Faculty Bibliography

The Platelet-Rich Plasma (PRP) for Knee Osteoarthritis Technology Overview is based on a systematic review of current scientific and clinical research. Through analysis of the current best evidence, this technology overview seeks to evaluate the efficacy of PRP for patients with knee osteoarthritis. The systematic literature review resulted in 54 articles: 36 high-quality and 18 moderate-quality. The findings of these studies were summarized to present findings on PRP versus control/placebo, acetaminophen, non-steroidal anti-inflammatory drugs, corticosteroids, exercise, prolotherapy, autologous conditioned serum, bone marrow aspirate concentrate, hyaluronic acid, and ozone therapy. In addition, the work group highlighted areas that needed additional research when evidence proved lacking on the topic and carefully noted the potential harms associated with an intervention, required resource utilization, acceptability, and feasibility.

Progranulin (PGRN), encoded by the GRN gene in humans, was originally isolated as a secreted growth factor that implicates in a multitude of processes ranging from regulation of tumorigenesis, inflammation to neural proliferation. Compelling evidence indicating that GRN mutation can lead to various common neuronal degenerative diseases and rare lysosomal storage diseases. These findings have unveiled a critical role for PGRN as a lysosomal protein in maintaining lysosomal function. The phenotypic spectrum of PGRN imbalance has expanded to encompass a broad spectrum of diseases, including autoimmune diseases, metabolic, musculoskeletal and cardiovascular diseases. These diseases collectively referred to as Progranulinopathy- a term encompasses the wide spectrum of disorders influenced by PGRN imbalance. Unlike its known extracellular function as a growth factor-like molecule associated with multiple membrane receptors, PGRN also serves as an intracellular co-chaperone engaged in the folding and traffic of its associated proteins, particularly the lysosomal hydrolases. This chaperone activity is required for PGRN to exert its diverse functions across a broad range of diseases, encompassing both the central nervous system and peripheral systems. In this comprehensive review, we present an update of the emerging role of PGRN in Progranulinopathy, with special focus on elucidating the intricate interplay between PGRN and a diverse array of proteins at various levels, ranging from extracellular fluids and intracellular components, as well as various pathophysiological processes involved. This review seeks to offer a comprehensive grasp of PGRN's diverse functions, aiming to unveil intricate mechanisms behind Progranulinopathy and open doors for future research endeavors.

BACKGROUND/UNASSIGNED:Significant heterogeneity in the classification and treatment of zone 3 proximal fifth metatarsal base fractures ("true Jones fractures") exists. This study compared time to clinical and radiographic healing between patients treated operatively and nonoperatively. We hypothesized that patients treated nonoperatively may demonstrate a greater time to clinical healing. METHODS/UNASSIGNED:This was a retrospective cohort study of patients presenting to a large, urban, academic medical center with "Jones" fractures between December 2012 and April 2022. Jones fractures were defined as fifth metatarsal base fractures occurring in the proximal metadiaphyseal region, distal to the articulation of the fourth and fifth metatarsals on the oblique radiographic view. Clinical healing was the time point at which the patient had returned to their baseline ambulatory status with no tenderness to palpation. Radiographic healing was the presence of bridging callus across at least 3 cortices. RESULTS/UNASSIGNED: = .331). Overall healing rate was 96% for the nonoperative group compared with 96.2% for the operative group. CONCLUSION/UNASSIGNED:In this study, nonoperative and operative treatment of true Jones fractures were associated with equivalent clinical and radiographic healing. The rate of delayed union in true Jones fractures was lower than previously described, and there was no difference in delayed union rate between nonoperative and operative management. LEVEL OF EVIDENCE/UNASSIGNED:Level III, retrospective cohort study.

