Mechanisms of Alcohol Addiction: Bridging Human and Animal Studies

Aim: The purpose of this brief narrative review is to address the complexities and benefits of extending animal alcohol addiction research to the human domain, emphasizing Allostasis and Incentive Sensitization, two models that inform many pre-clinical and clinical studies. Methods: The work reviewed includes a range of approaches, including: a) animal and human studies that target the biology of craving and compulsive consumption; b) human investigations that utilize alcohol self-administration and alcohol challenge paradigms, in some cases across 10 years; c) questionnaires that document changes in the positive and negative reinforcing effects of alcohol with increasing severity of addiction; and d) genomic structural equation modeling based on data from animal and human studies. Results: Several general themes emerge from specific study findings. First, positive reinforcement is characteristic of early stage addiction and sometimes diminishes with increasing severity, consistent with both Allostasis and Incentive Sensitization. Second, evidence is less consistent for the predominance of negative reinforcement in later stages of addiction, a key tenant of Allostasis. Finally, there are important individual differences in motivation to drink at a given point in time as well as person-specific change patterns across time. Conclusions: Key constructs of addiction, like stage and reinforcement, are by necessity operationalized differently in animal and human studies. Similarly, testing the validity of addiction models requires different strategies by the two research domains. Although such differences are challenging, they are not insurmountable, and there is much to be gained in understanding and treating addiction by combining pre-clinical and clinical approaches.Fil: Kramer, John. University of Iowa; Estados UnidosFil: Dick, Danielle M.. University of Virginia; Estados UnidosFil: King, Andrea. University of Chicago; Estados UnidosFil: Ray, Lara A.. University of California at Los Angeles; Estados UnidosFil: Sher, Kenneth J.. University of Missouri; Estados UnidosFil: Vena, Ashley. University of Chicago; Estados UnidosFil: Vendruscolo, Leandro F.. National Institutes of Health; Estados UnidosFil: Acion, Laura. University of Iowa; Estados Unidos. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Calculo. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Calculo; Argentin

DNA Fragmentation Simulation Method (FSM) and Fragment Size Matching Improve aCGH Performance of FFPE Tissues

Whole-genome copy number analysis platforms, such as array comparative genomic hybridization (aCGH) and single nucleotide polymorphism (SNP) arrays, are transformative research discovery tools. In cancer, the identification of genomic aberrations with these approaches has generated important diagnostic and prognostic markers, and critical therapeutic targets. While robust for basic research studies, reliable whole-genome copy number analysis has been unsuccessful in routine clinical practice due to a number of technical limitations. Most important, aCGH results have been suboptimal because of the poor integrity of DNA derived from formalin-fixed paraffin-embedded (FFPE) tissues. Using self-hybridizations of a single DNA sample we observed that aCGH performance is significantly improved by accurate DNA size determination and the matching of test and reference DNA samples so that both possess similar fragment sizes. Based on this observation, we developed a novel DNA fragmentation simulation method (FSM) that allows customized tailoring of the fragment sizes of test and reference samples, thereby lowering array failure rates. To validate our methods, we combined FSM with Universal Linkage System (ULS) labeling to study a cohort of 200 tumor samples using Agilent 1 M feature arrays. Results from FFPE samples were equivalent to results from fresh samples and those available through the glioblastoma Cancer Genome Atlas (TCGA). This study demonstrates that rigorous control of DNA fragment size improves aCGH performance. This methodological advance will permit the routine analysis of FFPE tumor samples for clinical trials and in daily clinical practice

Periodontal Diagnosis Affected by Variation in Terminology

BACKGROUND: The randomized case presentation (RCP) study is designed to assess the degree of diagnostic accuracy for described periodontal cases. This is to lay the basis for practitioner calibration in the Practitioners Engaged in Applied Research and Learning (PEARL) Network for future clinical studies. METHODS: The RCP consisted of 10 case scenarios ranging from periodontal health to gingivitis and mild, moderate, and severe periodontitis. Respondents were asked to diagnose the described cases. Survey diagnoses were compared to two existing classifications of periodontal disease status. The RCP was administered via a proprietary electronic data capture system maintained by the PEARL Data Coordinating Center. Standard analytic techniques, including frequency counts and cross-tabulations, were used for categorical data with mean and standard deviation and median values reported for continuous data elements. RESULTS: Demonstrable variations in periodontal assessment for health, gingivitis, and mild, moderate, and severe periodontitis were found among the 130 PEARL general practitioners who participated in the RCP survey. The highest agreement for diagnosis among dentists was for severe periodontitis (88%) and the lowest for gingivitis (55%). The highest percentage of variation was found in cases with health and gingivitis. CONCLUSIONS: There was variation among PEARL practitioners in periodontal diagnosis that may affect treatment outcomes. Our findings add clinical support to recent publications suggesting a need for standardization of terminology in periodontitis diagnosis

