Displaying publications 1 - 20 of 69 in total

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  1. Fulltext Recombinant measles virus vaccine expressing the Nipah virus glycoprotein protects against lethal Nipah virus challenge
    Yoneda M, Georges-Courbot MC, Ikeda F, Ishii M, Nagata N, Jacquot F, et al.
    PLoS One, 2013;8(3):e58414.
    PMID: 23516477 DOI: 10.1371/journal.pone.0058414
    Nipah virus (NiV) is a member of the genus Henipavirus, which emerged in Malaysia in 1998. In pigs, infection resulted in a predominantly non-lethal respiratory disease; however, infection in humans resulted in over 100 deaths. Nipah virus has continued to re-emerge in Bangladesh and India, and person-to-person transmission appeared in the outbreak. Although a number of NiV vaccine studies have been reported, there are currently no vaccines or treatments licensed for human use. In this study, we have developed a recombinant measles virus (rMV) vaccine expressing NiV envelope glycoproteins (rMV-HL-G and rMV-Ed-G). Vaccinated hamsters were completely protected against NiV challenge, while the mortality of unvaccinated control hamsters was 90%. We trialed our vaccine in a non-human primate model, African green monkeys. Upon intraperitoneal infection with NiV, monkeys showed several clinical signs of disease including severe depression, reduced ability to move and decreased food ingestion and died at 7 days post infection (dpi). Intranasal and oral inoculation induced similar clinical illness in monkeys, evident around 9 dpi, and resulted in a moribund stage around 14 dpi. Two monkeys immunized subcutaneously with rMV-Ed-G showed no clinical illness prior to euthanasia after challenge with NiV. Viral RNA was not detected in any organ samples collected from vaccinated monkeys, and no pathological changes were found upon histopathological examination. From our findings, we propose that rMV-NiV-G is an appropriate NiV vaccine candidate for use in humans.
    Matched MeSH terms: Cricetinae
  2. Establishment of a Nipah virus rescue system
    Yoneda M, Guillaume V, Ikeda F, Sakuma Y, Sato H, Wild TF, et al.
    Proc Natl Acad Sci U S A, 2006 Oct 31;103(44):16508-13.
    PMID: 17053073
    Nipah virus (NiV), a paramyxovirus, was first discovered in Malaysia in 1998 in an outbreak of infection in pigs and humans and incurred a high fatality rate in humans. Fruit bats, living in vast areas extending from India to the western Pacific, were identified as the natural reservoir of the virus. However, the mechanisms that resulted in severe pathogenicity in humans (up to 70% mortality) and that enabled crossing the species barrier were not known. In this study, we established a system that enabled the rescue of replicating NiVs from a cloned DNA by cotransfection of a constructed full-length cDNA clone and supporting plasmids coding virus nucleoprotein, phosphoprotein, and polymerase with the infection of the recombinant vaccinia virus, MVAGKT7, expressing T7 RNA polymerase. The rescued NiV (rNiV), by using the newly developed reverse genetics system, showed properties in vitro that were similar to the parent virus and retained the severe pathogenicity in a previously established animal model by experimental infection. A recombinant NiV was also developed, expressing enhanced green fluorescent protein (rNiV-EGFP). Using the virus, permissibility of NiV was compared with the presence of a known cellular receptor, ephrin B2, in a number of cell lines of different origins. Interestingly, two cell lines expressing ephrin B2 were not susceptible for rNiV-EGFP, indicating that additional factors are clearly required for full NiV replication. The reverse genetics for NiV will provide a powerful tool for the analysis of the molecular mechanisms of pathogenicity and cross-species infection.
    Matched MeSH terms: Cricetinae
  3. Fulltext A golden hamster model for human acute Nipah virus infection
    Wong KT, Grosjean I, Brisson C, Blanquier B, Fevre-Montange M, Bernard A, et al.
    Am J Pathol, 2003 Nov;163(5):2127-37.
