21 results on '"Tram, Nguyen K."'
Search Results
2. Home-Based Pediatric Hospice and Palliative Care Provider Visits: Effects on Healthcare Utilization
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Smith, Steven M., Grossoehme, Daniel H., Cicozi, Kate, Hiltunen, Audrey, Roth, Catherine, Richner, Gwendolyn, Kim, Stephani S., Tram, Nguyen K., and Friebert, Sarah
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- 2024
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3. Quantification of chemotherapy-induced changes in body composition in pediatric, adolescent, and young adult lymphoma using standard of care CT imaging
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Tram, Nguyen K., Chou, Ting-Heng, Ettefagh, Laila N., Deep, Kyra, Bobbey, Adam J., Audino, Anthony N., and Stacy, Mitchel R.
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- 2022
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4. Association of Pre-procedural Anxiety With Procedure-Related Pain During Outpatient Pediatric Burn Care: A Pilot Study
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Vest, Eurella, Armstrong, Megan, Olbrecht, Vanessa A, Thakkar, Rajan K, Fabia, Renata B, Groner, Jonathan I, Noffsinger, Dana, Tram, Nguyen K, and Xiang, Henry
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- 2023
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5. Operating Room Noise Environment and Behavior in Children Undergoing General Anesthesia: A Randomized Controlled Trial.
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Bozych, Marc, Tram, Nguyen K., Rice-Weimer, Julie, Cartabuke, Richard S., Tobias, Joseph D., Huffman, Jamie, Mpody, Christian, Uffman, Joshua C., and Ding, Xueqin
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CHILD behavior , *FOOD fussiness , *ANESTHESIOLOGISTS , *BEHAVIORAL assessment , *STIMULUS & response (Psychology) - Abstract
Background. Excessive operating room noise impairs communication, distracts from monitoring equipment, and may increase patient and provider stress. Aim. This study investigates the effects of reduced noise on perioperative behavior in children undergoing general anesthesia and on anesthesia provider response time. Methods. Healthy children (the American Society of Anesthesiologists class I‐II), 2–8 years of age, and their anesthesia providers were randomized into a control or treatment group exposed to reduced stimulation during induction and emergence. Primary outcomes were patient behavior and provider response time. Secondary outcomes were postoperative pain scores, provider responses exceeding 30 seconds, and median and maximum noise exposure. Results. 64 children (27 females and 37 males) were randomized into a control or treatment group, of whom 32 (50%) underwent tonsillectomy/adenoidectomy and 32 (50%) underwent dental procedures. The average age was 4.6 (SD 1.43) years. Children exposed to reduced noise were less likely to be "fussy about eating" (p = 0.042), more "interested in what goes on around them" (p = 0.008), and had fewer temper tantrums (p = 0.004) on postoperative day one or two and on postoperative day five, six, or seven. No other differences were found between groups in behavioral assessment scores or provider response times. Conclusions. Our study is the first to show that a low‐stimulus environment improves postdischarge behavior. Provider response time was unaffected by reduced noise, and the average and peak noise exposure levels did not exceed national safety guidelines. This trial is registered with NCT03507855 and NCT03504553. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Accommodative tissues influence the shape of the cornea and potentially drive corneal morphogenesis
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Tram, Nguyen K., Jiang, Pengfei, Jacobs, Kane M., Ruzga, Marissa N., Allen, Mallory G., Prieto, Ryan P., Carus, Sophie A., Reilly, Matthew A., and Swindle-Reilly, Katelyn E.
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- 2020
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7. Quantification of Skeletal Muscle Perfusion in Peripheral Artery Disease Using 18F-Sodium Fluoride Positron Emission Tomography Imaging.
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Ting-Heng Chou, Nabavinia, Mahboubeh, Tram, Nguyen K., Rimmerman, Eleanor T., Patel, Surina, Musini, Kumudha Narayana, Eisert, Susan Natalie, Wolfe, Tatiana, Wynveen, Molly K., Yuichi Matsuzaki, Takahiro Kitsuka, Ryuma Iwaki, Janse, Sarah A., Bobbey, Adam J., Breuer, Christopher K., Goodchild, Laurie, Malbrue, Raphael, Toshiharu Shinoka, Atway, Said A., and Go, Michael R.
