Displaying publications 61 - 80 of 2091 in total

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  1. Fulltext Anti-malarial and anti-inflammatory effects of Gleichenia truncata mediated through inhibition of GSK3β
    Suhaini S, Liew SZ, Norhaniza J, Lee PC, Jualang G, Embi N, et al.
    Trop Biomed, 2015 Sep;32(3):419-33.
    PMID: 26695202 MyJurnal
    Gleichenia truncata is a highland fern from the Gleicheniaceae family known for its traditional use among indigenous communities in Asia to treat fever. The scientific basis of its effect has yet to be documented. A yeast-based kinase assay conducted in our laboratory revealed that crude methanolic extract (CME) of G. truncata exhibited glycogen synthase kinase-3 (GSK3)-inhibitory activity. GSK3β is now recognized to have a pivotal role in the regulation of inflammatory response during bacterial infections. We have also previously shown that lithium chloride (LiCl), a GSK3 inhibitor suppressed development of Plasmodium berghei in a murine model of malarial infection. The present study is aimed at evaluating G. truncata for its anti-malarial and anti-inflammatory effects using in vivo malarial and melioidosis infection models respectively. In a four-day suppressive test, intraperitoneal injections of up to 250 mg/kg body weight (bw) G. truncata CME into P.berghei-infected mice suppressed parasitaemia development by >60%. Intraperitoneal administration of 150 mg/kg bw G. truncata CME into Burkholderia pseudomallei-infected mice improved survivability by 44%. G. truncata CME lowered levels of pro-inflammatory cytokines (TNF-α, IFN-γ) in serum and organs of B. pseudomallei-infected mice. In both infections, increased phosphorylations (Ser9) of GSK3β were detected in organ samples of animals administered with G. truncata CME compared to controls. Taken together, results from this study strongly suggest that the anti-malarial and anti-inflammatory effects elicited by G. truncata in part were mediated through inhibition of GSK3β. The findings provide scientific basis for the ethnomedicinal use of this fern to treat inflammation-associated symptoms.
    Matched MeSH terms: Mice, Inbred BALB C; Mice, Inbred ICR
  2. Fulltext Development of triplex real-time PCR and detection of Toxoplasma gondii DNA in infected mice tissues and spiked human samples
    Rahumatullah A, Khoo BY, Noordin R
    Trop Biomed, 2015 Jun;32(2):376-85.
    PMID: 26691266 MyJurnal
    Toxoplasma gondii is an important pathogen in veterinary and human medicine. In this study, a new multiplex TaqMan real-time PCR for detection of T. gondii DNA was developed. This assay consisted of new sets of primers and probes which targeted B1 gene and ITS-1 region of T. gondii, with Vibrio cholera gene as internal control. The B1 gene primers were designed to detect T. gondii RH strain, while the ITS-1 region primers detected most T. gondii strains. Specificity test using common protozoal and bacterial DNA revealed that the assay was very specific to T. gondii. Standard curves constructed using human body fluids spiked with T. gondii (RH and ME49 strains) showed that the sensitivity of the assay was one parasite, with R² value of 0.975 to 0.999 and efficiency of 97% to 99% for all types of samples. The assay performed on DNA extracted from tissues of mice infected with T. gondii showed that liver contained the highest parasite load for both strains of T. gondii. The multiplex real-time PCR developed in this study would be potentially useful for detection of T. gondii in human and animal samples.
    Matched MeSH terms: Mice
  3. Fulltext Interleukin-27 exhibited anti-inflammatory activity during Plasmodium berghei infection in mice
    Fazalul Rahiman SS, Basir R, Talib H, Tie TH, Chuah YK, Jabbarzare M, et al.
    Trop Biomed, 2013 Dec;30(4):663-80.
