• The Korean Journal of Food And Nutrition
• /
• v.32 no.4
• /
• pp.379-384
• /
• 2019

This study was to investigate the sorbic acid, benzoic acid and sulfur dioxide in commonly consumed beverages, snacks and instant ramens in Korea. A total of 150 food samples including 50 beverages, 50 snacks and 50 instant ramens were examined using the Korea Food Code method. Sorbic and benzoic acid were analyzed by the HPLC method, whereas sulfur dioxide was measured by Monnier-Williams method. Our results indicated that benzoic acid was detected in six beverages samples, and its concentration was in the range of 3.08-11.94 mg/kg. The contents of both sorbic and benzoic acid in 50 beverage samples did not exceed the residue allowance standards set by the Ministry of Food and Drug Safety (MFDS). Sulfur dioxide was detected in 12 beverages samples, but its content was lower than the detection limit specified in the method by the Korea Food Code. On the other hand, sorbic acid was not detected all samples. These results provide a basic data regarding sorbic acid, benzoic acid and sulfur dioxide in commonly consumed beverages, snacks and instant ramens in Korea.

• Biomolecules & Therapeutics
• /
• v.27 no.2
• /
• pp.193-200
• /
• 2019

Ceramide metabolism is known to be an essential etiology for various diseases, such as atopic dermatitis and Gaucher disease. Glucosylceramide synthase (GCS) is a key enzyme for the synthesis of glucosylceramide (GlcCer), which is a main ceramide metabolism pathway in mammalian cells. In this article, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine GCS activity using synthetic non-natural sphingolipid C8-ceramide as a substrate. The reaction products, C8-GlcCer for GCS, could be separated on a C18 column by reverse-phase high-performance liquid chromatography (HPLC). Quantification was conducted using the multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z $588.6{\rightarrow}264.4$ for C8-GlcCer at positive ionization mode. The calibration curve was established over the range of 0.625-160 ng/mL, and the correlation coefficient was larger than 0.999. This method was successfully applied to detect GCS in the human hepatocellular carcinoma cell line (HepG2 cells) and mouse peripheral blood mononuclear cells. We also evaluated the inhibition degree of a known GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) on GCS enzymatic activity and proved that this method could be successfully applied to GCS inhibitor screening of preventive and therapeutic drugs for ceramide metabolism diseases, such as atopic dermatitis and Gaucher disease.

• Medical Lasers
• /
• v.10 no.3
• /
• pp.170-175
• /
• 2021

Background and Objectives Cisplatin is an important chemotherapy drug for the treatment of head and neck cancer. Interstitial laser treatment (ILT) has cosmetic utility and is very important for maintaining the function of the head and neck after cancer treatment. This study examined the synergistic effects of locally injected cisplatin-epigel and high fever induced by an interstitial potassium titanyl phosphate (KTP) laser treatment on a xenografted human Heinz squamous cell carcinoma. Materials and Methods SNU-1041 (107 cells/0.1 ml) cells were xenografted into the back of nude mice by subcutaneous injection. The ILT group (n = 10) was treated with a KTP laser (1 J/mm³) through a cylindrical diffuser tip inserted into the tumor, monitoring the temperature at 43-45℃. In the combined treatment group (n = 10), local hyperthermia was induced by intratumoral injection of 100-200 ㎍ of cisplatin into a collagen-based gel carrier (cisplatin-epigel), which was released slowly four hours before ILT. After four weeks of follow-up, the treated tumors were evaluated for tumor remission and volume change. Results Eight (80%) of the combined group showed complete tumor remission at the four-week follow-up, whereas only three (30%) of the ILT group showed remission (30%) (p < 0.01). Conclusion The current study has shown the synergistic effects of a local cisplatin injection and high fever from ILT on a xenografted human Heinz squamous cell carcinoma.