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- 2024
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8. Preoperative gastric point-of-care ultrasound in nonelective surgical procedures in pediatric-aged patients.
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GHIMIRE, ANURANJAN, MOHARIR, ALOK, YOSHIKAZU YAMAGUCHI, TRAM, NGUYEN K., and TOBIAS, JOSEPH D.
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OPERATIVE surgery ,CHILD patients ,ULTRASONIC imaging ,GASTRIC emptying ,GASTRIC bypass ,POINT-of-care testing ,PEDIATRIC surgery - Abstract
Background: Airway management for nonelective surgical procedures in the setting of trauma, pain, and opioid use can be complicated by the potential for aspiration due to delayed gastric emptying. Point-of-care ultrasound (POCUS) remains a useful tool for evaluating gastric content and volume in various clinical settings. The authors evaluated gastric volume and content in children scheduled for urgent and semi-urgent procedures to assess their aspiration risk. Methods: After obtaining consent, gastric POCUS was performed in the preoperative holding area for pediatric patients scheduled for both elective and nonelective surgery. Qualitative and quantitative measurements of the gastric antrum were taken, and the risk of gastric aspiration was calculated. Additional data collected included patient demographics, the type of surgery, nil per os (NPO) status at the time of surgery, NPO status at the time of injury, and administration of opioids. Results: The study cohort included 100 patients ranging in age from 3 to 17 years old (mean age 9.2 years). Out of these 100 patients, gastric scanning was successfully conducted in 98 patients. Sixteen of fifty-nine nonelective patients (27%) had received opioids for pain control prior to surgery. Among the 34 patients who had suffered an acute injury, 7 (21%) had been NPO for <8 hours at the time of the injury. Ninety-nine out of hundred patients had been NPO for at least 6 hours at the time of the gastric ultrasound. Based on our gastric ultrasound findings, all patients who were appropriately NPO had either Grade 0 or Grade 1 risk for aspiration, indicating a low risk of aspiration. Conclusions: The preliminary data show that when patients presenting for nonelective surgery are appropriately NPO, they may have a low risk of aspiration. This information may help guide the choice of anesthetic induction technique, particularly when concerns exist about the safety of a rapid sequence induction. It allows for a more stable and controlled induction of anesthesia. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Application of behavioral economic strategies to enhance recruitment into a pediatric randomized clinical trial for postoperative pain relief: A randomized clinical trial.
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Karthic, Anitra, Orgil, Zandantsetseg, Tram, Nguyen K., Rice‐Weimer, Julie, Stevens, Jack, and Olbrecht, Vanessa A.
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ANALGESIA ,CLINICAL trials ,POSTOPERATIVE pain treatment ,POSTOPERATIVE pain ,VIRTUAL reality ,PATIENT selection - Abstract
Introduction: A major challenge in conducting clinical trials is recruitment. Trial under‐enrollment leads to underpowered studies. Behavioral economics offers strategies that may enhance trial recruitment. This study assessed the impact of behavioral economic strategies versus a standard biological approach to recruit children into a randomized clinical trial assessing a biofeedback‐based virtual reality intervention for postoperative pain management. We hypothesized the behavioral economics‐informed approach would increase enrollment into the future trial, intention to adhere to therapy, acceptability of the intervention, and perceived efficacy while decreasing perception of treatment burden and risk. Methods: This single‐center, prospective, randomized trial recruited patients 12‐18 years old undergoing surgery requiring postoperative admission and narcotic administration. Patient‐parent dyads were randomized to watch a behavioral economics‐informed (n = 64) or standard biological (n = 66) recruitment video about a study designed to assess impact of a virtual reality pain management intervention. Results: There was no difference in rates of intention to enroll in the study between groups (behavioral economics: 75%, control: 79%, p = 0.744) or in median response scores to questions regarding intention to adhere to therapy (4.0 [3.0, 4.0] vs. 4.0 [3.0, 4.0], p=0.084), acceptability of therapy (4.0 [3.0, 4.0] vs. 4.0 [3.0, 4.0], p = 0.376), perceptions of treatment burden (3.0 [3.0, 4.0] vs. 4.0 [3.0, 4.0], p=0.251), and efficacy (3.0 [3.0, 4.0] vs. 3.0 [3.0, 4.0], p = 0.914). Patients in the behavioral economics group were less likely to perceive risk associated with virtual reality versus the control group (behavioral economics: 2.0 [1.0, 2.0], control: 2.0 [2.0, 3.0], p = 0.023). Discussion: A behavioral economics‐informed video did not increase patients' intentions to enroll into a clinical trial assessing the impact of virtual reality intervention for postoperative pain management. Conclusion: Either approach would be sufficient for patient recruitment for this type of clinical trial since the overall intention to enroll rate was 77%. [ABSTRACT FROM AUTHOR]
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- 2023
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10. Impact of opioid law on prescriptions and satisfaction of pediatric burn and orthopedic patients: An epidemiologic study.
