Displaying publications 21 - 35 of 35 in total

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  1. Fulltext A description of an automorphism of a non-split metacyclic p-group
    Idham Arif Alias
    Pertanika Journal of Science & Technology, 2011;19(1):109-116.
    MyJurnal
    A map on a group is not necessarily an automorphism on the group. In this paper we study the necessary and sufficient conditions for a map on a non-split metacyclic p-group to be an automorphism, where we only consider p as an odd prime number. The metacyclic group can be defined by a presentation and it will be beneficial to have a direct relation between the parameters in the presentation and an automorphism of the group. We consider the action of an automorphism on the generators of the group mentioned. Since any element of a metacyclic group will be mapped to an element of the group by an automorphism, we can conveniently represent the automorphism in a matrix notation. We then use the relations and the regularity of the non-split metacyclic p-group to find conditions on each entry of the matrix in terms of the parameters in its presentation so that such a matrix does indeed represent an automorphism.
    Matched MeSH terms: Trypanosoma cruzi
  2. Possible role of inter-domain salt bridges in oligopeptidase B from Trypanosoma brucei: critical role of Glu172 of non-catalytic β-propeller domain in catalytic activity and Glu490 of catalytic domain in stability of OPB
    Fukumoto J, Ismail NI, Kubo M, Kinoshita K, Inoue M, Yuasa K, et al.
    J. Biochem., 2013 Nov;154(5):465-73.
    PMID: 23946505 DOI: 10.1093/jb/mvt077
    Oligopeptidase B (OPB) is a member of the prolyl oligopeptidase (POP) family of serine proteases. OPB in trypanosomes is an important virulence factor and potential pharmaceutical target. Characteristic structural features of POP family members include lack of a propeptide and presence of a β-propeller domain (PD), although the role of the β-PD has yet to be fully understood. In this work, residues Glu(172), Glu(490), Glu(524) and Arg(689) in Trypanosoma brucei OPB (Tb OPB), which are predicted to form inter-domain salt bridges, were substituted for Gln and Ala, respectively. These mutants were evaluated in terms of catalytic properties and stability. A negative effect on kcat/Km was obtained following mutation of Glu(172) or Arg(689). In contrast, the E490Q mutant exhibited markedly decreased thermal stability, although this mutation had less effect on catalytic properties compared to the E172Q and R689A mutants. Trypsin digestion showed that the boundary regions between the β-PD and catalytic domains (CDs) of the E490Q mutant are unfolded with heat treatment. These results indicated that Glu(490) in the CD plays a role in stabilization of Tb OPB, whereas Glu(172) in the β-PD is critical for the catalytic activity of Tb OPB.
    Matched MeSH terms: Trypanosoma brucei brucei/enzymology*
  3. Fulltext Active infection and morphometric study of Trypanosoma evansi among horses in Peninsula Malaysia
    Elshafie EI, Sani RA, Hassan L, Sharma R, Bashir A, Abubakar IA
    Trop Biomed, 2013 Sep;30(3):444-50.
    PMID: 24189674 MyJurnal
    Apart from occasional reports of clinical disease affecting horses, there is no information about Trypanosoma evansi in horses in Peninsula Malaysia. Thus, a cross-sectional study was conducted in eight states in Peninsula Malaysia to determine the active presence of T. evansi in horses. A total of 527 blood samples were obtained and examined by haematocrit centrifugation technique (HCT), Giemsa-stained thin blood smear (GSS), morphometric measurements, polymerase chain reaction (PCR) and cloning of PCR products. The results showed an overall parasitological prevalence of 0.57% (3/527, CI: 1.6-0.19%) with both HCT and GSS. Morphometric study revealed the mean total length of the trypanosomes including the free flagellum was 27.94 ± 2.63 μm. PCR successfully amplified a trypanosome specific 257 bp in 1.14% of samples (6/527, CI: 2.4-0.52%) and was confirmed by nucleotide sequences. The mean packed cell volume (PCV) for the positive cases detected by HCT was lower (23% ± 7.00) compared to the positive cases detected by PCR alone in the state of Terengganu (35% ± 4.73). In conclusion, this study showed T. evansi infection occurred in low frequency in horses in Peninsula Malaysia, and anaemia coincided with parasitaemic animals. PCR is considered as a sensitive diagnostic tool when parasitaemia is undetectable. The slight lengthier mean of parasite and anaemia may indicate a virulent strain of T. evansi circulating throughout the country. Thus, it's highly recommended to shed light on host-parasite relationship for better epidemiological understanding.
    Matched MeSH terms: Trypanosoma/cytology; Trypanosoma/genetics; Trypanosoma/isolation & purification*
  4. Seroprevalence and risk factors of Trypanosoma evansi infection in horses in Peninsular Malaysia
    Elshafie EI, Sani RA, Hassan L, Sharma R, Bashir A, Abubakar IA
    Res Vet Sci, 2013 Apr;94(2):285-9.
