👤 Calvin A Mok

To evaluate the lipid-lowering efficacy, safety, and adherence of switching from moderate- or low-intensity statin monotherapy to ezetimibe 10 mg/rosuvastatin 2.5 mg in Korean patients with type 2 diabetes mellitus (T2DM) and dyslipidaemia. This multicentre, open-label, single-arm, prospective study enrolled adults with T2DM and LDL-C ≥70 mg/dL despite ≥12 weeks of moderate or low-intensity statin therapy. Participants received ezetimibe 10 mg/rosuvastatin 2.5 mg once daily for 12 weeks. The primary endpoint was the proportion achieving LDL-C <70 mg/dL at Week 12. Secondary endpoints included changes in lipid and glycaemic parameters, subgroup analyses, and safety outcomes. Of 639 screened patients, 586 were included in the full analysis set (FAS). At Week 12, 62.3% (95% CI 58.4-66.2) achieved LDL-C <70 mg/dL. Mean LDL-C decreased by 26.0% from 90.9 ± 17.2 to 67.3 ± 19.3 mg/dL (p < 0.001). Total cholesterol, non-HDL-C, and apoB decreased significantly (all p < 0.001); HDL-C and triglycerides were unchanged (p = 0.914 and p = 0.393, respectively). HbA1c increased by 0.15 ± 0.53% and fasting glucose by 3.6 ± 24.7 mg/dL (both p < 0.001). HOMA-IR decreased by -0.22 ± 3.09, not significant (p = 0.085). Subgroup analyses showed greater LDL-C reductions in patients with BMI <23 kg/m Switching to ezetimibe 10 mg/rosuvastatin 2.5 mg achieved substantial LDL-C reductions, high goal attainment, excellent adherence, and good tolerability in Korean T2DM patients with dyslipidaemia. Show less

We assessed the coverage of molecular drug susceptibility testing (mDST) among patients with pulmonary multidrug/rifampicin-resistant tuberculosis (MDR/RR-TB) in South Korea and identified factors influencing the lack of mDST implementation. This retrospective study included patients with pulmonary MDR/RR-TB who initiated tuberculosis (TB) treatment between January 2015 and September 2021. Data were obtained from the K-TB-N cohort, an integrated national TB database linking three datasets. We assessed mDST coverage, temporal trends and factors associated with the lack of mDST implementation. mDST was defined as the use of the Xpert MTB/RIF assay or line probe assay (LPA) for isoniazid and rifampicin (first-line LPA). In total, 4637 patients were included in the analysis. Of the 4637 patients, 1342 (28.9%) did not undergo mDST; whereas, 3295 (71.1%) underwent mDST. Over the study period, a statistically significant annual increase in mDST coverage was observed, escalating from 49.1% in 2015 to 96.9% in 2021 (p<0.001). Throughout the study, the coverage of the Xpert MTB/RIF assay remained lower than that of LPA (22.1% vs 64.2%, p<0.001). Multivariable logistic regression analysis identified several factors independently associated with a decreased likelihood of mDST being conducted, including TB treatment initiation in secondary general hospitals, small hospitals or primary clinics, as well as in non-public-private mix (PPM) participating institutions. In addition, transfers between PPM-participating and non-participating institutions during the treatment period and sputum acid-fast bacilli smear-negative status were significantly associated with lower mDST uptake. Although the increasing mDST coverage is a positive development, further efforts are needed to achieve nationwide and universal implementation, particularly for the Xpert MTB/RIF assay, in South Korea. Show less

Induced pluripotent stem cells (iPSC) derived from healthy individuals are important controls for disease-modeling studies. Here we apply precision health to create a high-quality resource of control iPSCs. Footprint-free lines were reprogrammed from four volunteers of the Personal Genome Project Canada (PGPC). Multilineage-directed differentiation efficiently produced functional cortical neurons, cardiomyocytes and hepatocytes. Pilot users demonstrated versatility by generating kidney organoids, T lymphocytes, and sensory neurons. A frameshift knockout was introduced into MYBPC3 and these cardiomyocytes exhibited the expected hypertrophic phenotype. Whole-genome sequencing-based annotation of PGPC lines revealed on average 20 coding variants. Importantly, nearly all annotated PGPC and HipSci lines harbored at least one pre-existing or acquired variant with cardiac, neurological, or other disease associations. Overall, PGPC lines were efficiently differentiated by multiple users into cells from six tissues for disease modeling, and variant-preferred healthy control lines were identified for specific disease settings. Show less

