1.Contamination level and characterization of Staphyloccocus aureus associated with ready-to-eat foods, food handlers, and environmental factors
Hui Key Lee ; Lay Ching Chai ; Kwai Lin Thong
Malaysian Journal of Microbiology 2019;15(2):95-102
Aims:
Although several major food poisoning outbreaks caused by Staphylococcus aureus have been reported, monitoring of this pathogen is often neglected. The objectives of this study were to assess the contamination level of S. aureus and characterize the S. aureus isolated in ready-to-eat (RTE), food handlers, food contact surfaces, and table cleaning cloths (TCC).
Methodology and results:
A total of 150 RTE foods, 59 food contact surfaces (FCS) and 34 table cleaning cloths (TCC) from food premises were examined. The contamination level of S. aureus in RTE foods was at acceptable level. However, more than 10% of the FCS and TCC were contaminated with high levels of S. aureus (>1.0 Log CFU/cm2, >2.7 Log CFU/piece). Eighty-one isolated S. aureus including those isolated from hands of food handlers were further characterized by antimicrobial susceptibility testing, virulotyping and PFGE. Out of 81 isolates, only three were multidrug resistant. More than 96% (n = 78) of the S. aureus harboured at least one virulence gene. Almost half of the isolates carried at least one staphylococcal enterotoxin in which SEC was the most common enterotoxin detected.
Conclusion, significance and impact of study
The PFGE analysis showed that the S. aureus could be disseminated via the FCS, TCC and the hands of food handlers. Therefore, this study reiterates the importance of proper hand washing, sanitation of FCS and TCC, as well as continuous monitoring on S. aureus in food and the food handlers.
2.Complications after Hip Fracture in Children.
Hui Taek KIM ; Choon Key LEE ; Chong Il YOO
The Journal of the Korean Orthopaedic Association 2000;35(5):719-726
PURPOSE: To analyze complications and their effects on prognoses of children hip fractures. MATERIALS AND METHODS: 26 childhood hip fractures (6 type I, 7 type II, 10 type III, 3 type IV) were studied for 11 years (1986-1997) . We analyzed factors possibly related to complications and their effects on prognoses, especially avascular necrosis (AVN) of the femoral head. RESULTS: Of 26 patients, there were 7 AVN (27%) , 2 nonunions (8%) , 3 coxa vara (12%) , 9 premature epiphyseal closures (35%) , and 2 infections (8%) . Of 7 patients with AVN, 3 patients had type I fracture and 4 patients had type II fracture. No AVN developed in type III and IV fractures. Of 2 patients who had type I fracture with dislocation, all patients had AVN (100%) . Four of 14 patients who had displacement of the fracture site and one in 10 patients who had non-displacement fracture developed AVN. In our study of the incidence of AVN according to surgical reduction time after injury, 3 (60%) of 5 patients who were treated by surgical reduction within 6 hours and 4 (19%) out of 21 patients who were treated by surgical reduction after 6 hours developed AVN. CONCLUSION: In childhood hip fracture, surgical reduction time after trauma (<6 hours) did not seem to be a critical factor in preventing AVN. Force of injury and level of fracture site which jeopardize the blood supply to the femoral head were important factors. Age at time of injury was also important. Containment treatment of younger children (<10 years) and surgical treatment of older children (>10 years) were found to be an effective treatment of AVN. AVN concomitant with pyogenic infection had the worst prognosis.
Child*
;
Containment of Biohazards
;
Coxa Vara
;
Dislocations
;
Head
;
Hip Fractures
;
Hip*
;
Humans
;
Incidence
;
Necrosis
;
Prognosis
3.Indocyanine Green-Loaded PLGA Nanoparticles Conjugated with Hyaluronic Acid Improve Target Specificity in Cervical Cancer Tumors
Seonmin CHOI ; San-Hui LEE ; Sanghyo PARK ; Sun Hwa PARK ; Chaewon PARK ; Jaehong KEY
Yonsei Medical Journal 2021;62(11):1042-1051
Purpose:
Indocyanine green (ICG) is a promising agent for intraoperative visualization of tumor tissues and sentinel lymph nodes in early-stage gynecological cancer. However, it has some limitations, including a short half-life and poor solubility in aqueous solutions. This study aimed to enhance the efficacy of near-infrared (NIR) fluorescence imaging by overcoming the shortcomings of ICG using a nano-drug delivery system and improve target specificity in cervical cancer.
