Displaying publications 1 - 20 of 70 in total

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  1. Zhao D, Borkhanuddin MH, Wang W, Liu Y, Cech G, Zhai Y, et al.
    Parasitol Res, 2016 Nov;115(11):4317-4325.
    PMID: 27492197
    Thelohanellus kitauei is a freshwater myxosporean parasite causing intestinal giant cystic disease of common carp. To clarify the life cycle of T. kitauei, we investigated the oligochaete populations in China and Hungary. This study confirms two distinct aurantiactinomyxon morphotypes (Aurantiactinomyxon type 1 and Aurantiactinomyxon type 2) from Branchiura sowerbyi as developmental stages of the life cycle of T. kitauei. The morphological characteristics and DNA sequences of these two types are described here. Based on 18S rDNA sequence analysis, Aurantiactinomyxon type 1 (2048 bp) and Aurantiactinomyxon type 2 (2031 bp) share 99.2-99.4 %, 99.8-100 % similarity to the published sequences of T. kitauei, respectively. The 18S rDNA sequences of these two aurantiactinomyxon morphotypes share 99.4 % similarity, suggesting intraspecific variation within the taxon, possibly due to geographic origin. Phylogenetic analyses demonstrate the two aurantiactinomyxon types clustered with T. kitauei. Regardless, based on 18S rDNA synonymy, it is likely that Aurantiactinomyxon type 1 and 2 are conspecific with T. kitauei. This is the fourth elucidated two-host life cycle of Thelohanellus species and the first record of T. kitauei in Europe.
    Matched MeSH terms: Life Cycle Stages*
  2. Zaborowska J, Isa NF, Murphy S
    Inside Cell, 2016 04;1(2):106-116.
    PMID: 27398404
    Positive transcription elongation factor b (P-TEFb), which comprises cyclin-dependent kinase 9 (CDK9) kinase and cyclin T subunits, is an essential kinase complex in human cells. Phosphorylation of the negative elongation factors by P-TEFb is required for productive elongation of transcription of protein-coding genes by RNA polymerase II (pol II). In addition, P-TEFb-mediated phosphorylation of the carboxyl-terminal domain (CTD) of the largest subunit of pol II mediates the recruitment of transcription and RNA processing factors during the transcription cycle. CDK9 also phosphorylates p53, a tumor suppressor that plays a central role in cellular responses to a range of stress factors. Many viral factors affect transcription by recruiting or modulating the activity of CDK9. In this review, we will focus on how the function of CDK9 is regulated by viral gene products. The central role of CDK9 in viral life cycles suggests that drugs targeting the interaction between viral products and P-TEFb could be effective anti-viral agents.
    Matched MeSH terms: Life Cycle Stages
  3. Yapp DT, Yap SY
    J Ethnopharmacol, 2003 Mar;85(1):145-50.
    PMID: 12576213
    Malaria remains a global problem in the light of chloroquine-resistant strains of Plasmodium falciparum. New compounds are needed for the development of novel antimalarial drugs. Seed, leaf, and fruit skin extracts of Lansium domesticum, a common fruit tree in South-East Asia, are used by indigenous tribes in Sabah, Malaysia for treating malaria. The skin and aqueous leaf extracts of the tree were found to reduce parasite populations of the drug sensitive strain (3D7) and the chloroquine-resistant strain (T9) of P. falciparum equally well. The skin extracts were also found to interrupt the lifecycle of the parasite. The data reported here indicate that extracts of L. domesticum are a potential source for compounds with activity towards chloroquine-resistant strains of P. falciparum.
