Differential Spatial Gradients of Wheat Streak Mosaic Virus into Winter Wheat from a Central Mite-Virus Source.

The wheat curl mite (WCM), Aceria tosichella Keifer, transmits three potentially devastating viruses to winter wheat. An increased understanding of mite movement and subsequent virus spread through the landscape is necessary to estimate the risk of epidemics by the virus in winter wheat. Owing to the small size of WCMs, their dispersal via wind is hard to monitor; however, the viruses they transmit produce symptoms that can be detected with remote sensing. The objective of this study was to characterize the spatial dispersal of the virus from a central mite-virus source. Virus infection gradients were measured spatially by using aerial remote sensing, ground measurements, geostatistics, and a geographic information system between 2006 and 2009. The red edge position vegetation index as measured via aerial imagery was significantly correlated with in-field biophysical measurements. The occurrence of virus symptoms extended differentially in all directions from mite-virus source plots, and predictions from cokriging revealed an oval pattern surrounding the source but displaced to the southeast. The variable dispersal in different directions appeared to be influenced by the mite source density and wind direction and speed, but temperature also seemed likely to have affected mite spread. The spatial spread revealed in this study may be used to estimate the potential sphere of influence of mite-infested volunteer wheat in production fields. These risk parameter estimates require further validation, but they may potentially aid growers in making better virus management decisions regarding differential virus spread potential away from a central source.

Assessment of Selected Antibiotic Resistances in Ungrazed Native Nebraska Prairie Soils.

The inherent spatial heterogeneity and complexity of antibiotic-resistant bacteria and antibiotic resistance (AR) genes in manure-affected soils makes it difficult to sort out resistance that can be attributed to human antibiotic use from resistance that occurs naturally in the soil. This study characterizes native Nebraska prairie soils that have not been affected by human or food-animal waste products to provide data on background levels of resistance in southeastern Nebraskan soils. Soil samples were collected from 20 sites enumerated on tetracycline and cefotaxime media; screened for tetracycline-, sulfonamide-, ß-lactamase-, and macrolide-resistance genes; and characterized for soil physical and chemical parameters. All prairies contained tetracycline- and cefotaxime-resistant bacteria, and 48% of isolates collected were resistant to two or more antibiotics. Most (98%) of the soil samples and all 20 prairies had at least one tetracycline gene. Most frequently detected were (D), (A) (O), (L), and (B). Sulfonamide genes, which are considered a marker of human or animal activity, were detected in 91% of the samples, despite the lack of human inputs at these sites. No correlations were found between either phenotypic or genotypic resistance and soil physical or chemical parameters. Heterogeneity was observed in AR within and between prairies. Therefore, multiple samples are necessary to overcome heterogeneity and to accurately assess AR. Conclusions regarding AR depend on the gene target measured. To determine the impacts of food-animal antibiotic use on resistance, it is essential that background and/or baseline levels be considered, and where appropriate subtracted out, when evaluating AR in agroecosystems.

Comparison of Enrichment Broths for Supporting Growth of Shiga Toxin-Producing Escherichia coli.

Detection of Shiga toxin-producing Escherichia coli (STEC) in complex sample matrices remains challenging. In an attempt to improve detection, nonselective and selective enrichment broths were compared as follows: (1) trypticase soy broth (TSB) was compared with TSB plus novobiocin, vancomycin, rifampicin, bile salts, and potassium tellurite (TSB-NVRBT) for supporting growth of STEC in pure culture; (2) E. coli broth (EC), TSB, and TSB plus bile salts (mTSB) were compared for enrichment of STEC O26, O45, O103, O104, O111, O121, O145, and O157 (STEC-8) in inoculated cattle fecal samples; (3) EC, TSB, and mTSB were compared for the detection of STEC-8 in inoculated cattle fecal samples. Fecal samples were inoculated with wild-type STEC-8 or nalidixic acid- or rifampicin-resistant derivatives of the same strains at 100, 1000, or 10,000 colony-forming units per gram (CFU/g) of feces. In pure culture, the mean STEC CFU/mL following enrichment in TSB was 1.17 log10 greater than that in TSB-NVRBT (P < 0.05). In inoculated fecal samples, EC enrichment yielded growth of STEC-8 (6.42 log10 CFU/g) that was significantly greater than in TSB (6.23 log10 CFU/g; P < 0.05), and numerically but not significantly greater than in mTSB (6.37 log10 CFU/g; P = 0.60). Wild-type STEC strains were detected in 43.8 % (21/48) of the samples enriched in EC and mTSB compared to 27.1 % (13/48) of the samples enriched in TSB (P = 0.15). Overall, STEC grew significantly better when enriched in EC compared to TSB. Modification of TSB by the addition of bile salts improved the growth and detection of STEC compared to TSB alone.

