Identification and functional characterization of an RNA binding protein involved in defense signaling pathway and cell death in rice.

U-box containing ubiquitin E3 ligase proteins play key roles in the regulation of diverse developmental processes such as cell death, defense responses, and flowering in monocots and dicots. We have previously demonstrated that SPOTTED LEAF 11 (SPL11), a rice U-box E3 ubiquitin ligase, is essential for the fine tuning of programmed cell death (PCD) and flowering in rice. Loss of function spl11 gamma-ray mutant showed lesion mimics, enhanced resistance to two different rice pathogens and delayed flowering under the long day conditions (Zeng et al., 2004; Vega-Sanchez et al., 2008). To elucidate the molecular and biochemical mechanisms by which SPL11 controls PCD and/or flowering time, yeast two-hybrid (Y2H) screens were performed using SPL11 as the bait, and eight proteins were identified as putative SPL11 interactors (SPINs). Among them, SPIN1, a signal transduction and activation of RNA (STAR), interacts with SPL11 in the nucleus and represses flowering via transcriptional perturbation of heading date 3a (Hd3a), an ortholog of FLOWERING LOCUS T (FT) in Arabidopsis (Vega-Sanchez et al., 2008). Interestingly, another RNA-binding protein, RNA binding interactor of SPIN1 (RBS1), was identified through additional Y2H screens using SPIN1 as the bait. Transient expressions of RBS1 in rice protoplasts and leaves of Nicotiana benthamiana showed abrupt host cell death in both systems. In addition, over-expression of RBS1 in rice resulted in lesion mimicry and dwarfism in T1 generation. These results suggest that SPL11 might regulate program cell death through SPIN1/RBS1 protein complex.United States Department of Agricultur

Image-Based Hybrid Scaffold Design for Multiple Tissue Regeneration Application in Periodontal Engineering.

Periodontal disease is a common chronic inflammatory disease, which if left untreated, can cause periodontal tissue breakdown. The periodontal complex is a micron-scaled, tooth-supporting structure with a complicated topology, which makes it difficult to predict and quantify periodontal tissue destruction. Unlike conventional assessment methods, 3-D micro-computed tomography provides very accurate, precise high resolution images of the periodontal topology. Using natural spatiotemporal landmarks to create a region-of-interest from the roof-of-furcation to the root-apex, volumetric image analysis of the bone-tooth interface was performed. The results demonstrated excellent examiner reproducibility and reliability (ICC>0.99 and CV<1.5%) for both linear and volumetric bone parameters. In an orthodontic tooth movement study, micro-CT quantified the activity of osteoprotegerin stimulation to prevent bone resorption and tooth mobility. Human alveolar bone core biopsies were analyzed to obtain mineral tissue density profiles in order to predict dental implant stability. Because of this high reproducibility and reliability, other wide-reaching applications have potential for predicting periodontal therapy outcomes, orthodontic tooth movement, as well as evaluation of clinical dental implant stability. A major challenge in periodontal tissue engineering is the control of periodontal tissue neogenesis; micron-scaled and complicated multi-interface regeneration with a functional architecture. To promote this compartmentalized, multiple tissue regeneration with perpendicularly-oriented periodontal ligament fiber, a multi-layered hybrid scaffold was designed and manufactured using the rapid prototyping technique. To produce a periodontium-like environment, the polymeric hybrid scaffold was assembled with a periodontal cell/tissue guidable micro-architecture; a highly porous bone region, a vertically-oriented PDL architecture, and a human tooth dentin slice. This complex was subcutaneously transplanted with untreated human PDL cells and BMP-7 transduced human gingival fibroblast cells using the ectopic model system. In spite of non-biomechanical loading conditions, this approach resulted in periodontal-structural similarity. There was a perpendicular/oblique orientation of the fibrous connective PDL cells/tissues to the dentin surface, and mineralized tissue formation without any mineralized tissue formation in the PDL interface of the hybrid scaffold at both the 3 and 6 weeks. This dissertation study provides potential for functional restoration of tissue interface neogenesis applications and shows promise for both pre-clinical and clinical applications for translational regenerative medicine.Ph.D.Biomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/78755/1/chanho_1.pd

Total Laparoscopic Hysterectomy and Laparoscopy-Assisted Vaginal Hysterectomy

This study suggests that total laparoscopic hysterectomy and laparoscopic-assisted vaginal hysterectomy are safe and feasible with laparoscopic-assisted hysterectomy preferred in patients with a mass involving the lower uterine segment or those with a large uterus

Fabrication of Complex 3D Micro-Scale Scaffolds and Drug Delivery Devices using Dynamic Mask Projection Microstereolithography

Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissue engineered scaffolds with controlled biochemical and mechanical micro-architectures. A μSL system for tissue engineering was developed using a Digital Micromirror Device (DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for crosslinking the photoreactive polymer solution. The μSL system was designed with x-y resolution of ~2 μm and a vertical (z) resolution of ~1 μm. To demonstrate the use of μSL in tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight of ~1200 Da. The viscosity of the PPF was reduced to ~150 cP (at 50 o C) by mixing with diethyl fumarate (DEF) in the ratio of 7:3 (w/w). Finally, ~2 % (w/w) of (bis(2,4,6- trimethylbenzoyl) phenylphosphine oxide (BAPO) was added to the solution to serve as a photoinitiator. Cure depth experiments were performed to determine the curing characteristics of the synthesized PPF, and the resulting system and photopolymer were used to construct a variety of 3D porous scaffolds with interconnected pores between 100 and 150 μm and a micro-needle array with height of ~800 μm and individual tip diameters of ~20 μm. SEM and microscope images of the micro-architectures illustrate that the developed μSL system is a promising technology for producing biodegradable and biocompatible microstructures.Mechanical Engineerin

Characterization of ligature‐induced experimental periodontitis

We sought to better characterize the progression of periodontal tissue breakdown in rats induced by a ligature model of experimental periodontal disease (PD). A total of 60 male Sprague–Dawley rats were evenly divided into an untreated control group and a PD group induced by ligature bilaterally around first and second maxillary molars. Animals were sacrificed at 1, 3, 5, 7, 14, and 21 days after the induction of PD. Alveolar bone loss was evaluated by histomorphometry and microcomputed tomography (μCT). The immune‐inflammatory process in the periodontal tissue was assessed using descriptive histologic analysis and quantitative polymerase chain reaction (qPCR). This ligature model resulted in significant alveolar bone loss and increased inflammatory process of the periodontal tissues during the initial periods of evaluation (0–14 days). A significant increase in the gene expression of pro‐inflammatory cytokines, interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6), and tumor necrosis factor‐α (TNF‐α), and proteins involved in osteoclastogenesis, receptor activator of nuclear factor‐k B ligand (RANKL) and osteoprotegerin (OPG) was observed in the first week of analysis. In the later periods of evaluation (14–21 days), no significant alterations were noted with regard to inflammatory processes, bone resorption, and expression of cytokine genes. The ligature‐induced PD model resulted in progressive alveolar bone resorption with two different phases: Acute (0–14 days), characterized by inflammation and rapid bone resorption, and chronic (14–21 days) with no significant progression of bone loss. Furthermore, the gene expressions of IL‐6, IL‐1β, TNF‐α, RANKL, and OPG were highly increased during the progress of PD in the early periods.Research HighlightsLigature‐induced bone resorption in rats occurred in the initial periods after disease inductionThe bone resorption was characterized by two distinct phases: Acute (0–14 days), with pronounced inflammation and alveolar bone lossChronic phase (14–21 days): No further disease progressionSeveral pro‐inflammatory cytokines were increased during the progress of periodontitisPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147007/1/jemt23101_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147007/2/jemt23101.pd

What Questions do People Ask on a Human Papillomavirus Website? A Comparative Analysis of Public and Private Questions

Objective: In 2004, we launched the question and answer (Q&A) section on a human papillomavirus (HPV) website (www.hpvkorea.org) that provides ample and regularly updated information about HPV. The purpose of this study is to collect data pertaining to questions posed on this website about HPV and its related diseases and analyze the type of questions and frequency before and after introduction of HPV vaccine in Korea. Using these results, we intend to determine the clinical and practical implications for doctors treating HPV and for HPV website providers

Comparative Efficacy of Video and Text Instructional Modalities for an Oral Surgery Technique among Dental Students

Purpose: To gauge the efficacy of video media in pre-doctoral oral and maxillofacial surgery education and compare it to traditional text-based learning materials. Methods: Twenty novice dental students were randomly divided into two groups to place an Erich arch bar to the maxillary dentition of a dentoform. Group A was given a 10 minute video instruction while Group B was given 10 minutes to review written text instruction. All participants were given 45 minutes to place the arch bar on a dentoform while being recorded. This session concluded with a survey of student perceptions using the SEEQ. The students then alternated instructional modalities and again evaluated using the SEEQ. Two double-blinded clinical OMS faculty evaluated the recordings in accordance with the standards detailed in the ABPAS. Results: The difference in the post-instructional skill scores of Group A and Group B students was deemed not significant (p = 0.46). Overall, the students expressed significant preference for the video modality compared to the textual modality. The difference of the scores in each preference category between the video and text modalities were all found to be significant with p-values well below 0.05. Conclusion: Educators must remain cognizant towards the benefits of new technology and continue to explore newer, potentially more efficacious modalities such as interactive teaching materials. These benefits may be utilized to help increase student engagement and increase long-term retention of the material. It is imperative to understand the limits of each method and balance them strategically to offer comprehensive healthcare training