    Matched MeSH terms: Life Cycle Stages/drug effects
  4. Usman S, Abdull Razis AF, Shaari K, Amal MNA, Saad MZ, Mat Isa N, et al.
    PMID: 33371479 DOI: 10.3390/ijerph17249591
    Technological advances, coupled with increasing demands by consumers, have led to a drastic increase in plastic production. After serving their purposes, these plastics reach our water bodies as their destination and become ingested by aquatic organisms. This ubiquitous phenomenon has exposed humans to microplastics mostly through the consumption of sea food. This has led the World Health Organization (WHO) to make an urgent call for the assessment of environmental pollution due to microplastics and its effect on human health. This review summarizes studies between 1999 and 2020 in relation to microplastics in aquatic ecosystems and human food products, their potential toxic effects as elicited in animal studies, and policies on their use and disposal. There is a paucity of information on the toxicity mechanisms of microplastics in animal studies, and despite their documented presence in food products, no policy has been in place so far, to monitor and regulates microplastics in commercial foods meant for human consumption. Although there are policies and regulations with respect to plastics, these are only in a few countries and in most instances are not fully implemented due to socioeconomic reasons, so they do not address the problem across the entire life cycle of plastics from production to disposal. More animal research to elucidate pathways and early biomarkers of microplastic toxicity that can easily be detected in humans is needed. This is to create awareness and influence policies that will address this neglected threat to food safety and security.
    Matched MeSH terms: Life Cycle Stages
  5. Tsubouchi Y
    Tonan Ajia Kenkyu, 1993 Jun;31(1):3-17.
    PMID: 12157851
    The author describes changes in the size and characteristics of multiple-household compounds in Kelantan, Malaysia, during the period 1971-1991. It is found that "in Malay villages, multihouseholdcompounds were in earlier times...based on a bilateral residence rule in which one or more children, either male or female, would stay in the compound of their parents....A recent trend has been for more females to remain in the parental compound than males, reflecting the orientation toward independence among the males." (SUMMARY IN ENG)
    Matched MeSH terms: Life Cycle Stages*
  6. Takaoka H, Sofian-Azirun M, Ya'cob Z
    Zootaxa, 2014;3774:473-80.
    PMID: 24871514 DOI: 10.11646/zootaxa.3774.5.5
    Two new black fly species, Simulium (Gomphostilbia) tekamense and Simulium (Gomphostilbia) jerantutense, are described based on adult females emerged from pupae in Peninsular Malaysia, and assigned to the binuanense subgroup of the batoense species-group in the subgenus Gomphostilbia. Simulium (G.) tekamense sp. nov. is characterized in the female by the subcosta with 0-2 hairs, and presence of a  deep notch on the apex of the mediolongitudinal ridge of the cibarium, and in the pupa by one of two paired gill filaments of the middle triplet much thicker than the counter filament. Simulium (G.) jerantutense sp. nov. is characterized in the female by the short claw tooth 0.46 times the length of the claw, and in the pupa by the gill filaments arranged as [2+1+(1+2)]+2 filaments from dorsal to ventral. Taxonomic notes are given to distinguish these new species from related species.
    Matched MeSH terms: Life Cycle Stages
  7. Suárez-Morales E
    PLoS One, 2011;6(8):e22915.
    PMID: 21853055 DOI: 10.1371/journal.pone.0022915
    Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971-1980, 1991-2000, 2001-2010), each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records), followed by the Northwestern Atlantic (17%); the least surveyed areas include regions of the southern hemisphere (less than 3%). The Northeast Atlantic region harbors the highest number of known species (32 nominal species), followed by the Caribbean Sea/Gulf of Mexico (24), the Mediterranean/Black Sea (19), Indonesia-Malaysia-Philippines region (17), Japanese waters (17), and the Brazil-Argentina area (16). Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied.
