA expression of select rBDs, while short-term LPS exposure resulted in a smaller, but statistically non-significant, elevation in the myocardial expression of rBDs. Synthetic analogues of two naturally occurring cardiac rBDs were evaluated for in vitro activity. The synthetic rBD11 peptide exhibited antimicrobial activity against Staph aureus, and both rBDs exhibited chemoattraction of rat leukocytes. Our data suggests that rBDs might play a central role in the intrinsic immune mechanisms of the cardiovasuclar system, and possibly act as protectors of heart health.

Master of Science / Department of Clinical Sciences / David S. Hodgson / Peste des petits ruminants (PPR) is an economically important and highly contagious disease of sheep and goats. It is characterized by enteritis, stomatitis, pneumonia, and discharge from the nose and eyes. This report contains a review of PPR and its epidemiology in Afghanistan and other PPR- endemic countries followed by recommendations for dealing disease in Afghanistan. Studies showed that PPR is still endemic in Afghanistan’s neighboring countries including Pakistan, Iran, Tajikistan, and China. From January of 2009 to January of 2010, 852 outbreaks of PPR were reported to the OIE from 24 different countries. However, this study focuses on Afghanistan and some neighboring countries (Iran, Tajikistan). Animal clinics and Veterinary Field Units (VFUs) reported 7,741 cases of PPR from 2008 to 2009 in different parts of Afghanistan. A study by the Food and Agriculture Organization (FAO) in 2009 showed that PPR is endemic in various parts of Afghanistan. Seroprevalence of PPR varied from 0% in Kapisa to 48% in Herat province of Afghanistan. The last chapter of this report includes recommendations and guidelines regarding prevention and eradication of PPR from Afghanistan. These recommendations could help improve animal health and the economy of Afghanistan in the future.

Master of Science / Department of Clinical Sciences / Elizabeth G. Davis / Objective: To determine pharmacokinetic and pharmacodynamic properties of oral dexamethasone solution and powder compared to intravenous dexamethasone solution in healthy horses. Animals: 6 horses, 13-27 years if age, 385-630 kg Procedures: In a randomized, cross-over block design six healthy adult horses each received the following treatments 1) dexamethasone solution IV 0.05 mg/kg, 2) dexamethasone solution orally (PO) 0.05 mg/kg, and 3) dexamethasone powder PO 0.05 mg/kg all in the fed and fasted state. Each horse acted as an untreated control as secretion of cortisol was monitored for normal circadian rhythm. Quantification of plasma dexamethasone concentration and serum cortisol activity was determined by LC/MS and chemiluminescent enzyme immunoassay, respectively. Results: Each horse exhibited a circadian rhythm in cortisol secretion; however there was variation present between each horse. Mean cortisol concentrations at 6:00 AM and 8:00 AM were significantly higher than concentrations at 8:00 PM and 10:00PM. Cortisol concentrations were significantly less than base-line starting 1 hour post-administration of dexamethasone through 72 hours for the fasted treatment groups, and 2 hours through 48 hours for the fed groups. Pharmacokinetic modeling resulted in a two compartment model for the IV administration with elimination from the central compartment, and a one compartment model for orally administered dexamethasone. Oral, fasted, compounded powder achieved a significantly higher maximum concentration (Cmax) than both fasted and fed oral dexamethasone solutions. The AUC0inf for the orally administered compounded powder was significantly different when comparing fasted versus fed treatment groups. Bioavailability ranged between 33% and 70% among treatment groups, but due to the high variability there was not a significant difference. Conclusions and Clinical Relevance: Hospitalization of the horses did not have an effect on their circadian rhythm of cortisol secretion. Oral and intravenous administration of dexamethasone resulted in adrenal suppression with cortisol concentrations returning to base-line 48-72 hours post-administration. Although bioavailability was variable cortisol suppression was similar among all treatment groups. The variability in oral absorption will need to be taken in to account for oral dosing of dexamethasone.