Narrow grass hedges reduce tylosin and associated antimicrobial resistance genes in agricultural runoff.

Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobials and ARGs in runoff after land application of swine manure slurry. Plot-scale rainfall simulation tests were conducted on 0.75 m by 4.0 m plots designed to test three treatment factors: manure amendment (control plots receiving no manure vs. amended plots receiving manure based on 3 times N requirement), NGH (plots with a NGH vs. plots without a NGH), and rainfall events (days 1-3). Runoff generated during three 30-min simulated rainfall events was sampled and analyzed for antimicrobials and ARGs. Manure amendment was responsible for the presence of antimicrobial tylosin ( < 0.0001) and tylosin resistance gene (B) ( < 0.0001) in runoff. Narrow grass hedges proved to be effective in reducing tylosin ( < 0.0001) and (B) ( < 0.0347) in runoff. Manure amendment was responsible for the introduction of tylosin ( < 0.0482) and (B) ( = 0.0128) into the soil; however, it had no significant impact on the abundance of the 16S rRNA gene in soil. Results from this study suggest that NGHs could be a best management practice to control the transport of antimicrobials and ARGs in agricultural runoff.

Prevalence of Enterohemorrhagic Escherichia coli O26, O45, O103, O111, O121, O145, and O157 on Hides and Preintervention Carcass Surfaces of Feedlot Cattle at Harvest.

Cattle hides are a main source of enterohemorrhagic Escherichia coli (EHEC) contamination of beef carcasses. The objectives of this study were to (1) determine the prevalence of "top 6" non-O157 plus O157:H7 EHEC (EHEC-7) on feedlot cattle hides and their matched preintervention carcasses; (2) assess the agreement among detection methods for these matrices; and (3) conduct a molecular risk assessment of EHEC-7 isolates. Samples from 576 feedlot cattle were obtained at a commercial harvest facility and tested for EHEC-7 by a culture-based method and the polymerase chain reaction/mass spectrometry-based NeoSEEK(™) STEC Detection and Identification test (NS). Prevalence data were analyzed with generalized linear mixed models. The cumulative prevalence of EHEC-7 in hide samples as detected by NS was 80.7%, with a distribution of 49.9%, O145; 37.1%, O45; 12.5%, O103; 11.0%, O157; 2.2%, O111; 2.0%, O121; and 0.2%, O26. In contrast, the cumulative prevalence of EHEC-7 in hide samples by culture was 1.2%, with a distribution of 0.6%, O157; 0.4%, O26; 0.2%, O145; and 0%, O45, O103, O111, and O121. The cumulative prevalence of EHEC-7 on matched preintervention carcasses as detected by NS was 6.0%, with a distribution of 2.8%, O157; 1.6%, O145; 1.2%, O103; 1.1%, O45; 0.2%, O26; and 0.0%, O111 and O121. Although the culture-based method detected fewer positive hide samples than NS, it detected EHEC in five hide samples that tested negative for the respective organism by NS. McNemar's chi-square tests indicated significant (p<0.05) disagreement between methods. All EHEC-7 isolates recovered from hides were seropathotype A or B, with compatible virulence gene content. This study indicates that "top 6" and O157:H7 EHEC are present on hides, and to a lesser extent, preintervention carcasses of feedlot cattle at harvest. However, continued improvement in non-O157 detection methods is needed for accurate estimation of prevalence, given the discordant results across protocols.