    PMID: 24522137 MyJurnal
    Interleukin-27 (IL-27) has a pleiotropic role either as a pro-inflammatory or anti-inflammatory cytokine in inflammatory related diseases. The role and involvement of IL-27 during malaria was investigated and the effects of modulating its release on the production of major inflammatory cytokines and the histopathological consequences in major affected organs during the infection were evaluated. Results showed that IL-27 concentration was significantly elevated throughout the infection but no positive correlation with the parasitaemia development observed. Augmentation of IL-27 significantly elevated the release of anti-inflammatory cytokine, IL-10 whereas antagonising and neutralising IL-27 produced the opposite. A significant elevation of pro-inflammatory cytokines (IFN-γ and IL-6) was also observed, both during augmentation and inhibition of IL-27. Thus, it is suggested that IL-27 exerts an anti-inflammatory activity in the Th1 type response by signalling the production of IL-10 during malaria. Histopathological examination showed sequestration of PRBC in the microvasculature of major organs in malarial mice. Other significant histopathological changes include hyperplasia and hypertrophy of the Kupffer cells in the liver, hyaline membrane formation in lung tissue, enlargement of the white and red pulp followed by the disappearance of germinal centre of the spleen, and tubular vacuolation of the kidney tissues. In conclusion, it is suggested that IL-27 may possibly acts as an anti-inflammatory cytokine during the infection. Modulation of its release produced a positive impact on inflammatory cytokine production during the infection, suggesting its potential in malaria immunotherapy, in which the host may benefit from its inhibition.
    Matched MeSH terms: Mice, Inbred ICR; Mice
  4. Fulltext Effects of Tamarind (Tamarindus indicus Linn) seed extract on Russell's viper (Daboia russelli siamensis) venom
    Maung KM, Lynn Z
    Trop Biomed, 2012 Dec;29(4):580-7.
    PMID: 23202603
    Snake bite has been regarded as an important health problem in Myanmar since early 1960's. In the recent years, there has been growing interest in alternative therapies and therapeutic use of natural products, especially those derive from plants. In Myanmar and Indian traditional medicine, various plants have used as a remedy for treating snake bite. The present study was carried out to evaluate the effects of alcohol extract of Tamarind (Tamarindus indica Linn.) seed on some biologic properties of Russell's viper (Daboia russelli siamensis) venom (RVV). The Phospholipase A2 (PLA2) enzyme, coagulase enzyme and caseinolytic enzyme activities of Russell's viper venom (RVV) were reduced when mixed and incubated with the extract. When the RVV and the different amount of extracts were preincubated and injected intramuscularly into mice, all of them survived, but all the mice in the control group died. On the other hand, when RVV were injected first followed by the extract into mice, all of them died. If the extract was injected near the site where Russell's viper venom was injected, all the mice survived for more than 24 hours and the survival time prolonged but they all died within 96 hours. In conclusion, according to the results obtained, the extract neutralizes some biologic properties of the Russell's viper venom and prolonged the survival time if the extract was injected near the site where the Russell's viper venom was injected.
    Matched MeSH terms: Mice
  5. Fulltext Glycogen synthase kinase-3β inhibition improved survivability of mice infected with Burkholderia pseudomallei
    Tay TF, Maheran M, Too SL, Hasidah MS, Ismail G, Embi N
    Trop Biomed, 2012 Dec;29(4):551-67.
    PMID: 23202600
    The disease melioidosis, caused by the soil bacteria Burkholderia pseudomallei, often manifests as acute septicemia with high fatality. Glycogen synthase kinase-3β (GSK3β) plays a key role during the inflammatory response induced by bacteria. We used a murine model of acute melioidosis to investigate the effects of LiCl, a GSK3 inhibitor on experimental animal survivability as well as TNF-α, IL-1β, IFN-γ, IL-10 and IL-1Ra cytokine levels in blood, lung, liver and spleen of B. pseudomallei-infected mice. Our results showed that administration of 100 μg/g LiCl improved survivability of mice infected with 5 X LD50 of B. pseudomallei. Bacterial counts in spleen, liver and lungs of infected mice administered with LiCl were lower than non-treated controls. Our data also revealed that GSK3β is phosphorylated in the spleen, liver and lung of animals infected with B. pseudomallei. However in infected animals administered with LiCl, higher levels of pGSK3 were detected in the organs. Levels of proinflammatory cytokines (TNF-α, IL-1β and IFN-γ) and anti-inflammatory cytokines (IL-10 and IL-1Ra) in sera and organs tested were elevated significantly following B. pseudomallei infection. With GSK3β inhibition, pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β) were significantly decreased in all the samples tested whilst the levels of anti-inflammatory cytokines, IL-10 (spleen and lung) and IL-1Ra (spleen, liver and sera) were further elevated. This study represents the first report implicating GSK3β in the modulation of cytokine production during B. pseudomallei infection thus reiterating the important role of GSK3β in the inflammatory response caused by bacterial pathogens.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  6. Fulltext Immunogenicity of recombinant BCG-based vaccine expressing the 22 kDa of serine repeat antigen (SE22) of Plasmodium falciparum
    Teo WH, Nurul AA, Norazmi MN
    Trop Biomed, 2012 Jun;29(2):239-53.
