Displaying publications 1 - 20 of 70 in total

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  1. Zakaria NN, Malahubban M, Fakurazi S, And WSC, Rajaee AH
    Trop Life Sci Res, 2021 Mar;32(1):145-162.
    PMID: 33936556 DOI: 10.21315/tlsr2021.32.1.9
    Mud lobsters are crustaceans from the genus Thalassina which are lesser known and seldom seen but are nevertheless an important organism to the mangrove ecosystem. In Malaysia and Thailand, mud lobsters are eaten by locals as treatment for asthma. It is traditionally believed that they are effective in reducing the number of asthma attacks and severity of asthma symptoms. However, the therapeutic potential of mud lobster extract remains unclear and has not been fully elucidated or reported in any scientific study. The objectives of this study are to investigate the anti-inflammatory potential of mud lobster, Thalassina anomala extracts (hexane, chloroform and methanol) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, and to identify the potential bioactive compounds involved. An MTT assay was performed to determine the cytotoxicity of the T. anomala extracts on RAW 264.7 macrophages. Nitrite quantification assay and enzyme-linked immunosorbent assay (ELISA) were conducted to investigate the ability of the T. anomala extracts to suppress the secretion and expression of nitric oxide (NO), Prostaglandin E2 (PGE2) and proinflammatory cytokines (TNF-α, IL-6 and IL-1β) in LPS-stimulated macrophages. GC-MS analysis was done to identify putative metabolites. The hexane extract of T. anomala showed anti-inflammatory activity by significantly inhibiting the LPS-induced production of NO, PGE2, interleukin- (IL-) 6, IL-1β and tumour necrosis factor-alpha (TNF-α) in a concentration-dependent manner. Hexane extract treatment with 100 μg/mL has decreased the NO secretion into 37 μM. Meanwhile, hexane extract at concentration of 100 μg/mL able to significantly suppressed PGE2,TNF-α, IL-6 and IL-1β production into 2015 pg/mL, 2406 pg/mL, 460 pg/mL and 9.6 pg/mL, respectively. GC-MS analysis of the hexane extract revealed the presence of 19 putative compounds. The identified compounds were reported to have anti-inflammatory, antioxidant and antibacterial activities. These results suggest that the hexane extract of T. anomala potentially has anti-inflammatory properties and concentration dependently suppressed NO, PGE2 and proinflammatory cytokines' production in LPS-stimulated macrophages. The findings provide a rational basis of the traditional use of mud lobster for inflammation-associated ailments.
    Matched MeSH terms: Nitrites
  2. Zainal D, Baba A
    PMID: 9031425
    It is important to diagnose and treat urinary tract infection in children before renal damage has taken place. Hence a new screening procedure will be of interest. This study was conducted to evaluate the efficacy of urinary nitrite in screening for asymptomatic bacteriuria among school children compared to a more traditional method. Of the 44,816 school children investigated 240 (0.54%) students were judged to have bacteriuria ie 82 (0.19%) in boys and 158 (0.35%) in girls. Escherichia coli was the commonest organism isolated (28.75%). Urine dipstick testing for nitrite was found to have a low sensitivity and positive predictive value. While urinalysis for pyuria was noted to have a sensitivity of 77.9%, a specificity of 95.8% and a negative predictive value of 99.9%.
    Matched MeSH terms: Nitrites/urine*
  3. Yeo BH, Tang TK, Wong SF, Tan CP, Wang Y, Cheong LZ, et al.
    Front Pharmacol, 2021;12:631136.