Materials and Methods:
ICG and poly(lactic-co-glycolic acid) (PLGA) conjugated with polyethylenimine (PEI) were assembled to enhance stability. Hyaluronic acid (HA) was coated on PEI-PLGA-ICG nanoparticles to target CD44-positive cancer cells. The manufactured HA-ICG-PLGA nanoparticles (HINPs) were evaluated in vitro and in vivo on cervical cancer cells (SiHa; CD44+) and human dermal cells (ccd986sk; CD44-), respectively, using NIR imaging to compare intracellular uptake and to quantify the fluorescence intensities of cells and tumors.
Results:
HINPs were confirmed to have a mean size of 200 nm and a zeta-potential of 33 mV using dynamic light scattering. The stability of the HINPs was confirmed at pH 5.0–8.0. Cytotoxicity assays, intracellular uptake assays, and cervical cancer xenograft models revealed that, compared to free ICG, the HINPs had significantly higher internalization by cervical cancer cells than normal cells (p<0.001) and significantly higher accumulation in tumors (p<0.001) via CD44 receptor-mediated endocytosis.
Conclusion
This study demonstrated the successful application of HINPs as nanocarriers for delivering ICG to CD44-positive cervical cancer, with improved efficacy in NIR fluorescence imaging.
4.Indocyanine Green-Loaded PLGA Nanoparticles Conjugated with Hyaluronic Acid Improve Target Specificity in Cervical Cancer Tumors
Seonmin CHOI ; San-Hui LEE ; Sanghyo PARK ; Sun Hwa PARK ; Chaewon PARK ; Jaehong KEY
Yonsei Medical Journal 2021;62(11):1042-1051
Purpose:
Indocyanine green (ICG) is a promising agent for intraoperative visualization of tumor tissues and sentinel lymph nodes in early-stage gynecological cancer. However, it has some limitations, including a short half-life and poor solubility in aqueous solutions. This study aimed to enhance the efficacy of near-infrared (NIR) fluorescence imaging by overcoming the shortcomings of ICG using a nano-drug delivery system and improve target specificity in cervical cancer.
Materials and Methods:
ICG and poly(lactic-co-glycolic acid) (PLGA) conjugated with polyethylenimine (PEI) were assembled to enhance stability. Hyaluronic acid (HA) was coated on PEI-PLGA-ICG nanoparticles to target CD44-positive cancer cells. The manufactured HA-ICG-PLGA nanoparticles (HINPs) were evaluated in vitro and in vivo on cervical cancer cells (SiHa; CD44+) and human dermal cells (ccd986sk; CD44-), respectively, using NIR imaging to compare intracellular uptake and to quantify the fluorescence intensities of cells and tumors.
Results:
HINPs were confirmed to have a mean size of 200 nm and a zeta-potential of 33 mV using dynamic light scattering. The stability of the HINPs was confirmed at pH 5.0–8.0. Cytotoxicity assays, intracellular uptake assays, and cervical cancer xenograft models revealed that, compared to free ICG, the HINPs had significantly higher internalization by cervical cancer cells than normal cells (p<0.001) and significantly higher accumulation in tumors (p<0.001) via CD44 receptor-mediated endocytosis.
Conclusion
This study demonstrated the successful application of HINPs as nanocarriers for delivering ICG to CD44-positive cervical cancer, with improved efficacy in NIR fluorescence imaging.
5.Evaluation of Cat Brain Infarction Model Using MicroPET.
Jong Jin LEE ; Dong Soo LEE ; Yun Hui KIM ; Do Won HWANG ; Jin Su KIM ; Sang Moo LIM ; June Key CHUNG ; Myung Chul LEE
Korean Journal of Nuclear Medicine 2004;38(6):528-531
PURPOSE: PET has some disadvantage in the imaging of small animal due to poor resolution. With the advent of microPET scanner, it is possible to image small animals. However, the image quality was not good enough as human image. Due to larger brain, cat brain imaging was superior to mouse or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. MATERIALS AND METHODS: Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCl. A burr hole was made at 1cm right lateral to the bregma. Collagenase type IV 10 microliter was injected using 30 G needle for 5 minutes to establish the infarction model. 18F-FDG microPET (Concorde Microsystems Inc., Knoxville, TN) scans were performed 1, 11 and 32 days after the infarction. In addition, 18F-FDG PET scans were performed using human PET scanner (Gemini, Philips medical systems, CA, USA) 13 and 47 days after the infarction. RESULTS: Two cat brain infarction models were established. The glucose metabolism of an infarction lesion improved with time. An infarction lesion was also distinguishable in the human PET scan. CONCLUSION: We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using 18F-FDG microPET scanner.