Impact of local steroid or statin treatment of experimental temporomandibular joint arthritis on bone growth in young rats.

INTRODUCTION: Juvenile idiopathic arthritis in temporomandibular joints (TMJs) is often treated with intra-articular steroid injections, which can inhibit condylar growth. The purpose of this study was to compare simvastatin (a cholesterol-lowering drug that reduces TMJ inflammation) with the steroid triamcinolone hexacetonide in experimental TMJ arthritis. METHODS: Joint inflammation was induced by injecting complete Freund's adjuvant (CFA) into the TMJs of 40 growing Sprague Dawley rats; 4 other rats were left untreated. In the same intra-articular injection, one of the following was applied: (1) 0.5 mg of simvastatin in ethanol carrier, (2) ethanol carrier alone, (3) 0.15 mg of triamcinolone hexacetonide, (4) 0.5 mg of simvastatin and 0.15 mg of triamcinolone hexacetonide, or (5) nothing additional to the CFA. The animals were killed 28 days later, and their mandibles were evaluated morphometrically and with microcomputed tomography. RESULTS: The analysis showed that the TMJs subjected to CFA alone had decreased ramus height compared with those with no treatment (P <0.05). Groups that had injections containing the steroid overall had decreases in weight, ramus height, and bone surface density when compared with the CFA-alone group (P <0.0001). Groups that had injections containing simvastatin, however, had overall increases in weight (P <0.0001), ramus height (P <0.0001), condylar width (P <0.05), condylar bone surface density (P <0.05), and bone volume (P <0.0001) compared with the groups receiving the steroid injections, and they were not different from the healthy (no treatment) group. CONCLUSIONS: Treatment of experimentally induced arthritis in TMJs with intra-articular simvastatin preserved normal condylar bone growth.

Proposed shade guide for attached gingiva--a pilot study.

PURPOSE: The purpose of this study was to evaluate the effect of race, age, and gender on Commision Internationale de l'Eclairage Lab color space (CIELAB) values of attached gingival colors. The color coordinates of an optimal proposed attached gingival shade guide were also determined. MATERIAL AND METHODS: Participants (n = 120) were recruited to fulfill the following stratification of five age groups: 18-29, 30-39, 40-49, 50-59, and 60-85, with four racial categories (white, black, Asian, and others) and balanced for gender. Reflectance measurements of participants' attached gingiva were made using a spectroradiometer and Xenon arc lamp with a 45/0 optical configuration. A stepwise discriminant analysis was carried out to identify gingival color contribution from race, age, and gender. A hierarchical clustering analysis was used to identify color groups that clustered together. The coverage error of the proposed shade guide was calculated to the original gingival color. RESULTS: The stepwise discriminant analysis showed a statistically significant difference in gingival color contribution from the factors evaluated. Significant influence was found for the race/gender factors (p < 0.05), but not for age. The cluster analysis results revealed three cluster centroids with mean L*a*b* as follows: (1 = 51.0 ± 4.2, 27.7 ± 4.7, 18.3 ± 3.2), (2 = 61.4 ± 4.5, 24.3 ± 4.3, 17.6 ± 2.3), and (3 = 36.1 ± 4.1, 21 ± 4.9, 16 ± 5.2). The coverage errors to the following racial categories were: Asian (ΔE = 6.0 ± 4.8), black (ΔE = 6.7 ± 3.9), others (ΔE = 5.8 ± 2.9), and white (ΔE = 4.6 ± 2.7). CONCLUSIONS: The study showed that L*a*b* was significantly affected by race and gender. Clustering analysis was able to identify clusters in 120 participants for three gingival tones.

Growth of Shiga toxin-producing Escherichia coli (STEC) and impacts of chilling and post-inoculation storage on STEC attachment to beef surfaces.

