1.Fat Graft with Allograft Adipose Matrix and Magnesium Hydroxide-Incorporated PLGA Microspheres for Effective Soft Tissue Reconstruction
Dae-Hee KIM ; Da-Seul KIM ; Hyun-Jeong HA ; Ji-Won JUNG ; Seung-Woon BAEK ; Seung Hwa BAEK ; Tae-Hyung KIM ; Jung Chan LEE ; Euna HWANG ; Dong Keun HAN
Tissue Engineering and Regenerative Medicine 2022;19(3):553-563
BACKGROUND:
Autologous fat grafting is one of the most common procedures used in plastic surgery to correct soft tissue deficiency or depression deformity. However, its clinical outcomes are often suboptimal, and lack of metabolic and architectural support at recipient sites affect fat survival leading to complications such as cyst formation, calcification.Extracellular matrix-based scaffolds, such as allograft adipose matrix (AAM) and poly(lactic-co-glycolic) acid (PLGA), have shown exceptional clinical promise as regenerative scaffolds. Magnesium hydroxide (MH), an alkaline ceramic, has attracted attention as a potential additive to improve biocompatibility. We attempted to combine fat graft with regenerative scaffolds and analyzed the changes and viability of injected fat graft in relation to the effects of injectable natural, and synthetic (PLGA/MH microsphere) biomaterials.
METHODS:
In vitro cell cytotoxicity, angiogenesis of the scaffolds, and wound healing were evaluated using human dermal fibroblast cells. Subcutaneous soft-tissue integration of harvested fat tissue was investigated in vivo in nude mouse with random fat transfer protocol Fat integrity and angiogenesis were identified by qRT-PCR and immunohistochemistry.
RESULTS:
In vitro cell cytotoxicity was not observed both in AAM and PLGA/MH with human dermal fibroblast.PLGA/MH and AAM showed excellent wound healing effect. in vivo, the AAM and PLGA/MH retained volume compared to that in the only fat group. And the PLGA/MH showed the highest angiogenesis and anti-inflammation.
CONCLUSION
In this study, a comparison of the volume retention effect and angiogenic ability between autologous fat grafting, injectable natural, and synthetic biomaterials will provide a reasonable basis for fat grafting.
2.Humulus japonicus attenuates LPS-and scopolamine-induced cognitive impairment in mice
Jun GO ; Hye-Yeon PARK ; Da Woon LEE ; So-Young MAENG ; In-Bok LEE ; Yun Jeong SEO ; Jin-Pyo AN ; Won Keun OH ; Chul-Ho LEE ; Kyoung-Shim KIM
Laboratory Animal Research 2022;38(3):159-168
Background:
Neuroinflammation plays an important role in cognitive decline and memory impairment in neurodegenerative disorders. Previously, we demonstrated that Humulus japonicus (HJ) has anti-inflammatory effects in rodent models of Alzheimer’s disease and Parkinson’s disease. The present study aimed to examine the protective potential of HJ extracts against lipopolysaccharide (LPS)-induced cognitive impairment and scopolamine-induced amnesia in mouse models. Cognitive improvement of mice was investigated by novel object recognition test. For analyzing effects on neuroinflammation, immunohistochemistry and quantitative real-time polymerase chain reaction (qRTPCR) assays were performed.
Results:
We found that the oral administration of HJ significantly improved cognitive dysfunction induced by LPS in a novel object recognition test. The LPS-induced activation of microglia was notably decreased by HJ treatment in the cortex and hippocampus. HJ administration with LPS also significantly increased the mRNA expression of interleukin (IL)-10 and decreased the mRNA expression of IL-12 in the parietal cortex of mice. The increased expression of LPS-induced complement C1q B chain (C1bq) and triggering receptor expressed on myeloid cells 2 (Trem2) genes was significantly suppressed by HJ treatment. In addition, HJ administration significantly improved novel object recognition in a scopolamine-induced amnesia mouse model.
Conclusions
These findings revealed that HJ has a beneficial effect on cognitive impairment and neuroinflammation induced by systemic inflammation and on amnesia induced by scopolamine in mice.