    PMID: 23021152 DOI: 10.1016/j.rvsc.2012.09.004
    A cross-sectional study was designed to assess the seroprevalence and risk factors associated with Trypanosoma evansi infection among horses, using a total of 527 blood samples obtained from eight states in Peninsular Malaysia. A structured questionnaire was used to collect data on risk factors associated with T. evansi seroprevalence. The overall seroprevalence detected by card agglutination test for T. evansi (CATT/T. evansi) was 13.90% (73/527, CI: 11.2-17.1%). Female and exogenous horses showed a higher risk in association with the disease seroprevalence compared to other groups. The majority of the horse owners were not familiar with surra (85.30%). However, most of them were very cautious with the health of their animals. In conclusion, this study showed that T. evansi occurred in low frequency among horses in Peninsular Malaysia, and the good management system adopted by horse owners was probably responsible for the low T. evansi occurrence.
    Matched MeSH terms: Trypanosoma/classification*
  5. Fulltext Antitrypanosomal screening and cytotoxic effects of selected medicinal plants
    Dyary HO, Arifah AK, Sharma RS, Rasedee A, Mohd-Aspollah MS, Zakaria ZA, et al.
    Trop Biomed, 2014 Mar;31(1):89-96.
    PMID: 24862048 MyJurnal
    Trypanosoma evansi, the causative agent of "surra", infects many species of wild and domestic animals worldwide. In the current study, the aqueous and ethanolic extracts of six medicinal plants, namely, Aquilaria malaccensis, Derris elliptica, Garcinia hombroniana, Goniothalamus umbrosus, Nigella sativa, and Strobilanthes crispus were screened in vitro for activity against T. evansi. The cytotoxic activity of the extracts was evaluated on green monkey kidney (Vero) cells using MTT-cell proliferation assay. The median inhibitory concentrations (IC50) of the extracts ranged between 2.30 and 800.97 μg/ml and the median cytotoxic concentrations (CC50) ranged between 29.10 μg/ml and 14.53 mg/ml. The aqueous extract of G. hombroniana exhibited the highest selectivity index (SI) value of 616.36, followed by A. malaccensis aqueous extract (47.38). Phytochemical screening of the G. hombroniana aqueous extract revealed the presence of flavonoids, phenols, tannins, and saponins. It is demonstrated here that the aqueous extract of G. hombroniana has potential antitrypanosomal activity with a high SI, and may be considered as a potential source for the development of new antitrypanosomal compounds.
    Matched MeSH terms: Trypanosoma/drug effects*
  6. In vivo antitrypanosomal activity of Garcinia hombroniana aqueous extract
    Dyary HO, Arifah AK, Sharma RS, Rasedee A, Mohd Aspollah MS, Zakaria ZA, et al.
    Res Vet Sci, 2015 Jun;100:226-31.
    PMID: 25818171 DOI: 10.1016/j.rvsc.2015.03.007
    The anti-Trypanosoma evansi activity of Garcinia hombroniana (seashore mangosteen) leaves aqueous extract was tested on experimentally infected Sprague-Dawley rats. Treatment of infected rats with G. hombroniana extract resulted in a significantly extended post-infection longevity (p 
    Matched MeSH terms: Trypanosoma/drug effects*
  7. A MALAYAB BAT TRYPANOSOME RESEMBLING T. CRUZI AND T. VESPERTILIONIS
    DUNN FL
    Med J Malaysia, 1964 Sep;19:34-5.
    PMID: 14240059
    Matched MeSH terms: Trypanosoma*
  8. A comparative longitudinal study of bovine trypanosomiasis in tsetse-free and tsetse-infested zones of the Amhara Region, northwest Ethiopia
    Cherenet T, Sani RA, Speybroeck N, Panandam JM, Nadzr S, Van den Bossche P
    Vet Parasitol, 2006 Sep 10;140(3-4):251-8.
    PMID: 16675127
    A study was conducted to determine the incidence of trypanosome infections in cattle in tsetse-free and tsetse-infested zones of the Amhara Region of northwest Ethiopia. A total of six sentinel herds were established and the cattle observed during a period of 8 consecutive months. The prevalence of seropositive cattle was high in both the tsetse-free and tsetse-infested zones. The average monthly incidence of trypanosome infection, determined using molecular diagnostic tools, was 20.9% and 25.7% in the tsetse-free and the tsetse-infested zones, respectively. In the tsetse-free, Trypanosoma vivax was responsible for 90.9% of the cattle trypanosome infections. In the tsetse-infested zone, Trypanosoma congolense and T. vivax contributed almost equally to the trypanosome infections in cattle. Trypanosome infection, regardless of species, resulted in anaemia as evidenced by a significant decrease in the packed cell volume of the infected animal. The outcome of this longitudinal study suggests that control of trypanosomiasis in the Amhara Region cannot be achieved by tsetse control alone. Supplemental measures to include drug therapy and biting fly control are discussed.