Concern has been expressed surrounding the utility of studies describing the efficacy of antimicrobial interventions targeting the Shiga toxin-producing Escherichia coli (STEC) that inoculate chilled versus non-chilled beef carcasses. The objectives of this study were to evaluate the effects of chilling (non-chilled, chilled to surface temperature of ≤5 °C) on STEC attachment to brisket surfaces, and the effects of post-inoculation storage on STEC recovery. Paired briskets from split carcasses were separated; one brisket from each pair was kept non-chilled, while the other was chilled to a surface temperature of ≤5 °C prior to inoculation. Briskets were inoculated with a cocktail of eight STEC and then stored at 5 or 25 °C. At 0, 30, 60, 90 and 120 min post-inoculation, 30 cm(2) of tissue was aseptically excised, followed by selective enumeration of strongly and loosely attached STEC. A significant, though small (0.4 log10 CFU/cm(2)), difference in the numbers of strongly attached cells was observed between non-chilled and chilled briskets (p < 0.05). Significant effects on cell attachment by the interaction of chilling and post-inoculation storage period, or chilling and post-inoculation storage temperature, were identified (p < 0.05). Results indicate beef chilling and post-inoculation storage conditions influenced STEC attachment to beef.

Emission of volatile organic compounds after land application of cattle manure.

Beef cattle manure can serve as a valuable source of nutrients for crop production. However, emissions of volatile organic compounds (VOCs) after land application may pose an odor nuisance to downwind populations. This study was conducted to evaluate the effects of land application method, diet, soil moisture content, and time since manure application on VOC emissions. Manure was collected from feedlot pens where cattle were fed diets containing 0, 10, or 30% wet distillers grains with solubles (WDGS). Land application methods included surface-applying manure (i.e., no-tillage) or incorporating manure using disk tillage. The effects of soil moisture content on VOC emissions was determined by adding water to each of the plots approximately 24 h after manure application. Isovaleric acid, butyric acid, and 4-methylphenol contributed 28.9, 18.0, and 17.7%, respectively, of the total measured odor activity values. In general, the largest emissions of volatile fatty acids and aromatics were measured during the initial collection periods on the no-tillage plots under dry soil moisture conditions. Emissions of volatile fatty acids and aromatics were reduced after water additions because these compounds were stored in the soil-water matrix rather than released into the atmosphere. In contrast, sulfide emissions generally increased with the addition of the water, especially on the plots containing manure from the 30% WDGS diet. Sulfur content of manure increases with higher percentages of WDGS feed stock. Application method, diet, soil moisture content, and time since application should be considered when estimating VOC emissions.

Effects of mechanical stress and growth on the velocity of tooth movement.

INTRODUCTION: In this study, we investigated the effects of the magnitudes of applied stress and growth status on the speed of tooth movement. METHODS: Eighty-two maxillary canines in 41 subjects were retracted for 84 days by estimated stresses of 4, 13, 26, 52, or 78 kPa applied continuously via segmental mechanics. Dental impressions made at intervals of 1 to 14 days resulted in 9 or 10 dental casts per subject. Three-dimensional tooth movements were quantified using these casts, custom reference templates, and a measuring microscope. Serial height and cephalometric measurements determined growth status. RESULTS: Distal tooth movement was linear with no lag phase in 96% of the teeth. Speeds averaged 0.028, 0.040, 0.050, 0.054, and 0.061 mm per day (standard errors, ± 0.004) for 4, 13, 26, 52, and 78 kPa, respectively. The maximum difference in speed between teeth was 9:1. Teeth moved significantly faster (P <0.0001) in growing compared with nongrowing subjects, on average by 1.6-fold. Stress and speed of tooth movement were logarithmically related in growing (R(2) = 0.47) and nongrowing (R(2) = 0.34) subjects. Other tooth movements were relatively small, except for the distopalatal rotation of teeth moved by 78 kPa that averaged more than 19°. CONCLUSIONS: The speed of retraction was logarithmically related to the applied stress and was significantly faster in actively growing subjects compared with those who were not growing.