    PMID: 14578210 DOI: 10.1016/S0002-9440(10)63569-9
    A predominantly pig-to-human zoonotic infection caused by the novel Nipah virus emerged recently to cause severe morbidity and mortality in both animals and man. Human autopsy studies showed the pathogenesis to be related to systemic vasculitis that led to widespread thrombotic occlusion and microinfarction in most major organs especially in the central nervous system. There was also evidence of extravascular parenchymal infection, particularly near damaged vessels (Wong KT, Shieh WJ, Kumar S, Norain K, Abdullah W, Guarner J, Goldsmith CS, Chua KB, Lam SK, Tan CT, Goh KJ, Chong HT, Jusoh R, Rollin PE, Ksiazek TG, Zaki SR, Nipah Virus Pathology Working Group: Nipah virus infection: Pathology and pathogenesis of an emerging paramyxoviral zoonosis. Am J Pathol 2002, 161:2153-2167). We describe here a golden hamster (Mesocricetus auratus) model that appears to reproduce the pathology and pathogenesis of acute human Nipah infection. Hamsters infected by intranasal or intraperitoneal routes died within 9 to 29 days or 5 to 9 days, respectively. Pathological lesions were most severe and extensive in the hamster brain. Vasculitis, thrombosis, and more rarely, multinucleated endothelial syncytia, were found in blood vessels of multiple organs. Viral antigen and RNA were localized in both vascular and extravascular tissues including neurons, lung, kidney, and spleen, as demonstrated by immunohistochemistry and in situ hybridization, respectively. Paramyxoviral-type nucleocapsids were identified in neurons and in vessel walls. At the terminal stage of infection, virus and/or viral RNA could be recovered from most solid organs and urine, but not from serum. The golden hamster is proposed as a suitable model for further studies including pathogenesis studies, anti-viral drug testing, and vaccine development against acute Nipah infection.
    Matched MeSH terms: Cricetinae
  4. In vitro and in vivo characterization of chimeric duck Tembusu virus based on Japanese encephalitis live vaccine strain SA14-14-2
    Wang HJ, Liu L, Li XF, Ye Q, Deng YQ, Qin ED, et al.
    J Gen Virol, 2016 07;97(7):1551-1556.
    PMID: 27100268 DOI: 10.1099/jgv.0.000486
    Duck Tembusu virus (DTMUV), a newly identified flavivirus, has rapidly spread to China, Malaysia and Thailand. The potential threats to public health have been well-highlighted; however its virulence and pathogenesis remain largely unknown. Here, by using reverse genetics, a recombinant chimeric DTMUV based on Japanese encephalitis live vaccine strain SA14-14-2 was obtained by substituting the corresponding prM and E genes (named ChinDTMUV). In vitro characterization demonstrated that ChinDTMUV replicated efficiently in mammalian cells with small-plaque phenotype in comparison with its parental viruses. Mouse tests showed ChinDTMUV exhibited avirulent phenotype in terms of neuroinvasiveness, while it retained neurovirulence from its parental virus DTMUV. Furthermore, immunization with ChinDTMUV was evidenced to elicit robust IgG and neutralizing antibody responses in mice. Overall, we successfully developed a viable chimeric DTMUV, and these results provide a useful platform for further investigation of the pathogenesis of DTMUV and development of a live attenuated DTMUV vaccine candidate.
    Matched MeSH terms: Cricetinae
  5. Fulltext A VLP-based vaccine provides complete protection against Nipah virus challenge following multiple-dose or single-dose vaccination schedules in a hamster model
    Walpita P, Cong Y, Jahrling PB, Rojas O, Postnikova E, Yu S, et al.
    NPJ Vaccines, 2017;2:21.
