Effect of Tranexamic Acid on Intra- and Postoperative Bleeding in Eyelid Surgery: A Prospective, Randomized, Multicenter, Double-Masked, Control Trial.

PURPOSE: Pilot studies suggest that waiting 15 minutes after a subcutaneous tranexamic acid injection is associated with decreased intraoperative bleeding and postoperative ecchymosis in eyelid surgery. The outcomes of commencing eyelid surgery immediately after injection without a waiting period remain unexplored. METHODS: This prospective, randomized, multicenter, double-masked, controlled study examined bilateral symmetric upper and/or lower lid blepharoplasty or ptosis repair. Patients received tranexamic acid in 1 eyelid and control in the contralateral eyelid. The surgeon recorded the side with more intraoperative bleeding. Two masked graders evaluated periocular ecchymosis at postoperative day 0 and postoperative week 1 (POW 1) with a 5-point scale. At POW 1, patients reported subjective grading of bruising as increased on 1 side or similar on both sides. Results were analyzed with Wilcoxon signed-rank and sign tests. RESULTS: Of 130 patients, there was less eyelid ecchymosis on the tranexamic side at postoperative day 0 ( p = 0.001) and POW 1 ( p < 0.001). By surgery type, the 69 levator advancement surgeries had significantly less ecchymosis at postoperative day 0 ( p < 0.001) and POW 1 ( p = 0.001), while upper eyelid blepharoplasty, combined upper and lower lid blepharoplasty, and conjunctivomullerectomy trended toward significance. Of 68 patients reporting a POW 1 grading, 69% reported less bruising on the tranexamic side ( p < 0.001). Intraoperative bleeding was not significantly different between sides ( p = 0.930). CONCLUSIONS: Without a postinjection waiting period, subcutaneous tranexamic acid for eyelid surgery significantly decreased postoperative ecchymosis on postoperative day 0 and POW 1 but did not affect intraoperative bleeding. Subcutaneous tranexamic acid was not associated with any complications.

The Role of Serum Monocytes and Tissue Macrophages in Driving Left Ventricular Systolic Dysfunction and Cardiac Inflammation Following Subarachnoid Hemorrhage.

BACKGROUND: Neurocardiogenic injury is common after aneurysmal subarachnoid hemorrhage (aSAH) despite low prevalence of preexisting cardiac disease. Potential mechanisms include autonomic dysregulation due to excess catecholamines as well as systemic inflammation. Understanding how inflammation contributes to cardiac dysfunction may aid in identifying novel therapeutic strategies. Here, we investigated serum leukocytes as predictors of left ventricular systolic dysfunction in patients with aSAH. We also investigated increased cardiac macrophages in an animal model of SAH and whether immunomodulatory treatment could attenuate this inflammatory response. METHODS: We retrospectively analyzed 256 patients with aSAH admitted to University of Illinois Hospital between 2013 and 2019. Our inclusion criteria included patients with aSAH receiving an echocardiogram within 72 h of admission. Our primary outcome was echocardiographic evidence of systolic dysfunction. We performed multinomial regression and receiver operating curve analysis. We also used the endovascular perforation model of SAH in male Sprague-Dawley rats to assess for myocardial inflammation. Two days after surgery, hearts were collected and stained for the macrophage marker Iba-1. We compared the presence and morphology of macrophages in cardiac tissue isolated from SAH animals and sham controls treated with and without the immunomodulatory agent fingolimod. RESULTS: Of 256 patients with aSAH, 233 (91.0%) underwent echocardiography within 72 h of admission. Of 233, 81 (34.7%) had systolic dysfunction. Patients had baseline differences in the presence of hypertension, alcohol use, and admission Glasgow Coma Scale and Hunt-Hess score. On multivariable analysis, total leukocytes (odds ratio 1.312, p < 0.001), neutrophils (odds ratio 1.242, p = 0.012), and monocytes (odds ratio 6.112, p = 0.008) were independent predictors of reduced systolic function, whereas only monocytes (odds ratio 28.014, p = 0.030) predicted hyperdynamic function. Within the rodent heart, there were increased macrophages after SAH relative to controls, and this was attenuated by fingolimod treatment (p < 0.0001). CONCLUSIONS: Increased serum leukocytes are associated with abnormal left ventricular systolic function following aSAH. The strongest independent predictor of both reduced and hyperdynamic systolic function was increased monocytes. Increased cardiac macrophages after experimental SAH can also be targeted by using immunomodulatory drugs.

Sentinel lymph node assessment in melanoma: current state and future directions.

