Displaying publications 141 - 160 of 162 in total

Abstract:
Sort:
  1. Morphological and transcript changes in the biosynthesis of lignin in oil palm (Elaeis guineensis) during Ganoderma boninense infections in vitro
    Goh KM, Dickinson M, Supramaniam CV
    Physiol Plant, 2018 Mar;162(3):274-289.
    PMID: 28940509 DOI: 10.1111/ppl.12645
    Lignification of the plant cell wall could serve as the first line of defense against pathogen attack, but the molecular mechanisms of virulence and disease between oil palm and Ganoderma boninense are poorly understood. This study presents the biochemical, histochemical, enzymology and gene expression evidences of enhanced lignin biosynthesis in young oil palm as a response to G. boninense (GBLS strain). Comparative studies with control (T1), wounded (T2) and infected (T3) oil palm plantlets showed significant accumulation of total lignin content and monolignol derivatives (syringaldehyde and vanillin). These derivatives were deposited on the epidermal cell wall of infected plants. Moreover, substantial differences were detected in the activities of enzyme and relative expressions of genes encoding phenylalanine ammonia lyase (EC 4.3.1.24), cinnamate 4-hydroxylase (EC 1.14.13.11), caffeic acid O-methyltransferase (EC 2.1.1.68) and cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195). These enzymes are key intermediates dedicated to the biosynthesis of lignin monomers, the guaicyl (G), syringyl (S) and ρ-hydroxyphenyl (H) subunits. Results confirmed an early, biphasic and transient positive induction of all gene intermediates, except for CAD enzyme activities. These differences were visualized by anatomical and metabolic changes in the profile of lignin in the oil palm plantlets such as low G lignin, indicating a potential mechanism for enhanced susceptibility toward G. boninense infection.
    Matched MeSH terms: Phenylalanine Ammonia-Lyase/genetics; Phenylalanine Ammonia-Lyase/metabolism
  2. Molecular diversity of the ammonia-oxidizing bacteria community in disused tin-mining ponds located within Kampar, Perak, Malaysia
    Sow SL, Khoo G, Chong LK, Smith TJ, Harrison PL, Ong HK
    World J Microbiol Biotechnol, 2014 Feb;30(2):757-66.
    PMID: 24078113
    Disused tin-mining ponds make up a significant amount of water bodies in Malaysia particularly at the Kinta Valley in the state of Perak where tin-mining activities were the most extensive, and these abundantly available water sources are widely used in the field of aquaculture and agriculture. However, the natural ecology and physicochemical conditions of these ponds, many of which have been altered due to secondary post-mining activities, remains to be explored. As ammonia-oxidizing bacteria (AOB) are directly related to the nutrient cycles of aquatic environments and are useful bioindicators of environmental variations, the focus of this study was to identify AOBs associated with disused tin-mining ponds that have a history of different secondary activities in comparison to ponds which were left untouched and remained as part of the landscape. The 16S rDNA gene was used to detect AOBs in the sediment and water sampled from the three types of disused mining ponds, namely ponds without secondary activity, ponds that were used for lotus cultivation and post-aquaculture ponds. When the varying pond types were compared with the sequence and phylogenetic analysis of the AOB clone libraries, both Nitrosomonas and Nitrosospira-like AOB were detected though Nitrosospira spp. was seen to be the most ubiquitous AOB as it was present in all ponds types. However, AOBs were not detected in the sediments of idle ponds. Based on rarefaction analysis and diversity indices, the disused mining pond with lotus culture indicated the highest richness of AOBs. Canonical correspondence analysis indicated that among the physicochemical properties of the pond sites, TAN and nitrite were shown to be the main factors that influenced the community structure of AOBs in these disused tin-mining ponds.
    Matched MeSH terms: Ammonia/metabolism*
  3. Enhancement of Hsp70 synthesis protects common carp, Cyprinus carpio L., against lethal ammonia toxicity
    Sung YY, Roberts RJ, Bossier P
    J Fish Dis, 2012 Aug;35(8):563-8.
    PMID: 22724455 DOI: 10.1111/j.1365-2761.2012.01397.x
    Exposure to TEX-OE®, a patented extract of the prickly pear cactus (Opuntia ficus indica) containing chaperone-stimulating factor, was shown to protect common carp, Cyprinus carpio L., fingerlings against acute ammonia stress. Survival was enhanced twofold from 50% to 95% after exposure to 5.92 mg L(-1) NH(3) , a level determined in the ammonia challenge bioassay as the 1-h LD50 concentration for this species. Survival of TEX-OE®-pre-exposed fish was enhanced by 20% over non-exposed controls during lethal ammonia challenge (14.21 mg L(-1)  NH(3) ). Increase in the levels of gill and muscle Hsp70 was evident in TEX-OE®-pre-exposed fish but not in the unexposed controls, indicating that application of TEX-OE® accelerated carp endogenous Hsp70 synthesis during ammonia perturbation. Protection against ammonia was correlated with Hsp70 accretion.