    PMID: 29263876 DOI: 10.1038/s41541-017-0023-7
    Nipah virus is a highly lethal zoonotic paramyxovirus that was first recognized in Malaysia during an outbreak in 1998. During this outbreak, Nipah virus infection caused a severe febrile neurological disease in humans who worked in close contact with infected pigs. The case fatality rate in humans was approximately 40%. Since 2001, NiV has re-emerged in Bangladesh and India where fruit bats (Pteropus spp.) have been identified as the principal reservoir of the virus. Transmission to humans is considered to be bat-to-human via food contaminated with bat saliva, or consumption of contaminated raw date palm sap, although human-to-human transmission of Nipah virus has also been documented. To date, there are no approved prophylactic options or treatment for NiV infection. In this study, we produced mammalian cell-derived native Nipah virus-like particles composed of Nipah virus G, F and M proteins for use as a novel Nipah virus vaccine. Previous studies demonstrated that the virus-like particles were structurally similar to authentic virus, functionally assembled and immunoreactive. In the studies reported here, purified Nipah virus-like particles were utilized either alone or with adjuvant to vaccinate golden Syrian hamsters with either three-dose or one-dose vaccination regimens followed by virus challenge. These studies found that Nipah virus-like particle immunization of hamsters induced significant neutralizing antibody titers and provided complete protection to all vaccinated animals following either single or three-dose vaccine schedules. These studies prove the feasibility of a virus-like particle-based vaccine for protection against Nipah virus infection.
    Matched MeSH terms: Cricetinae
  6. Genotoxicity of goniothalamin in CHO cell line
    Umar-Tsafe N, Mohamed-Said MS, Rosli R, Din LB, Lai LC
    Mutat Res, 2004 Aug 8;562(1-2):91-102.
    PMID: 15279832
    Goniothalamin (GTN) is a styrylpyrrone derivative from Goniothalamus umbrosus and other Annonaceae species. It has been shown to have anti-cancer and apoptosis-inducing properties against various human tumour and animal cell lines. The compound has also been shown to be active in vivo against DMBA-induced rat mammary tumours and was reported as an anti-fertility agent in rats. The aim of our study was to assess the genotoxicity of GTN in CHO cells using the UKEMS guidelines. A metabolic activation fraction (S9) was prepared according to standard methods. The methylthiazoletetrazolium (MTT) screening assay was then carried out to determine the cytotoxicity index (IC50) of GTN. The average IC50 value was 12.45 (+/- 3.63)microM. The mitotic index (MI) assay was then performed to determine the clastogenicity indices (MI(C25), MI(C50) and MI(C100)) of GTN. The chromosome aberration (CA) induction assay using air-dried metaphase spread was then performed to investigate the clastogenic effects of goniothalamin. Benzo[a]pyrene (BaP) and ethylmethanesulphonate (EMS) were used as positive controls in the presence and absence of S9 metabolic activation, respectively. The anti-genotoxicity effect of GTN was also assessed using a combination of GTN and EMS, and GTN and BaP. Dose-responses of CA frequencies were determined for both, the genotoxicity and anti-genotoxicity effects. GTN on its own and when combined with positive controls, was found to induce and enhance CA, respectively. Chromatid and whole chromosome breaks/gaps, as well as interchanges, endoreduplications and ring chromosomes were the main types of aberration induced by GTN. The overall clastogenic effect of GTN was statistically significant. In conclusion, GTN is potentially a genotoxic or clastogenic substance without any anti-genotoxic properties.
    Matched MeSH terms: Cricetinae
  7. Fulltext Dual Actions of Mammalian and Piscine Gonadotropin-Inhibitory Hormones, RFamide-Related Peptides and LPXRFamide Peptides, in the Hypothalamic-Pituitary-Gonadal Axis
    Ubuka T, Parhar I
    Front Endocrinol (Lausanne), 2017;8:377.