Fate and transport of antimicrobials and antimicrobial resistance genes in soil and runoff following land application of swine manure slurry.

Due to the use of antimicrobials in livestock production, residual antimicrobials and antimicrobial resistance genes (ARGs) could enter the environment following the land application of animal wastes and could further contaminate surface and groundwater. The objective of this study was to determine the effect of various manure land application methods on the fate and transport of antimicrobials and ARGs in soil and runoff following land application of swine manure slurry. Swine manure slurries were obtained from facilities housing pigs that were fed chlortetracyline, tylosin or bacitracin and were land applied via broadcast, incorporation, and injection methods. Three rainfall simulation tests were then performed on amended and control plots. Results show that land application methods had no statistically significant effect on the aqueous concentrations of antimicrobials in runoff. However, among the three application methods tested broadcast resulted in the highest total mass loading of antimicrobials in runoff from the three rainfall simulation tests. The aqueous concentrations of chlortetracyline and tylosin in runoff decreased in consecutive rainfall events, although the trend was only statistically significant for tylosin. For ARGs, broadcast resulted in significantly higher erm genes in runoff than did incorporation and injection methods. In soil, the effects of land application methods on the fate of antimicrobials in top soil were compound specific. No clear trend was observed in the ARG levels in soil, likely because different host cells may respond differently to the soil environments created by various land application methods.

Effect of simvastatin injections on temporomandibular joint inflammation in growing rats.

PURPOSE: Juvenile idiopathic arthritis often affects the temporomandibular joint (TMJ), resulting in facial deformities, and intra-articular injections of anti-inflammatory steroids used in treatment may inhibit bone growth in the developing condyle. The purpose of this pilot study was to evaluate the anti-inflammatory properties of simvastatin (SIM), a bone anabolic drug, compared with the common steroid triamcinolone hexacetonide (TH) in experimental TMJ arthritis of growing rats. METHODS: Joint inflammation was induced by injecting complete Freund's adjuvant (CFA) into the TMJs of 32 growing (4-week-old) Sprague-Dawley rats while simultaneously receiving 1) ethanol drug carrier, 2) 0.1 mg of SIM, 3) 0.5 mg of SIM, or 4) 0.15 mg of TH. Six rats had no treatment to the TMJ. Animals were euthanized 28 days later, and TMJs were decalcified and stained with hematoxylin-eosin. RESULTS: Histopathologic TMJ results showed that CFA injection along with drug carrier induced increased thickness of the articular layer on the head of the condyle and inflammation of the retrodiscal area (CFA and ethanol). Although both TH and SIM reduced the articular layer thickness, 0.5 mg of SIM was more effective at reducing subsynovial inflammation. CONCLUSIONS: Intra-articular simvastatin showed anti-inflammatory properties in this TMJ model, prompting its further study in the growing TMJ, where bone anabolic properties would be important.

Proposed shade guide for human facial skin and lip: a pilot study.

STATEMENT OF PROBLEM: Currently, no commercially available facial shade guide exists in the United States for the fabrication of facial prostheses. PURPOSE: The purpose of this study was to measure facial skin and lip color in a human population sample stratified by age, gender, and race. Clustering analysis was used to determine optimal color coordinates for a proposed facial shade guide. MATERIAL AND METHODS: Participants (n=119) were recruited from 4 racial/ethnic groups, 5 age groups, and both genders. Reflectance measurements of participants' noses and lower lips were made by using a spectroradiometer and xenon arc lamp with a 45/0 optical configuration. Repeated measures ANOVA (α=.05), to identify skin and lip color differences, resulting from race, age, gender, and location, and a hierarchical clustering analysis, to identify clusters of skin colors) were used. RESULTS: Significant contributors to L*a*b* facial color were race and facial location (P<.01). b* affected all factors (P<.05). Age affected only b* (P<.001), while gender affected only L* (P<.05) and b* (P<.05). Analyses identified 5 clusters of skin color. CONCLUSIONS: The study showed that skin color caused by age and gender primarily occurred within the yellow-blue axis. A significant lightness difference between gender groups was also found. Clustering analysis identified 5 distinct skin shade tabs.