    Matched MeSH terms: Ammonia/poisoning*
  4. Nitric oxide (NO), citrulline-NO cycle enzymes, glutamine synthetase, and oxidative status in kainic acid-mediated excitotoxicity in rat brain
    Swamy M, Sirajudeen KN, Chandran G
    Drug Chem Toxicol, 2009;32(4):326-31.
    PMID: 19793024 DOI: 10.1080/01480540903130641
    Neuronal excitation, involving the excitatory glutamate receptors, is recognized as an important underlying mechanism in neurodegenerative disorders. To understand their role in excitotoxicity, the nitric oxide synthase (NOS), argininosuccinate synthetase (AS), argininosuccinate lyase (AL), glutamine synthetase (GS), and arginase activities, along with the concentration of nitrate/nitrite, thiobarbituric acid-reactive substances (TBARS), and total antioxidant status (TAS), were estimated in the cerebral cortex, cerebellum, and brain stem of rats subjected to kainic acid-mediated excitotoxicity. The results of this study clearly demonstrated the increased production of NO by increased activity of NOS. The increased activities of AS and AL suggest the increased and effective recycling of citrulline to arginine in excitotoxicity, making NO production more effective and contributing to its toxic effects. The decreased activity of GS may favor the prolonged availability of glutamic acid, causing excitotoxicity, leading to neuronal damage. The increased formation of TBARS and decreased TAS indicate the presence of oxidative stress in excitotoxicity.
    Matched MeSH terms: Glutamate-Ammonia Ligase/metabolism*
  5. Spatial assessment of Langat River water quality using chemometrics
    Juahir H, Zain SM, Aris AZ, Yusoff MK, Mokhtar MB
    J Environ Monit, 2010 Jan;12(1):287-95.
    PMID: 20082024 DOI: 10.1039/b907306j
    The present study deals with the assessment of Langat River water quality with some chemometrics approaches such as cluster and discriminant analysis coupled with an artificial neural network (ANN). The data used in this study were collected from seven monitoring stations under the river water quality monitoring program by the Department of Environment (DOE) from 1995 to 2002. Twenty three physico-chemical parameters were involved in this analysis. Cluster analysis successfully clustered the Langat River into three major clusters, namely high, moderate and less pollution regions. Discriminant analysis identified seven of the most significant parameters which contribute to the high variation of Langat River water quality, namely dissolved oxygen, biological oxygen demand, pH, ammoniacal nitrogen, chlorine, E. coli, and coliform. Discriminant analysis also plays an important role as an input selection parameter for an ANN of spatial prediction (pollution regions). The ANN showed better prediction performance in discriminating the regional area with an excellent percentage of correct classification compared to discriminant analysis. Multivariate analysis, coupled with ANN, is proposed, which could help in decision making and problem solving in the local environment.
    Matched MeSH terms: Ammonia/analysis
  6. Fulltext Primary, secondary metabolites, photosynthetic capacity and antioxidant activity of the Malaysian Herb Kacip Fatimah (Labisia Pumila Benth) exposed to potassium fertilization under greenhouse conditions
    Ibrahim MH, Jaafar HZ, Karimi E, Ghasemzadeh A
    Int J Mol Sci, 2012;13(11):15321-42.
    PMID: 23203128 DOI: 10.3390/ijms131115321
    A randomized complete block design was used to characterize the relationship between production of total phenolics, flavonoids, ascorbic acid, carbohydrate content, leaf gas exchange, phenylalanine ammonia-lyase (PAL), soluble protein, invertase and antioxidant enzyme activities (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) in Labisia pumila Benth var. alata under four levels of potassium fertilization experiments (0, 90, 180 and 270 kg K/ha) conducted for 12 weeks. It was found that the production of total phenolics, flavonoids, ascorbic acid and carbohydrate content was affected by the interaction between potassium fertilization and plant parts. As the potassium fertilization levels increased from 0 to 270 kg K/ha, the production of soluble protein and PAL activity increased steadily. At the highest potassium fertilization (270 kg K/ha) L. pumila exhibited significantly higher net photosynthesis (A), stomatal conductance (g(s)), intercellular CO(2) (C(i)), apparent quantum yield (ξ) and lower dark respiration rates (R(d)), compared to the other treatments. It was found that the production of total phenolics, flavonoids and ascorbic acid are also higher under 270 kg K/ha compared to 180, 90 and 0 kg K/ha. Furthermore, from the present study, the invertase activity was also found to be higher in 270 kg K/ha treatment. The antioxidant enzyme activities (APX, CAT and SOD) were lower under high potassium fertilization (270 kg K/ha) and have a significant negative correlation with total phenolics and flavonoid production. From this study, it was observed that the up-regulation of leaf gas exchange and downregulation of APX, CAT and SOD activities under high supplementation of potassium fertilizer enhanced the carbohydrate content that simultaneously increased the production of L. pumila secondary metabolites, thus increasing the health promoting effects of this plant.