    PMID: 29375482 DOI: 10.3389/fendo.2017.00377
    Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that decreases gonadotropin synthesis and release by directly acting on the gonadotrope or by decreasing the activity of gonadotropin-releasing hormone (GnRH) neurons. GnIH is also called RFamide-related peptide in mammals or LPXRFamide peptide in fishes due to its characteristic C-terminal structure. The primary receptor for GnIH is GPR147 that inhibits cAMP production in target cells. Although most of the studies in mammals, birds, and fish have shown the inhibitory action of GnIH in the hypothalamic-pituitary-gonadal (HPG) axis, several in vivo studies in mammals and many in vivo and in vitro studies in fish have shown its stimulatory action. In mouse, although the firing rate of the majority of GnRH neurons is decreased, a small population of GnRH neurons is stimulated by GnIH. In hamsters, GnIH inhibits luteinizing hormone (LH) release in the breeding season when their endogenous LH level is high but stimulates LH release in non-breeding season when their LH level is basal. Besides different effects of GnIH on the HPG axis depending on the reproductive stages in fish, higher concentration or longer duration of GnIH administration can stimulate their HPG axis. These results suggest that GnIH action in the HPG axis is modulated by sex-steroid concentration, the action of neuroestrogen synthesized by the activity of aromatase stimulated by GnIH, estrogen membrane receptor, heteromerization and internalization of GnIH, GnRH, and estrogen membrane receptors. The inhibitory and stimulatory action of GnIH in the HPG axis may have a physiological role to maintain reproductive homeostasis according to developmental and reproductive stages.
    Matched MeSH terms: Cricetinae
  8. Fulltext Design, Synthesis and Evaluation of New Indolylpyrimidylpiperazines for Gastrointestinal Cancer Therapy
    Tan A, Babak MV, Venkatesan G, Lim C, Klotz KN, Herr DR, et al.
    Molecules, 2019 Oct 11;24(20).
    PMID: 31614517 DOI: 10.3390/molecules24203661
    Human A3 adenosine receptor hA3AR has been implicated in gastrointestinal cancer, where its cellular expression has been found increased, thus suggesting its potential as a molecular target for novel anticancer compounds. Observation made in our previous work indicated the importance of the carbonyl group of amide in the indolylpyrimidylpiperazine (IPP) for its human A2A adenosine receptor (hA2AAR) subtype binding selectivity over the other AR subtypes. Taking this observation into account, we structurally modified an indolylpyrimidylpiperazine (IPP) scaffold, 1 (a non-selective adenosine receptors' ligand) into a modified IPP (mIPP) scaffold by switching the position of the carbonyl group, resulting in the formation of both ketone and tertiary amine groups in the new scaffold. Results showed that such modification diminished the A2A activity and instead conferred hA3AR agonistic activity. Among the new mIPP derivatives (3-6), compound 4 showed potential as a hA3AR partial agonist, with an Emax of 30% and EC50 of 2.89 ± 0.55 μM. In the cytotoxicity assays, compound 4 also exhibited higher cytotoxicity against both colorectal and liver cancer cells as compared to normal cells. Overall, this new series of compounds provide a promising starting point for further development of potent and selective hA3AR partial agonists for the treatment of gastrointestinal cancers.
    Matched MeSH terms: Cricetinae
  9. Melioidosis in Malaysia. II. Distribution of Pseudomonas pseudomallei in soil and surface water
    Strauss JM, Groves MG, Mariappan M, Ellison DW
    Am J Trop Med Hyg, 1969 Sep;18(5):698-702.
    PMID: 5810797
    Matched MeSH terms: Cricetinae
  10. Fulltext Biocompatibility and Cytotoxicity Study of Polydimethylsiloxane (PDMS) and Palm Oil Fuel Ash (POFA) Sustainable Super-Hydrophobic Coating for Biomedical Applications
    Sreekantan S, Hassan M, Sundera Murthe S, Seeni A
    Polymers (Basel), 2020 Dec 18;12(12).
    PMID: 33352856 DOI: 10.3390/polym12123034
    A sustainable super-hydrophobic coating composed of silica from palm oil fuel ash (POFA) and polydimethylsiloxane (PDMS) was synthesised using isopropanol as a solvent and coated on a glass substrate. FESEM and AFM analyses were conducted to study the surface morphology of the coating. The super-hydrophobicity of the material was validated through goniometry, which showed a water contact angle of 151°. Cytotoxicity studies were conducted by assessing the cell viability and cell morphology of mouse fibroblast cell line (L929) and hamster lung fibroblast cell line (V79) via tetrazolium salt 3-(4-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and microscopic methods, respectively. The clonogenic assay was performed on cell line V79 and the cell proliferation assay was performed on cell line L929. Both results validate that the toxicity of PDMS: SS coatings is dependent on the concentration of the super-hydrophobic coating. The results also indicate that concentrations above 12.5 mg/mL invariably leads to cell toxicity. These results conclusively support the possible utilisation of the synthesised super-hydrophobic coating for biomedical applications.
