Displaying publications 1 - 20 of 63 in total

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  1. Yap KL
    Malays J Pathol, 1994 Jun;16(1):49-56.
    PMID: 16329576
    The aim of this study was to optimize the conditions for the passive adsorption of polyclonal antibody onto plain surface polystyrene latex particles and its performance in a slide latex agglutination test for rotavirus antigen detection. Cleaning of latex particles by washing through repetitive centrifuging, decanting and resuspending in distilled water was adequate in removing surfactants from the particles' surfaces to enable coating. A study of antibody concentration, incubation temperature and buffer pH revealed that optimum coating was achieved with a 3-fold excess of antibody to the calculated total particle surface capacity for the antibody in a glycine-saline buffer of pH 9.2 at 40 degrees C for 4 hours. The ionic strength and pH of the latex suspending buffer and the sample buffer were critical factors determining the sensitivity of the test and the appearance of non-specific agglutination. Ultrasonication, addition of glycerol and Tween 20, either individually or in combination, were able to suppress non-specific agglutination in some batches of latex reagents. Polyethylene glycol 6000 enhanced the quality of agglutination as well as reduced the time of its appearance, especially in reagents that produced poor agglutination.
    Matched MeSH terms: Guinea Pigs
  2. Yahya MD, Watson RR
    Life Sci, 1987 Dec 07;41(23):2503-10.
    PMID: 2824957
    The immunomodulatory effects of morphine and the active components of marijuana, particularly tetrahydrocannabinol, on various aspects of the host immune parameters include alterations in humoral, cell-mediated and innate immunity. Most studies have shown immunosuppressive effects due to use of these abused substances, although there are reports that they may not produce any deleterious effect and may even enhance some aspects of host immunity. They reduce resistance to cancer growth and microbial pathogens in animals.
    Matched MeSH terms: Guinea Pigs
  3. Wong HC, Wong CC, Sagineedu SR, Loke SC, Lajis NH, Stanslas J
    Cell Biol Toxicol, 2014 Oct;30(5):269-88.
    PMID: 25070834 DOI: 10.1007/s10565-014-9282-5
    3,19-(3-Chloro-4-fluorobenzylidene)andrographolide (SRJ23), a new semisynthetic derivative of andrographolide (AGP), exhibited selectivity against prostate cancer cells in the US National Cancer Institute (NCI) in vitro anti-cancer screen. Herein, we report the in vitro growth inhibition and mechanisms of cell cycle arrest and apoptosis induced by SRJ23.
    Matched MeSH terms: Guinea Pigs
  4. Wilson CA, Berger JI, de Boer J, Sereda M, Palmer AR, Hall DA, et al.
    Hear Res, 2019 03 15;374:13-23.
    PMID: 30685571 DOI: 10.1016/j.heares.2019.01.009
    A common method for measuring changes in temporal processing sensitivity in both humans and animals makes use of GaP-induced Inhibition of the Acoustic Startle (GPIAS). It is also the basis of a common method for detecting tinnitus in rodents. However, the link to tinnitus has not been properly established because GPIAS has not yet been used to objectively demonstrate tinnitus in humans. In guinea pigs, the Preyer (ear flick) myogenic reflex is an established method for measuring the acoustic startle for the GPIAS test, while in humans, it is the eye-blink reflex. Yet, humans have a vestigial remnant of the Preyer reflex, which can be detected by measuring skin surface potentials associated with the Post-Auricular Muscle Response (PAMR). A similar electrical potential can be measured in guinea pigs and we aimed to show that the PAMR could be used to demonstrate GPIAS in both species. In guinea pigs, we compare the GPIAS measured using the pinna movement of the Preyer reflex and the electrical potential of the PAMR to demonstrate that the two are at least equivalent. In humans, we establish for the first time that the PAMR provides a reliable way of measuring GPIAS that is a pure acoustic alternative to the multimodal eye-blink reflex. Further exploratory tests showed that while eye gaze position influenced the size of the PAMR response, it did not change the degree of GPIAS. Our findings confirm that the PAMR is a sensitive method for measuring GPIAS and suggest that it may allow direct comparison of temporal processing between humans and animals and may provide a basis for an objective test of tinnitus.
    Matched MeSH terms: Guinea Pigs
  5. Westbury HA
    Rev. - Off. Int. Epizoot., 2000 Apr;19(1):151-9.
    PMID: 11189712
    The author provides an account of the discovery of a previously undescribed disease of horses and a description of the studies involved in determining the aetiology of the disease. The causative virus, now named Hendra virus (HeV), is the reference virus for a proposed new genus within the virus family Paramyxoviridae. The virus is a lethal zoonotic agent able to cause natural disease in humans and horses and experimentally induced disease in cats, guinea-pigs and mice. The virus also naturally infects species of the family Megachiroptera, mainly subclinically, and such animals are the natural host of HeV. The virus appears to transmit readily between species of Megachiroptera, but not readily between horses under natural and experimental conditions, or from horses to humans. The method of transmission from bats to horses is not known. Three incidents of HeV disease in horses have been recorded in Australia--two in 1994 which caused the death of two humans and fifteen horses and one in 1999 which involved the death of a single horse. Hendra virus is related to Nipah virus, the virus that caused disease and mortality in humans, pigs, dogs and cats in Malaysia during 1998 and 1999.
    Matched MeSH terms: Guinea Pigs
  6. Wali S, Gupta R, Yu JJ, Mfuh A, Gao X, Guentzel MN, et al.
    Metabolomics, 2016 Apr;12(4).
    PMID: 27642272
    INTRODUCTION: Chlamydia trachomatis (Ct), is the leading cause of sexually transmitted infections worldwide. Host transcriptomic- or proteomic profiling studies have identified key molecules involved in establishment of Ct infection or the generation of anti Ct-immunity. However, the contribution of the host metabolome is not known.