    Matched MeSH terms: Trypanosoma congolense/immunology; Trypanosoma congolense/isolation & purification; Trypanosoma vivax/immunology; Trypanosoma vivax/isolation & purification
  9. Seasonal prevalence of bovine trypanosomosis in a tsetse-infested zone and a tsetse-free zone of the Amhara Region, north-west Ethiopia
    Cherenet T, Sani RA, Panandam JM, Nadzr S, Speybroeck N, van den Bossche P
    Onderstepoort J Vet Res, 2004 Dec;71(4):307-12.
    PMID: 15732457
    During a period of four consecutive years, trypanosomosis surveys were conducted in a tsetse-infested and tsetse-free area of the Amhara Region of north-west Ethiopia. In each study area randomly selected communal cattle were sampled and their blood was investigated using parasitological diagnostic methods. At the same time the population of biting flies was sampled. The monthly average prevalence of trypanosome infections in cattle did not differ significantly between study areas. In both study areas, the prevalence of trypanosome infections was highest during the long rainy season. Trypanosome infections were mainly due to Trypanosoma vivax and they significantly reduced the average packed cell volume and the body condition of the animals. The monthly prevalence of infection was correlated with the density of biting flies, such as Tabanidae and Stomoxys spp., in the preceding month suggesting an important role of mechanical transmission in the epidemiology of trypanosomosis in both areas.
    Matched MeSH terms: Trypanosoma brucei brucei/isolation & purification; Trypanosoma congolense/isolation & purification; Trypanosoma vivax/isolation & purification
  10. Epidemiology of Trypanosoma evansi infection in crossbred dairy cattle in Malaysia
    Cheah TS, Sani RA, Chandrawathani P, Bahri S, Dahlan I
    Trop Anim Health Prod, 1999 Feb;31(1):25-31.
    PMID: 10399814
    An investigation into the epidemiology of Trypansoma evansi infection in crossbred dairy cattle was conducted for a period of 12 months on a dairy cattle farm in Penninsular Malaysia. The prevalence of parasitaemia was highest in lactating animals (13.4%), followed by those in the dry herd (8.8%), late pregnant animals (8.1%), early pregnant animals (4.7%), calves (0.3%) and heifers (0.2%). The prevalence of antigenaemia was highest in the lactating animals (54.7%), followed by that in dry animals (53.7%), heifers (51.1%), late pregnant animals (47.7%), early pregnant animals (46.5%) and calves (24.2%).
    Matched MeSH terms: Trypanosoma/pathogenicity*
  11. Ancistrobenomine a, the first naphthylisoquinoline oxygenated at Me-3, and related 5,1'-coupled alkaloids, from the "new" plant species ancistrocladusbenomensis
    Bringmann G, Dreyer M, Rischer H, Wolf K, Hadi HA, Brun R, et al.
    J Nat Prod, 2004 Dec;67(12):2058-62.
    PMID: 15620251
    Three new 5,1'-coupled naphthylisoquinoline alkaloids, ancistrobenomine A (1), 6-O-demethylancistrobenomine A (2), and 5'-O-demethylancistrocline (3), have been isolated from the stem bark of a botanically as yet undescribed highland liana Ancistrocladus sp., proposed to be named "A. benomensis" according to the region in Peninsular Malaysia where it has been discovered on the mountain of Gunung Benom. Two of the compounds possess an unprecedented structure with a novel hydroxymethylene group at C-3 of the fully dehydrogenated isoquinoline moiety. The structural elucidation was achieved by chemical, spectroscopic, and chiroptical methods. As typical of the so-called Ancistrocladaceae type, all of the compounds isolated bear an oxygen at C-6. Biological activities of these alkaloids against different protozoic pathogens are described.
    Matched MeSH terms: Trypanosoma/drug effects
  12. ent-Dioncophylleine A and related dehydrogenated naphthylisoquinoline alkaloids, the first Asian dioncophyllaceae-type alkaloids, from the "new"plant species Ancistrocladus benomensis
    Bringmann G, Dreyer M, Kopff H, Rischer H, Wohlfarth M, Hadi HA, et al.
    J Nat Prod, 2005 May;68(5):686-90.
