1.Longitudinal profile of plasma pregenomic RNA in patients with chronic hepatitis B infection on long-term nucleoside analogues and its interaction with clinical parameters
Lung-Yi MAK ; Mark ANDERSON ; Michael STEC ; Matthew Shing-Hin CHUNG ; Danny Ka-Ho WONG ; Rex Wan-Hin HUI ; Wai-Kay SETO ; Gavin CLOHERTY ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(2):460-473
Background:
s/Aims: Plasma pregenomic hepatitis B virus RNA (pgRNA) is a novel biomarker in chronic hepatitis B infection (CHB). We aimed to describe the longitudinal profile of pgRNA and factors influencing its levels in CHB patients on nucleoside analogue (NUC).
Methods:
Serial plasma samples from 1,354 CHB patients started on first-line NUC were evaluated. Time of NUC initiation was taken as baseline (year 0), followed by 1-year, 3-year and 5-year of NUC therapy. pgRNA was measured by Research Use Only RealTime HBV RNA v2.0 (0.2 mL) (Abbott Diagnostics) with lower limit of detection of 0.8 log U/mL (~20 copies/mL).
Results:
Among 1,354 subjects (median age at baseline 49.8 [interquartile range, IQR 40.2–57.3]) years, 65.2% male, 16.1% hepatitis B e antigen (HBeAg)-positive, 28.6% cirrhotic), baseline median HBV RNA was 3.68 (IQR 2.42–5.19) log U/mL. Upon NUC therapy, median pgRNA levels were 2.45 (IQR 1.82–3.62), 2.23 (IQR 1.67–3.05) and 2.14 (IQR 1.48–2.86) log U/mL at 1, 3 and 5 years, respectively, with the corresponding log U/mL reductions of 0.82, 1.20 and 1.54. Undetectable/ unquantifiable pgRNA was achieved in 13.5%, 15.9% and 20.1% of patients at 1, 3 and 5 years, respectively. Older age, male sex, HBeAg-negativity and high PAGE-B score were associated with lower pgRNA.
Conclusions
Plasma pgRNA declines are modest under NUC therapy, with only 16.3% achieving RNA undetectability after 5 years of first-line NUC indicating cccDNA silencing has not been achieved in the majority of patients. Clinical characteristics should be taken into consideration when interpreting the plasma pgRNA level.
2.Machine Learning-Based Computed Tomography-Derived Fractional Flow Reserve Predicts Need for Coronary Revascularisation Prior to Transcatheter Aortic Valve Implantation
Kai Dick David LEUNG ; Pan Pan NG ; Boris Chun Kei CHOW ; Keith Wan Hang CHIU ; Neeraj Ramesh MAHBOOBANI ; Yuet-Wong CHENG ; Eric Chi Yuen WONG ; Alan Ka Chun CHAN ; Augus Shing Fung CHUI ; Michael Kang-Yin LEE ; Jonan Chun Yin LEE
Cardiovascular Imaging Asia 2025;9(1):2-8
Objective:
Patients with severe symptomatic aortic stenosis are assessed for coronary artery disease (CAD) prior to transcatheter aortic valve implantation (TAVI) with treatment implications. Invasive coronary angiography (ICA) is the recommended modality but is associated with peri-procedural complications. Integrating machine learning (ML)-based computed tomography-derived fractional flow reserve (CT-FFR) into existing TAVI-planning CT protocol may aid exclusion of significant CAD and thus avoiding ICA in selected patients.
Materials and Methods:
A single-center, retrospective study was conducted, 41 TAVI candidates with both TAVI-planning CT and ICA performed were analyzed. CT datasets were evaluated by a ML-based CT-FFR software. Beta-blocker and nitroglycerin were not administered in these patients. The primary outcome was to identify significant CAD. The diagnostic performance of CT-FFR was compared against ICA.