    Matched MeSH terms: Cricetinae
  11. Fulltext Induction of Protective Immunity against Toxoplasmosis in BALB/c Mice Vaccinated with Toxoplasma gondii Rhoptry-1
    Sonaimuthu P, Ching XT, Fong MY, Kalyanasundaram R, Lau YL
    Front Microbiol, 2016;7:808.
    PMID: 27303390 DOI: 10.3389/fmicb.2016.00808
    Toxoplasma gondii is the causative agent for toxoplasmosis. The rhoptry protein 1 (ROP1) is secreted by rhoptry, an apical secretory organelle of the parasite. ROP1 plays an important role in host cell invasion. In this study, the efficacy of ROP1 as a vaccine candidate against toxoplasmosis was evaluated through intramuscular or subcutaneous injection of BALB/c mice followed by immunological characterization (humoral- and cellular-mediated) and lethal challenge against virulent T. gondii RH strain in BALB/c mice. Briefly, a recombinant DNA plasmid (pVAX1-GFP-ROP1) was expressed in CHO cells while expression of recombinant ROP1 protein (rROP1) was carried out in Escherichia coli expression system. Immunization study involved injection of the recombinant pVAX1-ROP1 and purified rROP1 into different group of mice. Empty vector and PBS served as two different types of negative controls. Results obtained demonstrated that ROP1 is an immunogenic antigen that induced humoral immune response whereby detection of a protein band with expected size of 43 kDa was observed against vaccinated mice sera through western blot analysis. ROP1 antigen was shown to elicit cellular-mediated immunity as well whereby stimulated splenocytes with total lysate antigen (TLA) and rROP1 from pVAX1-ROP1 and rROP1-immunized mice, respectively, readily proliferated and secreted large amount of IFN-γ (712 ± 28.1 pg/ml and 1457 ± 31.19 pg/ml, respectively) and relatively low IL-4 level (94 ± 14.5 pg/ml and 186 ± 14.17 pg/ml, respectively). These phenomena suggested that Th1-favored immunity was being induced. Vaccination with ROP1 antigen was able to provide partial protection in the vaccinated mice against lethal challenge with virulent RH strain of tachyzoites. These findings proposed that the ROP1 antigen is a potential candidate for the development of vaccine against toxoplasmosis.
    Matched MeSH terms: Cricetinae
  12. Low intensity ultrasound induced apoptosis in MCF-7 breast cancer cell lines
    Siti P.M. Bohari, Hamidreza Aboulkheyr E, Nur S. Johan, Nursyuhada F. Zainudin
    Sains Malaysiana, 2017;46:575-581.
    According to the World Cancer Research Fund International (WCRFI), breast cancer is the most common type of cancer in women worldwide with recorded 1.7 million new cases in 2012. The main line of treatments is still limited to chemotherapy, surgery and radiotherapy which could lead to a wide range of dangerous side effects. This study was conducted to evaluate the effect of low intensity ultrasound (LIUS) on cell proliferation, percentage of living and dead cells and the induction of apoptosis on the MCF-7 cell line with CHO cells as the control for non-cancerous group. In order to achieve the objective of this study, several methods of cell-bioguided assays were used including the MTT assay for cell proliferation, Live/Dead assay for the determination of both live and dead cells and gene expression study for the detection of apoptosis in the cells. The cytotoxicity and Live/Dead assays data provided preliminary data that the LIUS has potential to induce apoptosis in a wide population of breast cancer cells. Furthermore, the LIUS treatment induced the expression of p53-mRNA at a detectable level via qPCR analysis, indicating the activation of apoptosis. In short, our study suggested LIUS dosage used in this study could potentially show positive effects in the induction of apoptosis selectively on the MCF-7 with less harm to the control CHO cells.
