Displaying publications 61 - 80 of 460 in total

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  1. Yap CK, Ismail A, Omar H, Tan SG
    Environ Int, 2004 Feb;29(8):1097-104.
    PMID: 14680893
    Studies on toxicities and tolerances of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in the brown alga Isochrysis galbana and in the green-lipped mussel Perna viridis were conducted by short-term bioassays using endpoints growth production and mortality, respectively. The 5-day EC(50) and 24-h LC(50) of these heavy metals were determined in the brown alga and mussel, respectively. The EC(50) values calculated for the alga were 0.74 mg/l for Cd, 0.91 mg/l for Cu, 1.40 mg/l for Pb and 0.60 mg/l for Zn. The LC(50) values for the mussels were 1.53 mg/l for Cd, 0.25 mg/l for Cu, 4.12 mg/l for Pb and 3.20 mg/l for Zn. These LC(50) values were within the concentration ranges as reported by other authors who used P. viridis as the test organism. Based on these EC(50) and LC(50) values, the alga was most sensitive to Zn, followed by Cd, Cu and Pb while the mussel was most sensitive to Cu, followed by Cd, Zn and Pb. Differences in the trophic levels, metal handling strategies, biology and ecology of the primary producer (brown alga) and the primary consumer (mussel) are believed to be the plausible causes for the different toxicities and tolerances of the metals studied.
  2. Yap CK, Tan SG, Ismail A, Omar H
    Environ Int, 2004 Mar;30(1):39-46.
    PMID: 14664863
    It has been widely reported that heavy metal contamination in coastal waters can modify the allozyme profiles of marine organisms. Previous studies have recorded elevated metal concentrations in sediments and mussel tissues off Peninsular Malaysia. In the present study, horizontal starch gel electrophoresis was carried out to estimate the levels of allelic variation of the green-lipped mussel, Perna viridis, collected from one contaminated and three relatively uncontaminated sites off Peninsular Malaysia. Fourteen polymorphic loci were observed. In addition, the concentrations of cadmium, copper, lead, mercury and zinc were determined in the sediments and in the soft tissues of the mussels. Mussels from contaminated site, evidenced by high metal pollution indices (MPI) of the sediment and the mussel tissues, showed the highest percentage of polymorphic loci (78.6%), while those collected from the uncontaminated sites had lower MPI of the sediment and mussel tissue, and exhibited lower percentages of polymorphic loci (35.7-57.1%). The population from the contaminated site showed the highest excess of heterozygosity (0.289) when compared to that of the populations from the three uncontaminated sites (0.108-0.149). Allozyme frequencies at the phosphoglucomutase (PGM; E.C. 2.7.5.1) locus also differed between the contaminated and uncontaminated populations. Previous studies have shown that exposure to heavy metals can select or counter-select for particular alleles at this locus. The present results suggest that allozyme polymorphism in P. viridis is a potential biomonitoring tool for heavy metal contamination but further validation is required.
  3. Ramzisham ARM, Sagap I, Ismail AM
    Med J Malaysia, 2003 Mar;58(1):125-7.
    PMID: 14556338
    Bleeding into the rectus sheath is an uncommon but a well-recognised condition that mimics several other diagnoses of acute abdomen. A wide range of etiology has been proposed in association with this condition. It is often self-limiting, but can lead to unnecessary laparotomy if the diagnosis is not recognised.
  4. Ismail A, Hai OK, Kader ZA
    Biochem Biophys Res Commun, 1991 Nov 27;181(1):301-5.
    PMID: 1958200
    Current studies were undertaken to determine the presence of a specific antigenic protein on the outer membrane of Salmonella typhi. Immunoblot analysis using sera from patients with fevers revealed that the 50 kD band was specifically recognized only by typhoid sera. The 50 kD band located on the outer membrane is protein by nature and is not a Vi (capsular), dH (flagellar), or O9 (somatic) antigen of S. typhi. These results indicate the usefulness of the specific antigen in the development of a serodiagnostic test for typhoid fever since antibodies of both the IgM and IgG class responses were obtained.