Assessment of sentinel lymph node status is an important step in the evaluation of patients with melanoma for both prognosis and therapeutic management. Pathologists have an important role in this evaluation. The methodologies have varied over time, from the evaluation of dimensions of metastatic burden to determination of the location of the tumour deposits within the lymph node to precise cell counting. However, no single method of sentinel lymph node tumour burden measurement can currently be used as a sole independent predictor of prognosis. The management approach to sentinel lymph node-positive patients has also evolved over time, with a more conservative approach recently recognised for selected cases. This review gives an overview of past and current status in the field with a glimpse into future directions based on prior experiences and clinical trials.

TransTok - An analysis of surgical gender affirmation content on TikTok.

PURPOSE: Social media platforms are popular sources of medical information but may harbor harmful misinformation. This study aims to evaluate the effect of TikTok on the transgender population, which may be more likely to seek information from non-traditional sources because of high medical mistrust. METHODS: Twenty gender affirmation related hashtags were queried, with the top 25 videos per hashtag included for analysis. Videos were categorized based on the content and creator. Variables included likes, comments, shares, and video views. All "educational" videos were analyzed for reliability of information using a modified DISCERN (mDISCERN) score and the Patient Education Materials Assessment Tool (PMAT). Kruskal-Wallis H tests, Mann-Whitney U tests, and simple linear regression models were used in analysis. RESULTS: A total of 429 videos amassed 571,434,231 views, 108,050,498 likes, 2,151,572 comments, and 190,9744 shares. Patients were the majority of content creators (74.88%), with patient experiences being the majority of videos (36.07%). Non-physician creators had significantly higher likes and comments when compared to physicians (6185 vs. 1645, p = 0.028; 108 vs. 47, p = 0.016 respectively). Sixty "educational" videos were included in information reliability analysis. There were no significant differences between video characteristics of different content creators, even after stratifying according to physician status. Significant differences were observed in the reliability of information according to PMAT and mDISCERN scores, with physician created videos being significantly higher rated than non-physician created videos (0.90 vs. 0.84, p < 0.001; 3 vs. 2, p < 0.001, respectively). CONCLUSION: Lower quality information is associated with non-physician content creators. We encourage physicians to be continuously involved in creating quality information on TikTok.

Pseudocholinesterase deficiency in ophthalmology: a systematic review.

PURPOSE: Unexpected anesthesia-related complications are among the most feared outcomes of ambulatory surgery. One potential culprit is pseudocholinesterase deficiency, which most commonly presents with protracted apnea, necessitating prolonged mechanical ventilation. We report the first case of pseudocholinesterase deficiency in a Bengali person and the first systematic review of pseudocholinesterase deficiency in ophthalmology. This review analyzed the epidemiology, etiologies, presentation, evaluation, and treatment of pseudocholinesterase deficiency. METHODS: Searches were conducted in PubMed, Embase, and Medline through August of 2022 for publications related to pseudocholinesterase deficiency in ophthalmology. In total, 689 studies were screened by two independent reviewers with 26 full-text articles examined for inclusion eligibility. Nineteen studies were eligible and included in the final analysis. RESULTS: Of the 16 identified cases of pseudocholinesterase deficiency, nine (56%) were drug-induced, four (25%) were inherited deficiencies, and in one (6%) of the cases, the cause could not be determined. In two (13%) cases, pseudocholinesterase deficiency could not be confirmed or ruled out. The duration of post-operative apnea ranged from 10 minutes to 14 hours. Continued ventilatory support was the main treatment for all cases and all patients made a full recovery. CONCLUSIONS: Pseudocholinesterase deficiency is a rare, but potentially fatal, anesthetic complication that results in prolonged apnea, respiratory distress, and dependency on ventilators. Ophthalmologists should remain aware of this condition, especially when planning outpatient procedures, as ambulatory centers may have limited resources for managing prolonged post-operative complications.

Gender Authorship Trends Among Craniofacial Publications: A 20-Year Analysis.

