Displaying publications 61 - 80 of 105 in total

Abstract:
Sort:
  1. Fulltext Temporal and spatial trends in insecticide resistance in Anopheles arabiensis in Sudan: outcomes from an evaluation of implications of insecticide resistance for malaria vector control
    Ismail BA, Kafy HT, Sulieman JE, Subramaniam K, Thomas B, Mnzava A, et al.
    Parasit Vectors, 2018 03 02;11(1):122.
    PMID: 29499751 DOI: 10.1186/s13071-018-2732-9
    BACKGROUND: Long-lasting insecticidal nets (LLINs) (with pyrethroids) and indoor residual spraying (IRS) are the cornerstones of the Sudanese malaria control program. Insecticide resistance to the principal insecticides in LLINs and IRS is a major concern. This study was designed to monitor insecticide resistance in Anopheles arabiensis from 140 clusters in four malaria-endemic areas of Sudan from 2011 to 2014. All clusters received LLINs, while half (n = 70), distributed across the four regions, had additional IRS campaigns.

    METHODS: Anopheles gambiae (s.l.) mosquitoes were identified to species level using PCR techniques. Standard WHO insecticide susceptibility bioassays were carried out to detect resistance to deltamethrin (0.05%), DDT (4%) and bendiocarb (0.1%). TaqMan assays were performed on random samples of deltamethrin-resistant phenotyped and pyrethrum spray collected individuals to determine Vgsc-1014 knockdown resistance mutations.

    RESULTS: Anopheles arabiensis accounted for 99.9% of any anopheline species collected across all sites. Bioassay screening indicated that mosquitoes remained susceptible to bendiocarb but were resistance to deltamethrin and DDT in all areas. There were significant increases in deltamethrin resistance over the four years, with overall mean percent mortality to deltamethrin declining from 81.0% (95% CI: 77.6-84.3%) in 2011 to 47.7% (95% CI: 43.5-51.8%) in 2014. The rate of increase in phenotypic deltamethrin-resistance was significantly slower in the LLIN + IRS arm than in the LLIN-only arm (Odds ratio 1.34; 95% CI: 1.02-1.77). The frequency of Vgsc-1014F mutation varied spatiotemporally with highest frequencies in Galabat (range 0.375-0.616) and New Halfa (range 0.241-0.447). Deltamethrin phenotypic-resistance correlated with Vgsc-1014F frequency.

    CONCLUSION: Combining LLIN and IRS, with different classes of insecticide, may delay pyrethroid resistance development, but the speed at which resistance develops may be area-specific. Continued monitoring is vital to ensure optimal management and control.