    Matched MeSH terms: Cricetinae
  13. Mutagenic and clastogenic characterization of poststerilized poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer biosynthesized by Delftia acidovorans
    Siew EL, Rajab NF, Osman AB, Sudesh K, Inayat-Hussain SH
    J Biomed Mater Res A, 2009 Dec;91(3):786-94.
    PMID: 19051306 DOI: 10.1002/jbm.a.32290
    Polyhydroxyalkanoates (PHA) are naturally occurring biopolyesters that have great potential in the medical field. However, the leachables resulting from sterilization process of the biomaterials may exert toxic effect including genetic damage. Here, we demonstrate that although gamma-irradiation of poly(3-hydroxybutyrate-co-50 mol % 4-hydroxybutyrate) [P(3HB-co-4HB)] did not cause any change in the morphology by scanning electron microscopy, there was a significant degradation of this copolymer where the molecular weight was reduced by 37% after sterilization indicating the generation of leachables. Therefore, further investigation on the ability of the extract of this poststerilized copolymer to induce mutagenic effect was performed using Ames test (S. typhimurium strains TA1535 and TA1537) and umu test (S. typhimurium strain TA1535/pSK1002). Additionally, the capability of the extract to induce clastogenic effect was determined using Chinese hamster lung V79 fibroblast cells. Our results showed that with and without the presence of S9 metabolic activation, no mutagenic effects were observed in both Ames and umu tests when treated with P(3HB-co-4HB) extract. Similarly, treatment of P(3HB-co-4HB) extract in V79 fibroblast cells showed no significant production of micronuclei when compared with the positive control (Mitomycin C). Together, these results indicate that leachables of poststerilized P(3HB-co-4HB) cause no mutagenic and clastogenic effects.
    Matched MeSH terms: Cricetinae
  14. In vitro biocompatibility evaluation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer in fibroblast cells
    Siew EL, Rajab NF, Osman AB, Sudesh K, Inayat-Hussain SH
    J Biomed Mater Res A, 2007 May;81(2):317-25.
    PMID: 17120221
    Among the various biomaterials available for tissue engineering and therapeutic applications, microbial polyhydroxyalkanoates offer the most diverse range of thermal and mechanical properties. In this study, the biocompatibility of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB); containing 50 mol % of 4-hydroxybutyrate] copolymer produced by Delftia acidovorans was evaluated. The cytotoxicity, mode of cell death, and genotoxicity of P(3HB-co-4HB) extract against V79 and L929 fibroblast cells were assessed using MTT assay, acridine orange/propidium iodide staining, and alkaline comet assay, respectively. Our results demonstrate that P(3HB-co-4HB) treated on both cell lines were comparable with clinically-used Polyglactin 910, where more than 60% of viable cells were observed following 72-h treatment at 200 mg/mL. Further morphological investigation on the mode of cell death showed an increase in apoptotic cells in a time-dependent manner in both cell lines. On the other hand, P(3HB-co-4HB) at 200 mg/mL showed no genotoxic effects as determined by alkaline comet assay following 72-h treatment. In conclusion, our study indicated that P(3HB-co-4HB) compounds showed good biocompatibility in fibroblast cells suggesting that it has potential to be used for future medical applications.
    Matched MeSH terms: Cricetinae
  15. Genome structure of Sagiyama virus and its relatedness to other alphaviruses
    Shirako Y, Yamaguchi Y
    J Gen Virol, 2000 May;81(Pt 5):1353-60.