This study aims to identify gender disparities within the subspecialty of craniofacial surgery as women surgeons remain underrepresented in academia and leadership, arenas heavily dictated by research productivity.All craniofacial articles published in 3 major research journals from 2000 to 2020 were reviewed and evaluated in 5-year increments.Information regarding author gender, authorship distribution, geographic origin, and publication type was collected. ANOVA, χ2, and logistic regression modeling were used for analysis.In total, there were 3684 articles with 15 206 total authors-3128 (20.6%) were women, including 665 (21.3%) first authors, 1980 (63.2%) middle authors, and 487 (15.7%) senior authors. Mean women authorship increased significantly from 2000 to 2020 (0.33 vs 1.22 P < .001) with corresponding significant increases in first and senior authorship (8.63% vs 27.02; 5.65% vs 16.13%; P < .001). Statistically significant trends across time were observed for first and senior authorships (P < .001). Women were more likely to publish original publications as first and senior authors (OR: 1.83, P < .001; OR: 1.37, P = .0012). Women were less likely to publish editorial articles (OR 0.6, P < .001). The United States ranked third in publication output by female first authors but was behind all regions except Africa for output by female senior authors.Although female authorship has increased significantly over the last 2 decades, women remain a minority within the craniofacial literature. Further research is needed to elicit the root of these disparities.

The Spectrum of Spitz Melanocytic Lesions: From Morphologic Diagnosis to Molecular Classification.

Spitz tumors represent a distinct subtype of melanocytic lesions with characteristic histopathologic features, some of which are overlapping with melanoma. More common in the pediatric and younger population, they can be clinically suspected by recognizing specific patterns on dermatoscopic examination, and several subtypes have been described. We now classify these lesions into benign Spitz nevi, intermediate lesions identified as "atypical Spitz tumors" (or Spitz melanocytoma) and malignant Spitz melanoma. More recently a large body of work has uncovered the molecular underpinning of Spitz tumors, including mutations in the HRAS gene and several gene fusions involving several protein kinases. Here we present an overarching view of our current knowledge and understanding of Spitz tumors, detailing clinical, histopathological and molecular features characteristic of these lesions.

#Oculoplastics: An Analysis of TikTok's Top Oculoplastics Content.

PURPOSE: To analyze the source and quality of oculoplastics-related content on TikTok, a popular social media platform. METHODS: Twenty-five oculoplastics-related hashtags were queried. The top 20 videos for each hashtag were included. The number of views, likes, comments, and shares were recorded for each video. Each video was also categorized by the account owner and by video content characteristics. A subanalysis of the educational videos was conducted using the mDISCERN, Patient Education Materials Assessment Tool, and modified MICI scores to assess video quality, understandability and actionability, and medical accuracy, respectively. RESULTS: The included 386 videos amassed 218,997,134 views, 15,033,220 likes, 148,099 comments, and 276,445 shares. Patients were the leading content creators (38.1%), followed by nonophthalmology MDs/DOs (25.6%), and oculoplastic surgeons/ophthalmologists (16.3%). Physician-created videos received more visibility than nonphysician-created videos (median of 23,600 views and 22 shares), though this did not reach statistical significance. However, oculoplastic surgeon-posted content received the lowest median views and shares. The video category that amassed the most views was "live procedure/surgeries," followed by "educational" and "patient experience." Subanalysis of 46 educational videos revealed physicians were the chief creators, accounting for 67.4% of all educational videos. Physician-created content demonstrated statistically significant better understandability and actionability, as measured by the Patient Education Materials Assessment Tool ( p = 0.0053). CONCLUSION: Physicians play an important role in disseminating evidence-based medicine on social media. While oculoplastics-related TikTok videos are gaining traction, additional research is needed to improve the visibility of oculoplastic-surgeon posted content.

A 20-Year Analysis of Global Authorship Trends in Craniofacial Literature: Is the United States Falling Behind?

INTRODUCTION: Recent advances in craniofacial surgery have occurred in conjunction with a global proliferation of research. Although previous studies have examined geographic publication trends, little is known about these trends in the craniofacial literature. METHODS: All craniofacial articles published from 2000 to 2020 in 3 premier craniofacial surgery journals were evaluated in 5-year increments. Geographic origin, manuscript type, and authorship characteristics were collected. Changes in publication output, geographic origin, and content were analyzed. RESULTS: In total 3864 articles were analyzed, with the United States (U.S.) (33.46%) accounting for the majority, followed by Asia (27.04%), the Middle East (16.23%), and Europe (14.65%). The proportion of articles from the U.S. decreased significantly in the in the 20-year span (48.28% versus 33.53%, P < 0.001), whereas those originating from Asia and the Middle East increased significantly (18.62% versus 31.41% and 10.34% versus 15.66%, respectively, P < 0.001). After stratifying and selecting for regions with the greatest changes in publication output, the authors observed significant trends for the number of original investigations from 2000 to 2020 in the U.S. (Odds Ratio [OR] 1 versus 2.4, P < 0.001) and in Asia (OR 1 versus 1.8, P = 0.0052). Additionally, a significant trend in editorial/correspondence publications originating in the U.S. (OR 1 versus 0.74, P = 0.0102), Europe (OR 1 versus 0.38, P = 0.0186), and Asia (OR 1 versus 0.48, P = 0.0051) was observed. CONCLUSIONS: Despite rising craniofacial publications over the past 2 decades, there has been a diminishing proportion originating from the U.S.