  5. Perumal, V., Khoo, W.C., Abdul-Hamid, A., Ismail, A., Saari, K., Murugesu, S., et al.
    MyJurnal
    Momordica charantia, also known as bitter melon or ‘peria katak’ in Malaysia, is a member of the family Cucurbitaceae. Bitter melon is an excellent source of vitamins and minerals that made it extensively nutritious. Moreover, the seed, fruit and leave of the plant contain bioactive compounds with a wide range of biological activities that have been used in traditional medicines in the treatment of several diseases, including inflammation, infections, obesity and diabetes. The aim of this study was to evaluate changes in urinary metabolite profile of the normal, streptozotocin-induced type 1 diabetes and M. charantia treated diabetic rats using proton nuclear magnetic resonance (1H-NMR) -based metabolomics profiling. Study had been carried out by inducing diabetes in the rats through injection of streptozotocin, which exhibited type 1 diabetes. M. charantia extract (100 and 200 mg/kg body weight) was administrated to the streptozotocin-induced diabetic rats for one week. Blood glucose level after administration was measured to examine hypoglycemic effect of the extract. The results obtained indicated that M. charantia was effective in lowering blood glucose level of the diabetic rats. The loading plot of Partial Least Square (PLS) component 1 showed that diabetic rats had increased levels of lactate and glucose in urine whereas normal and the extract treated diabetic rats had higher levels of succinate, creatine, creatinine, urea and phenylacetylglycine in urine. While the loading plot of PLS component 2 showed a higher levels of succinate, citrate, creatine, creatinine, sugars, and hippurate in urine of normal rat compared to the extract treated diabetic rat. Administration of M. charantia extract was found to be able to regulate the altered metabolic processes. Thus, it could be potentially used to treat the diabetic patients.
    
  6. Yap CK, Ismail A, Tan SG, Omar H
    Environ Int, 2002 Apr;28(1-2):117-26.
    PMID: 12046948
    Total concentrations and speciation of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in surface sediment samples were correlated with the respective metal measured in the total soft tissue of the green-lipped mussel Perna viridis, collected from water off the west coast of Peninsular Malaysia. The aim of this study is to relate the possible differences in the accumulation patterns of the heavy metals in P. viridis to those in the surface sediment. The sequential extraction technique was employed to fractionate the sediment into 'freely leachable and exchangeable' (EFLE), 'acid-reducible,' 'oxidisable-organic' and 'resistant' fractions. The results showed that significant (P .05) was found between Zn in P viridis and all the sediment geochemical fractions of Zn and total Zn in the sediment. This indicated that Zn was possibly regulated from the soft tissue of P. viridis. The present results supported the use of P viridis as a suitable biomonitoring agent for Cd, Cu and Pb.
  7. Ismail AA, Mahboob T, Samudi Raju C, Sekaran SD
    Trop Biomed, 2019 Dec 01;36(4):888-897.
    PMID: 33597462
    Zika virus (ZIKV) is a mosquito-borne Flaviviruses. ZIKV is known to cause birth defect in pregnant women, especially microcephaly in the fetus. Hence, more study is required to understand the infection of Zika virus towards human brain microvascular endothelial cells (MECs). In this study, brain MECs were infected with ZIKV at MOI of 1 and 5 in vitro. The changes in barrier function and membrane permeability of ZIKV-infected brain MECs were determined using electric cell-substrate impedance sensing (ECIS) system followed by gene expression of ZIKV-infected brain MECs at 24 hours post infection using one-color gene expression microarray. The ECIS results demonstrated that ZIKV infection enhances vascular leakage by increasing cell membrane permeability via alteration of brain MECs barrier function. This was further supported by high expression of proinflammatory cytokine genes (lnc-IL6-2, TNFAIP1 and TNFAIP6), adhesion molecules (CERCAM and ESAM) and growth factor (FIGF). Overall, findings of this study revealed that ZIKV infection could alter the barrier function of brain MECs by altering adhesion molecules and inflammatory response.
  8. Shaharudin S, Ghosh AK, Ismail AA
    J Sports Med Phys Fitness, 2011 Dec;51(4):576-82.
    PMID: 22212259
    The present study was undertaken to evaluate the anaerobic capacity in repeated sprint cycling bouts during mid-luteal (ML) and mid-follicular (MF) phases of ovarian cycle.