  2. Mitochondrial Cytochrome Oxidase I Gene Sequence Analysis of Aedes Albopictus in Malaysia
    Ismail NA, Dom NC, Ismail R, Ahmad AH, Zaki A, Camalxaman SN
    J Am Mosq Control Assoc, 2015 Dec;31(4):305-12.
    PMID: 26675451 DOI: 10.2987/moco-31-04-305-312.1
    A study was conducted to establish polymorphic variation of the mitochondrial DNA encoding the cytochrome oxidase subunit 1 (CO1) gene in Aedes albopictus isolated from 2 hot spot dengue-infested areas in the Subang Jaya District, Malaysia. A phylogenetic analysis was performed with the use of sequences obtained from USJ6 and Taman Subang Mas (TSM). Comparison of the local CO1 sequences with a laboratory strain (USM), alongside reference strains derived from the GenBank database revealed low genetic variation in terms of nucleotide differences and haplotype diversity. Four methods were used to construct a phylogenetic tree and illustrate the genetic relationship of the 37 Ae. albopictus populations based on the CO1 sequences, namely neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML), and Bayesian method, which revealed a distinct relationship between isolates from USJ6 and TSM. Our findings provide new information regarding the genetic diversity among morphologically similar Ae. albopictus, which has not been reported to date.
  3. The Genetic Diversity, Haplotype Analysis, and Phylogenetic Relationship of Aedes albopictus (Diptera: Culicidae) Based on the Cytochrome Oxidase 1 Marker: A Malaysian Scenario
    Ismail NA, Adilah-Amrannudin N, Hamsidi M, Ismail R, Dom NC, Ahmad AH, et al.
    J Med Entomol, 2017 11 07;54(6):1573-1581.
    PMID: 28981849 DOI: 10.1093/jme/tjx126
    The global expansion of Ae. albopictus from its native range in Southeast Asia has been implicated in the recent emergence of dengue endemicity in Malaysia. Genetic variability studies of Ae. albopictus are currently lacking in the Malaysian setting, yet are crucial to enhancing the existing vector control strategies. The study was conducted to establish the genetic variability of maternally inherited mitochondrial DNA encoding for cytochrome oxidase subunit 1 (CO1) gene in Ae. albopictus. Twelve localities were selected in the Subang Jaya district based on temporal indices utilizing 120 mosquito samples. Genetic polymorphism and phylogenetic analysis were conducted to unveil the genetic variability and geographic origins of Ae. albopictus. The haplotype network was mapped to determine the genealogical relationship of sequences among groups of population in the Asian region. Comparison of Malaysian CO1 sequences with sequences derived from five Asian countries revealed genetically distinct Ae. albopictus populations. Phylogenetic analysis revealed that all sequences from other Asian countries descended from the same genetic lineage as the Malaysian sequences. Noteworthy, our study highlights the discovery of 20 novel haplotypes within the Malaysian population which to date had not been reported. These findings could help determine the genetic variation of this invasive species, which in turn could possibly improve the current dengue vector surveillance strategies, locally and regionally.
  4. Fulltext Termite Incidence on an Araucaria Plantation Forest in Teluk Bahang, Penang
    Jasmi AH, Ahmad AH
    Insects, 2011;2(4):469-74.
    PMID: 26467826 DOI: 10.3390/insects2040469
    A study was carried out to evaluate the incidence of termite attack on an Araucaria cunninghamii plantation at Teluk Bahang Forest Park (TBFP), Penang. The hilly plantation area was surveyed to determine the diversity of termite species present. Termite specimens were collected from standin Araucaria trees, underground monitoring (aggregation) stations, fallen logs, forest litter and mounds (nests). Seven species of termites were identified from 6 genera; Coptotermes curvignathus, Schedorhinotermes medioobscurus, Schedorhinotermes malaccensis, Odontotermes sarawakensis Parrhinotermes aequalis, Macrotermes malaccensis and Hospitalitermes hospitalis. A total of 289 Araucaria trees were inspected for signs of termite attack. Termite infestation of trees was determined mainly by the presence of mud on the trunk, but particularly around their butts at ground line. The most dominant termite species discovered infesting the Araucaria trees was Coptotermes curvignathus; accountable for 74% of all infestations. Schedorhinotermes medioobscurus and Odontotermes sarawakensis were commonly found infesting dead trees and/or tree stumps. Approximately 21.5% of all Araucaria trees in the plantation forest at Teluk Bahang were infested by termites.
  5. First description of the male of Phlebotomus betisi Lewis and Wharton, 1963 (Diptera: Psychodidae)
    Khadri MS, Depaquit J, Bargues MD, Ferté H, Mas-coma S, Lee HL, et al.
    Parasitol Int, 2008 Sep;57(3):295-9.
    PMID: 18378490 DOI: 10.1016/j.parint.2008.01.003
    The male of Phlebotomus (Larroussius) betisi is described from Malayan caves. Several males have been caught in association with P. betisi females. Males and females have been associated by ecology, biogeography, morphology and molecular biology (homology of the ND4 mtDNA sequences).
  6. Need for approval from others and face concerns as predictors of interpersonal conflict outcome in 29 cultural groups
    Lun VM, Smith PB, Grigoryan L, Torres C, Papastylianou A, Lopukhova OG, et al.
    Int J Psychol, 2023 Jan 27.
    PMID: 36707726 DOI: 10.1002/ijop.12895
    The extent to which culture moderates the effects of need for approval from others on a person's handling of interpersonal conflict was investigated. Students from 24 nations rated how they handled a recent interpersonal conflict, using measures derived from face-negotiation theory. Samples varied in the extent to which they were perceived as characterised by the cultural logics of dignity, honour, or face. It was hypothesised that the emphasis on harmony within face cultures would reduce the relevance of need for approval from others to face-negotiation concerns. Respondents rated their need for approval from others and how much they sought to preserve their own face and the face of the other party during the conflict. Need for approval was associated with concerns for both self-face and other-face. However, as predicted, the association between need for approval from others and concern for self-face was weaker where face logic was prevalent. Favourable conflict outcome was positively related to other-face and negatively related to self-face and to need for approval from others, but there were no significant interactions related to prevailing cultural logics. The results illustrate how particular face-threatening factors can moderate the distinctive face-concerns earlier found to characterise individualistic and collectivistic cultural groups.