    PMID: 33833681 DOI: 10.3389/fphar.2021.631136
    Edible bird's nest (EBN) is recognized as a nourishing food among Chinese people. The efficacy of EBN was stated in the records of traditional Chinese medicine and its activities have been reported in many researches. Malaysia is the second largest exporter of EBNs in the world, after Indonesia. For many years, EBN trade to China was not regulated until August 2011, when a safety alert was triggered for the consumption of EBNs. China banned the import of EBNs from Malaysia and Indonesia due to high level of nitrite. Since then, the Malaysia government has formulated Malaysia Standards for swiftlet farming (MS 2273:2012), edible bird's nest processing plant design and management (MS 2333:2010), and edible bird's nest product quality (MS 2334:2011) to enable the industry to meet the specified standards for the export to China. On the other hand, Indonesia's EBN industry formulated a standard operating procedure (SOP) for exportation to China. Both countries can export EBNs to China by complying with the standards and SOPs. EBN contaminants may include but not limited to nitrite, heavy metals, excessive minerals, fungi, bacteria, and mites. The possible source of contaminants may come from the swiftlet farms and the swiftlets or introduced during processing, storage, and transportation of EBNs, or adulterants. Swiftlet house design and management, and EBN processing affect the bird's nest color. Degradation of its optical quality has an impact on the selling price, and color changes are tied together with nitrite level. In this review, the current and future prospects of EBNs in Malaysia and Indonesia in terms of their quality, and the research on the contaminants and their effects on EBN color changes are discussed.
    Matched MeSH terms: Nitrites
  4. Wong, S.F., Lim, P.K.C., Mak, J.W., Ooi, S.S., Chen, D.K.F.
    MyJurnal
    Edible bird nests (EBNs) are highly demanded globally. The industry was recently affected by an import ban to China due to high nitrite levels.Subsequently, many concerns have been raised. In this study, the microbial composition of both raw and commercial EBNs was investigated. The raw EBNs were purchased from swiftlet farms: Kuala Sanglang (Perlis), Pantai Remis (Perak), Kluang (Johor), Kajang (Selangor) and Kota Bharu (Kelantan). The commercial nests were purchased from five different Chinese traditional medicinal shops (Companies A-E) in Malaysia and one from Indonesia (Medan). A total of 123 and 34 isolates were successfully identified from unboiled raw and commercial EBNs respectively. The highest average CFU (1.77 x 104) was associated with raw EBNs obtained from Kluang, while for the commercial EBNs, those obtained from Company M1 had the highest CFU (5.50 x 104). Bacillus sp. accounted for the highest isolated species from both unboiled raw and commercial EBNs. Bacillus sp. and Brevibacillus sp. were mainly isolated from the boiled EBNs. Bacillus spp. were the dominant bacterial groups in all the raw EBNs except for those obtained from Kajang. The average number of bacteria isolated from the raw EBNs (average = 7) was higher compared with those isolated from the commercial EBNs (average = 4). The highest average number of bacterial isolates was reported in the raw EBNs obtained from Kota Bharu. Among the commercial EBNs, one EBN sample each from Companies A and M1 showed the highest number of isolates (n = 10). In general, there was a significant reduction in the number of bacteria isolated after boiling the EBNs. Raw EBNs obtained from Kajang had a distinct pool of bacterial species where the majority of the isolated species belonged to Staphylococcus species. The associated health impacts of these microorganisms to the consumers and public need to be addressed.
    Matched MeSH terms: Nitrites
  5. Ving Ching Chong, Sarmila Muthukrishnan, Vikineswary Sabaratnam, Geok-Yuan Annie Tan
    Sains Malaysiana, 2015;44:1103-1110.
    Deterioration of water quality mainly due to high total ammonia nitrogen (TAN) and nitrite will affect the productivity of shrimp culture. In this study, three indigenous strains assigned as VCM5, VCM8 and VCM12 were evaluated for their ability to degrade TAN and nitrite. These strains were inoculated into shrimp aquaculture wastewater to enhance the degradation of TAN and nitrite. All the strains reduced TAN and nitrite level from the shrimp aquaculture wastewater significantly (p<0.05). Strain VCM5 (GenBank accession number KJ700465) and VCM8 (GenBank accession number KJ700464) showed 99.71% sequence similarity with the 16S rRNA gene type species Bacillus vietnamensis 15-1T (ABO99708) and strain VCM12 (GenBank accession number KJ700463) showed 99.05% sequence similarity with 16S rRNA gene sequence type species Gordonia bronchialis DSM43247T (CP001802).
