1.Profiling of endogenous metabolites and changes in intestinal microbiota distribution after GEN-001 (Lactococcus lactis) administration
Min-Gul KIM ; Suin KIM ; Ji-Young JEON ; Seol Ju MOON ; Yong-Geun KWAK ; Joo Young NA ; SeungHwan LEE ; Kyung-Mi PARK ; Hyo-Jin KIM ; Sang-Min LEE ; Seo-Yeon CHOI ; Kwang-Hee SHIN
The Korean Journal of Physiology and Pharmacology 2024;28(2):153-164
This study aimed to identify metabolic biomarkers and investigate changes in intestinal microbiota in the feces of healthy participants following administration of Lactococcus lactis GEN-001. GEN-001 is a single-strain L. lactis strain isolated from the gut of a healthy human volunteer. The study was conducted as a parallel, randomized, phase 1, open design trial. Twenty healthy Korean males were divided into five groups according to the GEN-001 dosage and dietary control.Groups A, B, C, and D1 received 1, 3, 6, and 9 GEN-001 capsules (1 × 1011 colony forming units), respectively, without dietary adjustment, whereas group D2 received 9 GEN-001 capsules with dietary adjustment. All groups received a single dose. Fecal samples were collected 2 days before GEN-001 administration to 7 days after for untargeted metabolomics and gut microbial metagenomic analyses; blood samples were collected simultaneously for immunogenicity analysis. Levels of phenylalanine, tyrosine, cholic acid, deoxycholic acid, and tryptophan were significantly increased at 5–6 days after GEN-001 administration when compared with predose levels. Compared with predose, the relative abundance (%) of Parabacteroides and Alistipes significantly decreased, whereas that of Lactobacillus and Lactococcus increased; Lactobacillus and tryptophan levels were negatively correlated. A single administration of GEN-001 shifted the gut microbiota in healthy volunteers to a more balanced state as evidenced by an increased abundance of beneficial bacteria, including Lactobacillus, and higher levels of the metabolites that have immunogenic properties.
2.Stability of acetylsalicylic acid in human blood collected using volumetric absorptive microsampling (VAMS) under various drying conditions
Seol Ju MOON ; Song-Hee HAN ; Yong-Geun KWAK ; Min-Gul KIM
Translational and Clinical Pharmacology 2022;30(1):57-69
Acetylsalicylic acid (ASA) is one of the most commonly used medications in global market, with a risk of intoxication in certain patients. However, monitoring blood drug concentration often requires frequent hospital visits; hence there is an unmet need to increase patientcentricity by conducting blood sampling at home. Volumetric absorptive microsampling (VAMS) is a device that allows collection of homogenous and accurate volume of blood without venipuncture, and can be utilized by patients who are not in hospital settings; but because ASA is prone to hydrolysis and stabilizing reagents cannot be added to VAMS samples, a way to improve sample stability must be developed. The objective of this study was to identify the cause of instability with ASA samples collected by VAMS, and to evaluate ways to improve sample stability. A liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used for analysis of ASA concentration in whole blood. Samples collected with VAMS were kept under different drying conditions (desiccator, pressurized, nitrogen gas and household vacuum sealer) and were compared to the control samples collected by conventional venous sampling. The recovery of ASA was about 31% of the control when VAMS sample was dried at room temperature, whereas VAMS samples under humidity controlled conditions showed more than 85% of recovery. Our results suggest that adequate level of humidity control was critical to ensure sample stability of ASA, and this humidity control could also be achieved at home using household vacuum sealer, thus enabling patient-centric clinical trials to be conducted.
3.Removal of Large Urinary Stone Using Percutaneous Nephrolithotomy in a Patient with Crohn's Disease
Young Joo PARK ; Dong Hoon BAEK ; Young Min KWAK ; Yong Bo PARK ; Dong Chan JOO ; Tae Kyung HA ; Da Mi KIM ; Geun Am SONG
Kosin Medical Journal 2021;36(2):180-186
Extraintestinal manifestation (EIM) of inflammatory bowel disease (IBD) is approximately 36%. Of genitourinary complications as an EIM of Crohn’s disease (CD), nephrolithiasis is the most common urinary complication in patients with CD. CD patients have been shown to have decreased urinary volume, pH, magnesium, and excretion of citrate, all of which are significant risk factors for nephrolithiasis. Genitourinary complications often occur in case of a severe longstanding disease and are associated with, the activity of bowel disease, especially in those who have undergone bowel surgery. As uncontrolled nephrolithiasis could impair renal function as well as adversely affect quality of life, proper monitoring, early detection, and prevention of the occurrence of urologic complications in CD is crucial. Few data are available about urolithiasis in patients with CD. Herein we report a case of a successful removal of a 2.7 cm calcium oxalate stone using percutaneous nephrolithotomy from a patient with long-standing CD with a previous surgery for small intestinal and colonic stricture.
