The Differential Effects of Buprenorphine and Methadone on Adolescent Mice.

This study focuses on understanding the consequences of administering opioid maintenance drugs, such as buprenorphine and methadone, on the adolescent brain. This is because that there are growing needs to treat opioid dependence and addiction in adolescents and there is a lack of studies that aim at explaining the effects of opioid maintenance drugs on the still-developing adolescent brain. The goal of this study is to enable physicians to conduct a science-based risk assessment on the proper use of these treatments for that age group. A recent study conducted in our lab has indicated potential risks in chronic exposure to certain opioids, specifically, morphine during adolescence. Morphine exposure was observed to change the signaling of D2/D3 dopamine receptors in adolescent mice. The D2/D3 dopamine receptor may mediate long-term mental changes in adolescents, specifically changes linked to mood and psychotic disorders. Thus, this study examined whether buprenorphine and methadone alter the responses of the D2/D3 dopamine receptors differently in an adolescent population. Adolescent mice were orally administered buprenorphine, methadone, or saline once daily for 6 days. Two hours or three days later, the mice were tested for their locomotor response to quinpirole, a D2/D3 dopamine receptor agonist. Buprenorphine-treated adolescent mice showed a similar response to that of the drug-naïve (saline-injected) group in their response to quinpirole. In contrast, an enhanced response was observed in methadone-treated adolescent animals. This effect was significantly higher two hours following the final dose of methadone, as compared to three days afterwards. As shown in this study, methadone exposure greatly disturbs the D2/D3 receptor’s signaling. This indicates that care should be taken when administering methadone to adolescents for addiction therapies as well as pain management. In contrast to methadone, buprenorphine appears to disrupt the D2/D3 dopamine receptor signaling in adolescents less. Therefore, this study may confirm that exposure to different opioids carries different risks, specifically in an adolescent population

Cystic Fibrosis Gene Therapy: Vector Systems

Since the discovery of the CFTR gene, researchers have been working to develop a gene therapy technique that helps to correct the causative gene in cystic fibrosis patients. Many vector delivery systems have been researched. However, even after years of clinical trials, there is still no FDA approved cystic fibrosis gene therapy technique. Researchers have found difficulty finding a vector system that has maintained high levels of expression over an extended period of time. This review investigates the early and current development of vector delivery systems, including viral and non-viral vectors, in a comparative study measuring efficiency. Currently, lentivirus vectors are a promising viral technique for CF patients, as well as nanoparticle delivery systems due to their enhanced gene expression and delivery efficiency. While the implementation of a cystic fibrosis gene therapy technique has been more challenging than previously expected, new research continues to bring the vector systems closer to reality

Contamination of Ring Dosimeters and Hands Among Proceduralists Performing Invasive Procedures

Ring dosimeters are radiation safety monitoring devices worn by proceduralists during invasive procedures requiring ionizing radiation. Since they are not single-use, contaminated ring dosimeters may confer a risk of hand contamination, and subsequently surgical glove contamination, procedural wound contamination, and procedural site infections. No previous study has quantified the risk of contamination on the hands of those wearing ring dosimeters, and research on fomites that could add infection risk in low-risk procedural settings remains scant. The aim of this novel pilot study was to measure the contamination risk of ring dosimeters on the hands of proceduralists wearing these rings and provide insight on fomite contamination during procedures where infections may be underreported. This observational study was conducted with select providers at UPMC Presbyterian and UPMC Shadyside hospitals in Pittsburgh, PA. Using convenience sampling, ring and ring finger samples were collected using sterile saline-moistened synthetic swabs before and after low-level disinfection (LLD) and hand hygiene (HH), respectively. The primary outcome was the reduction of bacterial contamination after pre-procedural HH and ring disinfection. As a secondary analysis, we compared finger contamination among ring dosimeter wearers and non-wearer controls. We report mean aerobic colony counts (ACCs) and the proportion of samples with any growth on pre-and post-HH fingers between ring wearers and non-wearers and on rings of those who wear them before and after disinfection. Pre-HH samples from the ring wearers had a higher mean of ACC than post-HH samples, but only 25% and 14% of samples showed growth, respectively. Pre-LLD samples had a mean of 1.1; however, post-LLD samples were not performed due to guideline non-adherence providers. Findings from this pilot study indicate that hand hygiene procedures are most likely sufficient and post procedural infection risk is therefore low. A full-scale study will be needed to fully assess the validity of safety measures associated with current ring dosimeter-related procedures as well as if other fomites in a similar situation is warranted. Evaluating the risk of procedural infections will continue to be vital in public health even in areas considered low risk

