1.Detection of dengue viruses and Wolbachia in Aedes aegypti and Aedes albopictus larvae from four urban localities in Kuala Lumpur, Malaysia
Teo, C.H.J. ; Voon, K. ; Mak, J.W
Tropical Biomedicine 2017;34(3):583-597
Dengue fever (DF) is currently one of the most important mosquito-borne diseases
that affects humans. Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by
four serotypes of dengue viruses (DENV-1 to DENV-4). The main vector transmitting dengue
is Aedes aegypti while Aedes albopictus acts as a secondary vector. As treatment is unavailable
and the first dengue vaccine approved in Mexico, Dengvaxia® has yet to be accepted worldwide,
prevention of the disease relies heavily on surveillance and control of mosquito vectors.
A transgene driver, Wolbachia was found to limit the transmission of dengue virus in Aedes
mosquitoes. Wolbachia alone was able to inhibit viral replication, dissemination and
transmission in A. aeygpti mosquitoes in experimental studies. In A. albopictus, Wolbachia
did not affect the replication of dengue virus but was able to reduce the viral infection of
mosquito salivary glands and limit transmission. Studies on Wolbachia have all been carried
out in adult Aedes mosquitoes, hence this study was conducted to determine the presence of
dengue virus serotypes and Wolbachia in A. aegypti and A. albopictus larvae collected from
ovitraps in four localities in Kuala Lumpur viz. Happy Gardens, IMU Bukit Jalil, Ampang and
Taman Yarl. Another objective of this study was to determine the association between dengue
virus serotypes and the presence of Wolbachia in A. aegypti and A. albopictus larvae. A total
of 300 mosquito larvae was collected; 99 (Happy Gardens), 85 (Bukit Jalil), 73 (Ampang) and
43 (Taman Yarl). Out of 300 larvae collected, 284 were identified as A. albopictus and 16
others were identified as A. aegypti. Of the 284 A. albopictus larvae collected, 211 (74.3%)
and 73 (25.7%) were found to be negative and positive for dengue virus respectively. The
dengue serotypes detected were 2 DENV-2 (2.7%), 58 DENV-3 (79.5%) and 13 DENV-4 (17.8%).
DENV-1 was not detected in any of the A. albopictus larvae. For A. aegypti, out of 16 A.
aegypti larvae collected, 12 (75%) were found to be negative and 4 (25%) were positive for
DENV-2. For the detection of Wolbachia in A. albopictus, 71 out of 284 (25%) and 213 (75%)
larvae were found to be positive and negative for Wolbachia respectively. For A. aegypti, 4
(25%) and 12 (75%) out of 16 larvae were positive and negative for Wolbachia respectively.
This is the first report of Wolbachia in A. albopictus and A. aegypti larvae in Malaysia. A chisquare
test analysis to determine the association between dengue virus and Wolbachia in A.
albopictus and A. aegypti larvae collected from the four localities in Kuala Lumpur showed
that there was no association (χ2 = 3.080; df = 1; P > 0.05).
2.Monoclonal antibody-escape variant of dengue virus serotype 1: Genetic composition and envelope protein expression
Chem, Y.K. ; Chua, K.B. ; Malik, Y. ; Voon, K.
Tropical Biomedicine 2015;32(2):344-351
Monoclonal antibody-escape variant of dengue virus type 1 (MabEV DEN-1) was
discovered and isolated in an outbreak of dengue in Klang Valley, Malaysia from December
2004 to March 2005. This study was done to investigate whether DEN152 (an isolate of
MabEV DEN-1) is a product of recombination event or not. In addition, the non-synonymous
mutations that correlate with the monoclonal antibody-escape variant were determined in
this study. The genomes of DEN152 and two new DEN-1 isolates, DENB04 and DENK154
were completely sequenced, aligned, and compared. Phylogenetic tree was plotted and the
recombination event on DEN152 was investigated. DEN152 is sub-grouped under genotype I
and is closely related genetically to a DEN-1 isolated in Japan in 2004. DEN152 is not a
recombinant product of any parental strains. Four amino acid substitutions were unique only
to DEN 152. These amino acid substitutions were Ser[326]Leu, Ser[340]Leu at the deduced E
protein, Ile[250]Thr at NS1 protein, and Thr[41]Ser at NS5 protein. Thus, DEN152 is an isolate of
the emerging monoclonal antibody-escape variant DEN-1 that escaped diagnostic laboratory
detection.