4.Pharmacokinetic properties and bioequivalence of gefitinib 250 mg in healthy Korean male subjects
Seol Ju MOON ; Yunjeong KIM ; Ji-Young JEON ; Shin-Jung PARK ; Yong-Geun KWAK ; Min-Gul KIM
Translational and Clinical Pharmacology 2021;29(3):171-179
Gefitinib is an anti-cancer drug used to treat non-small cell lung cancer. The objective of this study was to compare the pharmacokinetics and evaluate the bioequivalence of 2 orally administered gefitinib 250 mg tablets in healthy Korean subjects. A randomized, openlabel, single-dose, crossover bioequivalence study was conducted. A total of 50 healthy male volunteers were randomized into 2 sequence groups. During each treatment, the subjects received the test or reference formulation of 250 mg gefitinib with a washout period of 21 days. The plasma samples were collected at pre-dose and up to 144 hours post-dose, and plasma drug concentrations were measured using validated liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated, and the formulations were considered as bioequivalent if the 90% confidence intervals (CIs) of the geometric mean ratios were within the bioequivalence limits of 0.8 to 1.25. Forty-one subjects completed the study and were included in the pharmacokinetic analysis. The 90% CIs of the geometric mean ratios of the test formulation to the reference formulation were 0.8115 to 0.9993 for maximum plasma concentration and 0.9119 to 1.0411 for area under the plasma concentration versus time curve from dosing to the last measurable concentration. There were no serious or unexpected adverse events during the study. In healthy Korean adult subjects, the test and reference formulations of gefitinib 250 mg had similar pharmacokinetic parameters and similar plasma concentration-time profiles. The test formulation of gefitinib met the regulatory criteria for assuming bioequivalence. Both formulations were safe and well-tolerated.
5.Validation of LC-MS/MS method for determination of rosuvastatin concentration in human blood collected by volumetric absorptive microsampling (VAMS)
Seol Ju MOON ; Seon Eui LEE ; Yong-Geun KWAK ; Min-Gul KIM
Translational and Clinical Pharmacology 2021;29(3):125-134
In light of the shift toward patient-centric clinical trials, a measure of simplifying blood collection process and minimizing the volume of blood samples is on the rise. Volumetric absorptive microsampling (VAMS) is a microsampling device developed for blood sampling in non-hospital settings, which enables accurate hematocrit-independent collection of 10 or 20 µL of whole blood with a simple finger prick. In this study, liquid chromatography (LC)-tandem mass spectrometry workflow for quantification of rosuvastatin after VAMS sampling was developed and validated. The VAMS sample was stabilized by matrix drying and the optimum LC conditions and extraction methods were used to reach adequate sensitivity with lower limit of quantification verified at 1 ng/mL in 10 µL of blood. The bioanalytical method to quantify rosuvastatin from 1 to 100 ng/mL in VAMS sample was qualified by specificity, carryover, linearity, within-run and between-run reproducibility and stability. Inaccuracy was less than ± 6% and imprecision was less than 10% after analyzing the samples on 5 different days at all concentration levels. In addition, the feasibility of delivery to the analytical laboratory after home sampling during the guaranteed stability period of 10 days at room temperature was confirmed by evaluating concentration changes after VAMS sampling without adding pH buffer. Our results suggest that VAMS sampling did not have an effect on the stability of rosuvastatin, and it is a viable option for simple and accurate blood collection at home.
6.Protein tyrosine phosphatase 1B is a mediator of cyclic ADP ribose-induced Ca²⁺ signaling in ventricular myocytes.
