1.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.
2.Successful management of tracheal stenosis using tracheal stenting in a Russian Blue cat
Eunji HUR ; Yong Gwan PARK ; Jiyun CHA ; Min-Yeong LEE ; Jaekyoung LEE ; Hwi-Yool KIM ; Aryung NAM
Journal of Veterinary Science 2025;26(1):e15-
and Relevance: This case is the first instance of using tracheal stenting to effectively manage tracheal stenosis in a cat, successfully resolving a respiratory emergency, and ensuring long-term care.
3.Quetiapine competitively inhibits 5-HT3 receptor-mediatedcurrents in NCB20 neuroblastoma cells
Yong Soo PARK ; Gyu Min KIM ; Ho Jun SUNG ; Ju Yeong YU ; Ki-Wug SUNG
The Korean Journal of Physiology and Pharmacology 2025;29(3):373-384
The 5-hydroxytryptamine type3 (5-HT3 ) receptor, a ligand-gated ion channel, plays a critical role in synaptic transmission. It has been implicated in various neuropsychiatric disorders. This study aimed to elucidate the mechanism by which quetiapine, an atypical antipsychotic, could inhibit 5-HT3 receptor-mediated currents in NCB20 neuroblastoma cells. Whole-cell patch-clamp recordings were used to study effects of quetiapine on receptor ion channel kinetics and its competitive antagonism. Co-application of quetiapine shifted 5-HT concentration-response curve rightward, significantly increasing the EC50 without altering the maximal response (Emax ), suggesting a competitive inhibition. Quetiapine's IC50 varied with 5-HT concentration and treatment condition. The IC50 value of quetiapine was 0.58 μM with 3μM 5-HT and 25.23 μM with 10 μM 5-HT, indicating an inverse relationship between quetiapine efficacy and agonist concentration. Pretreatment of quetiapine significantly enhanced its inhibitory potency, reducing its IC50 from 25.23 μM to 0.20 μM.Interaction kinetics experiments revealed an IC50 of 5.17 μM for an open state of the 5-HT3 receptor, suggesting weaker affinity during receptor activation. Quetiapine also accelerated receptor deactivation and desensitization, suggesting that it could stabilize the receptor in non-conducting states. Additionally, quetiapine significantly prolonged recovery from desensitization without affecting recovery from deactivation, demonstrating its selective impact on receptor kinetics. Inhibition of the 5-HT3 receptor by quetiapine was voltage-independent, and quetiapine exhibited no usedependency, further supporting its role as a competitive antagonist. These findings provide insights into inhibitory mechanism of quetiapine on 5-HT3 receptor and suggest its potential therapeutic implications for modulating serotonergic pathways in neuropsychiatric disorders.
4.Haloperidol, a typical antipsychotic, inhibits 5-HT3 receptor-mediated currents in NCB-20 cells: a whole-cell patch-clamp study
Yong Soo PARK ; Gyu Min KIM ; Ho Jun SUNG ; Ju Yeong YU ; Ki-Wug SUNG
The Korean Journal of Physiology and Pharmacology 2025;29(3):349-358
Haloperidol is a typical antipsychotic drug effective in alleviating positive symptoms of schizophrenia by blocking dopamine receptor 2 (DR2). However, it is also known to produce neuropsychiatric effects by acting on various targets other than DR. In this study, we investigated effect of haloperidol on function of 5-hydroxytryptamine (5-HT) 3 receptor, a ligand-gated ion channel belonging to the serotonin receptor family using the whole-cell voltage clamp technique and NCB20 neuroblastoma cells. When co-applied with 5-HT, haloperidol inhibited 5-HT3 receptormediated currents in a concentration-dependent manner. A reduction in maximal effect (E max ) and an increase in EC 50 observed during co-application indicated that haloperidol could act as a non-competitive antagonist of 5-HT3 receptors. Haloperidol inhibited the activation of 5-HT3 receptor, while also accelerating their deactivation and desensitization. The inhibitory effect of haloperidol showed no significant difference between pre- and co-application. Haloperidol did not alter the reversal potential of 5-HT3 receptor currents. Furthermore, haloperidol did not affect recovery from deactivation or desensitization of 5-HT3 receptors. It did not show a use-dependent inhibition either. These findings suggest that haloperidol can exert its inhibitory effect on 5-HT3 receptors by allosterically preventing opening of ion channels. This mechanistic insight enhances our understanding of relationships between 5-HT3 receptors and pharmacological actions of antipsychotics.