    PMID: 22735846 MyJurnal
    The Plasmodium falciparum serine repeat antigen (SERA) is one of the promising blood-stage malarial vaccine candidates. In this study, recombinant Mycobacterium bovis bacille Calmette-Guerin (rBCG) expressing the 22 kDa protein (SE22) from the 47 kDa Nterminal domain of serine repeat antigen (SERA), generated in favour of mycobacterium codon usage, elicited specific immune response in BALB/c mice with a mixed Th1/Th2 profile. Immunized sera containing high levels of specific IgG1 and IgG2a against the epitope (as determined by ELISA) were reactive with fixed P. falciparum merozoites as demonstrated by indirect immunofluorescence assay (IFA). Furthermore, the lymphocyte proliferative response to SE22 antigen from rBCG-immunized mice was higher than that of controls. The expression of intracellular cytokines (IL-2, IL-4 and IFNγ) in CD4+- and CD8+-cells was also enhanced following in-vitro stimulation with SE22. These findings indicate that a rBCG-based vaccine candidate expressing a blood-stage antigen of P. falciparum could enhance both humoral and cellular immune responses, thus paving the way for the rational use of rBCG as a vaccine candidate against malaria.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  7. Fulltext Modulation of interleukin-18 release produced positive outcomes on parasitaemia development and cytokines production during malaria in mice
    Basir R, Hasballah K, Jabbarzare M, Gam LH, Abdul Majid AM, Yam MF, et al.
    Trop Biomed, 2012 Sep;29(3):405-21.
    PMID: 23018504 MyJurnal
    The involvement of interleukin-18 (IL-18) and the effects of modulating its release on the course of malaria infection were investigated using Plasmodium berghei ANKA infection in ICR mice as a model. Results demonstrated that plasma IL-18 concentrations in malarial mice were significantly elevated and positively correlated with the percentage parasitaemia development. Significant expressions of IL-18 were also observed in the brain, spleen and liver tissues. Slower development of parasitaemia was observed significantly upon inhibition and neutralization of IL-18, whereas faster development of parasitaemia was recorded when the circulating levels of IL-18 were further augmented during the infection. Inhibition and neutralization of IL-18 production also resulted in a significant decrease of plasma concentrations of pro-inflammatory cytokines (TNFα, IFNγ, IL-1α and IL-6), whereas the anti-inflammatory cytokine, IL-10, was significantly increased. Augmenting the release of IL- 18 during the infection on the other hand resulted in the opposite. Early mortality in malarial mice was also observed when the circulating levels of IL-18 were further augmented. Results proved the important role of IL-18 in immune response against malaria and suggest that IL-8 is pro-inflammatory in nature and may involve in mediating the severity of the infection through a pathway of elevating the pro-inflammatory cytokine and limiting the release of anti-inflammatory cytokine.
    Matched MeSH terms: Mice, Inbred ICR; Mice
  8. Fulltext Suppression of Plasmodium berghei parasitemia by LiCl in an animal infection model
    Nurul Aiezzah Z, Noor E, Hasidah MS
    Trop Biomed, 2010 Dec;27(3):624-31.
