Displaying publications 41 - 60 of 197 in total

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  1. Singh N, Menon V
    Med J Malaysia, 1973 Sep;28(1):47-9.
    PMID: 4273785
    Matched MeSH terms: Venoms/poisoning*
  2. Kwan SH, Abdul Aziz NHK, Ismail MN
    Protein Pept Lett, 2020;27(1):48-59.
    PMID: 31362651 DOI: 10.2174/0929866526666190730121711
    BACKGROUND: Channa striata are speculated to contain bioactive proteins with the ability to enhancing wound healing. It is commonly consumed after surgery for a faster recovery of the wound.

    OBJECTIVE: To identify the bioactive proteins and evaluate their ability in cell proliferation and angiogenesis promotion.

    MATERIAL AND METHODS: Freeze-Dried Water Extracts (FDWE) and Spray-Dried Water Extracts (SDWE) of C. striata were tested with MTT assay using EA.hy926 endothelial cell line and ex-vivo aortic ring assay. Later the proteins were fractionated and analysed using an LC-QTOF mass spectrometer. The data generated were matched with human gene database for protein similarity and pathway identification.

    RESULTS: Both samples have shown positive cell proliferation and pro-angiogenic activity. Four essential proteins/genes were identified, which are collagen type XI, actin 1, myosin light chain and myosin heavy chain. The pathways discovered that related to these proteins are integrin pathway, Slit-Robo signalling pathway and immune response C-C Chemokine Receptor-3 signalling pathway in eosinophils, which contribute towards wound healing mechanism.

    CONCLUSIONS: The results presented have demonstrated that C. striata FDWE and SDWE protein fractions contain bioactive proteins that are highly similar to human proteins and thus could be involved in the wound healing process via specific biological pathways.