5.Successful management of tracheal stenosis using tracheal stenting in a Russian Blue cat
Eunji HUR ; Yong Gwan PARK ; Jiyun CHA ; Min-Yeong LEE ; Jaekyoung LEE ; Hwi-Yool KIM ; Aryung NAM
Journal of Veterinary Science 2025;26(1):e15-
and Relevance: This case is the first instance of using tracheal stenting to effectively manage tracheal stenosis in a cat, successfully resolving a respiratory emergency, and ensuring long-term care.
6.Quetiapine competitively inhibits 5-HT3 receptor-mediatedcurrents in NCB20 neuroblastoma cells
Yong Soo PARK ; Gyu Min KIM ; Ho Jun SUNG ; Ju Yeong YU ; Ki-Wug SUNG
The Korean Journal of Physiology and Pharmacology 2025;29(3):373-384
The 5-hydroxytryptamine type3 (5-HT3 ) receptor, a ligand-gated ion channel, plays a critical role in synaptic transmission. It has been implicated in various neuropsychiatric disorders. This study aimed to elucidate the mechanism by which quetiapine, an atypical antipsychotic, could inhibit 5-HT3 receptor-mediated currents in NCB20 neuroblastoma cells. Whole-cell patch-clamp recordings were used to study effects of quetiapine on receptor ion channel kinetics and its competitive antagonism. Co-application of quetiapine shifted 5-HT concentration-response curve rightward, significantly increasing the EC50 without altering the maximal response (Emax ), suggesting a competitive inhibition. Quetiapine's IC50 varied with 5-HT concentration and treatment condition. The IC50 value of quetiapine was 0.58 μM with 3μM 5-HT and 25.23 μM with 10 μM 5-HT, indicating an inverse relationship between quetiapine efficacy and agonist concentration. Pretreatment of quetiapine significantly enhanced its inhibitory potency, reducing its IC50 from 25.23 μM to 0.20 μM.Interaction kinetics experiments revealed an IC50 of 5.17 μM for an open state of the 5-HT3 receptor, suggesting weaker affinity during receptor activation. Quetiapine also accelerated receptor deactivation and desensitization, suggesting that it could stabilize the receptor in non-conducting states. Additionally, quetiapine significantly prolonged recovery from desensitization without affecting recovery from deactivation, demonstrating its selective impact on receptor kinetics. Inhibition of the 5-HT3 receptor by quetiapine was voltage-independent, and quetiapine exhibited no usedependency, further supporting its role as a competitive antagonist. These findings provide insights into inhibitory mechanism of quetiapine on 5-HT3 receptor and suggest its potential therapeutic implications for modulating serotonergic pathways in neuropsychiatric disorders.
7.Haloperidol, a typical antipsychotic, inhibits 5-HT3 receptor-mediated currents in NCB-20 cells: a whole-cell patch-clamp study
Yong Soo PARK ; Gyu Min KIM ; Ho Jun SUNG ; Ju Yeong YU ; Ki-Wug SUNG
The Korean Journal of Physiology and Pharmacology 2025;29(3):349-358
Haloperidol is a typical antipsychotic drug effective in alleviating positive symptoms of schizophrenia by blocking dopamine receptor 2 (DR2). However, it is also known to produce neuropsychiatric effects by acting on various targets other than DR. In this study, we investigated effect of haloperidol on function of 5-hydroxytryptamine (5-HT) 3 receptor, a ligand-gated ion channel belonging to the serotonin receptor family using the whole-cell voltage clamp technique and NCB20 neuroblastoma cells. When co-applied with 5-HT, haloperidol inhibited 5-HT3 receptormediated currents in a concentration-dependent manner. A reduction in maximal effect (E max ) and an increase in EC 50 observed during co-application indicated that haloperidol could act as a non-competitive antagonist of 5-HT3 receptors. Haloperidol inhibited the activation of 5-HT3 receptor, while also accelerating their deactivation and desensitization. The inhibitory effect of haloperidol showed no significant difference between pre- and co-application. Haloperidol did not alter the reversal potential of 5-HT3 receptor currents. Furthermore, haloperidol did not affect recovery from deactivation or desensitization of 5-HT3 receptors. It did not show a use-dependent inhibition either. These findings suggest that haloperidol can exert its inhibitory effect on 5-HT3 receptors by allosterically preventing opening of ion channels. This mechanistic insight enhances our understanding of relationships between 5-HT3 receptors and pharmacological actions of antipsychotics.
