Displaying all 15 publications

Abstract:
Sort:
  1. Fulltext Observation of dendritic cell morphology under light, phase-contrast or confocal laser scanning microscopy
    Tan YF, Leong CF, Cheong SK
    Malays J Pathol, 2010 Dec;32(2):97-102.
    PMID: 21329180 MyJurnal
    Dendritic cells (DCs) are professional antigen presenting cells of the immune system. They can be generated in vitro from peripheral blood monocytes supplemented with GM-CSF, IL-4 and TNF alpha. During induction, DCs will increase in size and acquire multiple cytoplasmic projections when compared to their precursor cells such as monocytes or haematopoietic stem cells which are usually round or spherical. Morphology of DCs can be visualized by conventional light microscopy after staining or phase-contrast inverted microscopy or confocal laser scanning microscopy. In this report, we described the morphological appearances of DCs captured using the above-mentioned techniques. We found that confocal laser scanning microscopy yielded DCs images with greater details but the operating cost for such a technique is high. On the other hand, the images obtained through light microscopy after appropriate staining or phase contrast microscopy were acceptable for identification purpose. Besides, these equipments are readily available in most laboratories and the cost of operation is affordable. Nevertheless, morphological identification is just one of the methods to characterise DCs. Other methods such as phenotypic expression markers and mixed leukocyte reactions are additional tools used in the characterisation of DCs.
    Matched MeSH terms: Microscopy, Phase-Contrast*
  2. Sodium dodecyl sulphate as a rapid clearing agent for studying the hard parts of monogeneans and nematodes
    Wong WL, Tan WB, Lim LH
    J Helminthol, 2006 Mar;80(1):87-90.
    PMID: 16469180
    Hard structures of helminths have often been used for taxonomic identification but are usually not clearly defined when treated with conventional methods such as ammonium picrate-glycerin for monogeneans and glycerin for nematodes. The present study reports a rapid and simple technique to better resolve the hard parts of selected monogeneans and nematodes using 5-10% alkaline sodium dodecyl sulphate (SDS). In comparison with established methods, SDS-treated worms become more transparent. In monogeneans treated with SDS, clear details of the hooks, hook filaments, anchors, bars and the sclerotized copulatory organs could be observed. In SDS-treated nematodes, spicules and ornamentations of the buccal capsules could be clearly seen.
    Matched MeSH terms: Microscopy, Phase-Contrast/methods
  3. Fulltext Lipoproteins modulate growth and P-glycoprotein expression in drug-resistant HER2-overexpressed breast cancer cells
    Siti ZS, Seoparjoo AMI, Shahrul H
    Heliyon, 2019 Apr;5(4):e01573.
    PMID: 31183434 DOI: 10.1016/j.heliyon.2019.e01573
    Background: Drug resistance remains as a challenge in the treatment of HER2-overexpressed breast cancer. Emerging evidence from clinical studies show relation of oxidized low density lipoprotein (LDL) and very low density lipoprotein (VLDL) level with drug resistance. However, the underlying molecular mechanisms for this effect remain unclear. Therefore, the aim of this study was to determine the effects of oxidized-LDL and VLDL in drug-resistant HER2-overexpressed breast cancer cells.

    Methods: An in vitro cell model for tamoxifen-resistant HER2 overexpressed UACC732 cells was created using the pulse method. Cells were exposed to oxidized LDL (oxLDL) and very low density lipoprotein (VLDL) separately. Effects on cell morphology was studied using phase contrast microscopic changes. Percentage of cell viability was measured using proliferation assay kit. Development of tamoxifen resistance was determined based on P-gp expression with flow cytometry. Further analysis includedcell death measurement with flow cytometry method.

    Results: UACC732 cells exposed to VLDL exhibited fibroblast-like morphology. This was further supported by proliferation assay, where the percentage of cell viability achieved more than 100% with 100 μg/ml of VLDL exposure, indicating cell proliferation. Findings also showed that VLDL caused reduction in expression of Pgp in resistant cells compared to resistant cells alone (p = 0.02).

    Conclusion: Results of this study suggest that VLDL may play a role in growth of drug-resistant HER2-overexpressing cells. Lower expression of P-gp in presence of VLDL need to be investigated further.

    Matched MeSH terms: Microscopy, Phase-Contrast
  4. Segmentation Approach Towards Phase-Contrast Microscopic Images of Activated Sludge to Monitor the Wastewater Treatment
    Khan MB, Nisar H, Ng CA, Yeap KH, Lai KC
    Microsc Microanal, 2017 12;23(6):1130-1142.
