1.Ombitasvir/paritaprevir/ritonavir+dasabuvir and ribavirin associated drug-induced liver injury and syndrome of inappropriate secretion of anti-diuretic hormone: A case report
Rahul KUMAR ; John Chen HSIANG ; Jessica TAN ; Prem Harichander THURAIRAJAH
Clinical and Molecular Hepatology 2019;25(3):326-330
No abstract available.
Drug-Induced Liver Injury
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Ribavirin
2.Overexpression of P-glycoprotein induces acquired resistance to imatinib in chronic myelogenous leukemia cells.
Xing-Xiang PENG ; Amit K TIWARI ; Hsiang-Chun WU ; Zhe-Sheng CHEN
Chinese Journal of Cancer 2012;31(2):110-118
Imatinib, a breakpoint cluster region (BCR)-Abelson murine leukemia(ABL) tyrosine kinase inhibitor (TKI), has revolutionized the treatment of chronic myelogenous leukemia (CML). However, development of multidrug resistance(MDR) limits the use of imatinib. In the present study, we aimed to investigate the mechanisms of cellular resistance to imatinib in CML. Therefore, we established an imatinib-resistant human CML cell line(K562-imatinib) through a stepwise selection process. While characterizing the phenotype of these cells, we found that K562-imatinib cells were 124.6-fold more resistant to imatinib than parental K562 cells. In addition, these cells were cross-resistant to second- and third-generation BCR-ABL TKIs. Western blot analysis and reverse transcription-polymerase chain reaction(RT-PCR) demonstrated that P-glycoprotein(P-gp) and MDR1 mRNA levels were increased in K562-imatinib cells. In addition, accumulation of [14C]6-mercaptopurine (6-MP) was decreased, whereas the ATP-dependent efflux of [14C]6-MP and [3H]methotrexate transport were increased in K562-imatinib cells. These data suggest that the overexpression of P-gp may play a crucial role in acquired resistance to imatinib in CML K562-imatinib cells.
ATP Binding Cassette Transporter, Sub-Family B
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genetics
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metabolism
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Antineoplastic Agents
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pharmacology
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Benzamides
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Drug Resistance, Multiple
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Drug Resistance, Neoplasm
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Fusion Proteins, bcr-abl
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antagonists & inhibitors
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Gene Expression Regulation, Neoplastic
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Humans
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Imatinib Mesylate
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K562 Cells
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Mercaptopurine
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metabolism
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Methotrexate
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metabolism
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Piperazines
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pharmacology
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Protein Kinase Inhibitors
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pharmacology
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Protein-Tyrosine Kinases
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antagonists & inhibitors
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Pyrimidines
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pharmacology
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RNA, Messenger
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metabolism
3.VIEKIRA PAK associated drug-induced interstitial lung disease: Case series with systematic review of literature
Yu Jun WONG ; Si Yuan CHEW ; John Chen HSIANG ; Prem Harichander THURAIRAJAH ; Rahul KUMAR ; Eng Kiong TEO ; Roshni Sadashiv GOKHALE ; Imran Bin Mohamed NOOR ; Jessica TAN
Clinical and Molecular Hepatology 2019;25(2):218-222
No abstract available.
Lung Diseases, Interstitial
4.Cervical Vagal Nerve Stimulation Activates the Stellate Ganglion in Ambulatory Dogs.
Kyoung Suk RHEE ; Chia Hsiang HSUEH ; Jessica A HELLYER ; Hyung Wook PARK ; Young Soo LEE ; Jason GARLIE ; Patrick ONKKA ; Anisiia T DOYTCHINOVA ; John B GARNER ; Jheel PATEL ; Lan S CHEN ; Michael C FISHBEIN ; Thomas EVERETT ; Shien Fong LIN ; Peng Sheng CHEN
Korean Circulation Journal 2015;45(2):149-157
BACKGROUND AND OBJECTIVES: Recent studies showed that, in addition to parasympathetic nerves, cervical vagal nerves contained significant sympathetic nerves. We hypothesized that cervical vagal nerve stimulation (VNS) may capture the sympathetic nerves within the vagal nerve and activate the stellate ganglion. MATERIALS AND METHODS: We recorded left stellate ganglion nerve activity (SGNA), left thoracic vagal nerve activity (VNA), and subcutaneous electrocardiogram in seven dogs during left cervical VNS with 30 seconds on-time and 30 seconds off time. We then compared the SGNA between VNS on and off times. RESULTS: Cervical VNS at moderate (0.75 mA) output induced large SGNA, elevated heart rate (HR), and reduced HR variability, suggesting sympathetic activation. Further increase of the VNS output to >1.5 mA increased SGNA but did not significantly increase the HR, suggesting simultaneous sympathetic and parasympathetic activation. The differences of integrated SGNA and integrated VNA between VNS on and off times (DeltaSGNA) increased progressively from 5.2 mV-s {95% confidence interval (CI): 1.25-9.06, p=0.018, n=7} at 1.0 mA to 13.7 mV-s (CI: 5.97-21.43, p=0.005, n=7) at 1.5 mA. The difference in HR (DeltaHR, bpm) between on and off times was 5.8 bpm (CI: 0.28-11.29, p=0.042, n=7) at 1.0 mA and 5.3 bpm (CI 1.92 to 12.61, p=0.122, n=7) at 1.5 mA. CONCLUSION: Intermittent cervical VNS may selectively capture the sympathetic components of the vagal nerve and excite the stellate ganglion at moderate output. Increasing the output may result in simultaneously sympathetic and parasympathetic capture.