3.Port assisted closure of laparoscopic wound: A safe and feasible technique
Voon Meng Leow ; Faizah Mohd Sikandar ; Mohd Sharifudin Sharif ; Vasu Pillai Letchumanan ; Khuan Fuat Yang ; Manisekar K Subramaniam
The Medical Journal of Malaysia 2015;70(5):278-280
Objective: Various techniques and instruments have been
developed to provide safe and secure closure of
laparoscopic wounds. Herein we describe a simple method
to close laparoscopic supraumbilical wounds with the aid of
a laparoscopic port.
Method: This was a retrospective review of prospective data,
which were from 151 patients who underwent laparoscopic
cholecystectomy for symptomatic gallstone disease from
December 2009 to December 2010 in Sultanah Bahiyah
Hospital. A senior consultant hepato-pancreato-biliary (HPB)
surgeon and two HPB trainee surgeons performed the
operations. Postoperatively, all patients were followed up at
4 weeks.
Results: All patients successfully underwent closure of the
supraumbilical wound with the assistance of a 5mm
laparoscopic port. None of the patients had incisional hernia
on follow up.
Conclusion: Port assisted closure of supraumbilical
laparoscopic wounds is a feasible and safe technique.
Laparoscopy
4.Efficacy and Safety of Ceritinib 450 mg/day with Food and 750 mg/day in Fasted State in Treatment-Naïve Patients with ALK+ Non–Small Cell Lung Cancer: Results from the ASCEND-8 Asian Subgroup Analysis
Byoung Chul CHO ; Dong-Wan KIM ; Ullas BATRA ; Keunchil PARK ; Sang-We KIM ; Cheng-Ta YANG ; Pei-Jye VOON ; Virote SRIURANPONG ; K. Govind BABU ; Khalid AMIN ; Yingbo WANG ; Paramita SEN ; Khemaies SLIMANE ; Sarayut GEATER
Cancer Research and Treatment 2023;55(1):83-93
Purpose:
Previous report from the ASCEND-8 trial showed consistent efficacy with less gastrointestinal (GI) toxicity in patients with anaplastic lymphoma kinase-rearranged (ALK+) advanced/metastatic non–small cell lung cancer (NSCLC) treated with ceritinib 450-mg with food compared with 750-mg fasted. In this subgroup analysis, we report outcomes in Asian patients of the ASCEND-8 trial.
Materials and Methods:
Key efficacy endpoints were blinded independent review committee (BIRC)–assessed overall response rate (ORR) and duration of response (DOR) evaluated per Response Evaluation Criteria in Solid Tumors v1.1. Other efficacy endpoints were investigator-assessed ORR and DOR; BIRC- and investigator-assessed progression-free survival (PFS) and disease control rate; overall survival (OS). Safety was evaluated by frequency and severity of adverse events.
Results:
At final data cutoff (6 March 2020), 198 treatment-naïve patients were included in efficacy analysis, of which 74 (37%) comprised the Asian subset; 450-mg fed (n=29), 600-mg fed (n=19), and 750-mg fasted (n=26). Baseline characteristics were mostly comparable across study arms. At baseline, more patients in 450-mg fed arm (44.8%) had brain metastases than in 750-mg fasted arm (26.9%). Per BIRC, patients in the 450-mg fed arm had a numerically higher ORR, 24-month DOR rate and 24-month PFS rate than the 750-mg fasted arm. The 36-month OS rate was 93.1% in 450-mg fed arm and 70.9% in 750-mg fasted arm. Any-grade GI toxicity occurred in 82.8% and 96.2% of patients in the 450-mg fed and 750-mg fasted arms, respectively.
Conclusion
Asian patients with ALK+ advanced/metastatic NSCLC treated with ceritinib 450-mg fed showed numerically higher efficacy and lower GI toxicity than 750-mg fasted patients.
5.Bat coronavirus was detected positive from insectivorous bats in Krau Wildlife Reserve Forest
Siew, Z.Y. ; Lai, Z.J. ; Ho, Q.Y. ; Ter, H.C. ; Ho, S.H. ; Wong, S.T. ; Gani, M. ; Leong, P.P. ; Voon, K.
Tropical Biomedicine 2023;40(No.4):462-470
Bats are flying mammals with unique immune systems that allow them to hold many pathogens.
Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed
molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue
viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from
Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and
pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to
be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand
and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau
Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover,
the usage of primers for the broad detection of viruses should be reconsidered because geographical
variations might possibly affect the sensitivity of primers in a molecular approach.