    PMID: 29212566 DOI: 10.1017/S1431927617012673
    Image processing and analysis is an effective tool for monitoring and fault diagnosis of activated sludge (AS) wastewater treatment plants. The AS image comprise of flocs (microbial aggregates) and filamentous bacteria. In this paper, nine different approaches are proposed for image segmentation of phase-contrast microscopic (PCM) images of AS samples. The proposed strategies are assessed for their effectiveness from the perspective of microscopic artifacts associated with PCM. The first approach uses an algorithm that is based on the idea that different color space representation of images other than red-green-blue may have better contrast. The second uses an edge detection approach. The third strategy, employs a clustering algorithm for the segmentation and the fourth applies local adaptive thresholding. The fifth technique is based on texture-based segmentation and the sixth uses watershed algorithm. The seventh adopts a split-and-merge approach. The eighth employs Kittler's thresholding. Finally, the ninth uses a top-hat and bottom-hat filtering-based technique. The approaches are assessed, and analyzed critically with reference to the artifacts of PCM. Gold approximations of ground truth images are prepared to assess the segmentations. Overall, the edge detection-based approach exhibits the best results in terms of accuracy, and the texture-based algorithm in terms of false negative ratio. The respective scenarios are explained for suitability of edge detection and texture-based algorithms.
    Matched MeSH terms: Microscopy, Phase-Contrast
  5. Evaluation of Ultra-Microscopic Changes and Proliferation of Apoptotic Glioblastoma Multiforme Cells Induced by Velogenic Strain of Newcastle Disease Virus AF2240
    Ali- Saeed R, Alabsi AM, Ideris A, Omar AR, Yusoff K, Ali AM
    Asian Pac J Cancer Prev, 2019 Mar 26;20(3):757-765.
    PMID: 30909682
    Aim: Newcastle disease virus (NDV) is a member of genus Avulavirus within the family Paramyxoviridae. Interest
    of using NDV as an anticancer agent has arisen from its ability to kill tumor cells with limited toxicity to normal cells.
    Methods: In this investigation, the proliferation of brain tumor cell line, glioblastoma multiform (DBTRG.05MG)
    induced by NDV strain AF2240 was evaluated in-vitro, by using MTT proliferation assay. Furthermore, Cytological
    observations were studied using fluorescence microscopy and transmission electron microscopy, DNA laddering in
    agarose gel electrophoresis assay used to detect the mode of cell death and analysis of the cellular DNA content by
    flowcytometery. Results: MTT proliferation assay, Cytological observations using fluorescence microscopy and
    transmission electron microscopy show the anti-proliferation effect and apoptogenic features of NDV on DBTRG.05MG.
    Furthermore, analysis of the cellular DNA content showed that there was a loss of treated cells in all cell cycle phases
    (G1, S and G2/M) accompanied with increasing in sub-G1 region (apoptosis peak). Conclusion: It could be concluded
    that NDV strain AF2240 is a potent antitumor agent that induce apoptosis and its cytotoxicity increasing while increasing
    of time and virus titer.
    Matched MeSH terms: Microscopy, Phase-Contrast/methods*
  6. Redescriptions of species of Ancyrocephaloides Yamaguti, 1938 (Monogenea: Ancyrocephalidae) from triacanthid fishes caught off Peninsular Malaysia and a report of their haptoral secretions
    Lim LH, Gibson DI
    Syst Parasitol, 2008 Jan;69(1):59-73.
    PMID: 18030603
    Numerous specimens of Ancyrocephaloides triacanthi Yamaguti, 1938 and A. chauhani Bychowsky & Nagibina, 1975 were collected from two triacanthid fishes, Triacanthus biaculeatus and Tripodichthys blochii, off Peninsular Malaysia. The two monogenean species are redescribed and considered to be the only valid species of Ancyrocephaloides Yamaguti, 1938. Examinations of these worms revealed new features, e.g. the presence of exudates (both net-like and bundle-like) and superficial grooves in the anchors in both species, which necessitated re-descriptions of the two species and amendments to the generic diagnosis. Both species have relatively small anchors with two lateral superficial grooves along the shaft and point, peduncular glands and four large, pyriform secretory reservoirs in the peduncular-haptoral region, each with a single tubular extension to an associated anchor, and net-like structures (exudate) attached to the anchors. The net-like structures are one of the external manifestations of the secretion produced in the peduncular glands and stored in the pyriform secretory reservoirs. When released within the gill-tissue of the host, the exudate is in the form of bundles which extend within the gill-filament. The small anchors convey secretions from the secretory reservoirs via lateral superficial grooves into the gills as the anchors pierce the host tissue for attachment. The secretion coagulates as left and right thread-like bundles of exudate within the gill tissues and is only apparent as nets when it is released into the surrounding water. The recurved point of the anchor and position of the point of exudation allow the nets to remain attached to the anchor point, even after the detachment of the anchors from the gill tissue. This exudate possibly acts somewhat like a 'belay device' or 'safety belt', preventing the parasite from being washed away by the respiratory current during the onset of its leech-like locomotion, as well as assist the relatively small anchors in attachment.