    Matched MeSH terms: Fish Venoms/metabolism; Fish Venoms/chemistry*
  3. Nget Hong Tan, Chon Seng Tan
    Toxicon, 1988;26(11):989-96.
    PMID: 3245058
    The toxic and biological activities of four samples of Trimeresurus purpureomaculatus venom were examined. The lethality, protein composition and biological activities of the four venom samples were similar. Three of the venom samples had LD50 (i.v.) values of 0.9 micrograms/g while the fourth had a lower LD50 (i.v.) of 0.45 micrograms/g. All four venom samples exhibited hemorrhagic, edema-inducing, anticoagulant and thrombin-like activities as well as the usual enzymes found in crotalid venoms. DEAE-Sephacel ion exchange chromatographic fractionation of the venom yielded 10 protein fractions. Only two fractions (fractions A and F) were lethal to mice; the major lethal fraction being fraction F. This fraction had an LD50 (i.v.) of 0.2 micrograms/g and exhibited hemorrhagic, edema-inducing and thrombin-like activity. It also exhibited phospholipase A, arginine ester hydrolase, arginine amidase, protease, 5'-nucleotidase, acetylcholinesterase and alkaline phosphomonoesterase activities. The lethal potency of fraction F is potentiated by fraction G, which exhibited anticoagulant activity as well as hemorrhagic, edema-inducing and enzymatic activities. Fractions F plus G account for almost 100% of the lethal potency of the venom.
    Matched MeSH terms: Crotalid Venoms/metabolism; Crotalid Venoms/pharmacology*
  4. Tan TL, Ismail AK, Kong KW, Ahmad NK
    J Emerg Med, 2012 Apr;42(4):420-3.
    PMID: 22154775 DOI: 10.1016/j.jemermed.2011.03.038
    The paradise tree snake, Chrysopelea paradisi, is a rear-fanged colubrid. Like other members of the genus Chrysopelea, it is able to glide through the air, and thus, is commonly known as a "flying snake." There are few documented effects of its bite on humans.
    Matched MeSH terms: Snake Venoms/poisoning*
  5. Chan KE
    PMID: 524154
    Matched MeSH terms: Crotalid Venoms/pharmacology
  6. Devaraj T
    PMID: 524151
    Bleeding following bites by the Malayan Pit Viper can either be local or systemic. Bleeding at the site of the bite is due to the local action of the venom as a vasculotoxin. Systemic bleeding occurs with severe poisoning and appears to be mainly dependent on platelet deficiency and the co-existing defibrination syndrome appears to play a minor role in the initiation of bleeding. Thus in the clinical situation non-clotting blood with no overt bleeding can continue up to weeks when specific antivenene is not given. Assessment of the severity of poisoning can easily be made at the bedside. Specific viper antivenene rapidly corrects the spontaneous bleeding and clotting defect of severe systemic poisoning but has no effect on local poisoning.
    Matched MeSH terms: Snake Venoms
  7. Tan NH
    Arch Biochem Biophys, 1982 Oct 01;218(1):51-8.
    PMID: 7149742
    Matched MeSH terms: Elapid Venoms/isolation & purification*
  8. Soh KS, Chan KE
    Toxicon, 1974 Mar;12(2):151-8.
    PMID: 4859238
    Matched MeSH terms: Venoms/analysis; Venoms/pharmacology*
  9. 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.
    Matched MeSH terms: Venoms
  10. Armugam A, Earnest L, Chung MC, Gopalakrishnakone P, Tan CH, Tan NH, et al.
    Toxicon, 1997 Jan;35(1):27-37.
    PMID: 9028006
    cDNAs encoding three phospholipase A2 (PLA2) isoforms in Naja naja sputatrix were cloned and characterized. One of them encoded an acidic PLA2 (APLA) while the others encoded neutral PLA2 (NPLA-1 and NPLA-2). The specific characteristics of APLA and NPLA were attributed to mutations at nt139 and nt328 from G to C and G to A, respectively, resulting in amino acid substitutions from Asp20 and 83 in APLA to His20 and Asn83 in NPLA. Amino acid sequencing of purified protein also showed the presence of this Asp20 and His20 in APLA and NPLA, respectively. The cDNA encoding one of the PLA2 (NAJPLA-2A), when expressed in Escherichia coli, yielded a protein that exhibited PLA2 activity.
    Matched MeSH terms: Elapid Venoms/enzymology*; Elapid Venoms/genetics; Elapid Venoms/chemistry
  11. Baig MA, Swamy KB
    Indian J Pathol Microbiol, 2021 1 13;64(1):123-127.
    PMID: 33433421 DOI: 10.4103/IJPM.IJPM_900_19
    Background: In the laboratory, factor VIII can be measured by three different methodologies, such as one-stage clotting assay, two-stage clotting assay, and chromogenic assay. These assays differ in ease of use, variety of reagents available, sensitivity to mild hemophilia A, and interference from lupus anticoagulants (LACs). Certain factor VIII gene mutations can cause discrepancy in results between one-stage activated partial thromboplastin time (APTT) and chromogenic assays.

    Materials and Methods: The coagulometer for factor VIII assay is Sysmex CS-5100. All data were expressed as mean ± standard deviation (SD).

    Results: A total of 135 cases were studied. Of these, 100 cases were of mild hemophilia A diagnosed by molecular genetics and, 15 cases were positive for LAC, which were confirmed by dilute Russell Viper venom test. Clot-based one-stage APTT assay showed 65% sensitivity and 80% specificity in diagnosing mild hemophilia A cases and out of 15 LAC cases, it showed false positivity in five cases. Chromogenic assay showed 85% sensitivity and 90% specificity in diagnosing mild hemophilia cases and was 100% specific in excluding LAC cases.

    Conclusions: One-stage APTT assay is the most commonly used test for determining factor VIII levels but chromogenic assay are considered as the gold standard and recommended as the reference method by European Pharmacopoeia and ISTH subcommittee. Mild hemophilia A patients with missense mutations show discrepancy between the one-stage clot-based APTT assay and chromogenic assays for determination of factor VIII level and this can lead to misdiagnosis or misclassification of mild hemophilia A. Therefore, it is recommended that both the assays should be used in the evaluation of mild hemophilia cases.