Viscoelastic Properties of Human Facial Skin and Comparisons with Facial Prosthetic Elastomers.

Prosthesis discomfort and a lack of skin-like quality is a source of patient dissatisfaction with facial prostheses. To engineer skin-like replacements, knowledge of the differences between facial skin properties and those for prosthetic materials is essential. This project measured six viscoelastic properties (percent laxity, stiffness, elastic deformation, creep, absorbed energy, and percent elasticity) at six facial locations with a suction device in a human adult population equally stratified for age, sex, and race. The same properties were measured for eight facial prosthetic elastomers currently available for clinical usage. The results showed that the prosthetic materials were 1.8 to 6.4 times higher in stiffness, 2 to 4 times lower in absorbed energy, and 2.75 to 9 times lower in viscous creep than facial skin (p < 0.001). Clustering analyses determined that facial skin properties fell into three groups-those associated with body of ear, cheek, and remaining locations. This provides baseline information for designing future replacements for missing facial tissues.

Effects of animal diet, manure application rate, and tillage on transport of microorganisms from manure-amended fields.

Manure from cattle fed distillers' grain or corn diets was applied to fields, and the fields were subjected to rainfall simulation tests. Manure was added at three rates on till and no-till plots. Correlations between microbial transport and runoff characteristics were identified. Results indicate that diet affects phage but not bacterial transport from manure-amended fields.

Role of prostaglandin pathway and alendronate-based carriers to enhance statin-induced bone.

This study investigated the role of the prostaglandin (PG) pathway in locally applied, simvastatin-induced oral bone growth. The possibility of enhancing long-term bone augmentation with an alendronate-based carrier was initiated. Mandibles of 44 mature female rats were treated bilaterally with the following combinations: 2 mg of simvastatin in ethanol (SIM-EtOH), EtOH, 2 mg of simvastatin acid complexed with alendronate-beta-cyclodextrin conjugate (SIM/ALN-CD), ALN-CD, or ALN. Bone wash technology (injection of PBS and re-collection by suction) was used to sample injection sites at baseline (day 0), and 3, 7, 14, and 21 days post-treatment. After 21-24 or 48 days, histomorphometric analysis was done. The amount of PGE(2) in bone wash fluid was measured by ELISA, normalized by total protein, and compared between high and low bone growth groups (ANOVA) and correlated with subsequent bone histology at 21 days (Spearman). SIM-stimulated PGE(2) synthase and EP4 receptor mRNA in murine osteoblast and fibroblast cell lines were evaluated with real-time PCR. Single injections of 2 mg of SIM-EtOH induced significantly more new bone than control side after 21 days. PGE(2)/protein ratios peaked at day 7 and were correlated with the subsequent 21-day new bone width. The correlations at day 14 between PGE(2) and new bone width changed to a negative relationship in the test group. SIM-stimulated osteoblasts expressed increased mRNA levels of PGE receptor EP4, while SIM activated PGE synthesis in fibroblasts. SIM/ALN-CD tended to preserve bone long-term. Findings suggest that PGE pathway activation and higher levels of PGE(2) during the first week following SIM-induced bone growth are desirable, and alendronate-beta-cyclodextrin conjugates not only act as tissue-specific carriers, but preserve new bone.

POISSON COKRIGING AS A GENERALIZED LINEAR MIXED MODEL.

It is often of interest to predict spatially correlated count outcomes that follow a Poisson distribution. For example, in the environmental sciences we may want to predict pollen counts using temperature or precipitation data as auxiliary variables. To predict a Poisson outcome variable in the presence of an auxiliary variable, Poisson cokriging as a Generalized Linear Mixed Model (GLMM) is proposed. This model has a bivariate structure with a Poisson outcome variable and an auxiliary variable. A covariance matrix similar to that used in cokriging is assumed. A simulation study and a real data example using the number of microplastics in the digestive tracts of fish are presented. The results showed that Poisson cokriging methodology can be applied successfully in practice with small average errors and coverage close to 95%. The Poisson cokriging model can be a useful tool for spatial prediction.