Adult
;
Anesthesia
;
Animals
;
Brain Infarction*
;
Brain*
;
Cats*
;
Collagenases
;
Fluorodeoxyglucose F18
;
Glucose
;
Humans
;
Infarction
;
Ketamine
;
Male
;
Metabolism
;
Mice
;
Needles
;
Neuroimaging
;
Positron-Emission Tomography
;
Rats
;
Xylazine
6.Expression of Sodium/iodide Symporter Transgene in Neural Stem Cells.
Yun Hui KIM ; Dong Soo LEE ; Joo Hyun KANG ; Yong Jin LEE ; June Key CHUNG ; Myung Chul LEE
Korean Journal of Nuclear Medicine 2004;38(1):99-108
PURPOSE: The ability to noninvasively track the migration of neural progenitor cells would have significant clinical and research implications. We generated stably transfected F3 human neural progenitor cells with human sodium/iodide symporter (hNIS) for noninvasively tracking F3. In this study, the expression patterns of hNIS gene in F3-NIS were examined according to the cultured time and the epigenetic modulation. MATERIALS AND METHODS: F3 human neural stem cells had been obtained from Dr. Seung U. Kim (Ajou University, Suwon, Korea). hNIS and hygromycin resistance gene were linked with IRES (Internal Ribosome Entry Site) under control of CMV promoter. This construct was transfected to F3 with Liposome. To investigate the restoration of hNIS gene expression in F3-NIS, cells were treated with demethylating agent (5-Azacytidine) and Histone deacetylase inhibitor (Trichostatin A: TSA). The expression of hNIS was measured by I-125 uptake assay and RT-PCR analysis. RESULTS: The iodide uptake of the F3-NIS was higher 12.86 times than F3 cell line. According to the cell passage number, hNIS expression in F3-NIS gradually diminished. After treatment of 5-Azacytidine and TSA with serial doses (up to 20micro M, up to 62.5nM, respectively) for 24 hours, I-125 uptake and mRNA of hNIS in F3-NIS were increased. CONCLUSION: These results suggest that hNIS transfected F3 might undergo a change in its biological characters by cell passage. Therefore, the gene expression of exogenous gene transferred human stem cell might be affected to the epigenetic modulation such as promoter methylation and Histone deacetylation and to the cell culture conditions.
Azacitidine
;
Cell Culture Techniques
;
Cell Line
;
Epigenomics
;
Gene Expression
;
Gyeonggi-do
;
Histone Deacetylase Inhibitors
;
Histones
;
Humans
;
Ion Transport*
;
Liposomes
;
Methylation
;
Neural Stem Cells*
;
Ribosomes
;
RNA, Messenger
;
Stem Cells
;
Transgenes*
7.Development of Dual Reporter System of Mutant Dopamine 2 Receptor (D2R) and Sodium Iodide Symporter (NIS) Transgenes.
Do Won HWANG ; Dong Soo LEE ; Joo Hyun KANG ; Young Soo CHANG ; Yun Hui KIM ; Jae Min JEONG ; June Key CHUNG ; Myung Chul LEE
Korean Journal of Nuclear Medicine 2004;38(4):294-299
PURPOSE: Both human NIS and mutant D2R transgenes are proposed as reporting system in transplanted cell tracking. Using hepatoma cell lines, we constructed a dual reporter system containing human sodium-iodide symporter (hNIS) and dopamine 2 receptor (D2R) and compared its characteristics. MATERIALS AND METHODS: The recombinant plasmid (pIRES-hNIS/D2R) was constructed with IRES (internal ribosome entry site) under control of the CMV promoter. pIRES-hNIS/D2R was transfected to human hepatoma SK-Hep1 cell line with lipofectamine. HEP-ND (SK-Hep1-hNIS/D2R) cells stably expressing hNIS and D2R was established by selection with G418 for two weeks. RT-PCR was performed to investigate the expression of both hNIS and D2R genes. The expressions of hNIS and D2R were measured by 125I uptake assays and receptor binding assays. Specific binding of D2R to [3H]spiperone was verified by Scatchard plot with (+) butaclamol as a specific inhibitor. K (d) and B (max) values were estimated. The correlation between hNIS and D2R expression was compared by using each clone. RESULTS: Similar quantities of hNIS and D2R genes were expressed on HEP-ND as RT-PCR assays. HEP-ND cells showed 30 to 40 fold higher radioiodine uptakes than those of parental SK-Hep1 cells. 125I uptake in HEP-ND cells was completely inhibited by KClO4, a NIS inhibitor. Specific binding to HEP-ND cells was saturable and the K (d) and B (max) values for HEP-ND cells were 2.92 nM, 745.25 fmol/mg protein and 2.91nM, 1323 fmole/mg protein in two clones, respectively. The radioiodine uptake by hNIS activity and D2R binding was highly correlated. CONCLUSION: We developed a dual positron and gamma imaging reporter system of hNIS and D2R in a stably transfected cell line. We expect that D2R and hNIS genes can complement mutually as a nuclear reporting system or that D2R can be used as reporter gene when hNIS gene were used as a treatment gene.