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Armstrong, Megan, Groner, Jonathan I., Samora, Julie, Olbrecht, Vanessa A., Tram, Nguyen K., Noffsinger, Dana, Boyer, Edward W., and Xiang, Henry
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OPIOIDS ,SATISFACTION ,BURN patients ,CONVENIENCE sampling (Statistics) ,TIME series analysis ,PATIENT satisfaction - Abstract
Objectives: The objective of this study was to determine the reduction in prescribed opioid pain dosage units to pediatric patients experiencing acute pain and to assess patient satisfaction with pain control 90-day post discharge following the 2017 Ohio opioid prescribing cap law. Methods: The retrospective chart review included 960 pediatric (age 0–18 years) burn injury and knee arthroscopy patients treated between August 1, 2015-August 31, 2019. Prospectively, legal guardians completed a survey for a convenience sample of 50 patients. Opioid medications (days and morphine milligram equivalents (MMEs)/kg) prescribed at discharge before and after the Ohio law implementation were collected. Guardians reported experience and satisfaction with their child's opioid prescription at 90-days post discharge. Results: From pre-law to post-law, there was a significant decrease (p<0.001) within the burn and knee cohorts in the median days (1.7 to 1.0 and 5.0 to 3.8, respectively) and median total MMEs prescribed (15.0 to 2.5 and 150.0 to 90.0, respectively). An interrupted time series analysis revealed a statistically significant decrease in MMEs/kg and days prescribed at discharge when the 2017 Ohio opioid prescription law went into effect, with an abrupt level change. Prospectively, more than half of participants were satisfied (72% burn and 68% knee) with their pain control and felt they received the right amount of medication (84% burn and 56% knee). Inpatient opioid use was not changed pre- and post-law. Conclusions: Discharge opioids prescribed for pediatric burn and knee arthroscopy procedures has decreased from 2015–2019. Caregivers varied greatly in their satisfaction with pain control and the amount of opioid prescribed. [ABSTRACT FROM AUTHOR]
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- 2023
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11. Efficacy of an expanded preoperative survey during perioperative care to identify illicit substance use in teenagers and adolescents.
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Stone, Katelynn, Rice‐Weimer, Julie, Tram, Nguyen K., and Tobias, Joseph D.