    OBJECTIVES: The objective of this study was to determine the contribution of host metabolites in genital Ct infection.

    METHODS: We used high-performance liquid chromatography-mass spectrometry, and mapped lipid profiles in genital swabs obtained from female guinea pigs at days 3, 9, 15, 30 and 65 post Ct serovar D intravaginal infection.

    RESULTS: Across all time points assessed, 13 distinct lipid species including choline, ethanolamine and glycerol were detected. Amongst these metabolites, phosphatidylcholine (PC) was the predominant phospholipid detected from animals actively shedding bacteria i.e., at 3, 9, and 15 days post infection. However, at days 30 and 65 when the animals had cleared the infection, PC was observed to be decreased compared to previous time points. Mass spectrometry analyses of PC produced in guinea pigs (in vivo) and 104C1 guinea pig cell line (in vitro) revealed distinct PC species following Ct D infection. Amongst these, PC 16:0/18:1 was significantly upregulated following Ct D infection (p < 0.05, >twofold change) in vivo and in vitro infection models investigated in this report. Exogenous addition of PC 16:0/18:1 resulted in significant increase in Ct D in Hela 229 cells.

    CONCLUSION: This study demonstrates a role for host metabolite, PC 16:0/18:1 in regulating genital Ct infection in vivo and in vitro.

    Matched MeSH terms: Guinea Pigs
  7. Vijayapandi P, Annabathina V, SivaNagaSrikanth B, Manjunath V, Boggavarapu P, Mohammed P AK, et al.
    PMID: 24082330
    The present investigation was aimed at determining the effects of hexane, acetone, methanol and aqueous extracts of Acorus calamus leaves (ACHE, ACAE, ACME and ACAQE) on cholinergic and histaminic system using isolated frog rectus abdominis muscle and guinea pig ileum. A dose dependent potentiation of Ach response (anticholinesterase like effect) was found with ACAE and ACME at 0.25, 0.5, 0.75 and 1 mg/ml, but at higher dose of ACAE, ACME, ACAQE and ACHE (5, 20 mg/ml) inhibit the Ach response (antinicotinic effect). These results revealed biphasic effect of Acorus calamus leaves extracts on acetylcholine induced contractile response in isolated frog rectus abdominis muscle preparation (i.e. potentiation effect at lower dose and inhibitory effect at higher dose). Studies on isolated guinea pig ileum demonstrated antihistaminic effect in a dose dependent manner (100-1000 µg/ml) with ACAE, ACME and ACAQE. In addition, the dose dependent inhibition of Ach response (antimuscarinic effect) was observed with ACAE and ACME. In conclusion, Acorus calamus leaves extracts exerts antinicotinic, anticholinesterase like activities in isolated frog rectus abdominis muscle and antihistaminic, antimuscarinic effect in guinea pig ileum. It has been suggested that these observed activities can be further studied for therapeutic potential of Acorus calamus leaves in the treatment of cognitive disorders and asthma.
    Matched MeSH terms: Guinea Pigs
  8. Vadivelu J, Puthucheary SD, Phipps M, Chee YW
    J Med Microbiol, 1995 Mar;42(3):171-4.
    PMID: 7884797
    Eighteen strains of Aeromonas hydrophila from patients with bacteraemia were investigated for possible virulence factors. Cytotoxin and haemolysin were produced by all strains, whereas cholera toxin-like factor was produced by 33% of strains only. Enterotoxin production was not detected. Haemagglutination of guinea-pig, fowl and rabbit erythrocytes was demonstrated by 83%, 67% and 61% of strains, respectively. Fucose- and mannose-sensitive haemagglutinins were predominant. None of the strains agglutinated sheep erythrocytes. Extrachromosomal DNA was detected in 17 strains, 16 of which had a plasmid (3.6-5.1 MDa), the majority being between 4.6 and 5.1 MDa.
    Matched MeSH terms: Guinea Pigs
  9. Vadivelu J, Vellasamy KM, Thimma J, Mariappan V, Kang WT, Choh LC, et al.
    PLoS Negl Trop Dis, 2017 01;11(1):e0005241.
    PMID: 28045926 DOI: 10.1371/journal.pntd.0005241
    BACKGROUND: During infection, successful bacterial clearance is achieved via the host immune system acting in conjunction with appropriate antibiotic therapy. However, it still remains a tip of the iceberg as to where persistent pathogens namely, Burkholderia pseudomallei (B. pseudomallei) reside/hide to escape from host immune sensors and antimicrobial pressure.