Seon Ah PARK ; Bing Zhe HONG ; Ki Chan HA ; Uh Hyun KIM ; Myung Kwan HAN ; Yong Geun KWAK
Experimental & Molecular Medicine 2017;49(6):e341-
Cyclic ADP-ribose (cADPR) releases Ca²⁺ from ryanodine receptor (RyR)-sensitive calcium pools in various cell types. In cardiac myocytes, the physiological levels of cADPR transiently increase the amplitude and frequency of Ca²⁺ (that is, a rapid increase and decrease of calcium within one second) during the cardiac action potential. In this study, we demonstrated that cADPR levels higher than physiological levels induce a slow and gradual increase in the resting intracellular Ca²⁺ ([Ca²⁺](i)) level over 10 min by inhibiting the sarcoendoplasmic reticulum Ca²⁺ ATPase (SERCA). Higher cADPR levels mediate the tyrosine-dephosphorylation of α-actin by protein tyrosine phosphatase 1B (PTP1B) present in the endoplasmic reticulum. The tyrosine dephosphorylation of α-actin dissociates phospholamban, the key regulator of SERCA, from α-actin and results in SERCA inhibition. The disruption of the integrity of α-actin by cytochalasin B and the inhibition of α-actin tyrosine dephosphorylation by a PTP1B inhibitor block cADPR-mediated Ca²⁺ increase. Our results suggest that levels of cADPR that are relatively higher than normal physiological levels modify calcium homeostasis through the dephosphorylation of α-actin by PTB1B and the subsequent inhibition of SERCA in cardiac myocytes.
Action Potentials
;
Adenosine Diphosphate*
;
Adenosine Triphosphatases
;
Calcium
;
Cyclic ADP-Ribose
;
Cytochalasin B
;
Endoplasmic Reticulum
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Homeostasis
;
Muscle Cells*
;
Myocytes, Cardiac
;
Protein Tyrosine Phosphatase, Non-Receptor Type 1*
;
Protein Tyrosine Phosphatases*
;
Reticulum
;
Ryanodine Receptor Calcium Release Channel
;
Tyrosine
7.Dendroaspis natriuretic peptide regulates the cardiac L-type Ca2+ channel activity by the phosphorylation of alpha1c proteins.
Seon Ah PARK ; Tae Geun KIM ; Myung Kwan HAN ; Ki Chan HA ; Sung Zoo KIM ; Yong Geun KWAK
Experimental & Molecular Medicine 2012;44(6):363-368
Dendroaspis natriuretic peptide (DNP), a new member of the natriuretic peptide family, is structurally similar to atrial, brain, and C-type natriuretic peptides. However, the effects of DNP on the cardiac function are poorly defined. In the present study, we examined the effect of DNP on the cardiac L-type Ca2+ channels in rabbit ventricular myocytes. DNP inhibited the L-type Ca2+ current (ICa,L) in a concentration dependent manner with a IC50 of 25.5 nM, which was blocked by an inhibitor of protein kinase G (PKG), KT5823 (1 microM). DNP did not affect the voltage dependence of activation and inactivation of ICa,L. The alpha1c subunit of cardiac L-type Ca2+ channel proteins was phosphorylated by the treatment of DNP (1 microM), which was completely blocked by KT5823 (1 microM). Finally, DNP also caused the shortening of action potential duration in rabbit ventricular tissue by 22.3 +/- 4.2% of the control (n = 6), which was completely blocked by KT5823 (1 microM). These results clearly indicate that DNP inhibits the L-type Ca2+ channel activity by phosphorylating the Ca2+ channel protein via PKG activation.
Action Potentials/drug effects
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Animals
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Biological Transport/drug effects
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Calcium/metabolism
;
Calcium Channels, L-Type/*metabolism
;
Carbazoles/pharmacology
;
Cells, Cultured
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Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors
;
Elapid Venoms/*metabolism/pharmacology
;
Enzyme Activation
;
Heart
;
Heart Ventricles/drug effects
;
Myocytes, Cardiac/drug effects
;
Patch-Clamp Techniques
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Peptides/*metabolism/pharmacology
;
Phosphorylation/drug effects
;
Rabbits
8.Laparoscopic Primary Closure: A Better Method of Treatment in Perforated Peptic Ulcer Disease than Open Repair.