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OPERATING room nursing ,SUBSTANCE abuse ,PERIOPERATIVE care ,TOBACCO use ,CHILD patients ,CHILDREN'S hospitals - Abstract
Background: As illicit substance use can present several perioperative concerns, effective means to identify such practices are necessary to ensure patient safety. Identification of illicit substance use in pediatric patients may be problematic as screening may rely on parental reporting. Aims: The current study compares answers regarding use of illicit substances between a survey completed by the patient and the preoperative survey completed by parents or guardians. Methods: The study included patients presenting for surgery at Nationwide Children's Hospital, ranging in age from 12 to 21 years. After consent, patients completed a survey of six drop‐down questions using an iPad. The six questions involved the patient's history of alcohol, tobacco, marijuana, vaping, and opioid use. The results were compared to the answers obtained from the parents during a preoperative phone call. Results: The study cohort included surveys from 250 patients with a median age of 16 years. Survey data showed a statistically higher reporting of substance use or abuse from the patient study survey in comparison to the routine parental preoperative survey. Alcohol report rates were highest with 69 (27.6%) patients reporting use compared to only 5 parental reports (2%). There was a similar discrepancy in reported rates of vaping use (40 patient reports, 16.0% vs. 11 parental reports, 4.4%) and illicit substance use including marijuana (52 patient reports, 20.8% vs. 11 parental reports, 4.4%). Reported rates of tobacco use were lowest among the survey responses with 12 patient reports (4.8%) and 5 parental reports (2.0%). Conclusions: Identifying illicit substance and tobacco use via a phone survey of parents is inaccurate and does not allow for proper identification of use of these substances in patients ≤21 years of age presenting for surgery. An anonymous 2‐min survey completed by the patient more correctly identifies these issues. [ABSTRACT FROM AUTHOR]
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- 2023
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12. A ROTEM-guided algorithm aimed to reduce blood product utilization during neonatal and infant cardiac surgery.
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Naguib, Aymen N., Carrillo, Sergio A., Corridore, Marco, Bigelow, Amee M., Walczak, Ashley, Tram, Nguyen K., Hersey, Diane, Galantowicz, Mark, and Tobias, Joseph D.
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COMPUTER algorithms ,NEWBORN infants ,CARDIAC surgery ,THROMBELASTOGRAPHY ,BLOOD products - Abstract
Background: Neonates and infants undergoing cardiac surgery tend to receive high volumes of blood products. The use of rotational thromboelastometry (ROTEM®) has been shown to reduce the administration of blood products in adults after cardiac surgery. We sought to develop a targeted administration of blood products based on ROTEM® to reduce blood product utilization during and after neonatal and infant cardiac surgery. Methods: We conducted a retrospective review of data from a single center for neonates and infants undergoing congenital cardiac surgery using cardiopulmonary bypass (CPB) from September 2018-April 2019 (control group). Then, using a ROTEM® algorithm, we collected data prospectively between April-November 2021 (ROTEM group). Data collected included age, weight, gender, procedure, STAT score, CPB time, aortic cross-clamp time, volume, and type of blood products administered in the operating room and cardiothoracic intensive care unit (CTICU). In addition, ROTEM® data, coagulation profile in CTICU, chest tube output at 6 and 24 hours, use of factors concentrate, and thromboembolic complications were recorded. Results: The final cohort of patients included 28 patients in the control group and 40 patients in the ROTEM group. The cohort included neonates and infants undergoing the following procedures: arterial switch, aortic arch augmentation, Norwood procedure, and comprehensive stage II procedure. There were no differences in the demographics or procedure complexity between the two groups. Patients in the ROTEM® group received fewer platelets (36 ± 12 vs. 49 ± 27 mL/kg, p 0.028) and cryoprecipitate (8 ± 3 vs. 15 ± 10 mL/kg, p 0.001) intraoperatively when compared to the control group. Conclusion: The utilization of ROTEM® may have contributed to a significant reduction in some blood product administration during cardiac surgery for infants and neonates. ROTEM® data may play a role in reducing blood product administration in neonatal and infant cardiac surgery. [ABSTRACT FROM AUTHOR]
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- 2023
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13. Childhood obesity trends: Association with same‐day hospital admission in a National Outpatient Surgical Population.
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Tram, Nguyen K., Mpody, Christian, Owusu‐Bediako, Kwaku, Murillo‐Deluquez, Marcelino E., Tobias, Joseph D., and Nafiu, Olubukola O.