Advantages of the dental practice-based research network initiative and its role in dental education

Practice-based research networks (PBRNs) provide a novel venue in which providers can increase their knowledge base and improve delivery of care through participation in clinical studies. This article describes some aspects of our experience with a National Institute of Dental and Craniofacial Research-supported PBRN and discusses the role it can play in dental education. PBRNs create a structured pathway for providers to advance their professional development by participating in the process of collecting data through clinical research. This process allows practitioners to contribute to the goals of evidence-based dentistry by helping to provide a foundation of evidence on which to base clinical decisions as opposed to relying on anecdotal evidence. PBRNs strengthen the professional knowledge base by applying the principles of good clinical practice, creating a resource for future dental faculty, training practitioners on best practices, and increasing the responsibility, accountability, and scope of care. PBRNs can be the future pivotal instruments of change in dental education, the use of electronic health record systems, diagnostic codes, and the role of comparative effectiveness research, which can create an unprecedented opportunity for the dental profession to advance and be integrated into the health care system

Dentin caries activity in early occlusal lesions selected to receive operative treatment:findings from the Practitioners Engaged in Applied Research and Learning (PEARL) Network

BACKGROUND: Members of the practice-based research network Practitioners Engaged in Applied Research and Learning (PEARL) Network investigated the dentin caries activity in early occlusal lesions and its relationship to patient age, preoperative tooth sensitivity and radio-graphic appearance, as well as its influence on preparation depth and volume. METHODS: PEARL Network practitioner-investigators (P-Is) (n = 45), general dentists who were trained but whose methods were not calibrated, conducted a study regarding postoperative hypersensitivity in resin-based composite restorations. The P-Is enrolled as study participants 613 patients with occlusal carious lesions that, in the P-Is’ clinical judgment, required restoration. The P-Is used baseline radiographs to assess the depth and extent of the lesions. Data for 671 restorations included baseline sensitivity; ranking of dentin caries activity on the opening of the enamel; radiographic visibility (n = 652); and measurements of preparation depth, width and length. RESULTS: P-Is found rapidly progressing dentin caries in 38.5 percent (258 of 671) of lesions and slowly progressing (and potentially inactive dentin) caries in the remainder of the lesions. Rapidly progressing caries was not related to the participant’s age or participant-reported preoperative hypersensitivity but was related to the lesion depth as seen radiographically (P < .001) and depth (P < .001) and volume (P < .001) of the preparation. Molars had slightly higher but not statistically significant levels of caries activity. CONCLUSION: Rapidly progressing dentin caries, while present in only 38.5 percent of lesions, was related to the lesion’s radiographic appearance but not to the participant’s age or the study tooth’s pre-operative sensitivity. CLINICAL IMPLICATIONS: On the basis of the low level of rapidly progressing dentin caries in this study population and the fact that slowly progressing caries can be inactive or remineralizing, the authors advise sealing versus operative treatment of early or shallow occlusal lesions

Practice based research networks impacting periodontal care:PEARL initiative

In 2005, the National Institute of Dental and Craniofacial Research /National Institutes of Health funded the largest initiative to date to affect change in the delivery of oral care. This commentary provides the background for the first study related to periodontics in a Practice Based Research Network (PBRN). It was conducted in the Practitioners Engaged in Applied Research & Learning (PEARL) Network. The PEARL Network is headquartered at New York University College of Dentistry. The basic tenet of the PBRN initiative is to engage clinicians to participate in clinical studies, where they will be more likely to accept the results and to incorporate the findings into their practices. This process may reduce the translational gap that exists between new findings and the time it takes for them to be incorporated into clinical practice. The cornerstone of the PBRN studies is to conduct comparative effectiveness research studies to disseminate findings to the profession and improve care. This is particularly important because the majority of dentists practice independently. Having practitioners generate clinical data allows them to contribute in the process of knowledge development and incorporate the results in their practice to assist in closing the translational gap. With the advent of electronic health systems on the horizon, dentistry may be brought into the mainstream health care paradigm and the PBRN concept can serve as the skeletal framework for advancing the profession provided there is consensus on the terminology used