Master of Science / Department of Clinical Sciences / Mike D. Apley / Lameness is a common, costly, and painful affliction in cattle at all production levels. There are currently no compounds specifically approved for analgesia in cattle in the United States. We hypothesized that intra-articular amphotericin B produces a controlled, transient synovitis-arthritis in cattle and that this model would allow characterization of the analgesic effects of intravenous sodium salicylate. This study examined the efficacy of sodium salicylate for providing analgesia in an amphotericin B-induced bovine synovitis/arthritis model utilizing ten male Holstein calves, 4-6 months old, and weighing approximately 250 kg. The study used a repeated measures partial cross-over design with 2 phases consisting of 3 treatment periods within each phase. Calves were blocked by weight and randomly assigned to sodium salicylate (50mg/kg intravenously) or placebo group for phase 1. In period 1, lameness induction was simulated with a needle-prick of the coronary band, followed by drug or placebo administration. At predetermined timepoints, serial blood samples for cortisol and salicylate concentrations, electrodermal activity measurements, heart rates, and pressure mat data were collected. Visual lameness scores were recorded by a blinded observer. In period 2, lameness was induced with injection of amphotericin B into the distal interphalangeal joint followed by drug or placebo administration with sample collection as previously described. In period 3, drug or placebo was administered to the respective calves with sample collection. After a 10-day washout, Phase 2 was conducted with treatments crossed over between groups. Cortisol and salicylate samples were analyzed by competitive chemiluminescent immunoassay and fluorescence polarization immunoassay, respectively. The pharmacokinetic data were analyzed using compartmental analysis. Mean intravenous salicylate apparent volume of distribution (V[subscript]d) was 0.2 ± 0.005 L/kg, total body clearance (CL[subscript]B) was 4.3 ± 0.2 mL/min*kg, and elimination half life (T[subscript]1/2 el) was 36.9 ± 1.2 minutes. The repeated measures data were analyzed based on a univariate split-plot approach with a random effects-mixed model. Differences in stance phase duration and serum cortisol concentration values were seen between both periods and treatment group*periods; differences in heart rate, contact surface area, and contact pressure values were seen between periods, suggesting that our lameness model was effective. No differences were seen between treatment groups. When analyzed by visual lameness score, differences were seen in heart rate, contact surface area, contact pressure, and cortisol concentrations. Area under the time-effect curves, determined using the trapezoidal rule, had results similar to the repeated measures data, except for a difference in period for electrodermal activity. This amphoterecin B-induced synovitis/arthritis model is a useful tool for studying changes associated with lameness in cattle. Sodium salicylate was not effective in providing analgesia following lameness.

Master of Science / Department of Clinical Sciences / Thomas Schermerhorn / The use of continuous blood glucose monitors (CBGMs) has recently come into favor in human medicine for the control and monitoring of the diabetic patient. It allows for a higher degree of accuracy of the true glucose curve throughout a 72-hour period. With this information, physicians are better equipped to treat and manage diabetic patients. Recently, this modality has been verified for use in veterinary patients including cats and dogs. This is an excellent source of information, especially in the management of difficult to regulate veterinary patients. This device has potential for use in various applications, particularly for the monitoring of patients with various diseases under general anesthesia. In order to ensure accurate results do occur when an animal is under general anesthesia, the continuous blood glucose monitor was evaluated on apparently healthy patients under anesthesia for routine procedures such as ovariohysterectomies and orchiectomies. In this manner, the monitor was tested on anesthetized patients that had the potential to experience hypothermia, hypotension, and other anesthesia-associated complications that can be typical of patients that could benefit from the CGMS.

Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Thu Annelise Nguyen / Gap junctional intercellular channels allow the cells to communicate with each other. A breach in gap junctional intercellular communication (GJIC) affects cell growth and proliferation. In addition, many neoplastic cells exhibit a decrease in GJIC. Many factors that decrease GJIC have been shown to potentiate cancer formation. 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD), an environmental pollutant, is a carcinogen; however, its mechanism of carcinogenicity is unclear. Therefore, we examined the effect of TCDD on GJIC in MCF-7, a human breast cell line and normal mammary epithelial cells (HMEC). TCDD showed a decrease in GJIC in MCF-7 cells caused by increased phosphorylation of gap junctional protein, Cx43. PKCα-mediated phosphorylation of Cx43 was confirmed by inhibitor studies using calphostin C. Interestingly, TCDD affected GJIC in HMEC through a novel pathway involving redistribution of Cx43 to the perinuclear membrane. Our studies suggest that TCDD causes decrease in GJIC which could potentially lead to cancer. This also indicates that if GJIC is restored it could decrease cell growth and proliferation. Therefore, we investigated the role of substituted quinolines (PQ1), shown to bind with gap junctional proteins by computational docking. The results showed that indeed PQ1 significantly increases GJIC and exerts anti-tumor effect in human breast cancer cells compared to control without treatment or HMEC. We found an increase in GJIC, growth attenutation and increased apoptosis in T47D human breast cancer cell line. Our studies suggest that PQ1 is a novel gap junctional activator causing a decrease in tumor growth. Since PQ1 alone is effective in decreasing tumor growth in breast tumors, we proposed to test its efficacy with the current drug of choice for breast cancer, tamoxifen. The combinational treatment of tamoxifen and PQ1 showed a significant decrease in cell viability, increase in BAX (Bcl2-associated X), and, increase in caspase 3 activation compared to individual treatments. Hence, combinational treatment of PQ1 and tamoxifen can potentiate decrease in tumor growth. In conclusion, downregulation of gap junctions can potentiate tumor growth while restoration of GJIC can induce apoptosis and decrease tumor growth.