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CHILDHOOD obesity , *AMBULATORY surgery , *ELECTIVE surgery , *PUBLIC hospitals , *HOSPITAL admission & discharge , *OVERWEIGHT children , *LENGTH of stay in hospitals - Abstract
Background: Although the prevalence of obesity in the general population and its perioperative implications among children undergoing inpatient surgeries are well known, little is known about obesity prevalence among children scheduled for ambulatory surgery. Aims: Here, we report the trends of obesity and severe obesity among children who underwent ambulatory surgery across multiple centers in the United States and explore the association of obesity status with admission following elective ambulatory surgery. Materials and Methods: Using data from the American College of Surgeons National Surgical Quality Improvement Program‐Pediatric (2012–2019), we selected children 2–18 years old who underwent outpatient surgical procedures under general anesthesia and had documented height, weight, and body mass index (BMI) data. We estimated the prevalence of overweight, obesity (class 1), and severe obesity (class 2 and class 3) patients and explored their association with same‐day hospital admission, defined as hospital length of stay ≥1 day. Results: Data from 152 918 children (mean age: 9.7 ± 4.7 years) were analyzed. Of these, 16.4% (n = 25 007) were overweight, 13.8% (n = 21 085) were class 1 obese, 5.2% (n = 7879) were class 2 obese, and 3.0% (n = 4623) were class 3 obese. From 2012 to 2019, class 2 or 3 obesity prevalence increased by 26.7% and 32.5%, respectively. Overweight and obese children had relatively higher odds of same‐day hospital admission compared to healthy weight children (overweight odds ratio [95% confidence interval]: 1.05 [1.02, 1.08]; class 1 obesity: 1.04 [1.00, 1.07]; class 2 obesity: 1.09 [1.02, 1.16]; class 3 obesity: 1.20 [1.11, 1.30]). Discusion and Conclusion: The burden of obesity continues to increase in children scheduled for ambulatory surgery. Children with class 2 and class 3 obesity have higher rates of same‐day hospital admission following elective ambulatory surgery compared to healthy weight children, a factor that should be considered in scheduling these patients. [ABSTRACT FROM AUTHOR]
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- 2023
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14. A Multimodal Approach to Quantify Chondrocyte Viability for Airway Tissue Engineering.
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Chan, Coreena, Liu, Lumei, Dharmadhikari, Sayali, Shontz, Kimberly M., Tan, Zheng Hong, Bergman, Maxwell, Shaffer, Terri, Tram, Nguyen K., Breuer, Christopher K., Stacy, Mitchel R., and Chiang, Tendy
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Objectives/Hypothesis: Partially decellularized tracheal scaffolds have emerged as a potential solution for long‐segment tracheal defects. These grafts have exhibited regenerative capacity and the preservation of native mechanical properties resulting from the elimination of all highly immunogenic cell types while sparing weakly immunogenic cartilage. With partial decellularization, new considerations must be made about the viability of preserved chondrocytes. In this study, we propose a multimodal approach for quantifying chondrocyte viability for airway tissue engineering. Methods: Tracheal segments (5 mm) were harvested from C57BL/6 mice, and immediately stored in phosphate‐buffered saline at −20°C (PBS‐20) or biobanked via cryopreservation. Stored and control (fresh) tracheal grafts were implanted as syngeneic tracheal grafts (STG) for 3 months. STG was scanned with micro‐computed tomography (μCT) in vivo. STG subjected to different conditions (fresh, PBS‐20, or biobanked) were characterized with live/dead assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and von Kossa staining. Results: Live/dead assay detected higher chondrocyte viability in biobanked conditions compared to PBS‐20. TUNEL staining indicated that storage conditions did not alter the proportion of apoptotic cells. Biobanking exhibited a lower calcification area than PBS‐20 in 3‐month post‐implanted grafts. Higher radiographic density (Hounsfield units) measured by μCT correlated with more calcification within the tracheal cartilage. Conclusions: We propose a strategy to assess chondrocyte viability that integrates with vivo imaging and histologic techniques, leveraging their respective strengths and weaknesses. These techniques will support the rational design of partially decellularized tracheal scaffolds. Level of Evidence: N/A Laryngoscope, 133:512–520, 2023 [ABSTRACT FROM AUTHOR]
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- 2023
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15. The Roles of Vitreous Biomechanics in Ocular Disease, Biomolecule Transport, and Pharmacokinetics.
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Luo, Richard H., Tram, Nguyen K., Parekh, Ankur M., Puri, Raima, Reilly, Matthew A., and Swindle-Reilly, Katelyn E.