Butaclamol
;
Carcinoma, Hepatocellular
;
Cell Line
;
Cell Tracking
;
Clone Cells
;
Complement System Proteins
;
Dopamine*
;
Electrons
;
Genes, Reporter
;
Humans
;
Ion Transport*
;
Parents
;
Plasmids
;
Ribosomes
;
Sodium Iodide*
;
Sodium*
;
Transgenes*
8.L-tetrahydropalamatine inhibits tumor necrosis factor-α-induced monocyte-endothelial cell adhesion through downregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 involving suppression of nuclear factor-κ B signaling pathway.
Bin-rui YANG ; Nan YU ; Yan-hui DENG ; Pui Man HOI ; Bin YANG ; Guang-yu LIU ; Wei-hong CONG ; Simon Ming-yuen LEE
Chinese journal of integrative medicine 2015;21(5):361-368
OBJECTIVETo investigate whether I-tetrahydropalmatine (I-THP), an alkaloid mainly present in Corydalis family, could ameliorate early vascular inflammatory responses in atherosclerotic processes.
METHODSFluorescently labeled monocytes were co-incubated with human umbilical vein endothelial cells (HUVECs), which were pretreated with I-THP and then simulated with tumor necrosis factor (TNF)-α in absence of I-THP to determine if I-THP could reduce thecytokine-induced adhesion of monocytes to HUVECs. Then I-THP were further studied the underlying mechanisms through observing the transcriptional and translational level of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the nuclear translocation of nuclear factor (NF)-κ B in HUVECs.
RESULTSL-THP could block TNF-α-induced adhesion of monocytes to HUVECs and could significantly inhibited the expression of ICAM-1 and VCAM-1 on cell surface by 31% and 36% at 30 μ mol/L. L-THP pretreatment could also markedly reduce transcriptional and translational level of VCAM-1 as well as mildly reduce the total protein and mRNA expression levels of ICAM-1. Furthermore, I-THP attenuated TNF-α-stimulated NF-κ B nuclear translocation.
CONCLUSIONThese results provide evidences supporting that I-THP could be a promising compound in the prevention and treatment of the early vascular inflammatory reaction in atherosclerosis by inhibiting monocyte adhesion to vascular endothelial cell through downregulating ICAM-1 and VCAM-1 in vascular endothelial cell based on suppressing NF-κ B.
Berberine Alkaloids ; pharmacology ; Cell Adhesion ; drug effects ; Cell Nucleus ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; genetics ; metabolism ; Monocytes ; cytology ; drug effects ; metabolism ; NF-kappa B ; metabolism ; Protein Transport ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Signal Transduction ; drug effects ; Transcription Factor RelA ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology ; Vascular Cell Adhesion Molecule-1 ; genetics ; metabolism
9.Cognition enhancing effect of panax ginseng in Korean volunteers with mild cognitive impairment: a randomized, double-blind, placebo-controlled clinical trial
Key Chung PARK ; Hui JIN ; Renhua ZHENG ; Sehyun KIM ; Seung Eun LEE ; Bo Hyung KIM ; Sung Vin YIM
Translational and Clinical Pharmacology 2019;27(3):92-97
This study aimed to investigate the cognition-enhancing effect of Panax ginseng. A randomized, double-blind, placebo-controlled clinical trial was conducted to address the cognition-enhancing effects of Panax ginseng. A total of 90 Korean volunteers with mild cognitive impairment participated in this study. All subjects were allocated randomly into ‘Ginseng’ group or ‘Placebo’ group. All subjects were administered 3g of Panax ginseng powder or starch (placebo) for 6 months. The Korean version of the Mini-Mental Status Examination (K-MMSE), Korean version of Instrumental Activities of Daily Living (K-IADL), and Seoul Neuropsychological Screening Battery (SNSB) were used to assess the changes in cognitive function at the end of the 6 month study period. The subjects of the ‘Ginseng’ group improved significantly on the Rey Complex Figure Test (RCFT) immediate recall (P = 0.0405 and P = 0.0342 in per-protocol (PP) and intention-to-treat (ITT) analysis, respectively) and on the RCFT 20-min delayed recall (P = 0.0396 and P = 0.0355 in PP and ITT analysis, respectively) compared with ‘placebo’ group throughout the 6 months of Panax ginseng administration. There were no serious adverse events. These results suggest that Panax ginseng has a cognition-enhancing effect.