Results:
On per-patient level, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were 89%, 94%, 80%, 97% and 93%, respectively. On per-vessel level, the sensitivity, specificity, PPV, NPV and diagnostic accuracy were 75%, 94%, 67%, 96% and 92%, respectively. The area under the receiver operative characteristics curve per individual coronary vessels yielded overall 0.90 (95% confidence interval 85%–95%). ICA may be avoided in up to 80% of patients if CT-FFR results were negative.
Conclusion
ML-based CT-FFR can provide accurate screening capabilities for significant CAD thus avoiding ICA. Its integration to existing TAVI-planning CT is feasible with the potential of improving the safety and efficiency of pre-TAVI CAD assessment.
3.Longitudinal profile of plasma pregenomic RNA in patients with chronic hepatitis B infection on long-term nucleoside analogues and its interaction with clinical parameters
Lung-Yi MAK ; Mark ANDERSON ; Michael STEC ; Matthew Shing-Hin CHUNG ; Danny Ka-Ho WONG ; Rex Wan-Hin HUI ; Wai-Kay SETO ; Gavin CLOHERTY ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(2):460-473
Background:
s/Aims: Plasma pregenomic hepatitis B virus RNA (pgRNA) is a novel biomarker in chronic hepatitis B infection (CHB). We aimed to describe the longitudinal profile of pgRNA and factors influencing its levels in CHB patients on nucleoside analogue (NUC).
Methods:
Serial plasma samples from 1,354 CHB patients started on first-line NUC were evaluated. Time of NUC initiation was taken as baseline (year 0), followed by 1-year, 3-year and 5-year of NUC therapy. pgRNA was measured by Research Use Only RealTime HBV RNA v2.0 (0.2 mL) (Abbott Diagnostics) with lower limit of detection of 0.8 log U/mL (~20 copies/mL).
Results:
Among 1,354 subjects (median age at baseline 49.8 [interquartile range, IQR 40.2–57.3]) years, 65.2% male, 16.1% hepatitis B e antigen (HBeAg)-positive, 28.6% cirrhotic), baseline median HBV RNA was 3.68 (IQR 2.42–5.19) log U/mL. Upon NUC therapy, median pgRNA levels were 2.45 (IQR 1.82–3.62), 2.23 (IQR 1.67–3.05) and 2.14 (IQR 1.48–2.86) log U/mL at 1, 3 and 5 years, respectively, with the corresponding log U/mL reductions of 0.82, 1.20 and 1.54. Undetectable/ unquantifiable pgRNA was achieved in 13.5%, 15.9% and 20.1% of patients at 1, 3 and 5 years, respectively. Older age, male sex, HBeAg-negativity and high PAGE-B score were associated with lower pgRNA.
Conclusions
Plasma pgRNA declines are modest under NUC therapy, with only 16.3% achieving RNA undetectability after 5 years of first-line NUC indicating cccDNA silencing has not been achieved in the majority of patients. Clinical characteristics should be taken into consideration when interpreting the plasma pgRNA level.
4.Longitudinal profile of plasma pregenomic RNA in patients with chronic hepatitis B infection on long-term nucleoside analogues and its interaction with clinical parameters
Lung-Yi MAK ; Mark ANDERSON ; Michael STEC ; Matthew Shing-Hin CHUNG ; Danny Ka-Ho WONG ; Rex Wan-Hin HUI ; Wai-Kay SETO ; Gavin CLOHERTY ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(2):460-473
Background:
s/Aims: Plasma pregenomic hepatitis B virus RNA (pgRNA) is a novel biomarker in chronic hepatitis B infection (CHB). We aimed to describe the longitudinal profile of pgRNA and factors influencing its levels in CHB patients on nucleoside analogue (NUC).
Methods:
Serial plasma samples from 1,354 CHB patients started on first-line NUC were evaluated. Time of NUC initiation was taken as baseline (year 0), followed by 1-year, 3-year and 5-year of NUC therapy. pgRNA was measured by Research Use Only RealTime HBV RNA v2.0 (0.2 mL) (Abbott Diagnostics) with lower limit of detection of 0.8 log U/mL (~20 copies/mL).