    Matched MeSH terms: Viper Venoms
  12. Tang ELH, Tan NH, Fung SY, Tan CH
    Toxicon, 2019 Aug 22;169:91-102.
    PMID: 31445943 DOI: 10.1016/j.toxicon.2019.08.004
    The intraspecific geographical venom variations of Calloselasma rhodostoma from Malaysia (CR-M), Indonesia (CR-I), Thailand (CR-T) and Vietnam (CR-V) were investigated through 1D SDS-PAGE and nano-ESI-LCMS/MS. The venom antigenicity, procoagulant activities and neutralization using Thai C. rhodostoma Monovalent Antivenom (CRMAV) were also investigated. SDS-PAGE patterns of the venoms were relatively similar with minor variations. Proteomic analysis revealed that snake venom metalloproteinases (SVMPs, particularly P-I class), serine proteases (SVSPs) and snaclecs dominated the venom protein composition (68.96-81.80%), followed by L-amino acid oxidase (LAAO) and phospholipase A2 (PLA2) (7.37-11.08% and 5.18-13.81%, respectively), corroborating C. rhodostoma envenoming effects (hemorrhage, consumptive coagulopathy, thrombocytopenia and local tissue necrosis). Other proteins of lower abundances (2.82-9.13%) identified include cysteine-rich secretory proteins (CRISP), phospholipase B, phosphodiesterase, nerve growth factor, 5'-nucleotidase, aminopeptidase and hyaluronidase. All four venoms exhibited strong procoagulant effects which were neutralized by CRMAV to different extents. CRMAV immunoreactivity was high toward venoms of CR-M, CR-I and CR-T but relatively low for CR-V venom. Among the venom samples from different locales, CR-V venom proteome has the smallest SVMP composition while SVSP, PLA2 and phosphodiesterase were more abundant in the venom. These variations in C. rhodostoma venom protein composition could partly explain the differences seen in immunoreactivity. (198 words).
    Matched MeSH terms: Snake Venoms
  13. Tan NH, Saifuddin MN
    PMID: 1982873
    1. The edema-inducing activity of 24 venoms from snakes of the subfamilies of Elapinae, Hydrophiini, Crotalinae and Viperinae was determined. 2. All snake venoms tested are very potent edema inducers. The minimum edema doses of the venoms ranged from 0.16 to 3.41 micrograms per mouse paw. 3. The venoms induced a rapid onset edema which peaked within 1 h of injection and declined thereafter; at low dose, however, some venoms induced a rapid onset edema that sustained over a longer duration.
    Matched MeSH terms: Crotalid Venoms/administration & dosage; Crotalid Venoms/toxicity; Elapid Venoms/administration & dosage; Elapid Venoms/toxicity; Snake Venoms/administration & dosage; Snake Venoms/toxicity*; Viper Venoms/administration & dosage; Viper Venoms/toxicity
  14. Tan NH, Ponnudurai G
    PMID: 1360387
    1. The enzymatic, hemorrhagic, procoagulant and anticoagulant activities of venoms of some animals including snakes, lizards, toads, scorpions, spider, wasps, bees and ants were compared. 2. Snake venom was the richest source of enzymes among the animal venoms. Most other animal venoms were devoid of phosphodiesterase, L-amino acid oxidase, alkaline phosphomonoesterase and acetylcholinesterase activities and only a few exhibited arginine ester hydrolase activity. These venoms, however, exhibited wide ranges of protease, 5'-nucleotidase and hyaluronidase activities. Most of the animal venoms examined exhibited some phospholipase A activity. 3. Other than snake venoms, only venoms of the toad Bufo calamita and the lizards were hemorrhagic, and only venoms of the social wasps, social bees and harvester ant exhibited strong anticoagulant activity. Procoagulant activity occurs only in snake venoms.
    Matched MeSH terms: Amphibian Venoms/metabolism; Amphibian Venoms/pharmacology; Ant Venoms/metabolism; Ant Venoms/pharmacology; Bee Venoms/metabolism; Bee Venoms/pharmacology; Scorpion Venoms/metabolism; Scorpion Venoms/pharmacology; Snake Venoms/metabolism; Snake Venoms/pharmacology; Venoms/metabolism; Venoms/pharmacology*; Venoms/toxicity; Wasp Venoms/metabolism; Wasp Venoms/pharmacology
  15. Tan KY, Tan CH, Chanhome L, Tan NH
    PeerJ, 2017;5:e3142.
    PMID: 28392982 DOI: 10.7717/peerj.3142
    BACKGROUND: The monocled cobra (Naja kaouthia) is a medically important venomous snake in Southeast Asia. Its venom has been shown to vary geographically in relation to venom composition and neurotoxic activity, indicating vast diversity of the toxin genes within the species. To investigate the polygenic trait of the venom and its locale-specific variation, we profiled and compared the venom gland transcriptomes of N. kaouthia from Malaysia (NK-M) and Thailand (NK-T) applying next-generation sequencing (NGS) technology.

