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Toxicity and cross-neutralization of snake venoms from two lesser-known arboreal pit vipers in Southeast Asia: Trimeresurus wiroti and Trimeresurus puniceus

Lee LP, Tan KY, Tan CH

Toxicon, 2020 Oct 15;185:91-96.
PMID: 32585219 DOI: 10.1016/j.toxicon.2020.06.012

The lesser-known Sundaic lance-headed pit vipers Trimeresurus wiroti (Malaysia) and Trimeresurus puniceus (Indonesia) contribute to the disease burden of snakebite envenomation in Southeast Asia, but their venom toxicity and neutralization remain insufficiently investigated. This study demonstrated that both venoms were procoagulant (involving thrombin-like activity), hemorrhagic, and lethal to mice, with T. wiroti venom being more lethal (LD50 = 0.78 μg/g c.f. 1.21 μg/g). The hetero-specific antivenom from Thailand, Green Pit Viper Antivenom (GPVAV, raised against Trimeresurus albolabris) cross-reacted with T. wiroti and T. puniceus venoms with a higher efficacy of immunological binding activity for the latter. The antivenom was also effective in cross-neutralizing the procoagulant, hemorrhagic and lethal effects of the venoms. In lethality neutralization, GPVAV showed a potency of 0.79-1.05 mg venom per mL antivenom, corresponding to the complete neutralization of approximately 8-10 mg venom per unit vial of antivenom for T. wiroti and T. puniceus venoms. Taken together, it was inferred that T. wiroti, T. puniceus, and T. albolabris venoms share common toxin epitopes, thus enabling the cross-neutralization observed. These findings suggest that GPVAV may be potentially useful in the management of envenomation by T. wiroti and T. puniceus while awaiting clinical trial and validation.
Snake venom proteomics and antivenomics of two Sundaic lance-headed pit vipers: Trimeresurus wiroti (Malaysia) and Trimeresurus puniceus (Indonesia)

Lee LP, Tan KY, Tan CH

Comp Biochem Physiol Part D Genomics Proteomics, 2021 12;40:100875.
PMID: 34311411 DOI: 10.1016/j.cbd.2021.100875

Envenomation by two medically important Sundaic pit vipers, Trimeresurus wiroti (Malaysia) and Trimeresurus puniceus (Indonesia), causes hemotoxic syndrome with a potentially fatal outcome. Research on the compositions and antigenicity of these pit viper venoms is however lacking, limiting our understanding of the pathophysiology and treatment of envenomation. This study investigated the venom proteomes of both species through a protein decomplexation strategy, applying C18 reverse-phase high-performance liquid chromatography followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein identification through nano-electrospray ionization liquid chromatography-tandem mass spectrometry (nano-ESI-LCMS/MS) of trypsin-digested peptides. The venom antigenicity was profiled against the Thai Green Pit Viper Antivenom (GPVAV, a hetero-specific antivenom), using indirect enzyme-linked immunosorbent assay (ELISA). The venom proteomes of T. wiroti and T. puniceus consisted of 10 and 12 toxin families, respectively. The major proteins were of diverse snake venom serine proteases (19-30% of total venom proteins), snake venom metalloproteinases (17-26%), disintegrins (9-16%), phospholipases A2 (8-28%) and C-type lectins (~8%). These were putative snake toxins implicated in hemorrhage and coagulopathy, consistent with clinical hemotoxicity. GPVAV showed strong immunorecognition toward high and medium molecular weight proteins (e.g., SVMP and PLA2) in both venoms, while a lower binding activity was observed toward small proteins such as disintegrins. Conserved antigenicity in the major hemotoxins supported toxicity cross-neutralization by GPVAV and indicated that the immunorecognition of low molecular weight toxins may be optimized for improved binding efficacy. Taken together, the study provides insights into the pathophysiology and antivenom treatment of envenomation caused by T. wiroti and T. puniceus in the region.
Platelet-rich plasma injections for the treatment of hamstring injuries: a randomized controlled trial

A Hamid MS, Mohamed Ali MR, Yusof A, George J, Lee LP

Am J Sports Med, 2014 Oct;42(10):2410-8.
PMID: 25073598 DOI: 10.1177/0363546514541540