    Matched MeSH terms: Phenylalanine Ammonia-Lyase/metabolism
  7. Plant growth-promoting bacteria as potential bio-inoculants and biocontrol agents to promote black pepper plant cultivation
    Lau ET, Tani A, Khew CY, Chua YQ, Hwang SS
    Microbiol Res, 2020 Nov;240:126549.
    PMID: 32688172 DOI: 10.1016/j.micres.2020.126549
    Black pepper production in Malaysia was restricted by various diseases. Hazardous chemical products appear to be the best solution to control diseases in black pepper cultivation. However, persistence of chemical residues in peppercorns could affect the quality of exports and consumptions. Application of fertilizers is crucial to sustain pepper growth and high yield. But, continuous use of chemical fertilizers could affect the soil ecosystem and eventually restrict nutrient uptake by pepper roots. Therefore, we propose biological approaches as an alternative solution instead of chemical products to sustain pepper cultivation in Malaysia. In this study, we have isolated a total of seven indigenous rhizobacteria antagonistic to soil-borne Fusarium solani, the causal fungus of slow decline, the most serious debilitating disease of black pepper in Malaysia. The isolated bacteria were identified as Bacillus subtilis, Bacillus siamensis, Brevibacillus gelatini, Pseudomonas geniculata, Pseudomonas beteli, Burkholderia ubonensis and Burkholderia territorii. These bacteria were effective in production of antifungal siderophore with the amount of 53.4 %-73.5 % per 0.5 mL of cell-free supernatants. The bacteria also produced appreciable amount of chitinase with chitinolytic index was ranged from 1.19 to 1.76. The bacteria have shown phosphate solubilizing index within 1.61 to 2.01. They were also efficient in ACC deaminase (0.52 mM-0.62 mM) and ammonia (60.3 mM-75.3 mM) production. The isolated antagonists were efficacious in stimulation of black pepper plant growth and root development through IAA (10.5 μg/mL-42.6 μg/mL) secretion. In conclusion, the isolated rhizobacteria are potent to be developed not only as biocontrol agents to minimize the utilization of hazardous chemicals in black pepper disease management, but also developed as bio-fertilizers to improve black pepper plant growth due to their capabilities in plant growth-promotion.
    Matched MeSH terms: Ammonia/metabolism
  8. The combined effect of hypoxia and nutritional status on metabolic and ionoregulatory responses of common carp (Cyprinus carpio)
    Moyson S, Liew HJ, Diricx M, Sinha AK, Blust R, De Boeck G
    Comp Biochem Physiol A Mol Integr Physiol, 2015 Jan;179:133-43.
    PMID: 25263807 DOI: 10.1016/j.cbpa.2014.09.017
    In the present study, the combined effects of hypoxia and nutritional status were examined in common carp (Cyprinus carpio), a relatively hypoxia tolerant cyprinid. Fish were either fed or fasted and were exposed to hypoxia (1.5-1.8mg O2L(-1)) at or slightly above their critical oxygen concentration during 1, 3 or 7days followed by a 7day recovery period. Ventilation initially increased during hypoxia, but fasted fish had lower ventilation frequencies than fed fish. In fed fish, ventilation returned to control levels during hypoxia, while in fasted fish recovery only occurred after reoxygenation. Due to this, C. carpio managed, at least in part, to maintain aerobic metabolism during hypoxia: muscle and plasma lactate levels remained relatively stable although they tended to be higher in fed fish (despite higher ventilation rates). However, during recovery, compensatory responses differed greatly between both feeding regimes: plasma lactate in fed fish increased with a simultaneous breakdown of liver glycogen indicating increased energy use, while fasted fish seemed to economize energy and recycle decreasing plasma lactate levels into increasing liver glycogen levels. Protein was used under both feeding regimes during hypoxia and subsequent recovery: protein levels reduced mainly in liver for fed fish and in muscle for fasted fish. Overall, nutritional status had a greater impact on energy reserves than the lack of oxygen with a lower hepatosomatic index and lower glycogen stores in fasted fish. Fasted fish transiently increased Na(+)/K(+)-ATPase activity under hypoxia, but in general ionoregulatory balance proved to be only slightly disturbed, showing that sufficient energy was left for ion regulation.