    Matched MeSH terms: Microscopy, Phase-Contrast
  7. Two new species of Myliocotyle (Monogenea: Monocotylidae) from the gills of Aetomylaeus maculatus and A. nichofii (Elasmobranchii: Myliobatidae) from Sarawak, Borneo, Malaysia
    Chisholm LA, Whittington ID
    Folia Parasitol., 2004 Dec;51(4):304-10.
    PMID: 15729942
    Myliocotyle borneoensis sp. n. and M. multicrista sp. n. (Monocotylidae: Heterocotylinae) are described from the gills of the mottled eagle ray, Aetomylaeus maculatus (Gray), and the banded eagle ray A. nichofii (Bloch et Schneider) (Myliobatidae), respectively, collected from the northern coast of Malaysian Borneo. These are the first monogeneans to be described on elasmobranchs from Borneo. The formerly monotypic Myliocotyle (for M. pteromylaei) was distinguished from other monocotylids by the distribution and morphology of the eight sclerotised dorsal haptoral accessory structures and the morphology of the male copulatory organ. However, we have determined that M. pteromylaei has ten structures on the dorsal surface of the haptor. Myliocotyle borneoensis is distinguished from M. pteromylaei by the morphology of the male copulatory organ and its accessory piece. Myliocotyle multicrista has 12 sclerotised dorsal haptoral accessory structures and a male copulatory organ with two accessory pieces. Additional sclerotised ridges across the ventral surfaces of each loculus (except the posterior-most pair) are also present in M. multicrista. The diagnosis for Myliocotyle is revised given our discovery of additional dorsal haptoral accessory structures in the type species and to accommodate other new characters of the two new species. Anterior secretions of Myliocotyle are discussed.
    Matched MeSH terms: Microscopy, Phase-Contrast
  8. Effect of butylated hydroxytoluene on cryopreservation of Boer goat semen in Tris egg yolk extender
    Memon AA, Wahid H, Rosnina Y, Goh YM, Ebrahimi M, Nadia FM, et al.
    Anim. Reprod. Sci., 2011 Nov;129(1-2):44-9.
    PMID: 22024366 DOI: 10.1016/j.anireprosci.2011.10.004
    The aim of this study was to determine the effect of butylated hydroxytoluene (BHT), a lipid-soluble anti-oxidant added in different concentrations to the Tris egg yolk extenders on semen cytological parameters pre freezing and post thawing (motility, morphology, viability, acrosome integrity and membrane integrity) of Boer goat spermatozoa. A total of 40 ejaculates from four Boer goat bucks were collected using an artificial vagina. Ten replicates of the ejaculates were diluted with a Tris egg yolk based extender which contained various concentrations (0.5mM, 1.0mM, 2.0mM and 3.0mM) of butylated hydroxytoluene while one sample was processed without supplementation of antioxidant and served as control. The diluted semen was cooled at 4°C and loaded into the straw and then stored in liquid nitrogen. It was evident that supplementation of BHT produces positive effect in terms of motility, membrane integrity and acrosome integrity in comparison with the control group in cooled and frozen Boer goat semen. Results showed significant differences in motility, membrane integrity, acrosome integrity and viability of cooled and frozen Boer goat spermatozoa at different concentrations. Motility, membrane integrity, acrosome integrity and viability was significantly higher in all treated groups than the control group (P<0.05) while there was no significant differences (P>0.05) in morphology trait between all group in cooled semen. However, improvement (P<0.05) was observed only in terms of the membrane integrity and acrosome integrity compared to the control and other treated groups in frozen semen. In conclusion, BHT can be used in cryopreservation of Boer goat semen in order to reduce the oxidative stress on spermatozoa.
    Matched MeSH terms: Microscopy, Phase-Contrast/veterinary
  9. Microscopic analysis of a native Bacillus thuringiensis strain from Malaysia that produces exosporium-enclosed parasporal inclusion
    Chai PF, Rathinam X, Solayappan M, Ahmad Ghazali AH, Subramaniam S
    Microscopy (Oxf), 2014 Oct;63(5):371-5.