    Matched MeSH terms: Life Cycle Stages
  8. Srinivasan V, Ahmad AH, Mohamed M, Zakaria R
    PMID: 22537380
    Malaria remains a global health problem affecting more than 515 million people all over the world including Malaysia. It is on the rise, even within unknown regions that previous to this were free of malaria. Although malaria eradication programs carried out by vector control programs are still effective, anti-malarial drugs are also used extensively for curtailing this disease. But resistance to the use of anti-malarial drugs is also increasing on a daily basis. With an increased understanding of mechanisms that cause growth, differentiation and development of malarial parasites in rodents and humans, new avenues of therapeutic approaches for controlling the growth, synchronization and development of malarial parasites are essential. Within this context, the recent discoveries related to IP3 interconnected signalling pathways, the release of Ca2+ from intracellular stores of Plasmodium, ubiquitin protease systems as a signalling pathway, and melatonin influencing the growth and differentiation of malarial parasites by its effects on these signalling pathways have opened new therapeutic avenues for arresting the growth and differentiation of malarial parasites. Indeed, the use of melatonin antagonist, luzindole, has inhibited the melatonin's effect on these signalling pathways and thereby has effectively reduced the growth and differentiation of malarial parasites. As Plasmodium has effective sensors which detect the nocturnal plasma melatonin concentrations, suppression of plasma melatonin levels with the use of bright light during the night or by anti-melatonergic drugs and by using anti-kinase drugs will help in eradicating malaria on a global level. A number of patients have been admitted with regards to the control and management of malarial growth. Patents related to the discovery of serpentine receptors on Plasmodium, essential for modulating intra parasitic melatonin levels, procedures for effective delivery of bright light to suppress plasma melatonin levels and thereby arresting the growth and elimination of malarial parasites from the blood of the host are all cited in the paper. The purpose of the paper is to highlight the importance of melatonin acting as a cue for Plasmodium faciparum growth and to discuss the ways of curbing the effects of melatonin on Plasmodium growth and for arresting its life cycle, as a method of eliminating the parasite from the host.
    Matched MeSH terms: Life Cycle Stages/drug effects*
  9. Soudagar MEM, Kiong TS, Jathar L, Nik Ghazali NN, Ramesh S, Awasarmol U, et al.
    Chemosphere, 2024 Apr;353:141540.
    PMID: 38423144 DOI: 10.1016/j.chemosphere.2024.141540
    The development of algae is seen as a potential and ecologically sound approach to address the increasing demands in multiple sectors. However, successful implementation of processes is highly dependent on effective growing and harvesting methods. The present study provides a complete examination of contemporary techniques employed in the production and harvesting of algae, with a particular emphasis on their sustainability. The review begins by examining several culture strategies, encompassing open ponds, closed photobioreactors, and raceway ponds. The analysis of each method is conducted in a systematic manner, with a particular focus on highlighting their advantages, limitations, and potential for expansion. This approach ensures that the conversation is in line with the objectives of sustainability. Moreover, this study explores essential elements of algae harvesting, including the processes of cell separation, dewatering, and biomass extraction. Traditional methods such as centrifugation, filtration, and sedimentation are examined in conjunction with novel, environmentally concerned strategies including flocculation, electro-coagulation, and membrane filtration. It evaluates the impacts on the environment that are caused by the cultivation process, including the usage of water and land, the use of energy, the production of carbon dioxide, and the runoff of nutrients. Furthermore, this study presents a thorough examination of the current body of research pertaining to Life Cycle Analysis (LCA) studies, presenting a perspective that emphasizes sustainability in the context of algae harvesting systems. In conclusion, the analysis ends up with an examination ahead at potential areas for future study in the cultivation and harvesting of algae. This review is an essential guide for scientists, policymakers, and industry experts associated with the advancement and implementation of algae-based technologies.
    Matched MeSH terms: Life Cycle Stages
  10. Smith JP
    Res Popul Econ, 1991;7:131-56.
    PMID: 12317026
    Matched MeSH terms: Life Cycle Stages*
  11. Shodipo MO, Sikkel PC, Smit NJ, Hadfield KA
    Int J Parasitol Parasites Wildl, 2021 Apr;14:355-367.