    Matched MeSH terms: Ammonia/blood
  9. Fulltext Enhanced Contextual Fear Memory and Elevated Astroglial Glutamate Synthase Activity in Hippocampal CA1 BChE shRNA Knockdown Mice
    Chen S, Lin Z, Tan KL, Chen R, Su W, Zhao H, et al.
    Front Psychiatry, 2020;11:564843.
    PMID: 33061920 DOI: 10.3389/fpsyt.2020.564843
    Butyrylcholinesterase (BChE) efficiently hydrolyzes acetylcholine (ACh) at high concentrations when acetylcholinesterase (AChE) is substrate-inhibited. Recent studies have shown that BChE also has a function that is independent of ACh, but it has not been fully explored. Low BChE expression is accompanied with higher stress-induced aggression and ghrelin levels in stress models, and BChE knockout mice exhibit cognitive and memory impairments. However, the role of BChE in posttraumatic stress disorder (PTSD) remains unclear. In the present study, we investigated the role of BChE in contextual fear memory and its regulatory effect on the expression of factors related to the glutamate (Glu)-glutamine (Gln) cycle via knockdown studies. We used AAVs and lentiviruses to knockdown BChE expression in the mouse hippocampal CA1 region and C8D1A astrocytes. Our behavioral data from those mice injected with AAV-shBChE in the hippocampal CA1 region showed strengthened fear memory and increased dendritic spine density. Elevated Glu levels and glutamine synthetase (GS) enzyme activity were detected in contextual fear conditioned-BChE knockdown animals and astrocytes. We observed that an AAV-shBChE induced lowering of BChE expression in the hippocampus CA1 region enhanced contextual fear memory expression and promoted the astrocytic Glu-Gln cycle but did not elevate ACh-hydrolyzing activity. This study provides new insight into the regulatory role of BChE in cognition and suggests potential target for stress-related psychiatric disorder such as PTSD where patients experience fear after exposure to severe life-threatening traumatic events.
    Matched MeSH terms: Glutamate-Ammonia Ligase
  10. Fulltext Aquaponics recirculation system: a sustainable food source for the future water conserves and resources
    Azizah Endut, Fathurrahman Lananan, Ahmad Jusoh, Wan Norsani Wan Nik, Nora'aini Ali
    Malaysian Journal of Applied Sciences, 2018;1(1):1-12.
    MyJurnal
    The current and escalating extent of soil degradation, water scarcity and environmental concern
    plaguing agricultural productivity, demands re-assessing the direction of food production. Aquaponics
    is a concept relatively new to modern food production methods and can contribute to food security.
    This study was conducted to establish sustainable aquaculture systems that maximize benefits and
    minimize the accumulation of detrimental compounds and other types of negative impacts on both
    natural and social environments. This study carried out at an average inflow rate of 1.28 m/day to
    evaluate the operation of the aquaponics recirculation system (ARS) on nutrients removal and growth
    and yield of African catfish as well as water spinach. A special design of ARS was used to provide
    nitrification of fishery wastewater, where the combination of sands and gravels in hydroponics trough,
    providing both surfaces for biofuel development and cultivation area for plants. Removal efficiencies
    of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total ammonia nitrogen
    (TAN), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and orthophosphate (PO4
    3-
    ) were 82%, 89%,
    93%, 94%, 81%, and 80%, respectively. The feed conversion ratio (FCR) and specific growth rate
    (SGR) of African catfish were 1.08 and 3.34% day-1
    , respectively. The average water spinach
    production was 3.56 kg per m2
    . This study showed that ARS is a method of producing crop along with
    a healthy protein source and among the best alternatives for achieving economic and environmental
    sustainability.
    Matched MeSH terms: Ammonia
  11. Production of biodiesel from palm fatty acid distillate by microwave-assisted sulfonated glucose acid catalyst
    Nur Nazlina Saimon, Heng Khuan Eu, Anwar Johari, Norzita Ngadi, Mazura Jusoh, Zaki Yamani Zakaria
    Sains Malaysiana, 2018;47:109-115.