Results:
Among 1,354 subjects (median age at baseline 49.8 [interquartile range, IQR 40.2–57.3]) years, 65.2% male, 16.1% hepatitis B e antigen (HBeAg)-positive, 28.6% cirrhotic), baseline median HBV RNA was 3.68 (IQR 2.42–5.19) log U/mL. Upon NUC therapy, median pgRNA levels were 2.45 (IQR 1.82–3.62), 2.23 (IQR 1.67–3.05) and 2.14 (IQR 1.48–2.86) log U/mL at 1, 3 and 5 years, respectively, with the corresponding log U/mL reductions of 0.82, 1.20 and 1.54. Undetectable/ unquantifiable pgRNA was achieved in 13.5%, 15.9% and 20.1% of patients at 1, 3 and 5 years, respectively. Older age, male sex, HBeAg-negativity and high PAGE-B score were associated with lower pgRNA.
Conclusions
Plasma pgRNA declines are modest under NUC therapy, with only 16.3% achieving RNA undetectability after 5 years of first-line NUC indicating cccDNA silencing has not been achieved in the majority of patients. Clinical characteristics should be taken into consideration when interpreting the plasma pgRNA level.
5.A case report of a giant solitary juvenile polyp: from obstructed defecation syndrome to incontinence
Zhan Huai TEOH ; Jien Yen SOH ; Nasibah MOHAMAD ; Norzaliana ZAWAWI ; Andee Dzulkarnaen ZAKARIA ; Zaidi ZAKARIA ; Michael Pak-Kai WONG
Annals of Coloproctology 2024;40(Suppl 1):S27-S31
Juvenile polyps (JPs) are the most common polyps in pediatric patients. We present the case of an 18-year-old male patient with a giant solitary JP resembling solitary rectal ulcer syndrome (SRUS). The presenting history was rectal bleeding and symptoms of obstructed defecation syndrome. Colonoscopy revealed a polypoidal mass at the anorectal junction, with biopsy-confirmed SRUS. The symptoms worsened, and a protruding mass from the anus caused fecal incontinence. Pelvic magnetic resonance imaging showed a huge pedunculated mass occupying the low rectum with local compression of the urinary bladder. Transanal excision of the anal tumor was performed due to bleeding. A histopathological examination showed a JP with high-grade dysplasia. A histological examination to differentiate JPs and SRUS could be challenging based on a superficial forceps biopsy. Therefore, an excision biopsy is usually warranted with the understanding that adenomatous or malignant transformation is found in 5.6% to 12% of all JPs.
6.Impact of fatty liver on long-term outcomes in chronic hepatitis B: a systematic review and matched analysis of individual patient data meta-analysis
Yu Jun WONG ; Vy H. NGUYEN ; Hwai-I YANG ; Jie LI ; Michael Huan LE ; Wan-Jung WU ; Nicole Xinrong HAN ; Khi Yung FONG ; Elizebeth CHEN ; Connie WONG ; Fajuan RUI ; Xiaoming XU ; Qi XUE ; Xin Yu HU ; Wei Qiang LEOW ; George Boon-Bee GOH ; Ramsey CHEUNG ; Grace WONG ; Vincent Wai-Sun WONG ; Ming-Whei YU ; Mindie H. NGUYEN
Clinical and Molecular Hepatology 2023;29(3):705-720
Background/Aims:
Chronic hepatitis B (CHB) and fatty liver (FL) often co-exist, but natural history data of this dual condition (CHB-FL) are sparse. Via a systematic review, conventional meta-analysis (MA) and individual patient-level data MA (IPDMA), we compared liver-related outcomes and mortality between CHB-FL and CHB-no FL patients.
Methods:
We searched 4 databases from inception to December 2021 and pooled study-level estimates using a random- effects model for conventional MA. For IPDMA, we evaluated outcomes after balancing the two study groups with inverse probability treatment weighting (IPTW) on age, sex, cirrhosis, diabetes, ALT, HBeAg, HBV DNA, and antiviral treatment.