    PMID: 33898237 DOI: 10.1016/j.ijppaw.2021.03.004
    Due to their unusual life cycle that includes parasitic larval and free living adult stages, gnathiid isopods are typically overlooked in biodiversity surveys, even those that focus on parasites. While the Philippines sits within the region of highest marine biodiversity in the world, the coral triangle, no gnathiid species have been identified or described from that region. Here we present the first records of two gnathiid species collected from the Visayas, central Philippines: Gnathia malaysiensis Müller, 1993, previously described from Malaysia, and G. camuripenis Tanaka, 2004, previously described from southern Japan. This paper provides detailed morphological redescriptions, drawings and scanning electron microscope images as well as the first molecular characterisation of both species, Furthermore, a summary of the Central-Indo Pacific Gnathia species is provided.
    Matched MeSH terms: Life Cycle Stages
  12. Selvi S, Edah MA, Nazni WA, Lee HL, Azahari AH
    Trop Biomed, 2007 Jun;24(1):63-75.
    PMID: 17568379 MyJurnal
    Larvae and adults of Culex quinquefasciatus were used for the test undertaken for malathion resistant strain (F61 - F65) and permethrin resistant strain (F54 - F58). The results showed that the LC50 for both malathion (F61 - F65) and permethrin (F54 - F58) resistant Cx. quinquefasciatus increased steadily throughout the subsequent five generations, indicating a marked development of resistance. The adult female malathion resistant strain have developed a high resistance level to malathion diagnostic dosage with a resistance ratio of 9.3 to 17.9 folds of resistance compared with the susceptible Cx. quinquefasciatus. Permethrin resistance ratio remained as 1.0 folds of resistance at every generation. It was obvious that malathion resistance developed at a higher rate in adult females compared to permethrin. Enzyme-based metabolic mechanisms of insecticide resistance were investigated based on the biochemical assay principle. From the results obtained obviously shows that there is a significant difference (p < 0.05) in esterase level in both malathion and permethrin selected strains. Female malathion selected strain has the higher level of esterase activity compared to the female permethrin selected strain at (0.8 to 1.04) alpha-Na micromol/min/mg protein versus (0.15 to 0.24) alpha-Na micromol/min/mg protein respectively. This indicated increased level of non-specific esterase is playing an important role in resistance mechanism in female malathion selected strain. Permethrin selected strain exhibited non-specific esterase activity at a very low level throughout the different life stages compared to malathion selected strain. This study suggests that life stages play a predominant role in conferring malathion and permethrin resistance in Cx. quinquefasciatus.
    Matched MeSH terms: Life Cycle Stages
  13. Sargsian S, Chen Z, Lee SC, Robertson A, Thur RS, Sproch J, et al.
    Cell Rep, 2022 Nov 29;41(9):111725.
    PMID: 36450245 DOI: 10.1016/j.celrep.2022.111725
    Soil-transmitted intestinal worms known as helminths colonize over 1.5 billion people worldwide. Although helminth colonization has been associated with altered composition of the gut microbiota, such as increases in Clostridia, individual species have not been isolated and characterized. Here, we isolate and sequence the genome of 13 Clostridia from the Orang Asli, an indigenous population in Malaysia with a high prevalence of helminth infections. Metagenomic analysis of 650 fecal samples from urban and rural Malaysians confirm the prevalence of species corresponding to these isolates and reveal a specific association between Peptostreptococcaceae family members and helminth colonization. Remarkably, Peptostreptococcaceae isolated from the Orang Asli display superior capacity to promote the life cycle of whipworm species, including hatching of eggs from Trichuris muris and Trichuris trichiura. These findings support a model in which helminths select for gut colonization of microbes that support their life cycle.
    Matched MeSH terms: Life Cycle Stages
  14. Saifur RG, Dieng H, Hassan AA, Salmah MR, Satho T, Miake F, et al.
    PLoS One, 2012;7(2):e30919.
    PMID: 22363516 DOI: 10.1371/journal.pone.0030919
    BACKGROUND: The domestic dengue vector Aedes aegypti mosquitoes breed in indoor containers. However, in northern peninsular Malaysia, they show equal preference for breeding in both indoor and outdoor habitats. To evaluate the epidemiological implications of this peridomestic adaptation, we examined whether Ae. aegypti exhibits decreased survival, gonotrophic activity, and fecundity due to lack of host availability and the changing breeding behavior.