    Biodiesel, one of the renewable energy sources has gained attention for decades as the alternative fuel due to its remarkable properties. However, there are several drawbacks from the industrial production of biodiesel such as the spike in the production cost, environmental issues related to the usage of homogeneous catalyst and profitability in long term. One of the solutions to eliminate the problem is by utilizing low cost starting material such as palm fatty acid distillate (PFAD). PFAD is a byproduct from the refining of crude palm oil and abundantly available. Esterification of PFAD to biodiesel will be much easier with the presence of heterogeneous acid catalyst. Most of acid catalyst preparation involves series of heating process using conventional method. In this study, microwave was utilized in catalyst preparation, significantly reducing the reaction time from conventional heating method. The catalyst produced was characterized using X-Ray Diffraction (XRD), Brunauer Emmet and Teller (BET), Scanning Electron Microscopy (SEM), Temperature-Programmed Desorption - Ammonia (TPD-NH3) and Fourier Transform Infrared (FTIR) while percentage yield and conversion of the PFAD were analysed by gas chromatography - flame ionization detector (GC-FID) and acid-base titration, respectively. It has been demonstrated that the percentage yield of biodiesel from the PFAD by employing sulfonated glucose acid catalyst (SGAC) reached 98.23% under the following conditions: molar ratio of methanol to PFAD of 10:1, catalyst loading of 2.5% and reaction temperature of 70oC. The microwave-assisted SGAC showed its potential to replace the SGAC produced via conventional heating method.
    Matched MeSH terms: Ammonia
  12. An efficient oxic-anoxic process for treating low COD/N tropical wastewater: Startup, optimization and nitrifying community structure
    How SW, Nittami T, Ngoh GC, Curtis TP, Chua ASM
    Chemosphere, 2020 Nov;259:127444.
    PMID: 32640378 DOI: 10.1016/j.chemosphere.2020.127444
    In this study, we assessed and optimized a low-dissolved-oxygen oxic-anoxic (low-DO OA) process to achieve a low-cost and sustainable solution for wastewater treatment systems in the developing tropical countries treating low chemical oxygen demand-to-nitrogen ratio (COD/N) wastewater. The low-DO OA process attained complete ammonia removal and the effluent nitrate nitrogen (NO3-N) was below 0.3 mg/L. The recommended hydraulic retention time and sludge retention time (SRT) were 16 h and 20 days, respectively. The 16S rRNA sequencing data revealed that long SRT (20 days) encouraged the growth of nitrite-oxidizing bacteria (NOB) affiliated with "Candidatus Nitrospira defluvii". Comammox made up 10-20% of the Nitrospira community. NOB and comammox related to Nitrospira were enriched at long SRT (20 days) to achieve good low-DO nitrification performance. The low-DO OA process was efficient and has simpler design than conventional processes, which are keys for sustainable wastewater treatment systems in the developing countries treating low COD/N wastewater.
    Matched MeSH terms: Ammonia
  13. Plant growth promoting and antifungal asset of indigenous rhizobacteria secluded from saffron (Crocus sativus L.) rhizosphere
    Rasool A, Imran Mir M, Zulfajri M, Hanafiah MM, Azeem Unnisa S, Mahboob M
    Microb Pathog, 2021 Jan;150:104734.
    PMID: 33429050 DOI: 10.1016/j.micpath.2021.104734
    Saffron (Crocus sativus L.) is an important plant in medicine. The Kashmir Valley (J&K, India) is one of the world's largest and finest saffron producing regions. However, over the past decade, there has been a strong declining trend in saffron production in this area. Plant Growth Promoting Rhizobacteria (PGPR) are free living soil bacteria that have ability to colonize the surfaces of the roots and ability to boost plant growth and development either directly or indirectly. Using the efficient PGPR as a bio-inoculant is another sustainable agricultural practice to improve soil health, grain yield quality, and biodiversity conservation. In the present study, a total of 13 bacterial strains were isolated from rhizospheric soil of saffron during the flowering stage of the tubers and were evaluated for various plant growth promoting characteristics under in vitro conditions such as the solubilization of phosphate, production of indole acetic acid, siderophore, hydrocyanic acid, and ammonia production and antagonism by dual culture test against Sclerotium rolfsii and Fusarium oxysporum. All the isolates were further tested for the production of hydrolytic enzymes such as protease, lipase, amylase, cellulase, and chitinase. The maximum proportions of bacterial isolates were gram-negative bacilli. About 77% of the bacterial isolates showed IAA production, 46% exhibited phosphate solubilization, 46% siderophore, 61% HCN, 100% ammonia production, 69% isolates showed protease activity, 62% lipase, 46% amylase, 85% cellulase, and 39% showed chitinase activity. Three isolates viz., AIS-3, AIS-8 and AIS-10 were found to have the most plant growth properties and effectively control the growth of Sclerotium rolfsii and Fusarium oxysporum. The bacterial isolates were identified as Brevibacterium frigoritolerans (AIS-3), Alcaligenes faecalis subsp. Phenolicus (AIS-8) and Bacillus aryabhattai (AIS-10) respectively by 16S rRNA sequence analysis. Therefore, these isolated rhizobacterial strains could be a promising source of plant growth stimulants to increase cormlets growth and increase saffron production.