Shared Decision Making in Ophthalmology: A Scoping Review.

PURPOSE: Shared decision making (SDM) has been associated with improved patient satisfaction and outcomes in both medical and surgical specialties, but its role in ophthalmology has not been systematically examined. Using a scoping review of the literature, the purpose of this study was to explore the characteristics, implementation, and outcomes of SDM in ophthalmology. DESIGN: Scoping review of the literature. METHODS: Searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials through August 2021 for SDM in ophthalmology. The resulting 1602 studies were screened by 2 independent reviewers with 57 full-text articles examined for inclusion of an ophthalmologic diagnosis, as well as discussion of SDM or patient decision aids. Nineteen studies were eligible and qualitatively coded for 11 predetermined codes, which included patient outcomes, patient and physician requests for SDM, and methods of implementation. RESULTS: Of 19 included studies, all emphasized the value of SDM for ophthalmology and 2 studies reported improved patient outcomes. The most commonly examined topics were chronic ophthalmic diseases, such as cataracts and glaucoma. Limitations to SDM implementation were also universally discussed, including patients' lack of disease knowledge, communication barriers, and time restrictions. Although patient decision aids are an effective tool to mitigate these limitations, these have only been established for the subjects of cataracts and glaucoma. CONCLUSION: SDM is a methodology for patient-centered care that is regarded as a potentially useful tool in the field of ophthalmology. However, significant barriers exist to its effective implementation. Evidence-based research on if and how these barriers should be attenuated, as well as the development of additional patient decision aids for different ophthalmic diseases, are needed.

Pediatric firearm injury trends in the United States: A national trauma data bank (NTDB) analysis.

AIM OF STUDY: Firearm injuries are the second leading cause of injury-related death in the USA in children less than 18. We compared overall and intent-specific firearm hospitalizations across age group and race to understand recent trends. METHODS: A retrospective cohort of 20,083 children from the national trauma data bank involved in incidences of firearm discharges from 2013 to 2017 was divided by race, discharge intent, gun type, and four age groups: infants (ages 0-2), toddlers (3-6), children (7-12), and adolescents (13-18). Discharge intent and gun type were determined by ICD-9-CM and ICD-10-CM External Causes of Injury codes. Injury severity score (ISS), hospital discharge disposition, and length of stay (LOS) were used as predictors for morbidity and mortality. RESULTS: From 2013 to 2017, there were on an average 4016 firearm injuries reported to the NTDB (n = 20,083). 71% (n = 14,313) of the incidents were assaults. Victims who identified as African American and Caucasian made up 60% (n = 11,890) and 26% (n = 5162) of the total victims, respectively, and were predominantly male (86%, n = 17,202). Victims who identified as Caucasian made up 70% of suicides (n = 819), while African Americans made up 70% of assaults (n = 9733). 87% (n = 17,525) of the patient population were adolescents. The number of accidental firearm discharges compared to firearm assaults was greater for toddlers, while the opposite was true for infants, children, and adolescents. Average LOS by age group varied each year, though children had the highest total average LOS.  Average ISS was highest for infants and adolescents (11.5 and 10.4) and American Indians and Caucasians (10.1 and 11.1). Overall mortality rate was 6% (n = 1220) and had no significant differences between years. Mortality rate was highest for infants (7%, n = 25). CONCLUSIONS: Adolescent males and African Americans were disproportionately affected by overall and assault-specific firearm discharges. Firearm injury prevention legislation is critical to prevent these injures.

Eating Disorder Symptomatology Among Adolescents Presenting for Bariatric Surgery Candidacy: Examining Differences by Sex and Racial Minority Status.