    PMID: 10769079
    Sagiyama virus (SAG) is a member of the genus Alphavirus in the family Togaviridae, isolated in Japan from mosquitoes in 1956. We determined the complete nucleotide sequence of the SAG genomic RNA from the original stock virus which formed a mixture of plaques with different sizes, and that from a full-length cDNA clone, pSAG2, infectious RNA transcripts from which formed uniform large plaques on BHK-21 cells. The SAG genome was 11698 nt in length exclusive of the 3' poly(A) tail. Between the complete nucleotide sequences of the full-length cDNA clone, pSAG2, and the consensus sequence from the original stock virus, there were nine amino acid differences; two each in nsP1, nsP2 and E1, and three in E2, some of which may be responsible for plaque phenotypic variants in the original virus stock. SAG was most closely related to Ross River virus among other alphaviruses fully sequenced, with amino acid sequence identities of 86% in the nonstructural proteins and of 83% in the structural proteins. The 3' terminal 280 nt region of SAG was 82% identical to that of Barmah Forest virus, which was otherwise not closely related to SAG. Comparison of the nucleotide sequence of SAG with partial nucleotide sequences of Getah virus (GET), which was originally isolated in Malaysia in 1955 and is closely related to SAG in serology and in biology, showed near identity between the two viruses, suggesting that SAG is a strain of GET.
    Matched MeSH terms: Cricetinae
  16. Fulltext Regioselective Sequential Modification of Chitosan via Azide-Alkyne Click Reaction: Synthesis, Characterization, and Antimicrobial Activity of Chitosan Derivatives and Nanoparticles
    Sarwar A, Katas H, Samsudin SN, Zin NM
    PLoS One, 2015;10(4):e0123084.
    PMID: 25928293 DOI: 10.1371/journal.pone.0123084
    Recently, the attention of researchers has been drawn toward the synthesis of chitosan derivatives and their nanoparticles with enhanced antimicrobial activities. In this study, chitosan derivatives with different azides and alkyne groups were synthesized using click chemistry, and these were further transformed into nanoparticles by using the ionotropic gelation method. A series of chitosan derivatives was successfully synthesized by regioselective modification of chitosan via an azide-alkyne click reaction. The amino moieties of chitosan were protected during derivatization by pthaloylation and subsequently unblocked at the end to restore their functionality. Nanoparticles of synthesized derivatives were fabricated by ionic gelation to form complexes of polyanionic penta-sodium tripolyphosphate (TPP) and cationic chitosan derivatives. Particle size analysis showed that nanoparticle size ranged from 181.03 ± 12.73 nm to 236.50 ± 14.32 nm and had narrow polydispersity index and positive surface charge. The derivatives and corresponding nanoparticles were evaluated in vitro for antibacterial and antifungal activities against three gram-positive and gram-negative bacteria and three fungal strains, respectively. The minimum inhibitory concentration (MIC) of all derivatives ranged from 31.3 to 250 µg/mL for bacteria and 188 to1500 µg/mL for fungi and was lower than that of native chitosan. The nanoparticles with MIC ranging from 1.56 to 25 µg/mLfor bacteria and 94 to 750 µg/mL for fungi exhibited higher activity than the chitosan derivatives. Chitosan O-(1-methylbenzene) triazolyl carbamate and chitosan O-(1-methyl phenyl sulfide) triazolyl carbamate were the most active against the tested bacterial and fungal strains. The hemolytic assay on erythrocytes and cell viability test on two different cell lines (Chinese hamster lung fibroblast cells V79 and Human hepatic cell line WRL68) demonstrated the safety; suggesting that these derivatives could be used in future medical applications. Chitosan derivatives with triazole functionality, synthesized by Huisgen 1,3-dipolar cycloaddition, and their nanoparticles showed significant enhancement in antibacterial and antifungal activities in comparison to those associated with native, non-altered chitosan.
    Matched MeSH terms: Cricetinae
  17. Demodex aurati and Demodex criceti in the golden hamster (Mesocricetus auratus)
    Retnasabapathy A, Lourdusamy D
    Southeast Asian J. Trop. Med. Public Health, 1974 Sep;5(3):460.
    PMID: 4432113
    Matched MeSH terms: Cricetinae/parasitology*
  18. Gramine inhibits angiogenesis and induces apoptosis via modulation of TGF-β signalling in 7,12 dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinoma
    Ramu A, Kathiresan S, Ali Ahmed B
    Phytomedicine, 2017 Sep 15;33:69-76.