    METHODOLOGY/PRINCIPAL FINDINGS: This yearlong field surveillance identified Ae. aegypti breeding in outdoor containers on an enormous scale. Through a sequence of experiments incorporating outdoors and indoors adapting as well as adapted populations, we observed that indoors provided better environment for the survival of Ae. aegypti and the observed death patterns could be explained on the basis of a difference in body size. The duration of gonotrophic period was much shorter in large-bodied females. Fecundity tended to be greater in indoor acclimated females. We also found increased tendency to multiple feeding in outdoors adapted females, which were smaller in size compared to their outdoors breeding counterparts.

    CONCLUSION/SIGNIFICANCE: The data presented here suggest that acclimatization of Ae. aegypti to the outdoor environment may not decrease its lifespan or gonotrophic activity but rather increase breeding opportunities (increased number of discarded containers outdoors), the rate of larval development, but small body sizes at emergence. Size is likely to be correlated with disease transmission. In general, small size in Aedes females will favor increased blood-feeding frequency resulting in higher population sizes and disease occurrence.

    Matched MeSH terms: Life Cycle Stages/physiology
  15. Rashid SS, Liu YQ
    Sci Total Environ, 2021 Feb 20;756:143849.
    PMID: 33248794 DOI: 10.1016/j.scitotenv.2020.143849
    The occurrence of various micropollutants such as pharmaceuticals personal care products, endocrine disrupting chemicals (PPCPs/EDCs) and metals in municipal wastewater, and their poor removal efficiencies can lead to toxicity impact on humans, and freshwater and terrestrial ecosystems. Life cycle assessment is an efficient and effective tool to evaluate the environmental impact of wastewater treatment plants, but guidelines for toxicity assessment are lacking due to the complexity. This study aims to evaluate both life cycle inventory by including metals and PEC, and life cycle toxicity assessment (LCIA) methods namely CML-IA, Recipe, USEtox, EDIP 2003 and IMPACT 2002+ in midpoint category with a large centralised wastewater treatment plant in Malaysia as a case study. The removal efficiencies of metals and PPCPs/EDCs in the wastewater ranged from 9% to 99% and no clear patterns were found about occurrence and removal efficiencies of metals and PPCPs/EDCs in developing and developed countries. The inclusion of metals and PPCPs/EDCs in effluent resulted in 76% increase in freshwater ecotoxicity potential (FEP) and 88% increase in terrestrial ecotoxicity potential (TEP) while only 4% increase in human toxicity potential (HTP). The results indicate the importance of including direct emissions such as metals and PPCPs/EDCs even in low-strength municipal wastewater for environmental toxicity assessment. The comparison of five LCIA methods suggests that HTP assessment is more challenging due to inconsistency between five LCIA methods while CML-IA, Recipe, and IMPACT 2002+ achieved consistent human toxicity and ecotoxicity assessment results in the WWTP. The results highlight the importance of sampling and inclusion of metals and PPCPs/EDCs data especially prioritised micropollutants for life cycle toxicity assessment and recommends LCIA methods for ecotoxicity assessment of WWTPs in the current scientific development situation on toxicity studies, which can provide guidance to researchers for life cycle toxicity assessment of wastewater treatment.
    Matched MeSH terms: Life Cycle Stages
  16. Poinar GO, Jackson TA, Bell NL, Wahid MB
    Syst Parasitol, 2002 Jul;52(3):219-25.