Much is known about molecular mechanisms by which animals detect pathogenic microbes, but how animals sense beneficial microbes remains poorly understood. The roundworm Caenorhabditis elegans is a microbivore that must distinguish nutritive microbes from pathogens. We characterized a neural circuit used by C. elegans to rapidly discriminate between nutritive bacteria and pathogens. Distinct sensory neuron populations responded to chemical cues from nutritive Escherichia coli and pathogenic Enterococcus faecalis, and these neural signals are decoded by downstream AIB interneurons. The polyamine metabolites cadaverine, putrescine, and spermidine produced by E. coli activate this neural circuit and elicit positive chemotaxis. Our study shows how polyamine odorants can be sensed by animals as proxies for microbe identity and suggests that, hence, polyamines might have widespread roles brokering host-microbe interactions.

Obesity has a multifactorial etiology and is known to be a state of chronic low-grade inflammation, known as meta-inflammation. This state is associated with the development of metabolic disorders such as glucose intolerance and nonalcoholic fatty liver disease. Pyruvate is a glycolytic metabolite and a crucial node in various metabolic pathways. However, its role and molecular mechanism in obesity and associated complications are obscure. In this study, we reported that pyruvate substantially inhibited adipogenic differentiation in vitro and its administration significantly prevented HFD-induced weight gain, white adipose tissue inflammation, and metabolic dysregulation. To identify the target proteins of pyruvate, drug affinity responsive target stability was employed with proteomics, cellular thermal shift assay, and isothermal drug response to detect the interactions between pyruvate and its molecular targets. Consequently, we identified cytosolic phospholipase A2 (cPLA2) as a novel molecular target of pyruvate and demonstrated that pyruvate restrained diet-induced obesity, white adipose tissue inflammation, and hepatic steatosis in a cPLA2-dependent manner. Studies with global ablation of cPLA2 in mice showed that the protective effects of pyruvate were largely abrogated, confirming the importance of pyruvate/cPLA2 interaction in pyruvate attenuation of inflammation and obesity. Overall, our study not only establishes pyruvate as an antagonist of cPLA2 signaling and a potential therapeutic option for obesity, but it also sheds light on the mechanism of its action. Pyruvate's prior clinical use indicates that it can be considered a safe and viable alternative for obesity, whether consumed as a dietary supplement or as part of a regular diet.

RNA polymerase II (RNA Pol II) can backtrack during transcription elongation, exposing the 3' end of nascent RNA. Nascent RNA sequencing can approximate the location of backtracking events that are quickly resolved; however, the extent and genome-wide distribution of more persistent backtracking are unknown. Consequently, we developed a method to directly sequence the extruded, "backtracked" 3' RNA. Our data show that RNA Pol II slides backward more than 20 nt in human cells and can persist in this backtracked state. Persistent backtracking mainly occurs where RNA Pol II pauses near promoters and intron-exon junctions and is enriched in genes involved in translation, replication, and development, where gene expression is decreased if these events are unresolved. Histone genes are highly prone to persistent backtracking, and the resolution of such events is likely required for timely expression during cell division. These results demonstrate that persistent backtracking can potentially affect diverse gene expression programs.