Maximizing Northern Red Oak (Quercus rubra) Seedling Growth to Sustain Oak-Dominated Ecosystems in East Tennessee

The success of northern red oak (Quercus rubra L.) in the oak-hickory forest type and its growth and development into the overstory is of great concern due to the value of this species as a source of forest products and mast for wildlife. There is a general consensus that rapid oak seedling height growth occurs above certain threshold levels of light, soil moisture, and nutrients. If these specific levels and the relative importance of competition between northern red oak (NRO) seedlings and other individual plant species can be determined, then the implementation of more precise management practices that promote rapid NRO seedling height growth and more cost-efficient competition control treatments could be developed. The detection of genetic family differences among artificially regenerated NRO seedlings could also have future applications in advancing the competitive ability of NRO in the field. This study had three objectives. The first objective was to identify light, soil moisture, and nutrient levels in the immediate vicinity of NRO seedlings that lead to rapid height growth. The second objective was to establish which plant species are the most important competitors limiting these resources and thus the height growth and survival of NRO seedlings. The third objective was to identify potential genetic family differences among the NRO seedlings used in this experiment. This study was conducted on moderately productive sites in mature oak-hickory forests on the University of Tennessee Forestry Experiment Station at Oak Ridge in east Tennessee. A randomized complete block design was used, and the dependent variables were height growth and percent survival for all NRO seedlings. Six treatments were randomly assigned to equally sized plots within three blocks (10 hectares per block) during the summer of 2002. Blocking was based primarily on aspect, but also included stand structure, forest composition, and landscape position. In order of decreasing canopy cover, the treatments were: uncut (Control), 50% basal area retention (BAR), 25% BAR, 12.5% BAR, commercial clearcut (CCC), and silvicultural clearcut (SCC). Sixty premium artificially regenerated NRO seedlings from 18 different half-sibling families were then planted within each treatment in mid April of 2003. Significant differences in mean percent full photosynthetically active radiation (PAR) existed between nearly all treatments. The Control treatments received the lowest percent full PAR level at 3.84 percent and the SCC received the most at 86.67 percent. The north facing block was significantly different from the south facing and ridge top blocks receiving almost 8 percent less PAR on average. Soil moisture levels were not significantly affected by treatments or blocks. Greater than normal precipitation levels during the 2003 growing season may have influenced soil moisture and seedling performance. Macronutrient levels were not significant in explaining NRO performance in this study. Total height growth was noticeably greater (by more than 12 cm on average) in the Controls than all other treatments. Mortality was also highest in this treatment (10 percent) and most likely due to heavy shade. Very little mortality (\u3c2 percent) occurred in all other treatments combined. Fireweed (Erechtites hieracifolia L.) and horseweed (Erigeron canadensis L.) were the most abundant herbaceous species overtopping the NRO seedlings. They occurred mainly in the 25% BAR, 12.5% BAR, CCC and SCC totaling 7, 5, 12, and 5 percent of the total cover respectively. Yellow-poplar (Liriodendron tulipifera L.) and red maple (Acer rubrum L.) were the most abundant woody species in this study. Ranging from 17 cm to 29 cm, mean height growth differed significantly between genetic families. No differences in survival were detected between families. However, three genetic families had 100 percent survival and the family with the greatest mortality had 9 percent mortality. Multiple regression was conducted using the backward selection technique to determine the best model for predicting NRO seedling height growth in this study. The best model had nine independent variables for predicting NRO seedling growth with an R2 of 36.37 percent. Initial seedling height after planting and percent full PAR were the most significant variables in the model. PAR and initial seedling height both had a negative relationship with first year height growth. Initial root collar diameter was also significant and had a positive relationship with first year height growth. Potential woody competitors such as redbud (Cercis canadensis L.) and blackgum (Nyssa sylvatica Marsh) also proved to be significant in predicting NRO seedling height growth. Both species had a positive relationship with seedling growth in the 51-150 cm size class. Based on these first year results, greater height growth appears to be associated with less sunlight, although this seems to be the result of etiolation in the Controls. Yellow-poplar and red maple, which were the most abundant competitors in this study, do not appear to currently have any effect on NRO seedling height growth. Redbud and blackgum, on the other hand, seem to be possible indicators of good sites for NRO seedling height growth. Shorter seedlings with thicker root collar diameters exhibited more height growth than seedlings that were taller or had smaller root collar diameters