Rabbit Annulus Fibrosus Cells Express Neuropeptide Y, Which Is Influenced by Mechanical and Inflammatory Stress

Malcolm E. Dombrowski,Adam S. Olsen,Nicholas Vaudreuil,Brandon K. Couch,Qing Dong,Michelle Tucci,Joon Y. Lee,Nam V. Vo,Gwendolyn Sowa 대한척추신경외과학회 2020 Neurospine Vol.17 No.1

Objective: Rabbit annulus fibrosus (AF) cells were exposed to isolated or combined mechanical and inflammatory stress to examine the expression of neuropeptide Y (NPY). This study aims to explore the ability of AF cells to produce NPY in response to mechanical and inflammatory stress. Methods: Lumbar AF cells of 6- to 8-month-old female New Zealand white rabbits were harvested and exposed to combinations of inflammatory (interleukin-1β) and mechanical (6% or 18%) tensile stress using the Flexcell System. NPY concentrations were measured in the media via enzyme-linked immunosorbent assay. The presence of NPY receptor-type 1 (NPY-1R) in AF cells of rabbit intervertebral discs was also analyzed via immunohistochemistry and immunofluorescence. Results: Exposure to inflammatory stimuli showed a significant increase in the amount of NPY expression compared to control AF cells. Mechanical strain alone did not result in a significant difference in NPY expression. While combined inflammatory and mechanical stress did not demonstrate an increase in NPY expression at low (6%) levels of strain, at 18% strain, there was a large—though not statistically significant—increase in NPY expression under conditions of inflammatory stress. Lastly, immunofluorescence and immunohistochemistry of AF cells and tissue, respectively, demonstrated the presence of NPY-1R. Conclusion: These findings demonstrate that rabbit AF cells are capable of expressing NPY, and expression is enhanced in response to inflammatory and mechanical stress. Because both inflammatory and mechanical stress contribute to intervertebral disc degeneration (IDD), this observation raises the potential of a mechanistic link between low back pain and IDD.

Short Enantioselective Total Syntheses of Cheloviolenes A and B and Dendrillolide C via Convergent Fragment Coupling Using a Tertiary Carbon Radical

Garnsey, Michelle R.,Slutskyy, Yuriy,Jamison, Christopher R.,Zhao, Peng,Lee, Juyeol,Rhee, Young Ho,Overman, Larry E. American Chemical Society 2018 Journal of organic chemistry Vol.83 No.13

<P>The development of a convergent fragment coupling strategy for the enantioselective total syntheses of a group of rearranged spongian diterpenoids that harbor the <I>cis</I>-2,8-dioxabicyclo[3.3.0]octan-3-one unit is described. The key bond disconnection relies on a late-stage fragment coupling between a tertiary carbon radical and an electron-deficient alkene to unite two ring systems and form two new stereocenters, one of which is quaternary, in a stereoselective and efficient manner. This strategy is applied toward scalable 14-15 step syntheses of three rearranged spongian diterpenoids, cheloviolenes A and B, and dendrillolide C.</P> [FIG OMISSION]</BR>

Biomechanical investigation of arm position on deforming muscular forces in proximal humerus fractures

Christen E. Chalmers,David J. Wright,Nilay A. Patel,Hunter Hitchens,Michelle McGarry,Thay Q. Lee,John A. Scolaro 대한견주관절의학회 2022 대한견주관절의학회지 Vol.25 No.4

Background: Muscular forces drive proximal humeral fracture deformity, yet it is unknown if arm position can help mitigate such forces. Our hypothesis was that glenohumeral abduction and humeral internal rotation decrease the pull of the supraspinatus and subscapularis muscles, minimizing varus fracture deformity. Methods: A medial wedge osteotomy was performed in eight cadaveric shoulders to simulate a two-part fracture. The specimens were tested on a custom shoulder testing system. Humeral head varus was measured following physiologic muscle loading at neutral and 20° humeral internal rotation at both 0° and 20° glenohumeral abduction. Results: There was a significant decrease in varus deformity caused by the subscapularis (p<0.05) at 20° abduction. Significantly increasing humeral internal rotation decreased varus deformity caused by the subscapularis (p<0.05) at both abduction angles and that caused by the supraspinatus (p<0.05) and infraspinatus (p<0.05) at 0° abduction only. Conclusions: Postoperative shoulder abduction and internal rotation can be protective against varus failure following proximal humeral fracture fixation as these positions decrease tension on the supraspinatus and subscapularis muscles. Use of a resting sling that places the shoulder in this position should be considered.

Evaluating the Revised American Society for Gastrointestinal Endoscopy Guidelines for Common Bile Duct Stone Diagnosis

Jake S. Jacob,Michelle E. Lee,Erin Y. Chew,Aaron P. Thrift,Robert J. Sealock 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.2

Background/Aims: The American Society for Gastrointestinal Endoscopy (ASGE) revised its guidelines for risk stratification ofpatients with suspected choledocholithiasis. This study aimed to assess the diagnostic performance of the revision and to compare itto the previous guidelines. Methods: We conducted a retrospective cohort study of 267 patients with suspected choledocholithiasis. We identified high-riskpatients according to the original and revised guidelines and examined the diagnostic accuracy of both guidelines. We measured theassociation between individual criteria and choledocholithiasis. Results: Under the original guidelines, 165 (62%) patients met the criteria for high risk, of whom 79% had confirmedcholedocholithiasis. The categorization had a sensitivity and specificity of 68% and 55%, respectively, for the detectionof choledocholithiasis. Under the revised guidelines, 86 (32%) patients met the criteria for high risk, of whom 83% hadcholedocholithiasis. The revised categorization had a lower sensitivity and higher specificity of 37% and 80%, respectively. Thepositive predictive value of the high-risk categorization increased with the revision, reflecting a potential decrease in diagnosticendoscopic retrograde cholangiopancreatograpies (ERCPs). Stone visualized on imaging had the greatest specificity forcholedocholithiasis. Gallstone pancreatitis was not associated with the risk for choledocholithiasis. Conclusions: The 2019 revision of the ASGE guidelines decreases the utilization of ERCP as a diagnostic modality and offers animproved risk stratification tool.