3.Apixaban versus Warfarin in Patients with Chronic Kidney Disease; A Systematic Review and Meta-analysis
Jae Hyun NAM ; Chae Young KIM ; Yoo Kyung LEE ; Da Woom JUNG ; Hye Young GWAK ; Jee Eun CHUNG
Korean Journal of Clinical Pharmacy 2021;31(2):87-95
Background:
Patients with chronic kidney disease (CKD) are at a high risk of stroke-related morbidity, mortality, and bleeding. However, the overall risk/benefit of anticoagulant therapy among patients with CKD remains unclear.
Methods:
The MEDLINE, EMBASE, and CENTRAL databases were comprehensively searched until July 31, 2020, to investigate the safety and efficacy of apixaban in patients with stage 4 or 5 CKD, as compared with warfarin. The primary outcome was an incidence of major bleeding. Secondary outcomes included composite bleeding (major, clinically relevant, and minor bleeding), venous thromboembolism (VTE), stroke, and death.
Results:
In total, seven studies consisting of 10,816 patients were included. Compared with warfarin, apixaban was associated with a reduced risk of major bleeding (OR 0.49, 95% CI 0.41-0.58). In terms of composite bleeding, apixaban tended to pose a significantly lower risk than warfarin (OR 0.51, 95% CI 0.37-0.71). There was no difference between apixaban and warfarin with respect to the risk of stroke or death (stroke: OR 1.23, 95% CI 0.49-3.12; death: OR 0.73, 95% CI 0.45-1.18).
Conclusion
Among patients with stage 4 or 5 CKD, the use of apixaban was associated with a lower risk of bleeding compared to warfarin and was also found to pose no excess risk of thromboembolic events.
4.A comparative study on intraocular pressure under various anesthetics in cynomolgus monkeys (Macaca fascicularis)
Hong-Soo LEE ; Da-Hee KIM ; Sung-Hwan KIM ; Min-Sung KANG ; Han Na SUH
Laboratory Animal Research 2021;37(2):112-115
Background:
Nonhuman primates (NHPs) are superior model for ocular research due to its morphological and physiological similarities with humans. Thus, the effect of four different anesthetic combinations [ketamine (10 mg/ kg), ketamine + xylazine (7 + 0.6 mg/kg), zoletil (4 mg/kg), and zoletil + xylazine (4 + 0.2 mg/kg)] on intraocular pressure (IOP) was determined in cynomolgus monkeys.
Results:
The administration of ketamine + xylazine or zoletil + xylazine resulted in lower IOP compared to ketamine or zoletil alone. Moreover, the IOP in male monkeys was higher than in females. The difference between the right and left eye was not found.
Conclusions
Anesthetics affected the IOP, and gender differences should be considered when measuring the IOP of nonhuman primates (NHPs).
5.Application of an Intraoperative Neuromonitoring System Using a Surface Pressure Sensor in Parotid Surgery: A Rabbit Model Study
Eui-Suk SUNG ; Hyun-Keun KWON ; Sung-Chan SHIN ; Young-Il CHEON ; Jung-Woo LEE ; Da-Hee PARK ; Seong-Wook CHOI ; Hwa-Bin KIM ; Hye-Jin PARK ; Jin-Choon LEE ; Jung-Hoon RO ; Byung-Joo LEE
Clinical and Experimental Otorhinolaryngology 2021;14(1):131-136
Objectives:
. Facial nerve monitoring (FNM) can be used to identify the facial nerve, to obtain information regarding its course, and to evaluate its status during parotidectomy. However, there has been disagreement regarding the efficacy of FNM in reducing the incidence of facial nerve palsy during parotid surgery. Therefore, instead of using electromyography (EMG) to identify the location and state of the facial nerve, we applied an intraoperative neuromonitoring (IONM) system using a surface pressure sensor to detect facial muscle twitching. The objective of this study was to investigate the feasibility of using the IONM system with a surface pressure sensor to detect facial muscle twitching during parotidectomy.
Methods:
. We evaluated the stimulus thresholds for the detection of muscle twitching in the orbicularis oris and orbicularis oculi, as well as the amplitude and latency of EMG and the surface pressure sensor in 13 facial nerves of seven rabbits, using the same stimulus intensity.