    Matched MeSH terms: Ammonia
  14. Fulltext Poultry Slaughterhouse Wastewater Treatment Using Submerged Fibers in an Attached Growth Sequential Batch Reactor
    Aziz HA, Puat NNA, Alazaiza MYD, Hung YT
    Int J Environ Res Public Health, 2018 08 13;15(8).
    PMID: 30104522 DOI: 10.3390/ijerph15081734
    In this study, a sequential batch reactor (SBR) with different types of fibers was employed for the treatment of poultry slaughterhouse wastewater. Three types of fibers, namely, juite fiber (JF), bio-fringe fiber (BF), and siliconised conjugated polyester fiber (SCPF), were used. Four SBR experiments were conducted, using the fibers in different reactors, while the fourth reactor used a combination of these fibers. The treatment efficiency of the different reactors with and without fibers on biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia-nitrogen (NH₃-N), phosphorus (P), nitrite (NO₂), nitrate (NO₃), total suspended solids (TSS), and oil-grease were evaluated. The removal efficiency for the reactors with fibers was higher than that of the reactor without fibers for all pollutants. The treated effluent had 40 mg/L BOD₅ and 45 mg/L COD with an average removal efficiency of 96% and 93%, respectively, which meet the discharge limits stated in the Environmental Quality Act in Malaysia.
    Matched MeSH terms: Ammonia
  15. Risk factors associated with viral nervous necrosis in hybrid groupers in Malaysia and the high similarity of its causative agent nervous necrosis virus to reassortant red-spotted grouper nervous necrosis virus/striped jack nervous necrosis virus strains
    Ariff N, Abdullah A, Azmai MNA, Musa N, Zainathan SC
    Vet World, 2019 Aug;12(8):1273-1284.
    PMID: 31641308 DOI: 10.14202/vetworld.2019.1273-1284
    Background and Aim: Viral nervous necrosis (VNN) is a serious disease of several marine fish species. VNN causes 100% mortality in the larval stages, while lower losses have been reported in juvenile and adult fish. This study aimed to detect the occurrence of VNN while identifying its associated risk factors and the genotypes of its causative agent in a hybrid grouper hatchery in Malaysia.

    Materials and Methods: A batch of newly hatched hybrid grouper fry (Epinephelus fuscoguttatus × Epinephelus lanceolatus) were followed from the larval stage to market size. Samples of the hybrid groupers, water, live feed, and artificial fish pellets were collected periodically from day 0 to 180 in the hybrid grouper hatchery. Reverse transcription-polymerase chain reaction (RT-PCR) and nested PCR amplifications were carried out on VNN-related sequences. The phylogenetic tree including the sampled causative agent of VNN was inferred from the coat protein genes from all known Betanodavirus species using Molecular Evolutionary Genetics Analysis (MEGA). Pearson's correlation coefficient values were calculated to determine the strength of the correlation between the presence of VNN in hybrid grouper samples and its associated risk factors.

    Results: A total of 113 out of 146 pooled and individual samples, including hybrid grouper, water, and artificial fish pellet samples, demonstrated positive results in tests for the presence of VNN-associated viruses. The clinical signs of infection observed in the samples included darkened skin, deformation of the backbone, abdominal distension, skin lesions, and fin erosion. VNN was present throughout the life stages of the hybrid groupers, with the first detection occurring at day 10. VNN-associated risk factors included water temperature, dissolved oxygen content, salinity, ammonia level, fish size (adults more at risk than younger stages), and life stage (age). Detection of VNN-associated viruses in water samples demonstrated evidence of horizontal transmission of the disease. All the nucleotide sequences found in this study had high nucleotide identities of 88% to 100% to each other, striped jack nervous necrosis virus (SJNNV), and the reassortant strain red-spotted grouper NNV/SJNNV (RGNNV/SJNNV) isolate 430.2004 (GenBank accession number JN189932.1) (n=26). The phylogenetic analysis showed that quasispecies was present in each VNN-causing virus-positive sample, which differed based on the type of sample and life stage.

    Conclusion: This study was the first to confirm the existence of a reassortant strain (RGNNV/SJNNV) in hybrid groupers from Malaysia and Southeast Asia. However, the association between the mode of transmission and the risk factors of this virus needs to be investigated further to understand the evolution and potential new host species of the reassortant strain.