Results:
We screened 2,157 articles and included 19 eligible studies (17,955 patients: 11,908 CHB-no FL; 6,047 CHB-FL) in conventional MA, which found severe heterogeneity (I2=88–95%) and no significant differences in HCC, cirrhosis, mortality, or HBsAg seroclearance incidence (P=0.27–0.93). IPDMA included 13,262 patients: 8,625 CHB-no FL and 4,637 CHB-FL patients who differed in several characteristics. The IPTW cohort included 6,955 CHB-no FL and 3,346 CHB-FL well-matched patients. CHB-FL patients (vs. CHB-no FL) had significantly lower HCC, cirrhosis, mortality and higher HBsAg seroclearance incidence (all p≤0.002), with consistent results in subgroups. CHB-FL diagnosed by liver biopsy had a higher 10-year cumulative HCC incidence than CHB-FL diagnosed with non-invasive methods (63.6% vs. 4.3%, p<0.0001).
Conclusions
IPDMA data with well-matched CHB patient groups showed that FL (vs. no FL) was associated with significantly lower HCC, cirrhosis, and mortality risk and higher HBsAg seroclearance probability.
7.Multiple gastrointestinal melanoma causing small bowel intussusception
Jian Yang ENG ; Salehah TAHKIN ; Huzairi YAACOB ; Nor Hayati YUNUS ; Ahmad Shan Wani Mohamed SIDEK ; Michael Pak-Kai WONG
Annals of Coloproctology 2023;39(1):85-88
A 61-year-old gentleman presented with small bowel intussusception from small bowel melanoma intussusceptum. He complains of intermittent abdominal distension but no history of intestinal obstruction. Apart from this, he was also symptomatic anemia which required repeated transfusion for the past few months. The contrast-enhanced computed tomography of the abdomen shows an omental mass with small bowel intussusception. He then underwent an exploratory laparotomy with segmental resection of the affected segment. Histopathological examination confirmed primary gastrointestinal melanoma. Multiple small bowel malignant melanoma is a rare disease. It remains a controversial diagnosis as it may be a primary or metastasis from an unidentified or regressed primary cutaneous melanoma. Prompt surgical intervention enables us to obtain tissue diagnosis, prevent complete intestinal obstruction and strategize the goals of treatment for the patient.
8.Risk factors associated with low anterior resection syndrome: a cross-sectional study
See Liang LIM ; Wan Zainira WAN ZAIN ; Zalina ZAHARI ; Andee Dzulkarnaen ZAKARIA ; Mohd Nizam Md HASHIM ; Michael Pak-Kai WONG ; Zaidi ZAKARIA ; Rosnelifaizur RAMELY ; Ahmad Shanwani Mohamed SIDEK
Annals of Coloproctology 2023;39(5):427-434
Purpose:
Oncological outcomes following rectal cancer surgery have improved significantly over recent decades with lower recurrences and longer overall survival. However, many of the patients experienced low anterior resection syndrome (LARS). This study identified the prevalence and risk factors associated with the development of LARS.
Methods:
This cross-sectional study involved patients who were diagnosed with rectal cancer and had undergone sphincter-preserving low anterior resection from January 2011 to December 2020. Upon clinic follow-up, patients were asked to complete an interviewed based questionnaire (LARS score) designed to assess bowel dysfunction after rectal cancer surgery.
Results:
Out of 76 patients, 25 patients (32.9%) had major LARS, 10 patients (13.2%) had minor LARS, and 41 patients (53.9%) had no LARS. The height of tumor from anal verge showed an association with the development of major LARS (P=0.039). Those patients with less than 8 cm tumor from anal verge had an increased risk of LARS by 3 times compared to those with 8 cm and above (adjusted odds ratio, 3.11; 95% confidence interval, 1.06–9.13).