Results:
. The surface pressure sensor detected muscle twitching in the orbicularis oris and orbicularis oculi in response to a stimulation of 0.1 mA in all 13 facial nerves. The stimulus threshold did not differ between the surface pressure sensor and EMG.
Conclusion
. The application of IONM using a surface pressure sensor during parotidectomy is noninvasive, reliable, and feasible. Therefore, the IONM system with a surface pressure sensor to measure facial muscle twitching may be an alternative to EMG for verifying the status of the facial nerve.
6.Apixaban versus Warfarin in Patients with Chronic Kidney Disease; A Systematic Review and Meta-analysis
Jae Hyun NAM ; Chae Young KIM ; Yoo Kyung LEE ; Da Woom JUNG ; Hye Young GWAK ; Jee Eun CHUNG
Korean Journal of Clinical Pharmacy 2021;31(2):87-95
Background:
Patients with chronic kidney disease (CKD) are at a high risk of stroke-related morbidity, mortality, and bleeding. However, the overall risk/benefit of anticoagulant therapy among patients with CKD remains unclear.
Methods:
The MEDLINE, EMBASE, and CENTRAL databases were comprehensively searched until July 31, 2020, to investigate the safety and efficacy of apixaban in patients with stage 4 or 5 CKD, as compared with warfarin. The primary outcome was an incidence of major bleeding. Secondary outcomes included composite bleeding (major, clinically relevant, and minor bleeding), venous thromboembolism (VTE), stroke, and death.
Results:
In total, seven studies consisting of 10,816 patients were included. Compared with warfarin, apixaban was associated with a reduced risk of major bleeding (OR 0.49, 95% CI 0.41-0.58). In terms of composite bleeding, apixaban tended to pose a significantly lower risk than warfarin (OR 0.51, 95% CI 0.37-0.71). There was no difference between apixaban and warfarin with respect to the risk of stroke or death (stroke: OR 1.23, 95% CI 0.49-3.12; death: OR 0.73, 95% CI 0.45-1.18).
Conclusion
Among patients with stage 4 or 5 CKD, the use of apixaban was associated with a lower risk of bleeding compared to warfarin and was also found to pose no excess risk of thromboembolic events.
7.A comparative study on intraocular pressure under various anesthetics in cynomolgus monkeys (Macaca fascicularis)
Hong-Soo LEE ; Da-Hee KIM ; Sung-Hwan KIM ; Min-Sung KANG ; Han Na SUH
Laboratory Animal Research 2021;37(2):112-115
Background:
Nonhuman primates (NHPs) are superior model for ocular research due to its morphological and physiological similarities with humans. Thus, the effect of four different anesthetic combinations [ketamine (10 mg/ kg), ketamine + xylazine (7 + 0.6 mg/kg), zoletil (4 mg/kg), and zoletil + xylazine (4 + 0.2 mg/kg)] on intraocular pressure (IOP) was determined in cynomolgus monkeys.
Results:
The administration of ketamine + xylazine or zoletil + xylazine resulted in lower IOP compared to ketamine or zoletil alone. Moreover, the IOP in male monkeys was higher than in females. The difference between the right and left eye was not found.
Conclusions
Anesthetics affected the IOP, and gender differences should be considered when measuring the IOP of nonhuman primates (NHPs).
8.Application of Novel Intraoperative Neuromonitoring System Using an Endotracheal Tube With Pressure Sensor during Thyroid Surgery: A Porcine Model Study
Eui-Suk SUNG ; Sung-Chan SHIN ; Hyun-Keun KWON ; Jia KIM ; Da-Hee PARK ; Seong-Wook CHOI ; Sang-Hoon KIM ; Jin-Choon LEE ; Jung-Hoon RO ; Byung-Joo LEE
Clinical and Experimental Otorhinolaryngology 2020;13(3):291-298
Objectives:
. The loss of signal during intraoperative neuromonitoring (IONM) using electromyography (EMG) in thyroidectomy is one of the biggest problems. We have developed a novel IONM system with an endotracheal tube (ETT) with an attached pressure sensor instead of EMG to detect laryngeal twitching. The aim of the present study was to investigate the feasibility and reliability of this novel IONM system using an ETT with pressure sensor during thyroidectomy in a porcine model.