  9. Adam Z, Khamis S, Ismail A, Hamid M
    PMID: 22701507 DOI: 10.1155/2012/632763
    Ficus deltoidea from the Moraceae family has been scientifically proven to reduce hyperglycemia at different prandial states. In this study, we evaluate the mechanisms that underlie antihyperglycemic action of Ficus deltoidea. The results had shown that hot aqueous extract of Ficus deltoidea stimulated insulin secretion significantly with the highest magnitude of stimulation was 7.31-fold (P < 0.001). The insulin secretory actions of the hot aqueous extract involved K(+) (ATP) channel-dependent and K(+) (ATP)-channel-independent pathway. The extract also has the ability to induce the usage of intracellular Ca(2+) to trigger insulin release. The ethanolic and methanolic extracts enhanced basal and insulin-mediated glucose uptake into adipocytes cells. The extracts possess either insulin-mimetic or insulin-sensitizing property or combination of both properties during enhancing glucose uptake into such cells. Meanwhile, the hot aqueous and methanolic extracts augmented basal and insulin-stimulated adiponectin secretion from adipocytes cells. From this study, it is suggested that Ficus deltoidea has the potential to be developed as future oral antidiabetic agent.
  10. Arai T, Chino N, Zulkifli SZ, Ismail A
    J Fish Biol, 2012 Mar;80(3):692-7.
    PMID: 22380562 DOI: 10.1111/j.1095-8649.2011.03154.x
    Previous studies indicated that a tropical freshwater eel Anguilla bicolor bicolor occurs in Africa, India, Sri Lanka, Bangladesh, Myanmar, Indonesia and Australia, but an intensive survey has indicated an extended distribution range for the species into Peninsular Malaysia. Thus, A. b. bicolor is a native subspecies of Malaysia.
  11. Hajeb P, Jinap S, Ismail A, Mahyudin NA
    PMID: 22610296 DOI: 10.1007/978-1-4614-3414-6_2
    Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to humans in Malaysia will be useful in establishing the levels at which detrimental effects in both humans and marine life may occur, and therefore the levels at which warning should be raised or limits established. In particular, we believe that two or three monitoring centers should be established in Peninsular Malaysia, and one in East Malaysia for the specific purpose of monitoring for the presence of hazardous environmental chemicals, and particularly monitoring for heavy metals such as mercury that reach food that is subject to consistent human consumption.
  12. Yusof S, Ismail A, Alias MS
    Mar Pollut Bull, 2014 Aug 30;85(2):494-8.
    PMID: 24731878 DOI: 10.1016/j.marpolbul.2014.03.022
    Glyphosate is globally a widely used herbicide, yet there is little information on their toxicity to marine fishes. Java medaka, a small tropical fish native to coastal areas in several Southeast Asian countries, is viewed as a suitable candidate for toxicity test and thus was used for this study. Java medaka adults were cultured in the laboratory and the fertilized eggs of the F2 generation were exposed to different concentrations of glyphosate-based herbicide (100, 200, 300, 400 and 500 ppm) until they hatched. The survival and hatching rates of the embryos, changes in the heart rate and morphological impairments were recorded. Generally, survival and hatching percentage decreased as glyphosate concentration increased. Absence of pectoral fin(s) and cornea, permanently bent tail, irregular shaped abdomen, and cell disruption in the fin, head and abdomen are among the common teratogenic effects observed. Furthermore, risk factor also increased with the increased in glyphosate concentrations.
  13. Weinstein SA, Griffin R, Ismail AK
    Clin Toxicol (Phila), 2014 Apr;52(4):277-82.
    PMID: 24645905 DOI: 10.3109/15563650.2014.897352
    Non-front-fanged colubroid snakes (NFFC; formerly and artificially taxonomically assembled as "colubrids") comprise the majority of extant ophidian species. Although the medical risks of bites by a handful of species have been documented, the majority of these snakes have oral products (Duvernoy's secretions, or venoms) with unknown biomedical properties/unverified functions and their potential for causing harm in humans is unknown.
  14. Naji A, Ismail A, Kamrani E, Sohrabi T
    Bull Environ Contam Toxicol, 2014 Jun;92(6):674-9.