• BMB Reports
• /
• v.55 no.6
• /
• pp.267-274
• /
• 2022

Molecular imaging is used to improve the disease diagnosis, prognosis, monitoring of treatment in living subjects. Numerous molecular targets have been developed for various cellular and molecular processes in genetic, metabolic, proteomic, and cellular biologic level. Molecular imaging modalities such as Optical Imaging, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Computed Tomography (CT) can be used to visualize anatomic, genetic, biochemical, and physiologic changes in vivo. For in vivo cell imaging, certain cells such as cancer cells, immune cells, stem cells could be labeled by direct and indirect labeling methods to monitor cell migration, cell activity, and cell effects in cell-based therapy. In case of cancer, it could be used to investigate biological processes such as cancer metastasis and to analyze the drug treatment process. In addition, transplanted stem cells and immune cells in cell-based therapy could be visualized and tracked to confirm the fate, activity, and function of cells. In conventional molecular imaging, cells can be monitored in vivo in bulk non-invasively with optical imaging, MRI, PET, and SPECT imaging. However, single cell imaging in vivo has been a great challenge due to an extremely high sensitive detection of single cell. Recently, there has been great attention for in vivo single cell imaging due to the development of single cell study. In vivo single imaging could analyze the survival or death, movement direction, and characteristics of a single cell in live subjects. In this article, we reviewed basic principle of in vivo molecular imaging and introduced recent studies for in vivo single cell imaging based on the concept of in vivo molecular imaging.

• Korean Journal of Clinical Pharmacy
• /
• v.33 no.3
• /
• pp.195-201
• /
• 2023

Background: Hematocrit is usually measured from venous blood collected by invasive venipuncture. This study was performed to determine hematocrit accurately and precisely using minimally invasive volumetric absorptive microsampling (VAMS) technique. Such technique is to be applied to determining hematocrit in various clinical settings for the care, including therapeutic drug monitoring, of neonatal or epileptic patients, or patients with high risk of infection or bleeding. Methods: The study was performed using 31 VAMS samples obtained from 21 pancreatic cancer patients. Hematocrit was determined using the values of potassium concentrations obtained from blood in VAMS tips (Hct_VAMS). Hct_VAMS was compared with hematocrit measured from blood collected by venipuncture (Hct_VP). The accuracy and precision of Hct_VAMS in comparison to Hct_VP were evaluated using Bland-Altman plot, Deming regression and mountain plot. Results: Bland-Altman plot displayed a random scattering pattern of the differences between Hct_VAMS and Hct_VP with the mean bias of -0.010 and the 95% limit of agreement ranging from -0.063 to 0.044. Deming regression for Hct_VAMS and Hct_VP line demonstrated very small proportional and constant biases of 1.04 and -0.003, respectively. Mountain plot exhibited a narrow and symmetrical distribution of the differences with their median of -0.011 and central 95% range from -0.049 to 0.033. Conclusion: Hematocrit was accurately and precisely determined using less invasive VAMS technique. Such technique appears to be applicable to determining hematocrit in situations that venipuncture is not favorable or possible.

• Mass Spectrometry Letters
• /
• v.14 no.3
• /
• pp.91-103
• /
• 2023

As one of the most common mood disorders, numerous studies have shown depression is the main risk factor for non-suicidal self-harm. The pathogenesis of depression is complex, and a comprehensive and rapid measurement of monoamine neurotransmitters and their metabolites will be very helpful in understanding the pathogenesis of depression. Therefore, a rapid and sensitive underivatized liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous monitoring of the levels of ten neurotransmitters and their metabolites in rat serum and limbic system and successfully applied to quantify the changes of neurotransmitter levels in chronic unpredictable mild stress-induced rats. The analytes studied were mainly involved in tyrosine metabolism, tryptophan metabolism, and glutamate cycling pathways, which are important in the pathogenesis of depression. It had been verified the method was sensitive and effective, with satisfactory linearity, and met the requirements of biological sample determination. Levels of neurotransmitters in rat serum, hippocampus, amygdala, prefrontal cortex, striatum, and hypothalamus were determined via the method. The results showed serotonin, dopamine, norepinephrine, and their metabolites were decreased, glutamine was increased, and glutamate was disturbed in chronic unpredictable mild stress-induced depression rats. This method provides a new approach to studying the pathogenesis of depression and other neurological disorders.

• Journal of Biomedical Engineering Research
• /
• v.44 no.5
• /
• pp.315-323
• /
• 2023

The objective of this study is to identify the selective application targets for reporting on details of supply of class 1 and 2 medical devices as part of the improvement of the reports on details of supply of medical device system, and to analyze its effectiveness. Therapeutic materials covered by health insurance and secondhand medical devices were chosen based on the transparency of health insurance coverage and the management of medical device distribution. As a result, approximately 85% of groups can be excluded from the reporting requirements compared to reporting all items under Class 1 and 2 medical devices. This is expected to enhance the efficiency of supply reporting tasks. Additionally, the information on supply details managed by the regulatory authority can be utilized for statistical analysis and periodic monitoring, serving as fundamental data for the development of medical device-related policies and research in the field of medical devices.