Methods:
. We developed an ETT-attached pressure sensor that uses the piezoelectric effect to measure laryngeal muscle twitching. Stimulus thresholds, amplitude, and latency of laryngeal twitching evaluated using the pressure sensor were compared to those measured using transcartilage needle EMG. The measured amplitude changes by EMG and the pressure sensor during recurrent laryngeal nerve (RLN) traction injury were compared.
Results:
. No significant differences in stimulus threshold intensity between EMG and the pressure sensor were observed. The EMG amplitude detected at 0.3 mA, increased with increasing stimulus intensity. When the stimulus was more than 1.0 mA, the amplitude showed a plateau. In a RLN traction injury experiment, the EMG amplitude did not recover even 20 minutes after stopping RLN traction. However, the pressure sensor showed a mostly recovery.
Conclusion
. The change in amplitude due to stimulation of the pressure sensor showed a pattern similar to EMG. Pressure sensors can be feasibly and reliably used for RLN traction injury prediction, RLN identification, and preservation through the detection of laryngeal muscle twitching. Our novel IONM system that uses an ETT with an attached pressure sensor to measure the change of surface pressure can be an alternative to EMG in the future.
9.Gaining New Biological and Therapeutic Applications into the Liver with 3D In Vitro Liver Models
Sang Woo LEE ; Da Jung JUNG ; Gi Seok JEONG
Tissue Engineering and Regenerative Medicine 2020;17(6):731-745
BACKGROUND:
Three-dimensional (3D) cell cultures with architectural and biomechanical properties similar to those of natural tissue have been the focus for generating liver tissue. Microarchitectural organization is believed to be crucial to hepatic function, and 3D cell culture technologies have enabled the construction of tissue-like microenvironments, thereby leading to remarkable progress in Vitro models of human tissue and organs. Recently, to recapitulate the 3D architecture of tissues, spheroids and organoids have become widely accepted as new practical tools for 3D organ modeling. Moreover, the combination of bioengineering approach offers the promise to more accurately model the tissue microenvironment of human organs. Indeed, the employment of sophisticated bioengineered liver models show long-term viability and functional enhancements in biochemical parameters and disease-orient outcome.
RESULTS:
Various 3D in Vitro liver models have been proposed as a new generation of liver medicine. Likewise, new biomedical engineering approaches and platforms are available to more accurately replicate the in vivo 3D microarchitectures and functions of living organs. This review aims to highlight the recent 3D in Vitro liver model systems, including micropatterning, spheroids, and organoids that are either scaffold-based or scaffold-free systems. Finally, we discuss a number of challenges that will need to be addressed moving forward in the field of liver tissue engineering for biomedical applications.
CONCLUSION
The ongoing development of biomedical engineering holds great promise for generating a 3D biomimetic liver model that recapitulates the physiological and pathological properties of the liver and has biomedical applications.
10.Outbreak of Cyclosporiasis in Korean Travelers Returning from Nepal
Da-Won MA ; Myoung-Ro LEE ; Bora KU ; Shin-Hyeong CHO ; Sang-Eun LEE
The Korean Journal of Parasitology 2020;58(5):589-592
Cyclospora cayetanensis is an apicomplexan protozoan and is one of the most common pathogens causing chronic diarrhea worldwide. Eight stool samples with diarrheal symptom out of 18 Korean residents who traveled to Nepal were obtained, and examined for 25 enteropathogens including 16 bacterial species, 5 viral species, and 4 protozoans in stool samples as causative agents of water-borne and food-borne disease. Only C. cayetanensis was detected by nested PCR, and 3 PCR-positive samples were sequenced to confirm species identification. However, the oocysts of C. cayetanensis in fecal samples could not be detected by direct microscopy of the stained sample. As far as we know, this is the first report of a group infection with C. cayetanensis from a traveler visiting Nepal, and the second report of a traveler’s diarrhea by C. cayetanensis imported in Korea.

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