  7. Age-Stage, Two-Sex Life Table Characteristics of Aedes albopictus and Aedes Aegypti in Penang Island, Malaysia
    Maimusa HA, Ahmad AH, Kassim NF, Rahim J
    J Am Mosq Control Assoc, 2016 Mar;32(1):1-11.
    PMID: 27105211 DOI: 10.2987/moco-32-01-1-11.1
    The life table developmental attributes of laboratory colonies of wild strains of Aedes albopictus and Aedes aegypti were analyzed and compared based on the age-stage, two-sex life table. Findings inclusive in this study are: adult preoviposition periods, total preoviposition period, mean intrinsic rate of increase (r), mean finite rate of increase (λ), net reproductive rates (R0), and mean generation time (T). The total preadult development time was 9.47 days for Ae. albopictus and 8.76 days for Ae. aegypti. The life expectancy was 19.01 days for Ae. albopictus and 19.94 days for Ae. aegypti. Mortality occurred mostly during the adult stage. The mean development time for each stage insignificantly correlated with temperature for Ae. albopictus (r  =  -0.208, P > 0.05) and (r  =  -0.312, P > 0.05) for Ae. aegypti. The population parameters suggest that Ae. albopictus and Ae. aegypti populations are r-strategists characterized by a high r, a large R0, and short T. This present study provides the first report to compare the life parameters of Ae. albopictus and Ae. aegypti strains from Penang island, Malaysia.
  8. Fulltext Termite infestation associated with type of soil in pulau pinang, malaysia (isoptera: rhinotermitidae)
    Majid AH, Ahmad AH
    Trop Life Sci Res, 2013 Dec;24(2):91-5.
    PMID: 24575252 MyJurnal
    Nine soil samples from nine buildings infested with Coptotermes gestroi in Pulau Pinang, Malaysia, were tested for the type of soil texture. The soil texture analysis procedures used the hydrometer method. Four of nine buildings (44%) yielded loamy sand-type soil, whereas five of nine buildings (56%) contained sandy loam-type soil.
  9. The rise of hyperabundant native generalists threatens both humans and nature
    Moore JH, Gibson L, Amir Z, Chanthorn W, Ahmad AH, Jansen PA, et al.
    Biol Rev Camb Philos Soc, 2023 Oct;98(5):1829-1844.
    PMID: 37311559 DOI: 10.1111/brv.12985
    In many disturbed terrestrial landscapes, a subset of native generalist vertebrates thrives. The population trends of these disturbance-tolerant species may be driven by multiple factors, including habitat preferences, foraging opportunities (including crop raiding or human refuse), lower mortality when their predators are persecuted (the 'human shield' effect) and reduced competition due to declines of disturbance-sensitive species. A pronounced elevation in the abundance of disturbance-tolerant wildlife can drive numerous cascading impacts on food webs, biodiversity, vegetation structure and people in coupled human-natural systems. There is also concern for increased risk of zoonotic disease transfer to humans and domestic animals from wildlife species with high pathogen loads as their abundance and proximity to humans increases. Here we use field data from 58 landscapes to document a supra-regional phenomenon of the hyperabundance and community dominance of Southeast Asian wild pigs and macaques. These two groups were chosen as prime candidates capable of reaching hyperabundance as they are edge adapted, with gregarious social structure, omnivorous diets, rapid reproduction and high tolerance to human proximity. Compared to intact interior forests, population densities in degraded forests were 148% and 87% higher for wild boar and macaques, respectively. In landscapes with >60% oil palm coverage, wild boar and pig-tailed macaque estimated abundances were 337% and 447% higher than landscapes with <1% oil palm coverage, respectively, suggesting marked demographic benefits accrued by crop raiding on calorie-rich food subsidies. There was extreme community dominance in forest landscapes with >20% oil palm cover where two pig and two macaque species accounted for >80% of independent camera trap detections, leaving <20% for the other 85 mammal species >1 kg considered. Establishing the population trends of pigs and macaques is imperative since they are linked to cascading impacts on the fauna and flora of local forest ecosystems, disease and human health, and economics (i.e., crop losses). The severity of potential negative cascading effects may motivate control efforts to achieve ecosystem integrity, human health and conservation objectives. Our review concludes that the rise of native generalists can be mediated by specific types of degradation, which influences the ecology and conservation of natural areas, creating both positive and detrimental impacts on intact ecosystems and human society.
  10. Fulltext Equivalence and practice effect of alternate forms for Malay version of Auditory Verbal Learning Test (MAVLT)
    Munjir N, Othman Z, Zakaria R, Shafin N, Hussain NA, Desa AM, et al.
    EXCLI J, 2015;14:801-8.
    PMID: 26600750 DOI: 10.17179/excli2015-280
    This study aims to develop two alternate forms for Malay version of Auditory Verbal Learning Test (MAVLT) and to determine their equivalency and practice effect. Ninety healthy volunteers were subjected to the following neuropsychological tests at baseline, and at one month interval according to their assigned group; group 1 (MAVLT - MAVLT), group 2 (MAVLT - Alternate Form 1 - Alternate Form 1), and group 3 (MAVLT - Alternate Form 2 - Alternate Form 2). There were no significant difference in the mean score of all the trials at baseline among the three groups, and most of the mean score of trials between MAVLT and Alternate Form 1, and between MAVLT and Alternate Form 2. There was significant improvement in the mean score of each trial when the same form was used repeatedly at the interval of one month. However, there was no significant improvement in the mean score of each trial when the Alternate Form 2 was used during repeated neuropsychological testing. The MAVLT is a reliable instrument for repeated neuropsychological testing as long as alternate forms are used. The Alternate Form 2 showed better equivalency to MAVLT and less practice effects.