    METHODS: We used transmission electron microscopy (TEM) to investigate post-mortem tissue sections of patients with clinical melioidosis to identify the localisation of a recently identified gut microbiome, B. pseudomallei within host cells. The intranuclear presence of B. pseudomallei was confirmed using transmission electron microscopy (TEM) of experimentally infected guinea pig spleen tissues and Live Z-stack, and ImageJ analysis of fluorescence microscopy analysis of in vitro infection of A549 human lung epithelial cells.

    RESULTS: TEM investigations revealed intranuclear localization of B. pseudomallei in cells of infected human lung and guinea pig spleen tissues. We also found that B. pseudomallei induced actin polymerization following infection of A549 human lung epithelial cells. Infected A549 lung epithelial cells using 3D-Laser scanning confocal microscopy (LSCM) and immunofluorescence microscopy confirmed the intranuclear localization of B. pseudomallei.

    CONCLUSION: B. pseudomallei was found within the nuclear compartment of host cells. The nucleus may play a role as an occult or transient niche for persistence of intracellular pathogens, potentially leading to recurrrent episodes or recrudescence of infection.

    Matched MeSH terms: Guinea Pigs
  10. Tyagita, H., Bahaman, A.R., Jasni, S., Ibrahim, T.A.T., Fuzina, N.H.
    Jurnal Veterinar Malaysia, 2019;31(1):1-11.
    MyJurnal
    A tourist was infected with a new strain of leptospires namely, Leptospira icterohemorrhagiae serovar Lai strain Langkawi, when he was on vacation in Langkawi, Malaysia. The leptospiral strain was successfully isolated from the patient in the Netherland. In this study, the bacteria were retrieved from Holland and inoculated into fifteen guinea pigs in Universiti Putra Malaysia (UPM) to determine its pathogenicity. The main clinical symptoms in the guinea pigs were decreased appetite and jaundice. Blood profile showed high neutrophil, lymphocyte, PCV, RBC, haemoglobin, leukocyte and thrombocyte counts. Besides that, enhancement of electrolytes such as sodium (Na), chloride (Cl), and potassium (K) was also noted. Biochemical examination showed an increase alkaline phosphatase (ALP), aspartate transaminase (AST) and bilirubin levels. Albumin, alanine transaminase (ALT), blood urea, total protein and creatinine were low values. Histopathological examination under haematoxylin and eosin staining showed evidence of haemorrhages, congestion and oedema in all organs, with inflammatory cell infiltration characterized by neutrophils, lymphocytes and macrophages. Hydropic degeneration and cell necrosis were also common in the findings. Leptospires were detected from Day 2 p.i by silver staining and transmission electron microscopy (TEM). Rise in antibody titre was seen as early as Day 5 p.i and leptospiral DNA was detected by PCR in the kidneys and liver on Day 3 and Day 5, respectively. The findings were indicative of leptospirosis. This study demonstrated that guinea pigs are a suitable animal model to illustrate the clinical symptoms and pathological changes seen following infection with Leptospira icterohaemorrhagiae serovar Lai strain Langkawi. In general, the symptoms and changes seen in leptospirosis are similar to viral infections and the information and data from this present study would help differentiate infection due to leptospires from that of viral infection. Leptospiral infection has often been misdiagnosed to be viral infection such as influenza and dengue which have similar signs and symptoms as leptospirosis.
    Matched MeSH terms: Guinea Pigs
  11. Thiery I, Hamon S, Dumanoir VC, de Barjac H
    J Econ Entomol, 1992 Oct;85(5):1618-23.
    PMID: 1401480
    The safety of bacterial cells of Clostridium bifermentans serovar malaysia, which is highly toxic to mosquito larvae, was tested on mice, guinea pigs, rabbits, and goldfish. Inoculations of at least 1 x 10(8) cells per animal by routes recommended by World Health Organization (subcutaneous, percutaneous, inhalation, force-feeding, intraperitoneal, intravenous) and tests of subacute toxicity, anaphylactic shock, persistence in heart blood, and virulence by successive passages, were performed on mice, guinea pigs, or both. Growth was monitored for 1 mo before necropsy. Ocular irritation and skin scarification were tested with rabbits. C. bifermentans serovar malaysia did not induce any mortality or abnormal reactions in mammals at a dose 1,000 times higher than the level established by W.H.O. for the demonstration of safety. Bacterial cells are not toxic to goldfish at a dose 1,000 times higher than the LD50 for the target-mosquito larvae. We conclude that C. bifermentans serovar malaysia bacterial cells are safe for laboratory mammals and goldfish.
    Matched MeSH terms: Guinea Pigs
  12. Tay ST, Rohani MY, Ho TM, Devi S
    PMID: 12757225