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VITREOUS humor , *MACULA lutea , *ZOOLOGICAL specimens , *PHARMACOKINETICS , *BIOMECHANICS , *PROLIFERATIVE vitreoretinopathy - Abstract
The biomechanical properties of the vitreous humor and replication of these properties to develop substitutes for the vitreous humor have rapidly become topics of interest over the last two decades. In particular, the behavior of the vitreous humor as a viscoelastic tissue has been investigated to identify its role in a variety of processes related to biotransport, aging, and age-related pathologies of the vitreoretinal interface. A thorough search and review of peer-reviewed publications discussing the biomechanical properties of the vitreous humor in both human and animal specimens was conducted. Findings on the effects of biomechanics on vitreoretinal pathologies and vitreous biotransport were analyzed and discussed. The pig and rabbit vitreous have been found to be most mechanically similar to the human vitreous. Age-related liquefaction of the vitreous creates two mechanically unique phases, with an overall effect of softening the vitreous. However, the techniques used to acquire this mechanical data are limited by the in vitro testing methods used, and the vitreous humor has been hypothesized to behave differently in vivo due in part to its swelling properties. The impact of liquefaction and subsequent detachment of the vitreous humor from the posterior retinal surface is implicated in a variety of tractional pathologies of the retina and macula. Liquefaction also causes significant changes in the biotransport properties of the eye, allowing for significantly faster movement of molecules compared to the healthy vitreous. Recent developments in computational and ex vivo models of the vitreous humor have helped with understanding its behavior and developing materials capable of replacing it. A better understanding of the biomechanical properties of the vitreous humor and how these relate to its structure will potentially aid in improving clinical metrics for vitreous liquefaction, design of biomimetic vitreous substitutes, and predicting pharmacokinetics for intravitreal drug delivery. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Macro- and Microscale Properties of the Vitreous Humor to Inform Substitute Design and Intravitreal Biotransport.
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Tram, Nguyen K., Maxwell, Courtney J., and Swindle-Reilly, Katelyn E.
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VITREOUS humor , *RETINA , *MAGNITUDE (Mathematics) - Abstract
Research on the vitreous humor and development of hydrogel vitreous substitutes have gained a rapid increase in interest within the past two decades. However, the properties of the vitreous humor and vitreous substitutes have yet to be consolidated. In this paper, the mechanical properties of the vitreous humor and hydrogel vitreous substitutes were systematically reviewed. The number of publications on the vitreous humor and vitreous substitutes over the years, as well as their respective testing conditions and testing techniques were analyzed. The mechanical properties of the human vitreous were found to be most similar to the vitreous of pigs and rabbits. The storage and loss moduli of the hydrogel vitreous substitutes developed were found to be orders of magnitude higher in comparison to the native human vitreous. However, the reported modulus for human vitreous, which was most commonly tested in vitro, has been hypothesized to be different in vivo. Future studies should focus on testing the mechanical properties of the vitreous in situ or in vivo. In addition to its mechanical properties, the vitreous humor has other biotransport mechanisms and biochemical functions that establish a redox balance and maintain an oxygen gradient inside the vitreous chamber to protect intraocular tissues from oxidative damage. Biomimetic hydrogel vitreous substitutes have the potential to provide ophthalmologists with additional avenues for treating and controlling vitreoretinal diseases while preventing complications after vitrectomy. Due to the proximity and interconnectedness of the vitreous humor to other ocular tissues, particularly the lens and the retina, more interest has been placed on understanding the properties of the vitreous humor in recent years. A better understanding of the properties of the vitreous humor will aid in improving the design of biomimetic vitreous substitutes and enhancing intravitreal biotransport. [ABSTRACT FROM AUTHOR]
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- 2021
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17. Glutathione Improves the Antioxidant Activity of Vitamin C in Human Lens and Retinal Epithelial Cells: Implications for Vitreous Substitutes.
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Tram, Nguyen K., McLean, Rayna M., and Swindle-Reilly, Katelyn E.