BACKGROUND: Research on adolescent bariatric surgery candidates is limited by insufficient inclusion of ethnic minorities and males, and lack of consideration of the full spectrum of disordered eating behaviors (i.e., restriction, compensatory behaviors [e.g., purging], overeating/binge eating behaviors). OBJECTIVES: The current study investigated differences in the full range of disordered eating behaviors across sex and ethnicity among adolescents seeking bariatric surgery. SETTING: Teaching hospital, United States. METHODS: Data were collected using retrospective chart review of 79 adolescent bariatric surgery candidates (59% female, 46.8% Hispanic, MBMI = 50.2, SDBMI = 10.0, Mage = 17.3, SDage = 2.02) who had completed the self-reported Eating Disorder Diagnostic Scale for DSM-5 at intake. RESULTS: Approximately 33% of study participants met self-reported criteria for an eating disorder, with 35% endorsing binge eating behaviors and 50% endorsing compensatory behaviors. Few differences in behavior frequencies were observed across sex or racial/ethnic status. CONCLUSIONS: Findings underscore the importance of assessing the full spectrum of disordered eating behaviors among adolescent bariatric surgery candidates.

Intensity Modulated Proton Therapy for Hepatocellular Carcinoma: Initial Clinical Experience.

PURPOSE: Our purpose was to assess the safety and efficacy of intensity modulated proton therapy (IMPT) for the treatment of hepatocellular carcinoma (HCC). METHODS AND MATERIALS: A retrospective review was conducted on all patients who were treated with IMPT for HCC with curative intent from June 2015 to December 2018. All patients had fiducials placed before treatment. Inverse treatment planning used robust optimization with 2 to 3 beams. The majority of patients were treated in 15 fractions (n = 30, 81%, 52.5-67.5 Gy, relative biological effectiveness), whereas the remainder were treated in 5 fractions (n = 7, 19%, 37.5-50 Gy, relative biological effectiveness). Daily image guidance consisted of orthogonal kilovoltage x-rays and use of a 6° of freedom robotic couch. Outcomes (local control, progression free survival, and overall survival) were determined using Kaplan-Meier methods. RESULTS: Thirty-seven patients were included. The median follow-up for living patients was 21 months (Q1-Q3, 17-30 months). Pretreatment Child-Pugh score was A5-6 in 70% of patients and B7-9 in 30% of patients. Nineteen patients had prior liver directed therapy for HCC before IMPT. Eight patients (22%) required a replan during treatment, most commonly due to inadequate clinical target volume coverage. One patient (3%) experienced a grade 3 acute toxicity (pain) with no recorded grade 4 or 5 toxicities. An increase in Child-Pugh score by ≥ 2 within 3 months of treatment was observed in 6 patients (16%). At 1 year, local control was 94%, intrahepatic control was 54%, progression free survival was 35%, and overall survival was 78%. CONCLUSIONS: IMPT is safe and feasible for treatment of HCC.

A nationwide database analysis of demographics and outcomes related to Extracorporeal Membrane Oxygenation (ECMO) in congenital diaphragmatic hernia.

PURPOSE: The aim of the study was to understand the use of Extracorporeal Membrane Oxygenation (ECMO) in congenital diaphragmatic hernia (CDH) and its outcomes. METHODS: The 2016 Kid's Inpatient Database (KID) obtained from the national Healthcare Cost and Utilization Project (HCUP) was used to obtain CDH birth, demographic, and outcome data associated with ECMO use. Categorical variables were analyzed and odds ratios (OR) with 95% confidence intervals (CI) are reported for variables found to have significance (p < 0.05). Appropriate regressions were used for comparing categorical and continuous data using SPSS 25 for Macintosh. RESULTS: The database contained 1189 cases of CDH, of which 133 (11.2%) received ECMO. The overall mortality of neonates with CDH was 18.9% (225/1189). Newborns with CDH on ECMO had a survival of 46% (61/133) compared to 85.5% without ECMO (903/1056) (OR 6.966, p < 0.001, 95% CI 4.756-10.204). ECMO increased length of stay from 24.6 to 69.8 days (OR 2.834, p < 0.001, 95% CI 2.768-2.903) and average cost from $375,002.20 to $1641,586.83 (OR 4.378, p < 0.001, 95% CI 3.341-5.735). CONCLUSIONS: Increased length of stay, costs, and outcomes with ECMO use in CDH should prompt an examination of criteria necessitating ECMO.

Radiotherapy for malignant melanoma of the lacrimal sac.

Malignant melanoma of the lacrimal sac is an exceptionally rare tumor with a poor prognosis. We report two cases of malignant melanoma of the lacrimal sac: a 73 year-old female treated with primary surgical resection and a 75 year-old male treated with surgical resection, adjuvant proton beam radiotherapy, and adjuvant immunotherapy. We discuss the role of post-operative proton beam therapy and recent advancements in immunotherapy. These cases highlight the importance of early diagnosis and multi-modality treatment in this aggressive malignancy.