Conclusion
Results from our study show that low tumor height was a significant risk factor that has a negative impact on bowel function after surgery. The high prevalence of LARS emphasizes the need for study regarding risk factors and the importance of understanding the pathophysiology of LARS, in order for us to improve patient bowel function and quality of life after rectal cancer surgery.
9.Antimicrobial activity of two Antarctic Streptomyces strains
Chen ZiAng ; Teoh Chui Peng ; Fan Hui Yin ; Lavin Paris ; Wong Clemente Michael Vui Ling
Malaysian Journal of Microbiology 2023;19(no.6):678-684
Aims:
The search for new antibiotics is an ongoing effort and has expanded to pristine niche areas in the Antarctic in recent years due to the emergence of multi-drug resistant pathogens that outpaced the discovery of new antibiotics. We have recently isolated two new actinomycetes strains, INACH3013a and INACH3013b, which displayed antimicrobial properties from soil samples collected from Ardley Island, Antarctica. Hence, an investigation was carried out to identify them and to characterise the antimicrobial compounds produced.
Methodology and results:
Strains, INACH3013a and INACH3013b were identified based on their 16S rDNA sequence alignment to those in the GenBank. The results showed that strain INACH3013a was closest to Streptomyces spp. while strain INACH3013b was closest to Streptomyces corallincola and Streptomyces bullii. The extracellular compounds they produced were extracted using various solvents and the extracted compounds were tested against the test pathogens. The dichloromethane extracts from strains, INACH3013a and INACH3013b inhibited mainly Gram-positive pathogens that include Listeria monocytogenes, Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus equorum,
Bacillus cereus K3 and Enterococcus faecalis while extracts from strain INACH3013b also inhibited a Gram-negative pathogen, Klebsiella pneumonia 14x. Predominantly non-polar constituents seem responsible for antibacterial effects, with dichloromethane extracts proving most efficacious, followed by chloroform and ethyl acetate.
Conclusion, significance and impact of study
The research highlights the potential of Streptomyces spp. INACH3013a and INACH3013b as a source of potential novel antibiotics. This research explores Antarctic Streptomyces strains' antimicrobial capabilities, enabling the potential for the discovery of novel antibiotics and revealing how these compounds may have helped them to compete and survive in nutrient-deficient Antarctic niches.
10.Functional analysis of conserved hypothetical proteins from the Antarctic yeast, Glaciozyma antarctica PI12
Makdi Masnoddin ; Clemente Michael Wong Vui Ling ; Nur Athirah Yusof
Malaysian Journal of Microbiology 2023;19(no.6):766-776
Aims:
Recent discoveries have revealed that Glaciozyma antarctica PI12 has been discovered to encode numerous protein-coding genes that are crucial for thermal adaptation. However, more than 35% of the protein-coding genes for this species were identified as hypothetical proteins (HP). Nevertheless, over 35% of the protein-coding genes for this species were classified as hypothetical proteins (HP). Previous studies have documented the role of these uncharacterized proteins in the physiological regulation and cold adaptation of psychrophilic microorganisms. Thus, we aim to identify the structural features of the conserved HPs that were ideal for their function in response to temperature stress.
Methodology and results:
Three conserved HPs of G. antarctica, designated GaHP2, GaHP3 and GaHP4, were cloned, expressed purified and their function and structure were evaluated. Functional analysis showed that these proteins maintained their activities at low temperatures below 25 °C, but at a lower reaction rate. Meanwhile, thermal unfolding assays revealed the stability of GaHP2 and GaHP4 at high temperatures (43 °C), suggesting their non-ATPbinding chaperone activity. The comparative structural analysis demonstrated that the HPs exhibited cold-adapted traits, most notably increased flexibility in their 3D structures. For GaHP2, the aromatic residues can be linked to its heat stability. GaHP4's cold shock domain implies it regulates gene transcription and translation during temperature fluctuations.
Conclusion, significance and impact of study:
This study has established the structure-function relationships of the G. antarctica HPs and provided fundamental experimental data highlighting their importance in thermal stress response by maintaining a balance between molecular stability and structural flexibility.


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