    PMID: 21399604 MyJurnal
    Malaria, caused by the Plasmodium parasite is still a health problem worldwide due to resistance of the pathogen to current anti-malarials. The search for new anti-malarial agents has become more crucial with the emergence of chloroquine-resistant Plasmodium falciparum strains. Protein kinases such as mitogen-activated protein kinase (MAPK), MAPK kinase, cyclin-dependent kinase (CDK) and glycogen synthase kinase- 3(GSK-3) of parasitic protozoa are potential drug targets. GSK-3 is an enzyme that plays a vital role in multiple cellular processes, and has been linked to pathogenesis of several diseases such as type II diabetes and Alzheimer's disease. In the present study, the antiplasmodial property of LiCl, a known GSK-3 inhibitor, was evaluated in vivo for its antimalarial effect against mice infected with Plasmodium berghei. Infected ICR mice were intraperitoneally administered with LiCl for four consecutive days before (prophylactic test) and after (suppressive test) inoculation of P. berghei-parasitised erythrocytes. Results from the suppressive test (post-infection LiCl treatment) showed inhibition of erythrocytic parasitemia development by 62.06%, 85.67% and 85.18% as compared to nontreated controls for the 100 mg/kg, 300 mg/kg and 600 mg/kg dosages respectively. Both 300 mg/kg and 600 mg/kg LiCl showed similar significant (P<0.05) suppressive values to that obtained with chloroquine-treated mice (86% suppression). The prophylactic test indicated a significantly (P<0.05) high protective effect on mice pre-treated with LiCl with suppression levels relatively comparable to chloroquine (84.07% and 86.26% suppression for the 300 mg/kg and 600 mg/kg LiCl dosages respectively versus 92.86% suppression by chloroquine). In both the suppressive and prophylactic tests, LiCl-treated animals survived longer than their non-treated counterparts. Mortality of the non-treated mice was 100% within 6 to 7 days of parasite inoculation whereas mice administered with LiCl survived beyond 9 days. Healthy non-infected mice administered with 600 mg/ kg LiCl for four consecutive days also showed decreased mortality compared to animals receiving lower doses of LiCl; three of the seven mice intraperitoneally injected with the former dose of LiCl did not survive more than 24 h after administration of LiCl whereas animals given the lower LiCl doses survived beyond four days of LiCl administration. To date, no direct evidence of anti-malarial activity in vivo or in vitro has been reported for LiCl. Evidence of anti-plasmodial activity of lithium in a mouse infection model is presented in this study.
    Matched MeSH terms: Mice, Inbred ICR; Mice
  9. Fulltext Antigenic profile of Blomia tropicalis, Aleuroglyphus ovatus and Glycycometus malaysiensis
    Tang JC, Wong SF, Mak JW, Ho TM
    Trop Biomed, 2011 Aug;28(2):223-36.
    PMID: 22041741
    House dust mites and storage mites are well-known causes for allergenic diseases. The aim of this study was to investigate the immunogenic sites of Blomia tropicalis, Aleurogyphus ovatus and Glycycometus malaysiensis. The mites were maintained in a culture medium at 25ºC and 75% relative humidity. Mites were harvested either with heat escape or floatation method, purified, homogenized, quantified and used for the production of polyclonal antibody and immunostaining. For each species of mites, five male mice and five male rats were randomly selected and immunized intraperitoneally with respective crude mite extract at two-weekly intervals. Blomia tropicalis, A. ovatus or G. malaysiensis whole mites and paraffin-embedded mite sections were immunostained with the respective polyclonal antibody. The faecal pellets of mites were intensely stained for all the three species in the present study. The legs of sectioned A. ovatus were not immunogenic as compared with those of G. malaysiensis and B. tropicalis. The outer layer (cuticle) of whole mites and the eggs for these species were very immunogenic. Hence, the polyclonal antibodies obtained in this study may serve as potential tools in detecting the eggs and immature mites in environmental samples. Future studies should focus on the antigenic components of eggs since they were relatively abundant in dust and highly antigenic as seen in the present study.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  10. Fulltext In vitro and in vivo anticandidal activity of Swietenia mahogani methanolic seed extract
    Sahgal G, Ramanathan S, Sasidharan S, Mordi MN, Ismail S, Mansor SM
    Trop Biomed, 2011 Apr;28(1):132-7.