    PMID: 24943903 DOI: 10.1093/jmicro/dfu022
    The current study focused on the microscopic studies of a native Bacillus thuringiensis strain isolated from Malaysia, Bt-S84-13a, that produced an unusual crystal type. Primary detection of parasporal inclusions using a phase contrast microscope presented one to two small crystal proteins in the sporulating cells of Bt-S84-13a. Compound light microscopic examination of autolysed Bt-S84-13a cells stained with 0.133% Coomassie Brilliant Blue showed two types of crystal morphology: small crystals independent of spores and spore-associated crystals. Surface structure analysis with a scanning electron microscope revealed spherical-like, coarse and wrinkled-looking crystal in Bt-S84-13a. A close-up observation of the crystal morphology using a transmission electron microscope also demonstrated two parasporal inclusions in Bt-S84-13a. One inclusion was deposited against the forespore and was in a shape of incomplete rectangular. Another smaller inclusion was developed within the exosporium and was rectangular in shape. However, the latter inclusion was found lack in another bacterial cell which was still in the early stages of sporulation. This unique crystal morphology may imply some biological potential in Bt-S84-13a.
    Matched MeSH terms: Microscopy, Phase-Contrast
  10. Collagen as potential cell scaffolds for tissue engineering
    Annuar N, Spier RE
    Med J Malaysia, 2004 May;59 Suppl B:204-5.
    PMID: 15468889
    Selections of collagen available commercially were tested for their biocompatibility as scaffold to promote cell growth in vitro via simple collagen fast test and cultivation of mammalian cells on the selected type of collagen. It was found that collagen type C9791 promotes the highest degree of aggregation as well as cells growth. This preliminary study also indicated potential use of collagen as scaffold in engineered tissue.
    Matched MeSH terms: Microscopy, Phase-Contrast
  11. Fulltext Urinary erythrocyte morphology as a diagnostic aid in haematuria
    Ahmad G, Segasothy M, Morad Z
    Singapore Med J, 1993 Dec;34(6):486-8.
    PMID: 8153706
    The value of urinary erythrocyte morphology in diagnosing glomerular and nonglomerular haematuria was studied using phase contrast microscopy in 105 patients with significant haematuria. Fifty-eight (93.6%) out of 62 patients with glomerulonephritis had dysmorphic erythrocytes and 40 (93.1%) out of the 43 patients with nonglomerular disease had isomorphic erythrocytes in the urine. A mixed picture of glomerular and nonglomerular haematuria was seen in 5 patients. The sensitivity was 93.6%, the specificity was 97.7% and the positive predictive value was 98.3% for glomerulonephritis in patients with dysmorphic haematuria. The positive predictive value for a nonglomerular source of bleeding was 96.7% with isomorphic haematuria. It is concluded that phase contrast microscopic examination of erythrocytes in urine is a simple, inexpensive and noninvasive technique that reliably distinguishes between glomerular and nonglomerular bleeding in patients.
    Matched MeSH terms: Microscopy, Phase-Contrast
  12. Bone marrow mesenchymal stem cells differentiation and proliferation on the surface of coral implant
    Al-Salihi KA, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:45-6.
    PMID: 15468811
    This study was designed to evaluate the ability of natural coral implant to provide an environment for marrow cells to differentiate into osteoblasts and function suitable for mineralized tissue formation. DNA content, alkaline phosptatase (ALP) activity, calcium (Ca) content and mineralized nodules, were measured at day 3, day 7 and day 14, in rat bone marrow stromal cells cultured with coral discs glass discs, while cells alone and coral disc alone were cultured as control. DNA content, ALP activity, Ca content measurements showed no difference between coral, glass and cells groups at 3 day which were higher than control (coral disc alone), but there were higher measurement at day 7 and 14 in the cell cultured on coral than on glass discs, control cells and control coral discs. Mineralized nodules formation (both in area and number) was more predominant on the coral surface than in control groups. These results showed that natural coral implant provided excellent and favorable situation for marrow cell to differentiate to osteoblasts, lead to large amount of mineralized tissue formation on coral surface. This in vitro result could explain the rapid bone bonding of coral in vivo.
    Matched MeSH terms: Microscopy, Phase-Contrast
  13. Cytolytic effects and apoptosis induction of Newcastle disease virus strain AF2240 on anaplastic astrocytoma brain tumor cell line
    Ali R, Alabsi AM, Ali AM, Ideris A, Omar AR, Yusoff K, et al.
    Neurochem Res, 2011 Nov;36(11):2051-62.