• Journal of Hospice and Palliative Care
• /
• v.26 no.4
• /
• pp.185-189
• /
• 2023

Purpose: Limited research has been conducted on the prevalence of non-medical opioid use (NMOU) in Korean cancer patients who have received prescription opioids (PO). This study aimed to identify the potential proportion of NMOU in cancer patients who had been prescribed opioids in Korea. Methods: A retrospective cohort analysis was conducted on 14,728 patients who underwent cancer-related treatment between January 2009 and December 2019, using electronically collected data from a tertiary hospital in Korea. Information regarding the type and duration of opioid use was gathered. A detailed review of medical charts was carried out, focusing on patients who had been prescribed opioids for over 60 days beyond a 12-month period following the completion of their cancer treatment (long-term PO users). Results: Out of the 5,587 patients who were prescribed PO and followed up for at least 12 months, 13 cases of NMOU were identified, representing 0.23% of the patient population. Among the 204 long-term PO users, the rate was 6.37% (13/204). The most commonly misused opioids were oxycodone and fentanyl. For the group confirmed to have NMOU, the median duration of prescription was 1,327 days in total. Of the 13 patients diagnosed with NMOU, 9 reported withdrawal symptoms, 3 exhibited craving behavior for opioids, and 1 experienced both symptoms. Conclusion: This study found that 0.23% of cancer patients who had been prescribed opioids in Korea demonstrated NMOU. Despite this relatively low rate, careful monitoring is necessary to minimize the risk of NMOU in this population, especially among long-term PO users.

• Journal of Industrial Convergence
• /
• v.21 no.9
• /
• pp.23-32
• /
• 2023

Interest in Serious Games for Healthcare (SGHs) that can improve health through games is increasing. Digital Therapeutics (DTx) is a treatment that must be approved for effectiveness and safety, so it should follow the traditional drug distribution method, but SGHs are wellness products that are more flexible in terms of adoption and diffusion than DTx. SGHs are effective because it can provide customized services through continuous monitoring and feedback. When SGHs are applied to cognitive impairment treatment or behavioral correction, malfunctions and side effects are minor. This study developed research model based on the Valence Framework, gathered data from 142 undergraduates, and demonstrated that only the perceived benefits have a statistically significant positive (+) effect on SGHs acceptance intentions. Based on these results, this study suggests that SGHs companies should promote benefits in accepting SGHs for general users and they need for a distribution and analytics platform strategy based on a data-driven approach.

• The Korean Journal of Physiology and Pharmacology
• /
• v.28 no.2
• /
• pp.121-127
• /
• 2024

Vancomycin is a frequently used antibiotic in intensive care units, and the patient's renal clearance affects the pharmacokinetic characteristics of vancomycin. Several advantages have been reported for vancomycin continuous intravenous infusion, but studies on continuous dosing regimens based on patients' renal clearance are insufficient. The aim of this study was to develop a vancomycin serum concentration prediction model by factoring in a patient's renal clearance. Children admitted to our institution between July 1, 2021, and July 31, 2022 with records of continuous infusion of vancomycin were included in the study. Sex, age, height, weight, vancomycin dose by weight, interval from the start of vancomycin administration to the time of therapeutic drug monitoring sampling, and vancomycin serum concentrations were analyzed with the linear regression analysis of the mixed effect model. Univariable regression analysis was performed using the vancomycin serum concentration as a dependent variable. It showed that vancomycin dose (p < 0.001) and serum creatinine (p = 0.007) were factors that had the most impact on vancomycin serum concentration. Vancomycin serum concentration was affected by vancomycin dose (p < 0.001) and serum creatinine (p = 0.001) with statistical significance, and a multivariable regression model was obtained as follows: Vancomycin serum concentration (mg/l) = -1.296 + 0.281 × vancomycin dose (mg/kg) + 20.458 × serum creatinine (mg/dl) (adjusted coefficient of determination, R² = 0.66). This prediction model is expected to contribute to establishing an optimal continuous infusion regimen for vancomycin.