    PMID: 21602779 MyJurnal
    Swietenia mahogani crude methanolic (SMCM) seed extract was investigated for the antifungal activity against Candida albicans which has not been evaluated previously. The antifungal activity was evaluated against C. albicans via disk diffusion, minimum inhibition concentration (MIC), scanning electron microscope (SEM), transmission electron microscope (TEM) and time killing profile. The MIC value of SMCM seed extract is 12.5 mg/ml. The SEM and TEM findings showed there is morphological changes and cytological destruction of C. albicans at the MIC value. Animal model was used to evaluate the in vivo antifungal activity of SMCM seed extract. The colony forming unit (CFU) were calculated per gram of kidney sample and per ml of blood sample respectively for control, curative and ketaconazole treated groups. There was significant reduction for the CFU/ml of blood and CFU/g of kidney. This indicated that the extract was observed to be effective against C. albicans in vitro and in vivo conditions.
    Matched MeSH terms: Mice
  11. Fulltext Evaluation of difference in the neurotoxicity produced by dermal application of chlorpyrifos on the neonatal and adult mice
    Mitra NK, Lee MS, Nadarajah VD
    Trop Biomed, 2010 Apr;27(1):19-29.
    PMID: 20562809
    Dermal exposure to organophosphate pesticide is important because of its popular use. This study planned to compare the changes in serum acetylcholinesterase, paraoxonase and neuronal density of hippocampus and iso-cortex between two age groups of Swiss albino mice (18-day-old and 150-day-old) after dermal application of (1/2) LD50 of chlorpyrifos for 14 days. Statistically significant reduction was observed in serum acetylcholinesterase (Mann-Whitney test, p<0.05) and neuronal density (Independent samples t-test, p<0.05) in exposed groups compared to the control. The reduction in serum AChE and neuronal density was more pronounced in exposed adult mice than in exposed neonatal mice. The paraoxonase level was insignificant in control neonatal mice, whereas it was 890-fold more in exposed neonatal mice. Upregulated paraoxonase levels may be extrapolated to produce relatively lower reduction of cholinesterase and neuronal density in neonatal mice.
    Matched MeSH terms: Mice
  12. Fulltext Cloning, expression and protective capacity of 37 kDa outer membrane protein gene (ompH) of Pasteurella multocida serotype B:2
    Tan HY, Nagoor NH, Sekaran SD
    Trop Biomed, 2010 Dec;27(3):430-41.
    PMID: 21399583 MyJurnal
    The major outer membrane protein (OmpH) of 4 local Malaysian strains of Pasteurella multocida serotype B:2 were characterized in comparison to ATCC strains. Three major peptide bands of MW 26, 32 and 37 kDa were characterized using SDSPAGE. Two of these fragments, the 32 kDa and 37 kDa were observed to be more reactive with a mouse polyclonal antiserum in all of the local isolates as well as the ATCC strains in a Western blot. However, the 32 kDa fragment was found to cross react with other Gram negative bacteria. Therefore, the 37 kDa OmpH was selected as vaccine candidate. The 37 kDa ompH gene of the isolated strain 1710 was cloned into an Escherichia coli expression vector to produce large amounts of recombinant OmpH (rOmpH). The 37 kDa ompH gene of strain 1710 was sequenced. In comparison to a reference strain X-73 of the ompH of P. multocida, 39bp was found deleted in the 37 kDa ompH gene. However, the deletion did not shift the reading frame or change the amino acid sequence. The rOmpH was used in a mice protection study. Mice immunized and challenged intraperitoneally resulted 100% protection against P. multocida whilst mice immunized subcutaneously and challenged intraperitoneally only resulted 80% protection. The rOmpH is therefore a suitable candidate for vaccination field studies. The same rOmpH was also used to develop a potential diagnostic kit in an ELISA format.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  13. Fulltext Optimization of Toxoplasma gondii cultivation in VERO cell line
    Saadatnia G, Haj Ghani H, Khoo BY, Maimunah A, Rahmah N
    Trop Biomed, 2010 Apr;27(1):125-30.