BACKGROUND: A hamstring injury is one of the most common types of injury affecting athletes. Despite this, the optimal management of hamstring muscle injuries is not yet defined. The effect of autologous platelet-rich plasma (PRP) therapy on the recovery of hamstring injuries is unclear.
PURPOSE: To investigate the effect of a single PRP injection in the treatment of grade 2 hamstring muscle injuries.
STUDY DESIGN: Randomized controlled trial; Level of evidence, 2.
METHODS: Twenty-eight patients diagnosed with an acute hamstring injury were randomly allocated to autologous PRP therapy combined with a rehabilitation program or a rehabilitation program only. The primary outcome of this study was time to return to play. In addition, changes in pain severity and pain interference scores over time were examined.
RESULTS: Patients in the PRP group achieved full recovery significantly earlier than controls (P = .02). The mean time to return to play was 26.7 ± 7.0 days and 42.5 ± 20.6 days for the PRP and control groups, respectively (t(22) = 2.50, P = .02). [corrected]. Significantly lower pain severity scores were observed in the PRP group throughout the study. However, no significant difference in the pain interference score was found between the 2 groups.
CONCLUSION: A single autologous PRP injection combined with a rehabilitation program was significantly more effective in treating hamstring injuries than a rehabilitation program alone.
KEYWORDS: management; muscle injury; platelet-rich plasma (PRP); return to play
Fulltext Lipase-Secreting Bacillus Species in an Oil-Contaminated Habitat: Promising Strains to Alleviate Oil Pollution

Lee LP, Karbul HM, Citartan M, Gopinath SC, Lakshmipriya T, Tang TH

Biomed Res Int, 2015;2015:820575.
PMID: 26180812 DOI: 10.1155/2015/820575

Lipases are of great interest for different industrial applications due to their diversity and versatility. Among different lipases, microbial lipases are preferable due to their broad substrate specificity, and higher stability with lower production costs compared to the lipases from plants and animals. In the past, a vast number of bacterial species have been reported as potential lipases producers. In this study, the lipases-producing bacterial species were isolated from an oil spillage area in the conventional night market. Isolated species were identified as Bacillus species by biochemical tests which indicate their predominant establishment, and further screened on the agar solid surfaces using lipid and gelatin as the substrates. Out of the ten strains tested, four potential strains were subjected to comparison analysis of the lipolytic versus proteolytic activities. Strain 10 exhibited the highest lipolytic and proteolytic activity. In all the strains, the proteolytic activity is higher than the lipolytic activity except for strain 8, suggesting the possibility for substrate-based extracellular gene induction. The simultaneous secretion of both the lipase and protease is a mean of survival. The isolated bacterial species which harbour both lipase and protease enzymes could render potential industrial-based applications and solve environmental issues.
Fulltext Temporal dispersion in demyelination of POEMS syndrome and Castleman disease

Lau YH, Mohd Unit H, Lee LP, Loh WK, Hiew FL

Clin Neurophysiol Pract, 2020;5:112-117.
PMID: 32613149 DOI: 10.1016/j.cnp.2020.05.001

Objective: We detailed the electrophysiological patterns of peripheral nerve temporal dispersion across spectrum of POEMS syndrome and Castleman disease (CD).
Methods: Compound muscle action potentials (CMAP) duration of 3 patients with POEMS syndrome and 2 with hyaline vascular type CD without clonal plasma cell dyscrasia were retrospectively analysed.
Results: Median and ulnar nerves distal CMAP duration were prolonged in all patients irrespective of plasma cell dyscrasia or M protein. All lower limbs distal CMAP responses were absent. Greatest distal CMAP duration prolongation was observed in median nerves for POEMS syndrome (17.0 ms, 158% upper limit normal) and in ulnar nerves for CD (9.8 ms, 47% upper limit normal). Distal/proximal CMAP duration ratio of <0.7 were seen in 33% of median and ulnar nerves studied among POEMS syndrome. Among nerves with ratio >0.7, all had distal CMAP duration prolongation (Range 7%-158% of upper limit normal).
Conclusions: Abnormal distal CMAP dispersion is not uncommon in POEMS syndrome and CD without clonal plasma cell dyscrasia or M protein. POEMS syndrome has greater distal CMAP duration in median and ulnar nerves, particularly in median nerve that can reach up to 150% of upper limit normal, compared to <50% in CD.
Significance: Detailed electrophysiological analysis of distal CMAP duration may help in distinguishing POEMS syndrome and CD.
Bacterial regulatory RNAs: complexity, function, and putative drug targeting

Cheah HL, Raabe CA, Lee LP, Rozhdestvensky TS, Citartan M, Ahmed SA, et al.