Hereditary channelopathies and cardiomyopathies are potentially lethal and are clinically and genetically heterogeneous, involving at least 90 genes. Genetic testing can provide an accurate diagnosis, guide treatment, and enable cascade screening. The genetic basis among the Hong Kong Chinese population is largely unknown. We aimed to report on 28 unrelated patients with positive genetic findings detected from January 2006 to December 2015. Sanger sequencing was performed for 28 unrelated patients with a clinical diagnosis of channelopathies or cardiomyopathies, testing for the following genes: There were 17 males and 11 females; their mean age at diagnosis was 39 years (range, 1-80 years). The major clinical presentations included syncope, palpitations, and abnormal electrocardiography findings. A family history was present in 13 (46%) patients. There were 26 different heterozygous mutations detected, of which six were novel-two in We have characterised the genetic heterogeneity in channelopathies and cardiomyopathies among Hong Kong Chinese patients in a 10-year case series. Correct interpretation of genetic findings is difficult and requires expertise and experience. Caution regarding issues of non-penetrance, variable expressivity, phenotype-genotype correlation, susceptibility risk, and digenic inheritance is necessary for genetic counselling and cascade screening. Show less

Genome-wide association studies (GWAS) on Parkinson's disease (PD) have mostly been done in Europeans and Japanese. No study has been done in Han Chinese, which make up nearly a fifth of the world population. We conducted the first Han Chinese GWAS analysing a total of 22,729 subjects (5,125 PD cases and 17,604 controls) from Singapore, Hong Kong, Malaysia, Korea, mainland China and Taiwan. We performed imputation, merging and logistic regression analyses of 2,402,394 SNPs passing quality control filters in 779 PD cases, 13,227 controls, adjusted for the first three principal components. 90 SNPs with association P < 10-4 were validated in 9 additional sample collections and the results were combined using fixed-effects inverse-variance meta-analysis. We observed strong associations reaching genome-wide significance at SNCA, LRRK2 and MCCC1, confirming their important roles in both European and Asian PD. We also identified significant (P < 0.05) associations at 5 loci (DLG2, SIPA1L2, STK39, VPS13C and RIT2), and observed the same direction of associations at 9 other loci including BST1 and PARK16. Allelic heterogeneity was observed at LRRK2 while European risk SNPs at 6 other loci including MAPT and GBA-SYT11 were non-polymorphic or very rare in our cohort. Overall, we replicate associations at SNCA, LRRK2, MCCC1 and 14 other European PD loci but did not identify Asian-specific loci with large effects (OR > 1.45) on PD risk. Our results also demonstrate some differences in the genetic contribution to PD between Europeans and Asians. Further pan-ethnic meta-analysis with European GWAS cohorts may unravel new PD loci. Show less

Hand-foot syndrome (HFS) is a common adverse effect of capecitabine treatment. To compare the incidence and time to onset of grade 2 or greater HFS in patients receiving pyridoxine vs placebo and to identify biomarkers predictive of HFS. This single-center, randomized double-blind, placebo-controlled phase 3 trial conducted at National Cancer Centre Singapore assessed whether oral pyridoxine could prevent the onset of grade 2 or higher HFS in 210 patients scheduled to receive single-agent capecitabine chemotherapy for breast, colorectal, and other cancers. Patients were randomized to receive concurrent pyridoxine (200 mg) or placebo daily for a maximum of 8 cycles of capecitabine, with stratification by sex and use in adjuvant or neoadjuvant vs palliative setting. Patients were withdrawn from the study on development of grade 2 or higher HFS or cessation of capecitabine. Primary end point was the incidence of grade 2 or higher HFS in patients receiving pyridoxine. Secondary end points included the time to onset (days) of grade 2 or higher HFS and identification of biomarkers predictive of HFS, including baseline folate and vitamin B12 levels, as well as genetic polymorphisms with genome-wide arrays. In this cohort of 210 patients (median [range] age, 58 [26-82] years; 162 women) grade 2 or higher HFS occurred in 33 patients (31.4%) in the pyridoxine arm vs 39 patients (37.1%) in the placebo arm (P = .38). The median time to onset of grade 2 or higher HFS was not reached in both arms. In univariate analysis, the starting dose of capecitabine (odds ratio [OR], 1.99; 95% CI, 1.32-3.00; P = .001), serum folate levels (OR, 1.27; 95% CI, 1.10-1.47; P = .001), and red blood cell folate levels (OR, 1.25; 95% CI, 1.08-1.44; P = .003) were associated with increased risk of grade 2 or higher HFS. In multivariate analyses, serum folate (OR, 1.30; 95% CI, 1.12-1.52; P < .001) and red blood cell folate (OR, 1.28; 95% CI, 1.10-1.49; P = .001) were the only significant predictors of grade 2 or higher HFS. Grade 2 or higher HFS was associated with 300 DNA variants at genome-wide significance (P < 5 × 10-8), including a novel DPYD variant (rs75267292; P = 1.57 × 10-10), and variants in the MACF1 (rs183324967, P = 4.80 × 10-11; rs148221738, P = 5.73 × 10-10) and SPRY2 (rs117876855, P < 1.01 × 10-8; rs139544515, P = 1.30 × 10-8) genes involved in wound healing. Pyridoxine did not significantly prevent or delay the onset of grade 2 or higher HFS. Serum and red blood cell folate levels are independent predictors of HFS. clinicaltrials.gov Identifier: NCT00486213. Show less