    METHODS: The transcriptomes were sequenced on the Illumina HiSeq platform, assembled and followed by transcript clustering and annotations for gene expression and function. Pairwise or multiple sequence alignments were conducted on the toxin genes expressed. Substitution rates were studied for the major toxins co-expressed in NK-M and NK-T.

    RESULTS AND DISCUSSION: The toxin transcripts showed high redundancy (41-82% of the total mRNA expression) and comprised 23 gene families expressed in NK-M and NK-T, respectively (22 gene families were co-expressed). Among the venom genes, three-finger toxins (3FTxs) predominated in the expression, with multiple sequences noted. Comparative analysis and selection study revealed that 3FTxs are genetically conserved between the geographical specimens whilst demonstrating distinct differential expression patterns, implying gene up-regulation for selected principal toxins, or alternatively, enhanced transcript degradation or lack of transcription of certain traits. One of the striking features that elucidates the inter-geographical venom variation is the up-regulation of α-neurotoxins (constitutes ∼80.0% of toxin's fragments per kilobase of exon model per million mapped reads (FPKM)), particularly the long-chain α-elapitoxin-Nk2a (48.3%) in NK-T but only 1.7% was noted in NK-M. Instead, short neurotoxin isoforms were up-regulated in NK-M (46.4%). Another distinct transcriptional pattern observed is the exclusively and abundantly expressed cytotoxin CTX-3 in NK-T. The findings suggested correlation with the geographical variation in proteome and toxicity of the venom, and support the call for optimising antivenom production and use in the region. Besides, the current study uncovered full and partial sequences of numerous toxin genes from N. kaouthia which have not been reported hitherto; these include N. kaouthia-specific l-amino acid oxidase (LAAO), snake venom serine protease (SVSP), cystatin, acetylcholinesterase (AChE), hyaluronidase (HYA), waprin, phospholipase B (PLB), aminopeptidase (AP), neprilysin, etc. Taken together, the findings further enrich the snake toxin database and provide deeper insights into the genetic diversity of cobra venom toxins.