Determining the Effects of Lipophilic Drugs on Membrane Structure by Solid-State NMR Spectroscopy: The Case of the Antioxidant Curcumin

Barry, Jeffrey,Fritz, Michelle,Brender, Jeffrey R.,Smith, Pieter E. S.,Lee, Dong-Kuk,Ramamoorthy, Ayyalusamy American Chemical Society 2009 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.131 No.12

<P>Curcumin is the active ingredient of turmeric powder, a natural spice used for generations in traditional medicines. Curcumin's broad spectrum of antioxidant, anticarcinogenic, antimutagenic, and anti-inflammatory properties makes it particularly interesting for the development of pharmaceutical compounds. Because of curcumin's various effects on the function of numerous unrelated membrane proteins, it has been suggested that it affects the properties of the bilayer itself. However, a detailed atomic-level study of the interaction of curcumin with membranes has not been attempted. A combination of solid-state NMR and differential scanning calorimetry experiments shows curcumin has a strong effect on membrane structure at low concentrations. Curcumin inserts deep into the membrane in a transbilayer orientation, anchored by hydrogen bonding to the phosphate group of lipids in a manner analogous to cholesterol. Like cholesterol, curcumin induces segmental ordering in the membrane. Analysis of the concentration dependence of the order parameter profile derived from NMR results suggests curcumin forms higher order oligomeric structures in the membrane that span and likely thin the bilayer. Curcumin promotes the formation of the highly curved inverted hexagonal phase, which may influence exocytotic and membrane fusion processes within the cell. The experiments outlined here show promise for understanding the action of other drugs such as capsaicin in which drug-induced alterations of membrane structure have strong pharmacological effects.</P>

Biomechanical Comparison of the Latarjet Procedure with and without Capsular Repair

Matthew T. Kleiner,William B. Payne,Michelle H. McGarry,James E. Tibone,Thay Q. Lee 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.1

Background: The purpose of this study was to determine if capsular repair used in conjunction with the Latarjet procedure results in significant alterations in glenohumeral rotational range of motion and translation. Methods: Glenohumeral rotational range of motion and translation were measured in eight cadaveric shoulders in 90° of abduction in both the scapular and coronal planes under the following four conditions: intact glenoid, 20% bony Bankart lesion, modified Latarjet without capsular repair, and modified Latarjet with capsular repair. Results: Creation of a 20% bony Bankart lesion led to significant increases in anterior and inferior glenohumeral translation and rotational range of motion (p < 0.005). The Latarjet procedure restored anterior and inferior stability compared to the bony Bankart condition. It also led to significant increases in glenohumeral internal and external rotational range of motion relative to both the intact and bony Bankart conditions (p < 0.05). The capsular repair from the coracoacromial ligament stump to the native capsule did not significantly affect translations relative to the Latarjet condition; however it did cause a significant decrease in external rotation in both the scapular and coronal planes (p < 0.005). Conclusions: The Latarjet procedure is effective in restoring anteroinferior glenohumeral stability. The addition of a capsular repair does not result in significant added stability; however, it does appear to have the effect of restricting glenohumeral external rotational range of motion relative to the Latarjet procedure performed without capsular repair.

Exceptional reduction of the plastid genome of saguaro cactus (<i>Carnegiea gigantea</i>): Loss of the <i>ndh</i> gene suite and inverted repeat

Sanderson, Michael J.,Copetti, Dario,Bú,rquez, Alberto,Bustamante, Enriquena,Charboneau, Joseph L. M.,Eguiarte, Luis E.,Kumar, Sudhir,Lee, Hyun Oh,Lee, Junki,McMahon, Michelle,Steele, Kelly,Wing Botanical Society of America, Inc. (Columbus) * Bu 2015 American journal of botany Vol. No.

<P>• <I>Premise of the study:</I> Land-plant plastid genomes have only rarely undergone significant changes in gene content and order. Thus, discovery of additional examples adds power to tests for causes of such genome-scale structural changes.</P><P>• <I>Methods:</I> Using next-generation sequence data, we assembled the plastid genome of saguaro cactus and probed the nuclear genome for transferred plastid genes and functionally related nuclear genes. We combined these results with available data across Cactaceae and seed plants more broadly to infer the history of gene loss and to assess the strength of phylogenetic association between gene loss and loss of the inverted repeat (IR).</P><P>• <I>Key results:</I> The saguaro plastid genome is the smallest known for an obligately photosynthetic angiosperm (∼113 kb), having lost the IR and plastid <I>ndh</I> genes. This loss supports a statistically strong association across seed plants between the loss of <I>ndh</I> genes and the loss of the IR. Many nonplastid copies of plastid <I>ndh</I> genes were found in the nuclear genome, but none had intact reading frames; nor did three related nuclear-encoded subunits. However, nuclear <I>pgr5</I>, which functions in a partially redundant pathway, was intact.</P><P>• <I>Conclusions:</I> The existence of an alternative pathway redundant with the function of the plastid NADH dehydrogenase-like complex (NDH) complex may permit loss of the plastid <I>ndh</I> gene suite in photoautotrophs like saguaro. Loss of these genes may be a recurring mechanism for overall plastid genome size reduction, especially in combination with loss of the IR.</P>