  11. Fulltext Limited directed seed dispersal in the canopy as one of the determinants of the low hemi-epiphytic figs' recruitments in Bornean rainforests
    Nakabayashi M, Inoue Y, Ahmad AH, Izawa M
    PLoS One, 2019;14(6):e0217590.
    PMID: 31194749 DOI: 10.1371/journal.pone.0217590
    Ficus species are keystone plants in tropical rainforests, and hemi-epiphytic figs play a notably important role in forest ecosystems. Because hemi-epiphytic figs have strict germination requirements, germination and establishment stages regulate their populations. Despite the ecological importance of hemi-epiphytic figs in the rainforests, seed dispersal systems by fig-eating animals under natural conditions remain unknown because of the difficulty in tracing the destiny of dispersed seeds in the canopy. Therefore, seed dispersal effectiveness (SDE) has never been evaluated for hemi-epiphytic figs. We evaluated the SDE of hemi-epiphytic figs using qualitative and quantitative components by three relatively large-sized (> 3 kg) arboreal and volant animals in Bornean rainforests that largely depend on fig fruits in their diets: binturongs Arctictis binturong, Mueller's gibbons Hylobates muelleri, and helmeted hornbills Rhinoplax vigil. The SDE values of binturongs was by far the highest among the three study animals. Meanwhile, successful seed dispersal of hemi-epiphytic figs by gibbons and helmeted hornbills is aleatory and rare. Given that seed deposition determines the fate of hemi-epiphytic figs, the defecatory habits of binturongs, depositing feces on specific microsites in the canopy, is the most reliable dispersal method, compared to scattering feces from the air or upper canopy. We showed that reliable directed dispersal of hemi-epiphytic figs occurs in high and uneven canopy of Bornean rainforests. This type of dispersal is limited to specific animal species, and therefore it may become one of the main factors regulating low-success hemi-epiphytic fig recruitment in Bornean rainforests.
  12. Fulltext Temporal activity patterns suggesting niche partitioning of sympatric carnivores in Borneo, Malaysia
    Nakabayashi M, Kanamori T, Matsukawa A, Tangah J, Tuuga A, Malim PT, et al.
    Sci Rep, 2021 10 06;11(1):19819.
    PMID: 34615956 DOI: 10.1038/s41598-021-99341-6
    To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed temporal activity patterns of the sympatric carnivore species using 37,379 photos collected for more than 3 years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each time period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felid, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species with similar morphology and ecology did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least 2 or 3 years is necessary to understand animals' temporal activity patterns, especially for sun bears and civets, by camera-trapping and to establish effective protection measures.
  13. Fulltext Efficacy of cholecalciferol rodenticide to control wood rat, Rattus tiomanicus and its secondary poisoning impact towards barn owl, Tyto javanica javanica
    Noh AAM, Ahmad AH, Salim H
    Sci Rep, 2023 Feb 17;13(1):2854.
    PMID: 36808172 DOI: 10.1038/s41598-023-29499-8
    Studies were conducted on the potential use of cholecalciferol as an alternative to anticoagulant rodenticides to control common rat pest in oil palm plantations, i.e., wood rats, Rattus tiomanicus, and the secondary poisoning impact of cholecalciferol on barn owls, Tyto javanica javanica. The laboratory efficacy of cholecalciferol (0.075% a.i.) was compared with commonly used first-generation anticoagulant rodenticides (FGARs): chlorophacinone (0.005% a.i) and warfarin (0.05% a.i). The 6-day wild wood rat laboratory feeding trial showed cholecalciferol baits had the highest mortality rate at 71.39%. Similarly, the FGAR chlorophacinone recorded a mortality rate of 74.20%, while warfarin baits recorded the lowest mortality rate at 46.07%. The days-to-death of rat samples was in range of 6-8 days. The highest daily consumption of bait by rat samples was recorded for warfarin at 5.85 ± 1.34 g per day while the lowest was recorded in rat samples fed cholecalciferol, i.e., 3.03 ± 0.17 g per day. Chlorophacinone-treated and control rat samples recorded consumption of about 5 g per day. A secondary poisoning assessment on barn owls in captivity fed with cholecalciferol-poisoned rats showed after 7 days of alternate feeding, the barn owls appeared to remain healthy. All the barn owls fed with cholecalciferol-poisoned rats survived the 7-day alternate feeding test and throughout the study, up to 6 months after exposure. All the barn owls did not show any abnormal behavior or physical change. The barn owls were observed to be as healthy as the barn owls from the control group throughout the study.
  14. Fulltext Man with trauma following motorcycle crash
    Osman A, Ahmad AH, Yiing JLJ, Yusof ZM
    J Am Coll Emerg Physicians Open, 2020 Oct;1(5):1132-1134.
    PMID: 33145576 DOI: 10.1002/emp2.12212
  15. Helmet continuous positive airway pressure vs. high flow nasal cannula oxygen in acute cardiogenic pulmonary oedema: a randomized controlled trial
    Osman A, Via G, Sallehuddin RM, Ahmad AH, Fei SK, Azil A, et al.
    Eur Heart J Acute Cardiovasc Care, 2021 Dec 18;10(10):1103-1111.
    PMID: 34632507 DOI: 10.1093/ehjacc/zuab078
    AIMS : Non-invasive ventilation represents an established treatment for acute cardiogenic pulmonary oedema (ACPO) although no data regarding the best ventilatory strategy are available. We aimed to compare the effectiveness of helmet CPAP (hCPAP) and high flow nasal cannula (HFNC) in the early treatment of ACPO.