    Isolation of rickettsiae from patients' blood samples and organ samples of wild rodents from areas with high seroprevalence of rickettsial infections was attempted using cell culture assay and animal passages. L929 mouse fibroblast cells grown in 24 well tissue culture plate were inoculated with buffy coat of febrile patients and examined for the growth of rickettsiae by Giemsa, Gimenez staining and direct immunofluorescence assay. No rickettsiae were isolated from 48 patients' blood samples. No symptomatic infections were noted in mice or guinea pigs infected with 50 organ samples of wild rodents. There was no rickettsial DNA amplified from these samples using various PCR detection systems for Orientia tsutsugamushi, typhus and spotted fever group rickettsiae.
    Matched MeSH terms: Guinea Pigs
  13. Tan NH
    Arch Biochem Biophys, 1982 Oct 01;218(1):51-8.
    PMID: 7149742
    Matched MeSH terms: Guinea Pigs
  14. Sundram K, Nor RM
    Methods Mol Biol, 2002;186:221-32.
    PMID: 12013770
    Matched MeSH terms: Guinea Pigs
  15. Samud AM, Asmawi MZ, Sharma JN, Yusof AP
    Immunopharmacology, 1999 Sep;43(2-3):311-6.
    PMID: 10596868
    Crinum asiaticum Linn plant is used in Malaysia as a rheumatic remedy and to relieve local pain. In the present study, we examined the anti-inflammatory effects of this plant extract on carrageenan-induced hind paw oedema in mice. C. asiaticum was serially extracted with petroleum ether, followed by chloroform and lastly, methanol. The chloroform and methanol extracts of the plant given orally (50 mg kg-1) caused significant (p < 0.05; n = 7) reduction in paw oedema but the petroleum ether extract did not induce significant effect (p > 0.05) on paw oedema. The methanol extract was then dissolved in water and extracted consecutively with chloroform, ethyl acetate and butanol. The chloroform fraction of methanol extract (CFME) treatment (50 mg kg(-1)) significantly reduced (p < 0.05; n = 7) the acute paw oedema. This may indicate that active anti-inflammatory compounds are present in the CFME. In an attempt to study the mechanism of action of its anti-inflammatory activity, the effects of CFME on BK- and histamine-induced contractions were investigated in isolated rat uterus and guinea-pig ileum preparations, respectively. It was found that CFME caused dose-dependent reduction (p < 0.05; n = 6) of the contractile response induced by BK and shifted the log dose-response curve of histamine to the right. The present findings suggest that C. asiaticum possessed an anti-inflammatory activity as suggested by its use in traditional medicine. The anti-inflammatory activity of this plant could not have been due to its anti-bradykinin activities as CFME non-specifically inhibited BK-induced contraction. It also suggest that CFME may contain compound(s) with anti-histaminic properties. The significance of these findings is discussed.
    Matched MeSH terms: Guinea Pigs
  16. Ridzwan BH, Jais AM, Waton NG
    Gen. Pharmacol., 1988;19(4):631-6.
    PMID: 3410287
    1. 30 mg kg-1 chlorpromazine (CPZ) depleted more than half of the tissue histamine from lungs, stomach, ileum and skin of the normal guinea-pigs. However, the drug increased the tissue histamine content in scorbutic animals. 2. In contrast, reserpine depleted histamine from the four tested tissues in both normal and scorbutic animals, except those in the lungs of the control animals. 3. Ascorbic acid only depleted histamine from the stomach and ileum. 4. A 24 hr period was the time limit for CPZ to deplete the histamine in all the four tested tissues. 5. Histamine partially or completely recovered in the tissues after the next 24 hr.
    Matched MeSH terms: Guinea Pigs
  17. Ridzwan BH, Waton NG, Rozali BO, Jais AM, Maimun AH
    PMID: 1982866
    1. In vitro studies of non-specific histidine decarboxylase activity was low or absent in control guinea-pigs and unchanged 9 or 27 hr after chlorpromazine (CPZ) injection intraperitoneally. 2. However, specific histidine decarboxylase activity was found in the control tissues and was increased 9 hr but not 27 hr after CPZ injection.
    Matched MeSH terms: Guinea Pigs
  18. Ridzwan BH, Waton NG
    PMID: 1982867
    1. Oral administration of [14C]histamine induced the presence of small amounts of [14C]histamine in stomach and ileal tissues of control guinea-pigs. In contrast, much larger amounts were found after 8 h infusion. 2. Similar amounts of [14C]histamine were found in the tissues when [14C]histamine was given by intravenous infusion from 24-30 h after chlorpromazine injection.
    Matched MeSH terms: Guinea Pigs
  19. Quah CC, Kim KH, Lau MS, Kim WR, Cheah SH, Gundamaraju R
    PMID: 25392585
    BACKGROUND: The preference for a fairer skin-tone has become a common trend among both men and women around the world. In this study, seaweeds Sargassum polycystum and Padina tenuis were investigated for their in vitro and in vivo potentials in working as skin whitening agents. Seaweed has been used as a revolutionary skin repairing agent in both traditional and modern preparations. The high antioxidant content is one of the prime reasons for its potent action. It has been employed in traditional Chinese and Japanese medicine. For centuries, most medical practitioners in the Asian cultures have known seaweed as an organic source of vitamins, minerals, fatty acids like omega-3 and omega-6 and antioxidants. The present objective of the study was to evaluate the potent dermal protective effect of the two seaweeds Sargassum polycystum and Padina tenuis on human cell lines and guinea pigs.