Kaempferol is a dietary flavonol previously shown to regulate cellular lipid and glucose metabolism. However, its molecular mechanisms of action and target proteins have remained elusive, probably due to the involvement of multiple proteins. This study investigated the molecular targets of kaempferol. Ligand binding of kaempferol to liver X receptors (LXRs) was quantified by time-resolved fluorescence resonance energy transfer and surface plasmon resonance analyses. Kaempferol directly binds to and induces the transactivation of LXRs, with stronger specificity for the β-subtype (EC50 = 0.33 μM). The oral administration of kaempferol in apolipoprotein-E-deficient mice (150 mg/day/kg body weight) significantly reduced plasma glucose and increased high-density lipoprotein cholesterol levels and insulin sensitivity compared with the vehicle-fed control. Kaempferol also reduced plasma triglyceride concentrations and did not cause liver steatosis, a common side effect of potent LXR activation. In immunoblotting analysis, kaempferol reduced the nuclear accumulation of sterol regulatory element-binding protein-1 (SREBP-1). Our results show that the suppression of SREBP-1 activity and the selectivity for LXR-β over LXR-α by kaempferol contribute to the reductions of plasma and hepatic triglyceride concentrations in mice fed kaempferol. They also suggest that kaempferol activates LXR-β and suppresses SREBP-1 to enhance symptoms in metabolic syndrome. Show less

Bardet Biedl syndrome is a genetically heterogeneous ciliopathy with fourteen genes currently identified. To date, mutations in BBS7 and TTC8 (BBS8) were reported in 4.2% and 2.8% of BBS families respectively. We sequenced the coding regions of BBS7 and TTC8 in 35 BBS families of diverse ancestral backgrounds. In addition, the role of putative modifier genes on phenotype severity; NXNL1 and MGC1203 c.430C>T, was assessed. Genotype-phenotype correlation was explored in patients with identified mutations. Four novel pathogenic BBS7 changes were identified in 2/35 families (5.7%). In one family with two affected individuals with BBS7 mutations, a more severe phenotype was observed in association with a third mutation in BBS4. The overall retinal phenotype appeared more severe than that seen in patients with BBS1 mutations. This study confirms the small role of BBS7 and TTC8 in the overall mutational load of BBS patients. The variability of the ocular phenotype observed, could not be explained by the putative modifier genes; NXNL1 and MGC1203 c.430C>T. Show less

MIP-T3 is a human protein found previously to associate with microtubules and the kinesin-interacting neuronal protein DISC1 (Disrupted-in-Schizophrenia 1), but whose cellular function(s) remains unknown. Here we demonstrate that the C. elegans MIP-T3 ortholog DYF-11 is an intraflagellar transport (IFT) protein that plays a critical role in assembling functional kinesin motor-IFT particle complexes. We have cloned a loss of function dyf-11 mutant in which several key components of the IFT machinery, including Kinesin-II, as well as IFT subcomplex A and B proteins, fail to enter ciliary axonemes and/or mislocalize, resulting in compromised ciliary structures and sensory functions, and abnormal lipid accumulation. Analyses in different mutant backgrounds further suggest that DYF-11 functions as a novel component of IFT subcomplex B. Consistent with an evolutionarily conserved cilia-associated role, mammalian MIP-T3 localizes to basal bodies and cilia, and zebrafish mipt3 functions synergistically with the Bardet-Biedl syndrome protein Bbs4 to ensure proper gastrulation, a key cilium- and basal body-dependent developmental process. Our findings therefore implicate MIP-T3 in a previously unknown but critical role in cilium biogenesis and further highlight the emerging role of this organelle in vertebrate development. Show less