Gyou Ra LEE ; Jong Kyung PARK ; Sung Geun KIM ; Seung Hye CHOI ; Sang Seob YUN ; Seong LEE ; Hee Yong KWAK
Journal of Minimally Invasive Surgery 2012;15(1):1-6
PURPOSE: Perforation is a dreadful complication of peptic ulcer disease requiring immediate management. This study examined the feasibility of laparoscopic primary closure in perforated peptic ulcer disease to allow an earlier return to normal life. METHODS: This study reviewed our experience retrospectively with 72 consecutive patients treated with the simple closure of a perforated peptic ulcer disease in our hospital from December 2002 to January 2011. Thirty five patients were treated laparoscopically and the rest underwent open surgery. The operative time, nasogastric tube utilization, abdominal drain usage, time to oral feeding, hospital stay, postoperative complications and recurrence in both groups were compared. A student's t-test was used to make the comparisons. A p value<0.05 was considered significant. RESULTS: The operative time, use of nasogastric tubes, and abdominal drainage were similar in both groups. After laparoscopic surgery, the patients showed an earlier return to normal oral feeding and discharge than the open surgery group (4.17+/-0.62 vs. 5.03+/-2.34 days, p=0.040, 8.63+/-1.96 vs. 10.24+/-3.59 days, p=0.021, respectively). The decreased handling of tissue in laparoscopic surgery led to less wound infection (0 in laparoscopic surgery vs. 3 in open) and postoperative ileus (0 vs. 2). CONCLUSION: Laparoscopic repair of a perforated peptic ulcer is a safe and feasible treatment that offers early oral feeding and a shorter postoperative hospital stay.
Drainage
;
Handling (Psychology)
;
Humans
;
Ileus
;
Laparoscopy
;
Length of Stay
;
Operative Time
;
Peptic Ulcer
;
Postoperative Complications
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Recurrence
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Retrospective Studies
;
Wound Infection
9.The Meaning of Open Cholecystectomy for Acute Cholecystitis.
Hee Yong KWAK ; Sung Geun KIM ; Jong Kyoung PARK ; Seong LEE
Korean Journal of Hepato-Biliary-Pancreatic Surgery 2010;14(2):105-109
PURPOSE: Laparoscopic cholecystectomy has been used widely for effective management of acute cholecystitis. However, it has limitations. In this study, we compared laparoscopic approaches and an open method. The meaning of the open method was assessed again. METHODS: A retrospective review of 60 patients undergoing cholecystectomy for acute cholecystitis was done. Thirty patients were part of a laparoscopic cholecystectomy group; the other 30 patients were part of an open cholecystectomy group. Laparoscopic cholecystectomy was done using a 4-trochar method. We reviewed geographic characteristics, body mass index, white blood cell count, and clinical outcomes. RESULTS: Age, gallbladder wall thickness and white blood cell counts were significantly different between the 2 groups; operation time was not. The length of the postoperative hospital stay in the laparoscopic group was significantly shorter than that in the open group. There was one case of bile leakage in the laparoscopic group which was treated by endoscopic nasal bile drainage. CONCLUSION: Open cholecystectomy is still a valid choice for acute cholecystitis in the modern era of laparoscopic surgery. In severe cases, conversion is not a failure and should be done immediately if necessary.
Bile
;
Body Mass Index
;
Cholecystectomy
;
Cholecystectomy, Laparoscopic
;
Cholecystitis, Acute
;
Drainage
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Gallbladder
;
Humans
;
Laparoscopy
;
Length of Stay
;
Leukocyte Count
;
Retrospective Studies
10.Comparative Analysis of Serum Proteomes of Moyamoya Disease and Normal Controls.
Eun Jeong KOH ; Han Na KIM ; Tian Ze MA ; Ha Young CHOI ; Yong Geun KWAK
Journal of Korean Neurosurgical Society 2010;48(1):8-13
OBJECTIVE: The etiology and pathogenesis of moyamoya disease remain unclear. Furthermore, the definitive diagnostic protein-biomarkers for moyamoya disease are still unknown. The present study analyzed serum proteomes from normal controls and moyamoya patients to identify novel serological biomarkers for diagnosing moyamoya disease. METHODS: We compared the two-dimensional electrophoresis patterns of sera from moyamoya disease patients and normal controls and identified the differentially-expressed spots by matrix-assisted laser desorption/ionization-time-of flight mass spectrometry and electrospray ionization quadruple time-of-flight mass spectrometry. RESULTS: We found and analyzed 22 differently-expressed proteomes. Two proteins were up-regulated. Twenty proteins were down-regulated. Complement C1 inhibitor protein and apolipoprotein C-III showed predominantly changed expressions (complement C1 inhibitor protein averaged a 7.23-fold expression in moyamoya patients as compared to controls, while apolipoprotein C-III averaged a 0.066-fold expression). CONCLUSION: Although our study had a small sample size, our proteomic data provide serologic clue proteins for understanding moyamoya disease.
Apolipoprotein C-III
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Biomarkers
;
Complement C1 Inhibitor Protein
;
Electrophoresis
;
Humans
;
Mass Spectrometry
;
Moyamoya Disease
;
Proteins
;
Proteome
;
Sample Size

Result Analysis
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