    Matched MeSH terms: Ammonia
  16. Impacts of pig farming on the water quality of Serin River, Sarawak
    Ling T, Layang H, Then Y, Apun K
    Sains Malaysiana, 2006;35:45-50.
    In Sarawak, pig farm operators are required to treat the wastewater containing pig waste and spilt food in oxidation ponds before discharge. However, information on the impact of this industry on surface water quality is lacking. Therefore, the objective of this study is to determine the impact of pig farm effluent on the water quality of Serin River and its tributaries. Results of analysis show that the tributary that received pond effluent has significantly higher mean of total suspended solids (TSS), biochemical oxygen demand (BOD5) chemical oxygen demand (COD), ammonia-nitrogen (NH3 -N), reactive phosphorus (SRP) and Escherichia coli (E. coli) concentrations when compared to those of the tributary that did not receive pond effluent. Comparisons between the stations upstream and downstream of the discharge point indicated that BOD5 and COD were significantly higher at the downstream station that received pond effluent. Dissolved oxygen (DO) was the lowest at the tributary receiving effluent from pig farms with a mean of 2.40 mg/l. According to the Interim Water Quality Standard of the Department of Environment, water quality at the tributary that received pig farm effluent falls into Class III whereas that of the other stations falls into Class II. It is recommended that further studies be conducted on the management of waste to explore the possibility of turning the waste into a resource so that water quality of rivers can remain pristine for drinking and recreation.
    Matched MeSH terms: Ammonia
  17. Fulltext Global serum metabolomics profiling of colorectal cancer
    Hashim NAA, Ab-Rahim S, Suddin LS, Saman MSA, Mazlan M
    Mol Clin Oncol, 2019 Jul;11(1):3-14.
    PMID: 31289671 DOI: 10.3892/mco.2019.1853
    Accurate diagnosis of colorectal cancer (CRC) relies on the use of invasive tools such as colonoscopy and sigmoidoscopy. Non-invasive tools are less sensitive in detecting the disease, particularly in the early stage. A number of researchers have used metabolomics analyses on serum/plasma samples of patients with CRC compared with normal healthy individuals in an effort to identify biomarkers for CRC. The aim of the present review is to compare reported serum metabolomics profiles of CRC and to identify common metabolites affected among these studies. A literature search was performed to include any experimental studies on global metabolomics profile of CRC using serum/plasma samples published up to March 2018. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used to assess the quality of the studies reviewed. In total, nine studies were included. The studies used various analytical platforms and were performed on different populations. A pathway enrichment analysis was performed using the data from all the studies under review. The most affected pathways identified were protein biosynthesis, urea cycle, ammonia recycling, alanine metabolism, glutathione metabolism and citric acid cycle. The metabolomics analysis revealed levels of metabolites of glycolysis, tricarboxylic acid cycle, anaerobic respiration, protein, lipid and glutathione metabolism were significantly different between cancer and control samples. Although the majority of differentiating metabolites identified were different in the different studies, there were several metabolites that were common. These metabolites include pyruvic acid, glucose, lactic acid, malic acid, fumaric acid, 3-hydroxybutyric acid, tryptophan, phenylalanine, tyrosine, creatinine and ornithine. The consistent dysregulation of these metabolites among the different studies suggest the possibility of common diagnostic biomarkers for CRC.
    Matched MeSH terms: Ammonia
  18. Decreased glutamine synthetase, increased citrulline-nitric oxide cycle activities, and oxidative stress in different regions of brain in epilepsy rat model
    Swamy M, Yusof WR, Sirajudeen KN, Mustapha Z, Govindasamy C
    J Physiol Biochem, 2011 Mar;67(1):105-13.
    PMID: 20960085 DOI: 10.1007/s13105-010-0054-2
    To understand their role in epilepsy, the nitric oxide synthetase (NOS), argininosuccinate synthetase (AS), argininosuccinate lyase (AL), glutamine synthetase (GS), and arginase activities, along with the concentration of nitrate/nitrite (NOx), thiobarbituric acid reactive substances (TBARS), and total antioxidant status (TAS), were estimated in different regions of brain in rats subjected to experimental epilepsy induced by subcutaneous administration of kainic acid (KA). The short-term (acute) group animals were killed after 2 h and the long term (chronic) group animals were killed after 5 days of single injection of KA (15 mg/kg body weight). After decapitation of rats, the brain regions were separated and in their homogenates, the concentration of NOx, TBARS and TAS and the activities of NOS, AS, AL, arginase and glutamine synthetase were assayed by colorimetric methods. The results of the study demonstrated the increased activity of NOS and formation of NO in acute and chronic groups epilepsy. The activities of AS and AL were increased and indicate the effective recycling of citrulline to arginine. The activity of glutamine synthetase was decreased in acute and chronic groups of epilepsy compared to control group and indicate the modulation of its activity by NO in epilepsy. The activity of arginase was not changed in acute group; however it was decreased in chronic group and may favor increased production of NO in this condition. The concentration TBARS were increased and TAS decreased in acute and chronic groups of epilepsy and supports the oxidative stress in epilepsy.