Activities of Daily Living
;
Cognition
;
Mass Screening
;
Memory, Short-Term
;
Mild Cognitive Impairment
;
Panax
;
Seoul
;
Starch
;
Volunteers
10.Effect of Endothelial Microparticles Induced by Hypoxia on Migration and Angiogenesis of Human Umbilical Vein Endothelial Cells by Delivering MicroRNA-19b.
Hui-Zhu LIANG ; Su-Fang LI ; Feng ZHANG ; Man-Yan WU ; Chang-Long LI ; Jun-Xian SONG ; Chongyou LEE ; Hong CHEN
Chinese Medical Journal 2018;131(22):2726-2733
Background:
Microparticles (MPs) are small extracellular plasma membrane particles shed by activated and apoptotic cells, which are involved in the development of atherosclerosis. Our previous study found that microRNA (miR)-19b encapsulated within endothelial MPs (EMPs) may contribute to the upregulation of circulating miR-19b in unstable angina patients. Hypoxia is involved in atherosclerosis as a critical pathological stimulus. However, it still remains unclear whether the increase of miR-19b levels in EMPs is related to hypoxia and if the effect of miR-19b - wrapped within EMPs - stimulates hypoxia on vascular endothelial cells. This study aimed to explore the changes of miR-19b in EMPs induced by hypoxia as well as their effects on endothelial cells.
Methods:
Human umbilical vein endothelial cells (HUVECs) were cultured in vitro and arranged to harvest EMPs in two parts: the first part consisted of EMP and EMP and the second part included EMP, EMP, and EMP. Cell migration was detected by scratch migration and transwell chamber migration. Angiogenesis was assessed by tube formation assays. Furthermore, we predicted the target gene of miR-19b by bioinformatics analysis, and luciferase assay was used to verify the targeted gene of miR-19b. Data were analyzed by one-way analysis of variance. Student's t-test was used when two groups were compared.
Results:
Compared with EMP- and EMP-inhibited migration of cells by scratch migration assay (80.77 ± 1.10 vs. 28.37 ± 1.40, P < 0. 001) and transwell chamber migration assay (83.00 ± 3.46 vs. 235.00 ± 16.52, P < 0.01), the number of tube formations was markedly reduced by 70% in the EMP group (P < 0.001) in vitro analysis of HUVECs. Meanwhile, a strong inhibition of migration and tube formation of HUVECs in the presence of miR-19b-enriched EMP was observed. This effect might be due to the delivery of miR-19b in EMPs. Transforming growth factor-β2 (TGFβ2) was predicted to be one of the target genes of miR-19b, and we further confirmed that TGFβ2 was a direct target gene of miR-19b using the luciferase assay. The expression of TGFβ2 in HUVECs was inhibited by treatment with EMP and EMP.
Conclusions
MiR-19b in EMPs induced by hypoxia could reduce endothelial cell migration and angiogenesis by downregulating TGFβ2 expression, which may have inhibited the progression of atherosclerosis.
Cell Hypoxia
;
genetics
;
physiology
;
Cell Movement
;
genetics
;
physiology
;
Endothelial Cells
;
metabolism
;
Human Umbilical Vein Endothelial Cells
;
metabolism
;
Humans
;
MicroRNAs
;
genetics
;
metabolism
;
Neovascularization, Physiologic
;
genetics
;
physiology
;
Transforming Growth Factor beta2
;
genetics
;
metabolism