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VITAMIN C , *EPITHELIAL cells , *ANTIOXIDANTS , *VITREOUS humor , *GLUTATHIONE , *ELLAGIC acid - Abstract
Tissues in the eye are particularly susceptible to oxidative damage due to light exposure. While vitamin C (ascorbic acid) has been noted as a vital antioxidant in the vitreous humor, its physiological concentration (1–2 mM) has been shown to be toxic to retinal and lens epithelial cells in in vitro cell culture. We have explored adding vitamin C to hydrogel vitreous substitutes as a potential therapeutic to prevent oxidative damage to intraocular tissues after vitrectomy. However, vitamin C degrades rapidly even when loaded at high concentrations, limiting its long-term effectiveness. Glutathione, another antioxidant found abundantly in the lens at concentrations of 2–10 mM, was proposed to be used in conjunction with vitamin C. Cell viability and reactive oxygen species activity of human retinal and lens epithelial cells treated with various combinations of vitamin C, glutathione, hydrogen peroxide, and a hydrogel vitreous substitute were determined using CellTiter-Glo luminescent cell viability assay and dichlorofluorescein assay, respectively. The vitamin C remaining in hydrogel vitreous substitute or glutathione-vitamin C solutions was determined using a microplate reader at 265 nm wavelength, compared against standard solutions with known concentrations. Glutathione protected the lens and retinal cells from the negative effect of vitamin C on cell viability and prolonged the antioxidant effect of vitamin C in vitro. While the detected reading of pure vitamin C solution decreased rapidly from 100% to 10% by 3 days, glutathione provided a significant extension to vitamin C stability, with 70% remaining after 14 days when the glutathione was used at physiological concentrations found in the lens (2–10 mM). These results indicate glutathione might be an effective addition to vitamin C in intraocular implants, including potential vitreous substitutes, and warrants additional studies on the effectiveness of the vitamin C – glutathione combination in preventing oxidative stress post-vitrectomy. [ABSTRACT FROM AUTHOR]
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- 2021
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18. Dual assessment of abnormal microvascular foot perfusion and lower extremity calcium burden in a patient with critical limb ischemia using hybrid SPECT/CT imaging.
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Chou, Ting-Heng, Tram, Nguyen K, Eisert, Susan Natalie, Bobbey, Adam J, Atway, Said A, Go, Michael R, and Stacy, Mitchel R
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COMPUTED tomography , *SINGLE-photon emission computed tomography , *HYPERPERFUSION , *PERFUSION , *TRAUMATIC amputation , *TIBIAL arteries , *CALCIUM - Abstract
Radiotracer imaging allows for noninvasive detection and quantification of abnormalities in angiosome foot perfusion in diabetic patients with critical limb ischemia and nonhealing wounds. A 60-year-old male presented with critical limb ischemia (CLI), which was associated with second toe gangrene of the left foot (Panel A-1), a left limb ankle-brachial index (ABI) of 0.65, and bilateral claudication. [Extracted from the article]
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- 2021
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19. Independent control of matrix adhesiveness and stiffness within a 3D self-assembling peptide hydrogel.
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Hogrebe, Nathaniel J., Reinhardt, James W., Tram, Nguyen K., Debski, Anna C., Agarwal, Gunjan, Reilly, Matthew A., and Gooch, Keith J.