    Matched MeSH terms: Glutamate-Ammonia Ligase/metabolism*
  19. Effects of acute ammonia toxicity on nitric oxide (NO), citrulline-NO cycle enzymes, arginase and related metabolites in different regions of rat brain
    Swamy M, Zakaria AZ, Govindasamy C, Sirajudeen KN, Nadiger HA
    Neurosci Res, 2005 Oct;53(2):116-22.
    PMID: 16009439
    Nitric oxide (NO) is involved in many pathophysiological processes in the brain. NO is synthesized from arginine by nitric oxide synthase (NOS) enzymes. Citrulline formed as a by-product of the NOS reaction, can be recycled to arginine by successive actions of argininosuccinate synthetase (ASS) and argininosuccinate lyase (ASL) via the citrulline-NO cycle. Hyperammonemia is known to cause poorly understood perturbations of the citrulline-NO cycle. To understand the role of citrulline-NO cycle in hyperammonemia, NOS, ASS, ASL and arginase activities, as well as nitrate/nitrite (NOx), arginine, ornithine, citrulline, glutamine, glutamate and GABA were estimated in cerebral cortex (CC), cerebellum (CB) and brain stem (BS) of rats subjected to acute ammonia toxicity. NOx concentration and NOS activity were found to increase in all the regions of brain in acute ammonia toxicity. The activities of ASS and ASL showed an increasing trend whereas the arginase was not changed. The results of this study clearly demonstrated the increased formation of NO, suggesting the involvement of NO in the pathophysiology of acute ammonia toxicity. The increased activities of ASS and ASL suggest the increased and effective recycling of citrulline to arginine in acute ammonia toxicity, making NO production more effective and contributing to its toxic effects.
    Matched MeSH terms: Ammonia/toxicity*
  20. Anticancer potential of rosmarinic acid and its improved production through biotechnological interventions and functional genomics
    Swamy MK, Sinniah UR, Ghasemzadeh A
    Appl Microbiol Biotechnol, 2018 Sep;102(18):7775-7793.
    PMID: 30022261 DOI: 10.1007/s00253-018-9223-y
    Rosmarinic acid (RA) is a highly valued natural phenolic compound that is very commonly found in plants of the families Lamiaceae and Boraginaceae, including Coleus blumei, Heliotropium foertherianum, Rosmarinus officinalis, Perilla frutescens, and Salvia officinalis. RA is also found in other members of higher plant families and in some fern and horned liverwort species. The biosynthesis of RA is catalyzed by the enzymes phenylalanine ammonia lyase and cytochrome P450-dependent hydroxylase using the amino acids tyrosine and phenylalanine. Chemically, RA can be produced via methods involving the esterification of 3,4-dihydroxyphenyllactic acid and caffeic acid. Some of the derivatives of RA include melitric acid, salvianolic acid, lithospermic acid, and yunnaneic acid. In plants, RA is known to have growth-promoting and defensive roles. Studies have elucidated the varied pharmacological potential of RA and its derived molecules, including anticancer, antiangiogenic, anti-inflammatory, antioxidant, and antimicrobial activities. The demand for RA is therefore, very high in the pharmaceutical industry, but this demand cannot be met by plants alone because RA content in plant organs is very low. Further, many plants that synthesize RA are under threat and near extinction owing to biodiversity loss caused by unscientific harvesting, over-collection, environmental changes, and other inherent features. Moreover, the chemical synthesis of RA is complicated and expensive. Alternative approaches using biotechnological methodologies could overcome these problems. This review provides the state of the art information on the chemistry, sources, and biosynthetic pathways of RA, as well as its anticancer properties against different cancer types. Biotechnological methods are also discussed for producing RA using plant cell, tissue, and organ cultures and hairy-root cultures using flasks and bioreactors. The recent developments and applications of the functional genomics approach and heterologous production of RA in microbes are also highlighted. This chapter will be of benefit to readers aiming to design studies on RA and its applicability as an anticancer agent.
    Matched MeSH terms: Phenylalanine Ammonia-Lyase
Related Terms
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links