    METHODS AND RESULTS : Single-centre randomized controlled trial of patients admitted to the emergency department due to ACPO with hypoxemia and dyspnoea on face mask oxygen therapy. Patients were randomly assigned with a 1:1 ratio to receive hCPAP or HFNC and FiO2 set to achieve an arterial oxygen saturation >94%. The primary outcome was a reduction in respiratory rate; secondary outcomes included changes in heart rate, PaO2/FiO2 ratio, Heart rate, Acidosis, Consciousness, Oxygenation, and Respiratory rate (HACOR) score, Dyspnoea Scale, and intubation rate. Data were collected before hCPAP/HFNC placement and after 1 h of treatment. Amongst 188 patients randomized, hCPAP was more effective than HFNC in reducing respiratory rate [-12 (95% CI; 11-13) vs. -9 (95% CI; 8-10), P 

  16. Fulltext Man with right shoulder pain
    Osman A, Chan PF, Ahmad AH
    J Am Coll Emerg Physicians Open, 2020 Dec;1(6):1742-1743.
    PMID: 33392588 DOI: 10.1002/emp2.12262
  17. Fulltext Potential Role of Honey in Learning and Memory
    Othman Z, Zakaria R, Hussain NHN, Hassan A, Shafin N, Al-Rahbi B, et al.
    Med Sci (Basel), 2015 Apr 09;3(2):3-15.
    PMID: 29083387 DOI: 10.3390/medsci3020003
    The composition and physicochemical properties of honey are variable depending on its floral source and often named according to the geographical location. The potential medicinal benefits of Tualang honey, a multifloral jungle honey found in Malaysia, have recently been attracting attention because of its reported beneficial effects in various diseases. This paper reviews the effects of honey, particularly Tualang honey, on learning and memory. Information regarding the effects of Tualang honey on learning and memory in human as well as animal models is gleaned to hypothesize its underlying mechanisms. These studies show that Tualang honey improves morphology of memory-related brain areas, reduces brain oxidative stress, increases brain-derived neurotrophic factor (BDNF) and acetylcholine (ACh) concentrations, and reduces acetylcholinesterase (AChE) in the brain homogenates. Its anti-inflammatory roles in reducing inflammatory trigger and microglial activation have yet to be investigated. It is hypothesized that the improvement in learning and memory following Tualang honey supplementation is due to the significant improvement in brain morphology and enhancement of brain cholinergic system secondary to reduction in brain oxidative damage and/or upregulation of BDNF concentration. Further studies are imperative to elucidate the molecular mechanism of actions.
  18. Fulltext Profiling the Research Landscape on Cognitive Aging: A Bibliometric Analysis and Network Visualization
    Othman Z, Abdul Halim AS, Azman KF, Ahmad AH, Zakaria R, Sirajudeen KNS, et al.
    Front Aging Neurosci, 2022;14:876159.
    PMID: 35572132 DOI: 10.3389/fnagi.2022.876159
    OBJECTIVES: This study aimed to profile the cognitive aging research landscape from 1956 to 2021.