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STIFFNESS (Mechanics) ,HYDROGELS ,PEPTIDES ,CELL differentiation ,MESENCHYMAL stem cells - Abstract
A cell’s insoluble microenvironment has increasingly been shown to exert influence on its function. In particular, matrix stiffness and adhesiveness strongly impact behaviors such as cell spreading and differentiation, but materials that allow for independent control of these parameters within a fibrous, stromal-like microenvironment are very limited. In the current work, we devise a self-assembling peptide (SAP) system that facilitates user-friendly control of matrix stiffness and RGD (Arg-Gly-Asp) concentration within a hydrogel possessing a microarchitecture similar to stromal extracellular matrix. In this system, the RGD-modified SAP sequence KFE-RGD and the scrambled sequence KFE-R DG can be directly swapped for one another to change RGD concentration at a given matrix stiffness and total peptide concentration. Stiffness is controlled by altering total peptide concentration, and the unmodified base peptide KFE-8 can be included to further increase this stiffness range due to its higher modulus. With this tunable system, we demonstrate that human mesenchymal stem cell morphology and differentiation are influenced by both gel stiffness and the presence of functional cell binding sites in 3D culture. Specifically, cells 24 hours after encapsulation were only able to spread out in stiffer matrices containing KFE-RGD. Upon addition of soluble adipogenic factors, soft gels facilitated the greatest adipogenesis as determined by the presence of lipid vacuoles and PPARγ-2 expression, while increasing KFE-RGD concentration at a given stiffness had a negative effect on adipogenesis. This three-component hydrogel system thus allows for systematic investigation of matrix stiffness and RGD concentration on cell behavior within a fibrous, three-dimensional matrix. Statement of Significance Physical cues from a cell’s surrounding environment—such as the density of cell binding sites and the stiffness of the surrounding material—are increasingly being recognized as key regulators of cell function. Currently, most synthetic biomaterials used to independently tune these parameters lack the fibrous structure characteristic of stromal extracellular matrix, which can be important to cells naturally residing within stromal tissues. In this manuscript, we describe a 3D hydrogel encapsulation system that provides user-friendly control over matrix stiffness and binding site concentration within the context of a stromal-like microarchitecture. Binding site concentration and gel stiffness both influenced cell spreading and differentiation, highlighting the utility of this system to study the independent effects of these material properties on cell function. [ABSTRACT FROM AUTHOR]
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- 2018
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20. Prognostic Value of Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging for Predicting Venous Thromboembolism in Children With Lymphoma.
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Beall, Maren, Deep, Kyra, Tram, Nguyen K., Nabavinia, Mahboubeh, Janse, Sarah A., Chou, Ting-Heng, Hardisky, Dariya, Bobbey, Adam J., Kerlin, Bryce A., Audino, Anthony N., and Stacy, Mitchel R.
- Abstract
Background: Positron emission tomography (PET)/computed tomography (CT) imaging can detect changes in arterial inflammation, but has not been used to evaluate chemotherapy-induced venous inflammation or assess risk for venous thromboembolism (VTE) in pediatric oncology. Therefore, the purpose of this study was to evaluate the prognostic value of fluorine-18-fluorodeoxyglucose PET/CT imaging of venous inflammation for predicting VTE occurrence in the 12 months after lymphoma diagnosis in pediatric, adolescent, and young adult patients. Methods: Pediatric, adolescent, and young adult patients with lymphoma diagnoses (n=71) who underwent whole-body PET/CT imaging at initial staging of disease and first therapeutic follow-up were retrospectively evaluated for serial changes in lower extremity venous uptake of fluorine-18-fluorodeoxyglucose. PET/CT images were used to segment and quantify serial changes in fluorine-18-fluorodeoxyglucose uptake for veins of interest (ie, popliteal and femoral). Incidence of VTE was assessed for 12 months after lymphoma diagnosis. Results: PET/CT detected a significantly higher inflammatory response in the femoral (P =0.012) and popliteal (P =0.013) veins of patients who experienced a VTE event compared with those who remained VTE free in the 12 months after diagnosis. The area under the curve values for receiver operator characteristics analyses were 0.76 (femoral vein) and 0.77 (popliteal vein) based on incidence of VTE occurrence. Univariate analyses demonstrated that PET/CT-derived changes in femoral (P =0.008) and popliteal (P =0.002) vein inflammation were significantly associated with VTE-free survival at 12 months after diagnosis. Conclusions: Fluorine-18-fluorodeoxyglucose PET/CT imaging detects treatment-induced venous toxicity that may provide insight into risk of VTE events in pediatric and adolescent and young adult patients with lymphoma. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
- View/download PDF
21. A Hydrogel Vitreous Substitute that Releases Antioxidant.
- Author
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Tram, Nguyen K., Jiang, Pengfei, Torres‐Flores, Tiara C., Jacobs, Kane M., Chandler, Heather L., and Swindle‐Reilly, Katelyn E.
- Published
- 2020
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