    PMID: 12075153
    A new nematode, Elaeolenchus parthenonema n. g., n. sp., is described from the palm-pollinating weevil Elaeidobius kamerunicus Faust. The new genus is placed in the Anandranematidae n. fam., which, together with the genus Anandranema Poinar et al., 1993, is characterised by nematodes having only a single autotokous generation in the insect host. This is the first report of a member of this superfamily reproducing only parthenogenetically. The development of E. parthenonema and its effect on the weevil host is discussed, along with a phylogenetic synopsis of the families of the Sphaerularioidea Lubbock 1861. The Beddingiidae n. fam. is proposed for Beddingia Blinova & Korenchenko, 1986, comprising the original Deladenus parasites of Hymenoptera that possess both free-living and parasitic amphimictic generations in their life-cycles. This family is considered to have the most primitive type of development in the superfamily.
    Matched MeSH terms: Life Cycle Stages
  17. Muchtaridi M, Fauzi M, Khairul Ikram NK, Mohd Gazzali A, Wahab HA
    Molecules, 2020 Sep 01;25(17).
    PMID: 32882868 DOI: 10.3390/molecules25173980
    Over the years, coronaviruses (CoV) have posed a severe public health threat, causing an increase in mortality and morbidity rates throughout the world. The recent outbreak of a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the current Coronavirus Disease 2019 (COVID-19) pandemic that affected more than 215 countries with over 23 million cases and 800,000 deaths as of today. The situation is critical, especially with the absence of specific medicines or vaccines; hence, efforts toward the development of anti-COVID-19 medicines are being intensively undertaken. One of the potential therapeutic targets of anti-COVID-19 drugs is the angiotensin-converting enzyme 2 (ACE2). ACE2 was identified as a key functional receptor for CoV associated with COVID-19. ACE2, which is located on the surface of the host cells, binds effectively to the spike protein of CoV, thus enabling the virus to infect the epithelial cells of the host. Previous studies showed that certain flavonoids exhibit angiotensin-converting enzyme inhibition activity, which plays a crucial role in the regulation of arterial blood pressure. Thus, it is being postulated that these flavonoids might also interact with ACE2. This postulation might be of interest because these compounds also show antiviral activity in vitro. This article summarizes the natural flavonoids with potential efficacy against COVID-19 through ACE2 receptor inhibition.
    Matched MeSH terms: Life Cycle Stages
  18. Mohd. Bakri, M., Whittaker, D.A.
    Ann Dent, 2003;10(1):-.
    MyJurnal
    The ultrastructure of the odontoblast reflects the certain phases that the cell undergoes in their lifecycle. Ultrastructure studies of the odontoblasts have often been carried out using young teeth. In this study, teeth from an older individual have been used to study the odontoblasts from the crown and root area. The odontoblasts from the crown area retain their columnar shape while odontoblasts from the root area appeared to be flattened. The organelles present in the odontoblasts either from the crown or root area was observed to be reduced.
    Matched MeSH terms: Life Cycle Stages
  19. Mohd Dzaki, Mohd Amir, Sanuri, Ishak
    MyJurnal
    Magnetic actuator driven switchgear is a new medium voltage switchgear technology. In this switchgear, the conventional spring mechanism which is used to operate the circuit breaker is replaced with a magnetic actuator mechanism. The suitability of this technology in the Malaysian utility network specifically in highly loaded areas with frequent switching was assessed via a field evaluation. Preliminary results indicated that magnetic actuator driven switchgear perform commendably on the safety aspect, on-site performance monitoring and online diagnostic test results. However, there are several concerns that need to be addressed such as the ease of installation, substation system requirements, high life cycle cost and reliability of components, before this technology can be used widely.
    Matched MeSH terms: Life Cycle Stages
  20. Mohd Abd Razak MR, Afzan A, Ali R, Amir Jalaluddin NF, Wasiman MI, Shiekh Zahari SH, et al.
    PMID: 25510573 DOI: 10.1186/1472-6882-14-492
    The development of resistant to current antimalarial drugs is a major challenge in achieving malaria elimination status in many countries. Therefore there is a need for new antimalarial drugs. Medicinal plants have always been the major source for the search of new antimalarial drugs. The aim of this study was to screen selected Malaysian medicinal plants for their antiplasmodial properties.
    Matched MeSH terms: Life Cycle Stages
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