    METHODS: A total of 3,779 documents were retrieved from the Scopus database for the bibliometric analysis and network visualization. By comparing each keyword's overall connection strength (centrality), frequency (density), and average year of publication (novelty) to the calculated median values acquired from the overlay view of the VOSviewer map, the enhanced strategic diagrams (ESDs) were constructed.

    RESULTS: The findings showed an increasing trend in the number of publications. The United States leads the contributing countries in cognitive aging research. The scientific productivity pattern obeyed Lotka's law. The most productive researcher was Deary, I. J., with the highest number of publications. The collaborative index showed an increasing trend from 1980 onwards. Frontiers in Aging Neuroscience is the most prestigious journal in the field of cognitive aging research. In Bradford core journals zone 1, the top 10 core journals of cognitive aging research provided more than half of the total articles (697, or 55.36 percent).

    CONCLUSIONS: For the next decades, the trending topics in cognitive aging research include neuropsychological assessment, functional connectivity, human immunodeficiency virus (HIV), decision-making, gender, compensation, default mode network, learning and memory, brain-derived neurotrophic factor (BDNF), obesity, D-galactose, epigenetics, frailty, mortality, mini-mental state examination (MMSE), anxiety, and gait speed.

  19. Insight into potential mechanisms of hypobaric hypoxia-induced learning and memory deficit - Lessons from rat studies
    Qaid E, Zakaria R, Sulaiman SF, Yusof NM, Shafin N, Othman Z, et al.
    Hum Exp Toxicol, 2017 Dec;36(12):1315-1325.
    PMID: 28111974 DOI: 10.1177/0960327116689714
    Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia-induced memory deficit.
  20. Fulltext Tualang Honey Ameliorates Hypoxia-induced Memory Deficits by Reducing Neuronal Damage in the Hippocampus of Adult Male Sprague Dawley Rats
    Qaid EYA, Zakaria R, Mohd Yusof NA, Sulaiman SF, Shafin N, Othman Z, et al.
    Turk J Pharm Sci, 2020 Oct;17(5):555-564.
    PMID: 33177938 DOI: 10.4274/tjps.galenos.2019.32704
    Objectives: A growing body of evidence indicates that hypoxia exposure causes learning and memory deficits. An effective natural therapeutic approach has, however, not been explored widely. Our previous studies found that Tualang honey administration protected learning and memory functions in ovariectomized rats. Therefore, the present study investigated its efficacy in ameliorating hypoxia-induced memory deficits in adult male Sprague Dawley rats.

    Materials and Methods: The rats were divided into four groups: i) Normoxia treated with sucrose (n=12), ii) Normoxia treated with Tualang honey (n=12), iii) Hypoxia treated with sucrose (n=12), and iv) Hypoxia treated with Tualang honey (n=12). Tualang honey (0.2 g/kg/BW) and sucrose (1 mL of 7.9%) supplementations were administered orally to the rats daily for 14 days. Then the hypoxia groups were exposed to hypoxia (~11%) for 7 days, while the normoxia groups were kept in normal conditions. Following exposure to hypoxia, the rats' memories were analyzed using a novel object recognition task and T-maze test.

    Results: The data revealed that rats exposed to hypoxia showed significant impairment in short-term memory (STM), spatial memory (p<0.01), and long-term memory (LTM) when compared to the normoxia group. Hypoxia rats treated with Tualang honey showed significant improvement in STM, LTM, and spatial memory (p<0.05) compared with those treated with sucrose (p<0.05). Tualang honey also reduced neuronal damage in the hippocampus of adult male Sprague Dawley rats exposed to hypoxia.

    Conclusion: It is suggested that Tualang honey pretreatment has protective effects against hypoxia-induced memory deficits, possibly through its antioxidant contents.

Related Terms
    Try searching for something
Filters
Contact Us

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

External Links