    PMID: 21671106 DOI: 10.1007/s11064-011-0529-8
    Newcastle disease virus (NDV) is a member of genus Avulavirus within the family Paramyxoviridae. Interest of using NDV as an anticancer agent has arisen from its ability to kill tumor cells with limited toxicity to normal cells. In this investigation, the cytotolytic properties of NDV strain AF2240 were evaluated on brain tumor cell line, anaplastic astrocytoma (U-87MG), by using MTT assay. Cytological observations were studied using fluorescence microscopy and transmission electron microscopy to show the apoptogenic features of NDV on U-87MG. DNA laddering in agarose gel electrophoresis and terminal deoxyribonucleotide transferase-mediated dUTP-X nick end-labeling staining assay confirmed that the mode of cell death was by apoptosis. However, analysis of the cellular DNA content by flowcytometery showed that there was a loss of treated U-87MG cells in all cell cycle phases (G1, S and G2/M) accompanied with increasing in sub-G1 region (apoptosis peak). Early apoptosis was observed 6 h post-inoculation by annexin-V flow-cytometry method. It could be concluded that NDV strain AF2240 is a potent antitumor agent that induce apoptosis and its cytotoxicity increasing while increasing of time and virus titer.
    Matched MeSH terms: Microscopy, Phase-Contrast
  14. Fulltext Xanthohumol induces growth inhibition and apoptosis in ca ski human cervical cancer cells
    Yong WK, Abd Malek SN
    Evid Based Complement Alternat Med, 2015;2015:921306.
    PMID: 25949267 DOI: 10.1155/2015/921306
    We investigate induction of apoptosis by xanthohumol on Ca Ski cervical cancer cell line. Xanthohumol is a prenylated chalcone naturally found in hop plants, previously reported to be an effective anticancer agent in various cancer cell lines. The present study showed that xanthohumol was effective to inhibit proliferation of Ca Ski cells based on IC50 values using sulforhodamine B (SRB) assay. Furthermore, cellular and nuclear morphological changes were observed in the cells using phase contrast microscopy and Hoechst/PI fluorescent staining. In addition, 48-hour long treatment with xanthohumol triggered externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells. Additionally, xanthohumol mediated S phase arrest in cell cycle analysis and increased activities of caspase-3, caspase-8, and caspase-9. On the other hand, Western blot analysis showed that the expression levels of cleaved PARP, p53, and AIF increased, while Bcl-2 and XIAP decreased in a dose-dependent manner. Taken together, these findings indicate that xanthohumol-induced cell death might involve intrinsic and extrinsic apoptotic pathways, as well as downregulation of XIAP, upregulation of p53 proteins, and S phase cell cycle arrest in Ca Ski cervical cancer cells. This work suggests that xanthohumol is a potent chemotherapeutic candidate for cervical cancer.
    Matched MeSH terms: Microscopy, Phase-Contrast
  15. Effect of extracts from Phyllanthus watsonii Airy Shaw on cell apoptosis in cultured human breast cancer MCF-7 cells
    Ramasamy S, Abdul Wahab N, Zainal Abidin N, Manickam S
    Exp. Toxicol. Pathol., 2013 Mar;65(3):341-9.
    PMID: 22217449 DOI: 10.1016/j.etp.2011.11.005
    Species of Phyllanthus have traditionally been used for hundreds of years for treating many ailments including diabetes, anemia, bronchitis and hepatitis. The present study aims to investigate the cytotoxic and apoptotic effects of methanol (PWM), hexane (PWH) and ethyl acetate (PWE) extracts from the leaves of the endemic plant Phyllanthus watsonii Airy Shaw (Phyllanthaceae) on MCF-7 human breast cancer cells. We observed that the PWM, PWH and PWE extracts were cytotoxic and selectively inhibited the growth and proliferation of MCF-7 cells compared to untreated control in a dose dependent manner with an IC(50) of 12.7 ± 4.65, 7.9 ± 0.60 and 7.7 ± 0.29 μg/ml, respectively. However, the extracts were not toxic at these concentrations to normal human lung fibroblast MRC-5 cells. Cell death induced by PWM, PWH and PWE extracts were mainly due to apoptosis which was characterized by apoptotic morphological changes and a nuclear DNA fragmentation. Caspase-3 activation following P. watsonii extracts treatment was also evident for apoptotic cell death which was preceded by an S phase cell cycle perturbation. The results suggested that the cytotoxic activity of P. watsonii extracts was related to an early event of cell cycle perturbation and a later event of apoptosis. Hence, P. watsonii displays potential to be further exploited in the discovery and development of new anticancer agents.
    Matched MeSH terms: Microscopy, Phase-Contrast
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links