The effect of local simvastatin delivery strategies on mandibular bone formation in vivo.

Systemic simvastatin is known to reduce cholesterol and stimulate modest bone formation, but local surgical placement in polylactic acid domes causes robust bone formation and local swelling. A less invasive and more flexible injection protocol was studied to evaluate the bone-inducing effects compared to surgical implantation. Bone formation rate, short- and long-term bone augmentation histology, and mechanical properties were evaluated to characterize the new bone in a rat bilateral mandible model (test and control sides in same animal). Results demonstrated that multiple (3) injections of 0.5 mg simvastatin effectively reduced soft tissue swelling while preserving bone growth (60% increase of bone width at 24 days) compared to simvastatin dome placement (43% increase at 24 days). Compared to controls, bone formation rate was significantly higher on the simvastatin side, especially in the dome. Three-point bending tests revealed higher maximum force to fracture and stiffness at 24 days with simvastatin injections. Long-term evaluation showed that 55% of maximum new bone formed 24 days post-injection was retained at 90 days.

Injectable simvastatin in periodontal defects and alveolar ridges: pilot studies.

BACKGROUND: Topical injection of simvastatin in methylcellulose gel was shown to stimulate bone growth and inflammation over mouse calvaria and in rat mandible models. The purpose of these pilot studies was to evaluate the potential of locally injected simvastatin in human-sized periodontal defects. METHODS: Chronic periodontal defects were created bilaterally in seven 1-year-old beagle dogs: 3-walled intrabony defects distal of the mandibular second premolar and mesial of the fourth premolar and Class II furcation defects at the buccal furcation of the mandibular first molars. The edentulous space distal to the mandibular canine was left undisturbed. After 16 weeks of healing, defect sites were treated with scaling and root planing, and mandible sides were randomly selected to receive three weekly injections of 0.5 mg simvastatin in 30 microl methylcellulose gel and contralateral gel alone (n=3) or 2.0 mg simvastatin/methylcellulose gel and contralateral gel alone (n=4). Two months following drug application, block sections, including teeth and surrounding tissues, and submandibular lymph nodes were obtained for histomorphometric analysis. RESULTS: Two trends were noted in this pilot study: buccal edentulous ridge thickness was 29% greater with simvastatin, 0.5 mg, compared to gel alone (P=0.0845), and the simvastatin groups had bone-height loss in interproximal intrabony and furcation defects, but the length of new cementum in the interproximal intrabony defects was greater with simvastatin, 0.5 mg (0.35+/-0.14 mm), compared to gel alone (0.06+/-0.15 mm; P=0.069). No new cementum was found in furcations. CONCLUSIONS: Multiple injections of simvastatin are not appropriate for the treatment of intrabony or furcation defects. However, this approach shows potential to augment bone thickness in closed alveolar environments.

Factors associated with practice decisions of Nebraska veterinarians regarding type of practice and community size.

Nebraska veterinary practitioners were surveyed to collect data about background characteristics and other factors related to veterinarians' decision to include or not include food animals in their practices and to practice in rural versus urban communities. Background characteristics that were significantly (p < or = 0.05) associated with choosing food-animal practice included growing up on a working farm or ranch; having parents who owned livestock; growing up in a town with a population of less than 10,000; majoring in animal science at university; being male; and having a primary interest, at the time of entering veterinary college, in food animal-exclusive or mixed-animal veterinary practice. The primary factor for choosing the community in which to practice was rural/urban lifestyle for rural veterinarians, while this factor was second for urban veterinarians. For all groups of veterinarians, the primary consideration in selecting their current practice was the species orientation of the practice. The primary reason for not choosing food-animal practice was better working conditions and lifestyle in companion-animal practice, followed by greater interest elsewhere.