    PMID: 20562822
    In vitro culture of Toxoplasma gondii can provide tachyzoites which are active, viable and with desirable purity. Thus the aim of this study was to optimize the cell culture method for T. gondii propagation to obtain a consistent source of parasites with maximum yield and viability, but minimum host cell contamination for use in production of excretory-secretory antigen. Tachyzoites with seed counts of 1x10(6), 1x10(7) and 1x10(8) harvested from infected mice were added to VERO cells of different degrees of confluence, namely 50%, 85% and 100%, and examined periodically using an inverted microscope. When the maximum release of the tachyzoites was observed from the host cells, the culture supernatant was removed and the tachyzoites harvested. Using a Neubauer chamber, the percentages of viable tachyzoites and host cell contamination were determined using trypan blue stain. Parameters that gave the best yield and purity of viable tachyzoites were found to be as follows: VERO cells at 85% confluence in DMEM medium and inoculum comprising 1x10(7) tachyzoites. After about 3 days post infection, the tachyzoites multiplied 78x, with a yield of ~7.8x10(8) per flask, 99% viability and 3% host cell contamination. This study has successfully optimized the method of propagation of T. gondii tachyzoites in VERO cells which produce parasites with high yield, purity and viability.
    Matched MeSH terms: Mice
  14. Fulltext Phagocytic activity and pro-inflammatory cytokines production by the murine macrophage cell line J774A.1 stimulated by a recombinant BCG (rBCG) expressing the MSP1-C of Plasmodium falciparum
    Rapeah S, Dhaniah M, Nurul AA, Norazmi MN
    Trop Biomed, 2010 Dec;27(3):461-9.
    PMID: 21399587 MyJurnal
    Macrophages are involved in innate immunity against malaria due to their ability to phagocytose infected erythrocytes and produce inflammatory cytokines, which are important for controlling parasite growth during malaria infection. In this study, the ability of a recombinant BCG (rBCG) vaccine expressing the 19-kDa C-terminus of merozoite surface protein-1 (MSP1-C) of Plasmodium falciparum, to stimulate the phagocytic activity and secretion of pro-inflammatory cytokines by the macrophage cell line J774A.1 was measured at varying times. The results demonstrate the ability of the rBCG construct to activate the inflammatory action of macrophages, which is important as a first-line of defence in clearing malaria infections.
    Matched MeSH terms: Mice
  15. Fulltext Antimalarial properties of Goniothalamin in combination with chloroquine against Plasmodium yoelii and Plasmodium berghei growth in mice
    Mohd Ridzuan MA, Ruenruetai U, Noor Rain A, Khozirah S, Zakiah I
    Trop Biomed, 2006 Dec;23(2):140-6.
    PMID: 17322815 MyJurnal
    Malaria is a disease which is still endemic and has become a disastrous scourge because of the emergence of antimalarial drug resistant Plasmodium falciparum. A new approach in addressing this is in developing a combination drug. This study is to show the enhancement of antimalarial properties, when single compound, goniothalamin combine with standard drug, chloroquine. Based on 4 Day Test, percentage of parasite growth on treated infected mice were determined. Oral treatment with 1 mg/kg BW of chloroquine on experimental mice suppressed 70% and 76.7% of both Plasmodium yoelii and Plasmodium berghei, respectively. The infection of P. berghei in mice was inhibited less than 50% by goniothalamin individual treatment at all doses in this study. About 27.8% and 18.5% inhibition of infection were observed in P. yoelii infected mice treated with 30 mg/kg and 60 mg/kg of goniothalamin respectively and the suppression exceed more than 50% at higher doses (90 and 120 mg/kg). Combination of 1 mg/kg chloroquine with either 30 mg/kg or 60 mg/kg of goniothalamin decreased the parasitemia of P. yoelii infected mice more than 90% and prolong the survival up to 100% after treatment. Similar treatment to P. berghei infected mice only shows about 60% reduction of parasitemia. The study findings showed that antimalarial property of goniothalamin was enhanced by combination with chloroquine at lower dose of each drug.
    Matched MeSH terms: Mice
  16. Fulltext The detection and characterization of pathogenic Leptospira and the use of OMPs as potential antigens and immunogens
    Gebriel AM, Subramaniam G, Sekaran SD
    Trop Biomed, 2006 Dec;23(2):194-207.