Crit Rev Biochem Mol Biol, 2018 08;53(4):335-355.
PMID: 29793351 DOI: 10.1080/10409238.2018.1473330

Over the past decade, RNA-deep sequencing has uncovered copious non-protein coding RNAs (npcRNAs) in bacteria. Many of them are key players in the regulation of gene expression, taking part in various regulatory circuits, such as metabolic responses to different environmental stresses, virulence, antibiotic resistance, and host-pathogen interactions. This has contributed to the high adaptability of bacteria to changing or even hostile environments. Their mechanisms include the regulation of transcriptional termination, modulation of translation, and alteration of messenger RNA (mRNA) stability, as well as protein sequestration. Here, the mechanisms of gene expression by regulatory bacterial npcRNAs are comprehensively reviewed and supplemented with well-characterized examples. This class of molecules and their mechanisms of action might be useful targets for the development of novel antibiotics.
Characterizing and applying immunoglobulins in snakebite diagnostics: A simple and rapid venom detection assay for four medically important snake species in Southeast Asia

Lee LP, Tan CH, Khomvilai S, Sitprija V, Chaiyabutr N, Tan KY

Int J Biol Macromol, 2023 May 01;236:123727.
PMID: 36863668 DOI: 10.1016/j.ijbiomac.2023.123727

Snakebite envenoming is a medical emergency requiring urgent and specific treatment. Unfortunately, snakebite diagnostics are scarce, time-consuming and lacking specificity. Hence, this study aimed to develop a simple, quick and specific snakebite diagnostic assay using animal antibodies. Anti-venom horse immunoglobulin G (IgG) and chicken immunoglobulin Y (IgY) were produced against the venoms of four major medically important snake species in Southeast Asia, i.e., the Monocled Cobra (Naja kaouthia), Malayan Krait (Bungarus candidus), Malayan Pit Viper (Calloselasma rhodostoma), and White-lipped Green Pit Viper (Trimeresurus albolabris). Different capture:detection configurations of double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) were constructed using both immunoglobulins, and the horse IgG:IgG-HRP configuration was found to be most selective and sensitive in detecting the corresponding venoms. The method was further streamlined to develop a rapid immunodetection assay, which is able to produce a visual color change within 30 min for discrimination between different snake species. The study shows it is feasible to develop a simple, quick and specific immunodiagnostic assay using horse IgG, which can be derived directly from antisera prepared for antivenom production. The proof-of-concept indicates it is a sustainable and affordable approach in keeping with on-going antivenom manufacturing activities for specific species in the region.
Fulltext Non-protein coding RNA genes as the novel diagnostic markers for the discrimination of Salmonella species using PCR

Nithya R, Ahmed SA, Hoe CH, Gopinath SC, Citartan M, Chinni SV, et al.

PLoS One, 2015;10(3):e0118668.
PMID: 25774907 DOI: 10.1371/journal.pone.0118668

Salmonellosis, a communicable disease caused by members of the Salmonella species, transmitted to humans through contaminated food or water. It is of paramount importance, to generate accurate detection methods for discriminating the various Salmonella species that cause severe infection in humans, including S. Typhi and S. Paratyphi A. Here, we formulated a strategy of detection and differentiation of salmonellosis by a multiplex polymerase chain reaction assay using S. Typhi non-protein coding RNA (sRNA) genes. With the designed sequences that specifically detect sRNA genes from S. Typhi and S. Paratyphi A, a detection limit of up to 10 pg was achieved. Moreover, in a stool-seeding experiment with S. Typhi and S. Paratyphi A, we have attained a respective detection limit of 15 and 1.5 CFU/mL. The designed strategy using sRNA genes shown here is comparatively sensitive and specific, suitable for clinical diagnosis and disease surveillance, and sRNAs represent an excellent molecular target for infectious disease.
RNomic identification and evaluation of npcTB_6715, a non-protein-coding RNA gene as a potential biomarker for the detection of Mycobacterium tuberculosis

Kanniappan P, Ahmed SA, Rajasekaram G, Marimuthu C, Ch'ng ES, Lee LP, et al.

J Cell Mol Med, 2017 10;21(10):2276-2283.
PMID: 28756649 DOI: 10.1111/jcmm.13148

Technological advances in RNA biology greatly improved transcriptome profiling during the last two decades. Besides the discovery of many small RNAs (sRNA) that are involved in the physiological and pathophysiological regulation of various cellular circuits, it becomes evident that the corresponding RNA genes might also serve as potential biomarkers to monitor the progression of disease and treatment. sRNA gene candidate npcTB_6715 was previously identified via experimental RNomic (unpublished data), and we report its application as potential biomarker for the detection of Mycobacterium tuberculosis (MTB) in patient samples. For proof of principle, we developed a multiplex PCR assay and report its validation with 500 clinical cultures, positive for Mycobacteria. The analysis revealed 98.9% sensitivity, 96.1% specificity, positive and negative predictive values of 98.6% and 96.8%, respectively. These results underscore the diagnostic value of the sRNA gene as diagnostic marker for the specific detection of MTB in clinical samples. Its successful application and the general ease of PCR-based detection compared to standard bacterial culture techniques might be the first step towards 'point-of-care' diagnostics of Mycobacteria. To the best of our knowledge, this is the first time for the design of diagnostic applications based on sRNA genes, in Mycobacteria.