8.Quetiapine competitively inhibits 5-HT3 receptor-mediatedcurrents in NCB20 neuroblastoma cells
Yong Soo PARK ; Gyu Min KIM ; Ho Jun SUNG ; Ju Yeong YU ; Ki-Wug SUNG
The Korean Journal of Physiology and Pharmacology 2025;29(3):373-384
The 5-hydroxytryptamine type3 (5-HT3 ) receptor, a ligand-gated ion channel, plays a critical role in synaptic transmission. It has been implicated in various neuropsychiatric disorders. This study aimed to elucidate the mechanism by which quetiapine, an atypical antipsychotic, could inhibit 5-HT3 receptor-mediated currents in NCB20 neuroblastoma cells. Whole-cell patch-clamp recordings were used to study effects of quetiapine on receptor ion channel kinetics and its competitive antagonism. Co-application of quetiapine shifted 5-HT concentration-response curve rightward, significantly increasing the EC50 without altering the maximal response (Emax ), suggesting a competitive inhibition. Quetiapine's IC50 varied with 5-HT concentration and treatment condition. The IC50 value of quetiapine was 0.58 μM with 3μM 5-HT and 25.23 μM with 10 μM 5-HT, indicating an inverse relationship between quetiapine efficacy and agonist concentration. Pretreatment of quetiapine significantly enhanced its inhibitory potency, reducing its IC50 from 25.23 μM to 0.20 μM.Interaction kinetics experiments revealed an IC50 of 5.17 μM for an open state of the 5-HT3 receptor, suggesting weaker affinity during receptor activation. Quetiapine also accelerated receptor deactivation and desensitization, suggesting that it could stabilize the receptor in non-conducting states. Additionally, quetiapine significantly prolonged recovery from desensitization without affecting recovery from deactivation, demonstrating its selective impact on receptor kinetics. Inhibition of the 5-HT3 receptor by quetiapine was voltage-independent, and quetiapine exhibited no usedependency, further supporting its role as a competitive antagonist. These findings provide insights into inhibitory mechanism of quetiapine on 5-HT3 receptor and suggest its potential therapeutic implications for modulating serotonergic pathways in neuropsychiatric disorders.
9.Haloperidol, a typical antipsychotic, inhibits 5-HT3 receptor-mediated currents in NCB-20 cells: a whole-cell patch-clamp study
Yong Soo PARK ; Gyu Min KIM ; Ho Jun SUNG ; Ju Yeong YU ; Ki-Wug SUNG
The Korean Journal of Physiology and Pharmacology 2025;29(3):349-358
Haloperidol is a typical antipsychotic drug effective in alleviating positive symptoms of schizophrenia by blocking dopamine receptor 2 (DR2). However, it is also known to produce neuropsychiatric effects by acting on various targets other than DR. In this study, we investigated effect of haloperidol on function of 5-hydroxytryptamine (5-HT) 3 receptor, a ligand-gated ion channel belonging to the serotonin receptor family using the whole-cell voltage clamp technique and NCB20 neuroblastoma cells. When co-applied with 5-HT, haloperidol inhibited 5-HT3 receptormediated currents in a concentration-dependent manner. A reduction in maximal effect (E max ) and an increase in EC 50 observed during co-application indicated that haloperidol could act as a non-competitive antagonist of 5-HT3 receptors. Haloperidol inhibited the activation of 5-HT3 receptor, while also accelerating their deactivation and desensitization. The inhibitory effect of haloperidol showed no significant difference between pre- and co-application. Haloperidol did not alter the reversal potential of 5-HT3 receptor currents. Furthermore, haloperidol did not affect recovery from deactivation or desensitization of 5-HT3 receptors. It did not show a use-dependent inhibition either. These findings suggest that haloperidol can exert its inhibitory effect on 5-HT3 receptors by allosterically preventing opening of ion channels. This mechanistic insight enhances our understanding of relationships between 5-HT3 receptors and pharmacological actions of antipsychotics.
10.Successful management of tracheal stenosis using tracheal stenting in a Russian Blue cat
Eunji HUR ; Yong Gwan PARK ; Jiyun CHA ; Min-Yeong LEE ; Jaekyoung LEE ; Hwi-Yool KIM ; Aryung NAM
Journal of Veterinary Science 2025;26(1):e15-
and Relevance: This case is the first instance of using tracheal stenting to effectively manage tracheal stenosis in a cat, successfully resolving a respiratory emergency, and ensuring long-term care.

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