    PMID: 17322822 MyJurnal
    The detection of leptospires in patient blood in the first week of the disease using PCR provides an early diagnostic tool. PCR using two sets of primers (G1/G2 and B64-I/B64-II) tested with samples seeded with 23 leptospiral strains from pathogenic and non-pathogenic strains was able to amplify leptospiral DNA from pathogenic strains only. Of the 39 antibody negative samples collected from patients suspected for leptospirosis, only 1 sample (2.6%) was PCR positive. Using LSSP-PCR, the G2 primers allowed the characterization of Leptopira species to 10 different genetic signatures which may have epidemiological value in determining species involved in outbreaks. Leptospiral outer membrane proteins from three strains were purified and reacted against patients sera and gave rise to different profiles for pathogenic and non-pathogenic strains. Lymphocytes of mice injected with OMPs proliferated and released IFN(-3) when stimulated in vitro using Leptospira OMP as antigens. This suggests that an immune response could be established using leptospiral OMPs as a putative vaccine. OMPs were also used in a Dot-ELISA to detect antibodies against Leptospira pathogens in humans.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  17. Fulltext Characterisation of a truncated Toxoplasma gondii surface antigen 2 (SAG2) secreted by the methylotrophic yeast Pichia pastoris
    Lau YL, Shamilah H, Fong MY
    Trop Biomed, 2006 Dec;23(2):186-93.
    PMID: 17322821 MyJurnal
    A truncated form of surface antigen 2 (SAG2) of the protozoan parasite Toxoplasma gondii was cloned and expressed in the methylotrophic yeast Pichia pastoris. This recombinant antigen, designated as recSAG2-N, contained only the N-terminal half of the native SAG2. The recSAG2-N was secreted by the Pichia pastoris into the culture supernatant, and it was harvested by using the trichloroacetic acid precipitation method. Specificity of recSAG2-N was evaluated in western blot assays. Fifty human serum samples, including 32 from confirmed cases of toxoplasmosis, were tested. Results from the assays showed that recSAG2-N reacted with sera from the toxoplasmosis cases only. In vivo experiments showed that serum from mice which received recSAG2-N reacted with the native SAG2 of T. gondii.
    Matched MeSH terms: Mice
  18. Therapeutic effects of Schistosoma mansoni soluble egg antigen in high fat diet induced dyslipidemia, hepatic and cardiovascular pathology in mice
    Toulah FH, El-Aswad BEW, Harba NM, Naguib YM
    Trop Biomed, 2018 Dec 01;35(4):893-907.
    PMID: 33601839
    High-fat diet (HFD) can cause hyperlipidemia, fatty liver and cardiovascular disorders. Herein, we evaluated therapeutic effects and possible underlying mechanisms of actions of Schistosoma mansoni soluble egg antigen (SEA) against experimental HFD induced dyslipidemia, hepatic and cardiovascular pathology. Forty Swiss albino mice were divided into four groups (10 each); mice fed standard diet (SD), mice fed HFD, mice fed HFD for 8 weeks then infected by S. mansoni cercaria (HFD+I) and mice fed HFD for 8 weeks then treated with SEA (HFD+SEA), all mice were euthanized 16 weeks after starting the experiment. HFD+SEA mice showed significantly (p<0.001) reduced total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG), and significantly (p<0.05) increased high-density lipoprotein cholesterol (HDL-C) comparing to HFD mice with non-significant difference with HFD+I mice group. Doppler flowmetry showed significantly (p<0.01) lower arterial resistance and significantly (p<0.05) higher blood flow velocity in HFD+SEA and HFD+I mice groups than HFD mice. HFD+SEA mice revealed improving in liver and aortic pathology and these were better than HFD+I mice group. HFD+SEA and HFD+I mice groups had less myocardium lipid deposits, but still showing some congested blood vessels. HFD myocardium revealed strong CD34+ expression on immunohistochemistry study, while that of HFD+SEA showed weak and HFD+I mice had moderate expressions. HFD+SEA mice had significantly (p<0.01) lower serum IL-1β and vascular endothelial growth factor (VEGF) and significantly (p<0.001) higher serum transforming growth factor beta 1 (TGF-β1) and IL-10 than HFD mice with non-significant difference with HFD+I mice. In conclusion, SEA lowered serum lipids, improved aortic function, decreased liver and cardiovascular pathology in HFD mice, so, it is recommended to purify active molecules from SEA to develop anti-dyslipidemic treatment.