OBJECTIVES/OBJECTIVE:The authors report no conflict of interest.To determine if short-term immobilization with a rigid long arm plaster elbow splint after surgery of the arm, elbow, or forearm results in superior outcomes compared with a soft dressing with early motion. DESIGN/METHODS:Prospective Randomized Control Trial. SETTING/METHODS:Academic Medical Center. PATIENT SELECTION CRITERIA/UNASSIGNED:Patients undergoing operative treatment for a mid-diaphysis or distal humerus, elbow, or forearm fracture were consented and randomized according to the study protocol for postoperative application of a rigid elbow splint (10-14 days in a plaster Sugar Tong Splint for forearm fracture or a Long Arm plaster Splint for 10-14 for all others) or soft dressing and allowing immediate free range of elbow and wrist motion (range of motion [ROM]). OUTCOME MEASURES AND COMPARISONS/UNASSIGNED:Self-reported pain (visual analog score or VAS), Healthscale (0-100, 100 denoting excellent health), and physical function (EuroQol 5 Dimension or EQ-5D) surveyed on postoperative days 1-5 and 14 were compared between groups. Patient-reported pain score (0-10, 10 denoting highest satisfaction) at week 6, time to fracture union, ultimate disabilities of the arm, shoulder, and hand score, and elbow ROM were also collected for analysis. Incidence of complications were assessed. RESULTS:Hundred patients (38 men to 62 women with a mean age of 55.7 years) were included. Over the first 5 days and again at postop day 14, the splint cohort reported a higher "Healthscale" from 0 to 100 than the nonsplint group on all study days ( P = 0.041). There was no difference in reported pain between the 2 study groups over the same interval ( P = 0.161 and 0.338 for least and worst pain, respectively), and both groups reported similar rates of treatment satisfaction ( P = 0.30). Physical function ( P = 0.67) and rates of wound problems ( P = 0.27) were similar. Additionally, the mean time to fracture healing was similar for the splint and control groups (4.6 ± 2.8 vs. 4.0 ± 2.2 months, P = 0.34). Ultimate elbow ROM was similar between the study groups ( P = 0.48, P = 0.49, P = 0.61, and P = 0.51 for elbow extension, flexion, pronation, and supination, respectively). CONCLUSIONS:Free range of elbow motion without splinting produced similar results compared with elbow immobilization after surgical intervention for a fracture to the humerus, elbow, and forearm. There was no difference in patient-reported pain outcomes, wound problems, or elbow ROM. Immobilized patients reported slightly higher "healthscale" ratings than nonsplinted patients and, however, reported similar rates of satisfaction. Both treatment strategies are acceptable after upper extremity fracture surgery. LEVEL OF EVIDENCE/METHODS:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

OBJECTIVES/OBJECTIVE:The objective of this study was to ascertain outcome differences after fixation of unstable rotational ankle fractures allowed to weight-bear 2 weeks postoperatively compared with 6 weeks. DESIGN/METHODS:Prospective case-control study. SETTING/METHODS:Academic medical center; Level 1 trauma center. PATIENT SELECTION CRITERIA/UNASSIGNED:Patients with unstable ankle fractures (OTA/AO:44A-C) undergoing open reduction internal fixation (ORIF) were enrolled. Patients requiring trans-syndesmotic fixation were excluded. Two surgeons allowed weight-bearing at 2 weeks postoperatively (early weight-bearing [EWB] cohort). Two other surgeons instructed standard non-weight-bearing until 6 weeks postoperatively (non-weight-bearing cohort). OUTCOME MEASURES AND COMPARISONS/UNASSIGNED:The main outcome measures included the Olerud-Molander questionnaire, the SF-36 questionnaire, and visual analog scale at 6 weeks, 3 months, 6 months, and 12 months postoperatively and complications, return to work, range of ankle motion, and reoperations at 12 months were compared between the 2 cohorts. RESULTS:One hundred seven patients were included. The 2 cohorts did not differ in demographics or preinjury scores ( P > 0.05). Six weeks postoperatively, EWB patients had improved functional outcomes as measured by the Olerud-Molander and SF-36 questionnaires. Early weight-bearing patients also had better visual analog scale scores (standardized mean difference -0.98, 95% confidence interval [CI] -1.27 to -0.70, P < 0.05) and a greater proportion returning to full capacity work at 6 weeks (odds ratio = 3.42, 95% CI, 1.08-13.07, P < 0.05). One year postoperatively, EWB patients had improved pain measured by SF-36 (standardized mean difference 6.25, 95% CI, 5.59-6.92, P < 0.01) and visual analog scale scores (standardized mean difference -0.05, 95% CI, -0.32 to 0.23, P < 0.01). There were no differences in complications or reoperation at 12 months ( P > 0.05). CONCLUSIONS:EWB patients had improved early function, final pain scores, and earlier return to work, without an increased complication rate compared with those kept non-weight-bearing for 6 weeks. LEVEL OF EVIDENCE/METHODS:Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.