Isobutanol production freed from biological limits using synthetic biochemistry.

Cost competitive conversion of biomass-derived sugars into biofuel will require high yields, high volumetric productivities and high titers. Suitable production parameters are hard to achieve in cell-based systems because of the need to maintain life processes. As a result, next-generation biofuel production in engineered microbes has yet to match the stringent cost targets set by petroleum fuels. Removing the constraints imposed by having to maintain cell viability might facilitate improved production metrics. Here, we report a cell-free system in a bioreactor with continuous product removal that produces isobutanol from glucose at a maximum productivity of 4 g L-1 h-1, a titer of 275 g L-1 and 95% yield over the course of nearly 5 days. These production metrics exceed even the highly developed ethanol fermentation process. Our results suggest that moving beyond cells has the potential to expand what is possible for bio-based chemical production.

Wnt7A is a putative prognostic and chemosensitivity marker in human malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor that has a poor prognosis, limited treatment options, and a worldwide incidence that is expected to increase in the next decade. We evaluated Wnt7A expression in 50 surgically resected tumor specimens using quantitative PCR. The expression values, were assessed by clinicopathological factors and K-M and Cox's regression with OS. The mean level of Wnt7A expression had a significant correlation with International Mesothelioma Interest Group (IMIG) stage (P<0.034), gender, smoking history and ethnicity, respectively (P=0.020, P=0.014, P=0.039). In the univariate analysis, low Wnt7A expression was a significant negative factor for overall survival (P=0.043, HR=2.30). However, multivariate Cox's regression revealed no significant factors for overall survival (low Wnt7A: P=0.051, HR=2.283; non-epithelioid subtype: P=0.050, HR=2.898). In patients with epithelioid tumors, those with low Wnt7A expression had significantly worse prognosis (P=0.019, HR=2.98). In patients with epithelioid tumors, females had significantly better prognosis than males (P=0.035). In patients who did not have neoadjuvant chemotherapy, prognosis was significantly more favorable for patients with high Wnt7A expression than for those with low Wnt7A expression (P=0.031). Among the patients with low Wnt7A-expressing tumors, those who received neoadjuvant chemotherapy had better prognosis than those who did not (P=0.024). The results of our study suggest that Wnt7A expression is a putative prognostic factor and a predictor of chemosensitivity.

Successful Treatment of Giant Basal Cell Carcinoma with Topical Imiquimod 5% Cream with Long Term Follow-up.

The use of the topical Imiquimod 5% cream offers a noninvasive, nonsurgical, and an effective option for the treatment of primary small (<2 cm) superficial basal cell carcinoma (sBCC). However, reports about successful treatment of giant (>5 cm) BCC with topical Imiquimod 5% cream are rare. We present our experience in the treatment of two giant tumors (6 × 8 cm(2), 5.2 × 4.2 cm(2)) of BCC on the face with Imiquimod 5% cream, 2 to 3 days/week for 12 weeks. Both the tumors were cured with clinical and pathological evidence, one with 6-year follow-up and the other with 3.5-year follow-up.

Trophic stimulation of articular chondrocytes by late-passage mesenchymal stem cells in coculture.

Coculture of mesenchymal stem cells (MSCs) with articular chondrocytes (ACs) increases glycosaminoglycan (GAG) accumulation compared to monoculture. MSCs might (1) differentiate into ACs (progenitor role) and/or (2) stimulate AC matrix metabolism (trophic role). MSCs lose the ability to undergo chondrogenesis after extended passaging. We hypothesized that MSCs act predominantly as progenitors, and that late-passage MSCs without chondrogenic potential would be unable to increase GAG in coculture. Early- and late-passage human MSCs (hMSCs) were grown in pellet monoculture under chondrogenic conditions and in pellet coculture with bovine ACs. Chondrogenesis was assessed with GAG quantification, safranin-O staining, and quantitative PCR (qPCR). Contributions of human and bovine cells were assessed with species-specific qPCR and human-specific immunostaining. Late-passage hMSCs did not undergo chondrogenesis in monoculture with chondrogenic stimuli or in coculture with ACs. Early-passage hMSCs underwent chondrogenesis only in response to chondrogenic stimuli. Coculture pellets in both cases accumulated as much GAG/DNA as monoculture AC pellets. Aggrecan transcription was not increased in coculture. Late-passage hMSCs that do not undergo chondrogenesis are capable of stimulating GAG accumulation in coculture with ACs. This supports a trophic effect of hMSCs on ACs. hMSCs may have therapeutic utility even after prolonged passaging.