    Matched MeSH terms: Mice
  19. Serine protease inhibitor, serpin, is a biomarker following Schistosoma mansoni re-infection in mice
    Mohammed ES, El-Dakhly KM
    Trop Biomed, 2021 Jun 01;38(2):63-67.
    PMID: 33973574 DOI: 10.47665/tb.38.2.039
    Schistosomiasis is a chronic parasitic disease affecting mostly low income and resourcelimited countries. Despite the distribution of the curative medicine, praziquantel (PZQ), the frequency of re-infection is commonly reported, thus, making a difficulty to discriminate treatment failure after re-infection. Therefore, assessing Schistosoma mansoni re-infection after praziquantel administration is crucial to prove the treatment efficacy and to break the transmission of infection in endemic areas. The evolution of highly sensitive and specific diagnostic markers, reliable to detect the re-infection and to evaluate the treatment efficacy, is required to control schistosomiasis. In this study, the potential role of serpin recombinant antigen of S. mansoni as a biomarker of re-infection and chemotherapeutic efficacy has been assessed. Therefore, 20 mice were experimentally challenged and re-challenged with 50 S. mansoni cercariae and divided into 4 equal groups; the first included infected mice (control positive), the second group was twice infected with S. mansoni and left untreated, the third included mice twice infected then treated with praziquantel following the last challenge, and the forth one remained uninfected and untreated (control negative). The current findings demonstrated that high levels of IgG and IgG1 bound to serpin were detected following the re-infection and rapidly declined post treatment. In summary, S. mansoni recombinant serpin could be used as a promising marker to discriminate S. mansoni re-infection and evaluated the efficacy of treatment. The translation of such a potential tool in endemic areas will provide a significant support for the elimination and control programs against schistosomiasis.
    Matched MeSH terms: Mice
  20. Insights into immunopathology and triggering of apoptosis in chronic cerebral toxoplasmosis using murine models
    El Saftawy EA, Shash RY, Aboulhoda BE, Arsanyos SF, Albadawi EA, Abou-Fandoud SM, et al.
    Trop Biomed, 2021 Jun 01;38(2):53-62.
    PMID: 33973573 DOI: 10.47665/tb.38.2.037
    BACKGROUND: toxoplasmosis is a cosmopolitan protozoan disease with a wide range of neuropathology. Recent studies identified its potential association with several mental disorders e.g. schizophrenia dependable on apoptosis in their pathogenesis. We investigated value of toxoplasmosis to induce apoptosis of the neuronal cells.

    METHODS: per-orally infected C57BL/6 mice with 15-20 cysts of the avirulent T. gondii Beverly strain at 9-11 weeks of age were examined 12 weeks later during parasite establishment. Distributions of the parasite's cysts and the histopathological lesions in the brains were analyzed using Image J software. Relative expression of TNF-α and iNOS of cell-mediated immunity (CMI), Bax (pro-apoptosis) and Bcl-2 (anti-apoptosis) were all assessed using immunohistochemistry.

    RESULTS: higher parasite burden was seen in the forebrain with p value <= 0.05. Dramatically increased TNF-α, iNOS, and Bax expressions with Bax/Bcl-2 ratio 2.42:0.52 were reported (p value <= 0.05). The significant correlation between Bax data and different CMI biomarkers including TNF-α and i-NOS was evaluated. Interestingly, no significant correlation was seen between TNF-α, iNOS, Bax and Bcl-2 expressions and location of the parasite. However, Bax/Bcl-2 ratio was statistically correlated with CMI biomarkers and whole sample mean parasite burden, p value <= 0.05.

    CONCLUSION: Chronic toxoplasmosis exhibits an immense pro-apoptotic signal on the cerebral tissues of experimental mice.

    Matched MeSH terms: Mice, Inbred C57BL; Mice
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