Animals
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Autonomic Nervous System
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Dogs*
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Electrocardiography
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Heart Rate
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Stellate Ganglion*
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Vagus Nerve Stimulation*
5.Point-of-care hepatitis C screening with direct access referral to improve linkage to care among halfway house residents: a pilot randomised study.
John Chen HSIANG ; Pream SINNASWAMI ; Mui Yok LEE ; Meng Meng ZHANG ; Kwang Ee QUEK ; Keng Hwee TAN ; Yew Meng WONG ; Prem Harichander THURAIRAJAH
Singapore medical journal 2022;63(2):86-92
INTRODUCTION:
Linkage to care among individuals with substance misuse remains a barrier to the elimination of the hepatitis C virus (HCV). We aimed to determine whether point-of-care (PoC) education, screening and staging for liver disease with direct access to hospitals would improve linkage to care among this group.
METHODS:
All participants were offered PoC education and HCV screening. HCV-positive participants were randomised to standard care (controls) or direct access, which provided a direct pathway to hospitals. Linkage to care was determined by reviewing electronic medical records. Linkage of care cascade was defined as attendance at the specialist clinic, confirmation of viraemia by HCV RNA testing, discussion about HCV treatment and initiation of treatment.
RESULTS:
351 halfway house residents were screened. The overall HCV prevalence was 30.5% (n = 107), with 69 residents in the control group and 38 in the direct access group. The direct access group had a significantly higher percentage of cases linked to specialist review for confirmatory RNA testing (63.2% vs. 40.6%, p = 0.025), HCV treatment discussion (p = 0.009) and treatment initiation (p = 0.01) compared to the controls. Overall, only 12.6% (n = 13) had treatment initiation during follow-up. PoC HCV screening with direct access referral had significantly higher linkage to HCV treatment initiation (adjusted odds ratio 9.13, p = 0.005) in multivariate analysis.
CONCLUSION
PoC HCV screening with direct access improves linkage to care and simplifies the HCV care cascade, leading to improved treatment uptake. PoC education, screening, diagnosis and treatment may be an effective strategy to achieving HCV micro-elimination in this population.
Antiviral Agents/therapeutic use*
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Halfway Houses
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Hepacivirus/genetics*
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Hepatitis C/epidemiology*
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Humans
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Pilot Projects
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Point-of-Care Systems
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RNA
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Referral and Consultation
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Substance Abuse, Intravenous/epidemiology*
6.Effects of proton pump inhibitor on the human gut microbiome profile in multi-ethnic groups in Singapore.
Seok Hwee KOO ; Jing DENG ; Daphne Shih Wen ANG ; John Chen HSIANG ; Lian Shien LEE ; Shafiq AAZMI ; Elsa Haniffah Mejia MOHAMED ; Hong YANG ; Siew Yoon YAP ; Lay Kek TEH ; Mohd Zaki SALLEH ; Edmund Jon Deoon LEE ; Tiing Leong ANG
Singapore medical journal 2019;60(10):512-521
INTRODUCTION:
The objectives of this study were to examine the effects of ethnicity, gender and a proton pump inhibitor (PPI), omeprazole, on the human gut microbiome. PPIs are commonly used for the treatment of acid-related disorders. We hypothesised that PPI therapy might perturb microbial communities and alter the gut microbiome.
METHODS:
Healthy subjects of Chinese (n = 12), Malay (n = 12) and Indian (n = 10) ancestry, aged 21-37 years, were enrolled. They provided a baseline stool sample (Day 1) and were then given a course of omeprazole at therapeutic dose (20 mg daily) for seven days. Stool samples were collected again on Day 7 and 14 (one week after stopping omeprazole). Microbial DNA was extracted from the stool samples, followed by polymerase chain reaction, library construction, 16S rRNA sequencing using Illumina MiSeq, and statistical and bioinformatics analyses.
RESULTS:
The findings showed an increase in species richness (p = 0.018) after omeprazole consumption on Day 7, which reverted to baseline on Day 14. There were significant increases in the relative abundance of Streptococcus vestibularis (p = 0.0001) and Veillonella dispar (p = 0.0001) on Day 7, which diminished on Day 14. Faecalibacterium prausnitzii, Sutterella stercoricanis and Bacteroides denticanum were characteristic of Chinese, Malays and Indians, respectively. Lactobacillaceae and Bacteroides xylanisolvens were the signature taxa of male and female subjects, respectively.
CONCLUSION
The study demonstrated alterations in the gut microbiome following omeprazole treatment. This may explain the underlying pathology of increased risk of Clostridium difficile infections associated with omeprazole therapy.