    PMID: 28887922 DOI: 10.1016/j.phymed.2017.05.008
    BACKGROUND: Transforming growth factor-β (TGF-β) and its receptors are considered as a novel target in cancer chemotherapy. Gramine, an indole alkaloid, possesses various pharmacological properties including antiproliferative and anticancer. However, the anti-angiogenic property remains unexplored.

    PURPOSE: The present study was designed to evaluate the anti-angiogenic and apoptosis induction properties of gramine through inhibiting TGF-β on DMBA induced oral squamous cell carcinoma (OSCC) in the hamster buccal pouch (HBP).

    METHODS: The effects of gramine on TGF-β signalling in DMBA induced carcinogenic events such as angiogenesis and apoptosis were analysed by studying the mRNA expression using RT-PCR, protein expression by western blot and histopathological analysis using haematoxylin and eosin (H & E) staining.

    RESULTS: Gramine significantly inhibited phosphorylation and nuclear translocation of Smad2 and Smad4 by blocking activity of the TGFβ-RII, RI and activation of inhibitory Smad7. Gramine inhibited angiogenic markers such as MMP-2, MMP-9, HIF-1α, VEGF, and VEGF-R2 as well as increased TIMP-2 expression. Furthermore, gramine induced apoptosis in DMBA induced tumour bearing animals by up regulating the pro apoptotic proteins Bax, cytochrome C, apaf-1, caspase-9 caspase-3 and PARP.

    CONCLUSION: In this study, we clearly demonstrated that gramine treatment diminishes angiogenesis and induces apoptosis in hamster buccal pouch (HBP) carcinogenesis by modulating TGF-β signals.

    Matched MeSH terms: Cricetinae
  19. Development of Wuchereria bancrofti in the domestic cat
    Ramachandran CP, Sandosham AA, Sivanandam S
    Med J Malaya, 1966 Jun;20(4):333.
    PMID: 4224348
    Matched MeSH terms: Cricetinae
  20. Complete nucleotide sequence of RNA segment 3 of bluetongue virus serotype 2 (Ona-A). Phylogenetic analyses reveal the probable origin and relationship with other orbiviruses
    Pritchard LI, Gould AR, Wilson WC, Thompson L, Mertens PP, Wade-Evans AM
    Virus Res, 1995 Mar;35(3):247-61.
    PMID: 7785314
    The nucleotide sequence of the RNA segment 3 of bluetongue virus (BTV) serotype 2 (Ona-A) from North America was determined to be 2772 nucleotides containing a single large open reading frame of 2703 nucleotides (901 amino acid). The predicted VP3 protein exhibited general physiochemical properties (including hydropathy profiles) which were very similar to those previously deduced for other BTV VP3 proteins. Partial genome segment 3 sequences, obtained by polymerase chain reaction (PCR) sequencing, of BTV isolates from the Caribbean were compared to those from North America, South Africa, India, Indonesia, Malaysia and Australia, as well as other orbiviruses, to determine the phylogenetic relationships amongst them. Three major BTV topotypes (Gould, A.R. (1987) Virus Res. 7, 169-183) were observed which had nucleotide sequences that differed by approximately 20%. At the molecular level, geographic separation had resulted in significant divergence in the BTV genome segment 3 sequences, consistent with the evolution of distinct viral populations. The close phylogenetic relationship between the BTV serotype 2 (Ona-A strain) from Florida and the BTV serotypes 1, 6 and 12 from Jamaica and Honduras, indicated that the presence of BTV serotype 2 in North America was probably due to an exotic incursion from the Caribbean region as previously proposed by Sellers and Maaroof ((1989) Can. J. Vet. Res. 53, 100-102) based on trajectory analysis. Conversely, nucleotide sequence analysis of Caribbean BTV serotype 17 isolates suggested they arose from incursions which originated in the USA, possibly from a BTV population distinct from those circulating in Wyoming.
    Matched MeSH terms: Cricetinae
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