    PMID: 15921410
    Three new fully dehydrogenated naphthylisoquinoline alkaloids, the 7,1'-coupled ent-dioncophylleine A (3a), the likewise 7,1'-coupled 5'-O-demethyl-ent-dioncophylleine A (4), and the 7,8'-linked dioncophylleine D (5), have been isolated from the leaves of the recently described Malaysian highland liana Ancistrocladusbenomensis. All of them lack an oxygen function at C-6; this so-called Dioncophyllaceae-type structural subclass had previously been found only in naphthylisoquinoline alkaloids from West and Central African plants. Moreover, compounds 3a and 4 are the first fully dehydrogenated, i.e., only axially chiral, naphthylisoquinoline alkaloids of this type that are optically active; compound 5, by contrast, is fully racemic, due to its configurationally unstable biaryl axis. The structural elucidation was achieved by spectroscopic and chiroptical methods. Biological activities of these alkaloids against different protozoan parasites are described.
    Matched MeSH terms: Trypanosoma cruzi/drug effects; Trypanosoma brucei rhodesiense/drug effects
  13. Fulltext Epidemiology of blood parasitic infections in the urban rat population in peninsular Malaysia
    Alias SN, Sahimin N, Edah MA, Mohd-Zain SN
    Trop Biomed, 2014 Jun;31(2):230-40.
    PMID: 25134892 MyJurnal
    A total of 719 wild rats were captured from four localities representing the west (Kuala Lumpur), east (Kuantan), north (Georgetown) and south (Malacca) to determine the diversity of blood protozoan from the urban wild rat population in peninsular Malaysia. Five rat species were recovered with Rattus rattus diardii being the most dominant species, followed by Rattus norvegicus, Rattus exulans, Rattus annandalei and Rattus argentiventer. Two blood protozoan species were found infecting the rodent population namely, Plasmodium sp. (42.1%) and Trypanosoma lewisi (25.0%). This study reports the presence of Plasmodium sp. for the first time in the rodent population in Malaysia. Two main intrinsic factors were identified affecting the parasitic infections. Trypanosoma lewisi infections were influenced by host age and sex with infections observed higher in male and juvenile rats meanwhile Plasmodium sp. infections were observed almost similar in both sexes. However, infections were higher in sub-adult rats.
    Matched MeSH terms: Trypanosoma lewisi/isolation & purification*
  14. Fulltext Molecular detection of Theileria species, Anaplasma species, Candidatus Mycoplasma haemobos, Trypanosoma evansi and first evidence of Theileria sinensis-associated bovine anaemia in crossbred Kedah-Kelantan x Brahman cattle
    Agina OA, Shaari MR, Isa NMM, Ajat M, Zamri-Saad M, Mazlan M, et al.
    BMC Vet Res, 2021 Jul 18;17(1):246.
    PMID: 34275459 DOI: 10.1186/s12917-021-02902-0
    BACKGROUND: Serious disease outbreaks in cattle are usually associated with blood pathogens. This study aims to detect blood pathogens namely Theileria species, Anaplasma species, Candidatus Mycoplasma haemobos and Trypanosoma evansi, and determine their phylogenetic relationships and haemato-biochemical abnormalities in naturally infected cattle.

    METHODS: Molecular analysis was achieved by PCR amplification and sequencing of PCR amplicons of 18SrRNA gene of Theileria species, 16SrRNA genes of Anaplasma and Mycoplasma species, MPSP genes of T. orientalis and T. sinensis, MSP4 gene of A. marginale, 16SrRNA gene of Candidatus Mycoplasma haemobos, and RoTat1.2 VSG gene of Trypanosoma evansi, in sixty-one (61) clinically ill Kedah-Kelantan x Brahman cattle in Pahang, Malaysia.

    RESULTS: A total of 44 (72.13%) cattle were infected with more than one blood pathogen. Theileria species was the blood pathogen with the highest molecular detection rate (72.13, 95% CI 59.83-81.81%). Nucleotide blast analyses of all sequences demonstrated high degree of molecular similarity (98-100%) in comparison with their respective reference sequences. Analysis of 18SrRNA gene sequences of Theileria species and 16SrRNA gene sequences of Anaplasma species revealed Theileria sinensis and Anaplasma platys respectively as additional species detected in these cattle. MPSP-PCR analysis was conducted for further confirmation of T. sinensis. The blood picture of eight infected cattle groups revealed poikilocytosis, anisocytosis, rouleaux formation and degenerative left shift. High mean erythrocyte fragility values were common in infected cattle groups. Anaemia of the macrocytic normochromic type and spherocytes were observed in the T. evansi and Anaplasma platys + Theileria sinensis double species co-infected cattle group. Normocytic normochromic anaemia was observed in the T. sinensis infected cattle group. Significant (p 

    Matched MeSH terms: Trypanosoma/genetics; Trypanosoma/isolation & purification
  15. Outbreaks of trypanosomiasis and the seroprevalence of T. evansi in a deer breeding centre in Perak, Malaysia
    Adrian MS, Sani RA, Hassan L, Wong MT
    Trop Anim Health Prod, 2010 Feb;42(2):145-50.
    PMID: 19642008 DOI: 10.1007/s11250-009-9406-8
    Matched MeSH terms: Trypanosoma/isolation & purification*
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