    Matched MeSH terms: Elapid Venoms
  16. Hia YL, Tan KY, Tan CH
    Acta Trop, 2020 Jul;207:105460.
    PMID: 32278639 DOI: 10.1016/j.actatropica.2020.105460
    The banded krait, Bungarus fasciatus is a medically important venomous snake in Asia. The wide distribution of this species in Southeast Asia and southern China indicates potential geographical variation of the venom which may impact the clinical management of snakebite envenomation. This study investigated the intraspecific venom variation of B. fasciatus from five geographical locales through a venom decomplexing proteomic approach, followed by toxinological and immunological studies. The venom proteomes composed of a total of 9 toxin families, comprising 22 to 31 proteoforms at varying abundances. The predominant proteins were phospholipase A2 (including beta-bungarotoxin), Kunitz-type serine protease inhibitor (KSPI) and three-finger toxins (3FTx), which are toxins that cause neurotoxicity and lethality. The venom lethality varied with geographical origins of the snake, with intravenous median lethal doses (LD50) ranging from 0.45-2.55 µg/g in mice. The Thai Bungarus fasciatus monovalent antivenom (BFMAV) demonstrated a dose-dependent increasing immunological binding activity toward all venoms; however, its in vivo neutralization efficacy varied vastly with normalized potency values ranging from 3 to 28 mg/g, presumably due to the compositional differences of dominant proteins in the different venoms. The findings support that antivenom use should be optimized in different geographical areas. The development of a pan-regional antivenom may be a more sustainable solution for the treatment of snakebite envenomation.
    Matched MeSH terms: Elapid Venoms/analysis*; Elapid Venoms/immunology; Elapid Venoms/toxicity
  17. Oukkache N, Ahmad Rusmili MR, Othman I, Ghalim N, Chgoury F, Boussadda L, et al.
    Life Sci, 2015 Mar 1;124:1-7.
    PMID: 25623852 DOI: 10.1016/j.lfs.2014.12.031
    Scorpion venoms contain complex mixtures of molecules, including peptides. These peptides specifically bind to various targets, in particular ion channels. Toxins modulating Na(+), K(+), Ca(2+) and Cl(-) currents were described from venoms. The Androctonus and Buthus geni of scorpions are widely distributed in Morocco. Their stings can cause pain, inflammation, necrosis, muscle paralysis and death. The myotoxicity is predominantly associated with neurotoxic effects and is a cause of mortality and morbidity. In this study, pharmacological effects of venoms were investigated in vitro on neuromuscular transmission.
    Matched MeSH terms: Scorpion Venoms/toxicity*; Scorpion Venoms/chemistry
  18. Kozlov SA, Lazarev VN, Kostryukova ES, Selezneva OV, Ospanova EA, Alexeev DG, et al.
    Sci Data, 2014;1:140023.
    PMID: 25977780 DOI: 10.1038/sdata.2014.23
    A comprehensive transcriptome analysis of an expressed sequence tag (EST) database of the spider Dolomedes fimbriatus venom glands using single-residue distribution analysis (SRDA) identified 7,169 unique sequences. Mature chains of 163 different toxin-like polypeptides were predicted on the basis of well-established methodology. The number of protein precursors of these polypeptides was appreciably numerous than the number of mature polypeptides. A total of 451 different polypeptide precursors, translated from 795 unique nucleotide sequences, were deduced. A homology search divided the 163 mature polypeptide sequences into 16 superfamilies and 19 singletons. The number of mature toxins in a superfamily ranged from 2 to 49, whereas the diversity of the original nucleotide sequences was greater (2-261 variants). We observed a predominance of inhibitor cysteine knot toxin-like polypeptides among the cysteine-containing structures in the analyzed transcriptome bank. Uncommon spatial folds were also found.
    Matched MeSH terms: Spider Venoms/genetics*; Spider Venoms/chemistry
  19. Srilatha PS
    Saudi J Gastroenterol, 2007 Oct-Dec;13(4):197-9.
    PMID: 19858647 DOI: 10.4103/1319-3767.36754
    Synchronous tumors are well documented in the gastrointestinal tract. Various combinations have been studied. There are a few studies, which highlight the incidental finding of the yellow beauty-the "carcinoid" of the duodenum simultaneously occurring with the venomous "diffuse gastric adenocarcinoma". This is a report one such case in a 58 year-old man, who unfortunately died on the 4th postoperative day due to cardiopulmonary arrest.
    Matched MeSH terms: Venoms
  20. Farooq AV, Gibbons AG, Council MD, Harocopos GJ, Holland S, Judelson J, et al.
    Am J Ophthalmol, 2017 Feb;174:119-125.
    PMID: 27793603 DOI: 10.1016/j.ajo.2016.10.007
    PURPOSE: To report a series of patients who developed corneal toxicity after exposure to aquarium coral palytoxin.

    DESIGN: Multicenter retrospective case series.

    METHODS: Retrospective review.

    RESULTS: Seven patients presented with corneal findings ranging from superficial punctate epitheliopathy to bilateral corneal melt with subsequent perforation. Among those with mild corneal findings, resolution was achieved with topical steroids and lubrication, whereas some patients who developed progressive corneal melt required therapeutic penetrating keratoplasty. The history in all patients revealed exposure to aquarium zoanthid corals shortly before disease onset. A review of the literature revealed that there are few prior reports of coral-associated corneal toxicity and that some species of coral secrete a substance known as palytoxin, a potent vasoconstrictor that inhibits the membranous sodium-potassium ATPase pump across cell types and can cause rapid death if inhaled or ingested.

    CONCLUSIONS: This is the largest case series to date demonstrating patients with aquarium coral palytoxin-associated corneal toxicity, and is the first to provide details of related histopathologic findings. Similar to other forms of toxic keratoconjunctivitis, a detailed history and careful clinical assessment are required, as well as timely removal of the offending agent from the patients' ocular milieu and environment. Mild ocular surface and corneal disease may be treated effectively with aggressive topical steroid therapy and lubrication. Given the potential severity of ocular as well as systemic adverse effects, there should be increased awareness of this entity among eye care professionals, aquarium enthusiasts, and the general public.

    Matched MeSH terms: Cnidarian Venoms
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