    MATERIAL AND METHODS: Seaweeds were extracted with ethanol and further fractionated with hexane, ethyl acetate and water. The extracts were tested for mushroom tyrosinase inhibitory activity, cytotoxicity in human epidermal melanocyte (HEM), and Chang cells. Extracts with potent melanocytotoxicity were formulated into cosmetic cream and tested on guinea pigs in dermal irritation tests and de-pigmentation assessments.

    RESULTS: Both Sargassum polycystum and Padina tenuis seaweeds showed significant inhibitory effect on mushroom tyrosinase in the concentration tested. SPEt showed most potent cytotoxicity on HEM (IC50 of 36µg/ml), followed by SPHF (65µg/ml), and PTHF (78.5µg/ml). SPHF and SPEt reduced melanin content in skin of guinea pigs when assessed histologically.

    CONCLUSION: SPEt, SPHF and PTHF were able to inhibit HEM proliferation in vitro, with SPHF being most potent and did not cause any dermal irritation in guinea pigs. The results obtained indicate that SPHF is a promising pharmacological or cosmetic agent.

    Matched MeSH terms: Guinea Pigs
  20. Okuno T, Okada T, Kondo A, Suzuki M, Kobayashi M, Oya A
    Bull World Health Organ, 1968;38(4):547-63.
    PMID: 5302450
    The immunological characteristics of 26 strains of Japanese encephalitis virus (JEV) isolated in Japan and Malaya between 1935 and 1966 have been investigated mainly by the antibody-absorption variant of the haemagglutination-inhibition test, and to a certain extent also by conventional haemagglutination-inhibition and complement-fixation tests. The antibody-absorption technique shows promise as a routine method for the immunotyping of JEV.At present, two immunotypes can be distinguished. One comprises 2 strains, Nakayama-NIH and I-58, and is designated as the I-58 immunotype. The other immunotype, JaGAr 01, comprises 17 strains which share the characteristics of the JaGAr 01 strain, including one subline of the Nakayama strain, Nakayama-Yakken. The Nakayama-RFVL strain was found to have the characteristics of both immunotypes. The I-58 immunotype differs more markedly from related arboviruses, such as the Murray Valley encephalitis virus and the West Nile Eg101 strain, than does the JaGAr 01 immunotype.Evidence is presented which suggests that a given JEV strain can change immunotype on repeated passage through mice.
    Matched MeSH terms: Guinea Pigs
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