    PMID: 24590446 DOI: 10.1007/s00128-014-1243-4
    Metallothionein (MT) concentrations in gill and liver tissues of Oreochromis mossambicus were determined to assess biological response of fish to levels of some metals. Metal concentrations in gill and liver tissues of O. mossambicus ranged from 0.6 to 2.6 for Cd, 16 to 52 for Zn, 0.5 to 17 for Cu and 2 to 67 for T-Hg (all in μg/g wet weight, except for T-Hg in ng/g wet weight). Accumulation of Cd, Zn, Cu and Hg (μg/g wet weight) in the liver and gills of O. mossambicus were in the order of liver > gills. The concentrations of Cd, Zn, Cu and Hg in fish tissues were correlated with MT content. The increases in MT levels from the reference area Puchong Tengah compared to the polluted area Kampung Seri Kenangan were 3.4- and 3.8-fold for gills and livers, respectively. The results indicate that MT concentrations were tissue-specific, with the highest levels in the liver. Therefore, the liver can act as a tissue indicator in O. mossambicus in the study area.
  15. Yin SA, Ismail A, Zulkifli SZ
    Trop Life Sci Res, 2012 Dec;23(2):27-38.
    PMID: 24575231 MyJurnal
    Swamp eel, Monopterus albus is one of the common fish in paddy fields, thus it is suitable to be a bio-monitor for heavy metals pollution studies in paddy fields. This study was conducted to assess heavy metals levels in swamp eels collected from paddy fields in Kelantan, Malaysia. The results showed zinc [Zn (86.40 μg/g dry weight)] was the highest accumulated metal in the kidney, liver, bone, gill, muscle and skin. Among the selected organs, gill had the highest concentrations of lead (Pb), cadmium (Cd) and nickel (Ni) whereas muscle showed the lowest total metal accumulation of Zn, Pb, copper (Cu), Cd and Ni. Based on the Malaysian Food Regulation, the levels of Zn and Cu in edible parts (muscle and skin) were within the safety limits. However, Cd, Pb and Ni exceeded the permissible limits. By comparing with the maximum level intake (MLI), Pb, Ni and Cd in edible parts can still be consumed. This investigation indicated that M. albus from paddy fields of Kelantan are safe for human consumption with little precaution.
  16. Meng CC, Jalil AM, Ismail A
    Molecules, 2009;14(1):200-9.
    PMID: 19127248 DOI: 10.3390/molecules14010200
    Chocolate contains a wide range of antioxidants that includes soluble phenolic compounds (phenolic acids, catechin, epicatechin, and proanthocyanidins), insoluble polymeric phenolics and methylxanthines. The objective of this study was to determine phenolic and theobromine contents in dark (DC), milk (MC), and white (WC) chocolates commonly found in the Malaysian marketplace. Total phenolic and flavonoids were determined by means of a spectrometric assay, while catechin, epicatechin and theobromine were quantified using a reverse-phase HPLC method. Dark chocolates exhibited the highest phenolics and flavonoids contents, followed by milk and white chocolates. Catechin and epicatechin were major flavonoids detected in dark chocolates. Theobromine was detected in dark and milk chocolates, but not in white chocolates. A high correlation (r= 0.93) between total phenolic and flavonoid contents, indicating that the major phenolic compounds in dark chocolates belong to the flavonoid class. When nutrition and health promotion are of concern, dark chocolates would be recommended over milk and white chocolates owing to their higher contents of antioxidant phenolic compounds.
  17. Balaram P, Kien PK, Ismail A
    Int J Med Microbiol, 2009 Mar;299(3):177-85.
    PMID: 18845475 DOI: 10.1016/j.ijmm.2008.08.004
    Bacterial persistence is of major concern worldwide in the control of a number of bacterial infections. The carriers who are asymptomatic act as reservoirs of the bacteria. Knowledge of the host response, of the persistence process, and of the potential of biological mediators as diagnostic markers is essential towards development of prophylactic and treatment modalities for these diseases. Immune mechanisms related to recognition and elimination of the bacteria play pivotal roles in the control of bacterial infections. The majority of the studies on bacterial infections detail the immune mechanisms in the active phase of infection, and reports on the immune status in carriers are scanty. The present review describes the role of recognition molecules (TLRs) and the immune mediators (cytokines) in bacterial persistence. It appears that the TLR-mediated induction of cytokine profiles differs in active infection and bacterial persistence, with an active Th1 response being beneficial for the clearance of a high load of bacteria and at the same time conducive for the persistence of low bacterial load. Immunomodulation aiming at stimulation of the immune responses should be carried out with care as it could give rise to a carrier state in individuals with low load of the bacteria.
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