    Matched MeSH terms: Nitrites
  6. Tan SN, Sani D, Lim CW, Ideris A, Stanslas J, Lim CTS
    PMID: 32051689 DOI: 10.1155/2020/8068797
    Edible bird's nest (EBN) which is solidified swiftlet's saliva contains high nutritional value. It is widely consumed in countries like Malaysia, Indonesia, and Thailand. However, previous proximate analysis of Malaysia EBN was not representative of all the regions in Malaysia. In recent years, safety issues such as high nitrate and nitrite contents, presence of heavy metal, adulteration, fungal infection, and cancer cell stimulation were associated with EBN. Hence, this study aimed to determine the proximate analysis, safety profile during normal weather and hazy periods, and its effect on cancer cells stimulation in Malaysia-farmed EBN. Seven raw cleaned EBN samples were sourced from 6 different regions in Malaysia. Proximate analysis and safety profile were performed using official AOCA methods and Malaysian Standard. High protein (53.03-56.37%) and carbohydrate content (27.97-31.68%) with an acceptable level of moisture (10.8-14.04%) and ash (2.22-3.38%) were reported. A good safety profile was obtained with low nitrite and nitrate levels, with undetectable heavy metals and no significant growth of pathogenic microorganism except mould. Epidermal growth factor was detected but below the quantification level with the chicken EGF ELISA kit. The microculture tetrazolium (MTT) assay was performed for growth stimulation assessment comparing human EGF and EBN. There was no significant cell growth observed in cancer cells after EBN treatment. In conclusion, EBN Malaysia has a good nutritional profile, free of heavy metals, and an acceptable level of nitrate, nitrite, and microorganism profile except for mould contents. Furthermore, the in vitro study indicated that EBN was not associated with cancer cell growth.
    Matched MeSH terms: Nitrites
  7. Tan EW, Simon SE, Numan A, Khalid M, Tan KO
    Colloids Surf B Biointerfaces, 2024 Mar;235:113793.
    PMID: 38364521 DOI: 10.1016/j.colsurfb.2024.113793
    Breast cancer is a global health concern that requires personalized therapies to prevent relapses, as conventional treatments may develop resistance over time. Photothermal therapy using spectral radiation or intense light emission is a broad-spectrum treatment that induces hyperthermia-mediated cancer cell death. MXene, a two-dimensional material, has been reported to have potential biological applications in photothermal therapy for cancer treatment. In this study, we investigated the apoptotic activity of MXene and UV-irradiated MXene in MCF-7 breast cancer cells by treating them with varying concentrations of MXene. The cytotoxicity of MXene and UV was evaluated by analyzing cellular morphology, nuclei condensation, caspase activation, and apoptotic cell death. We also assessed the effect of the combined treatment on the expression and cellular distribution of Tubulin, a key component of microtubules required for cell division. At low concentrations of MXene (up to 100 µg/ml), the level of cytotoxicity in MCF-7 cells was low. However, the combined treatment of MXene and UV resulted in a synergistic increase in cytotoxicity, causing rounded cellular morphology, condensed nuclei, caspase activation, and apoptotic cell death. Furthermore, the treatment reduced Tubulin protein expression and cellular distribution, indicating a potent inducer of cell death with potential application for cancer treatment. The study demonstrates that the combined treatment of MXene and UVB irradiation is a promising strategy for inducing apoptotic cell death in breast cancer cells, suggesting its potential as a therapeutic intervention for breast cancer.
    Matched MeSH terms: Nitrites*
  8. Syahida A, Israf DA, Permana D, Lajis NH, Khozirah S, Afiza AW, et al.
    Immunol Cell Biol, 2006 Jun;84(3):250-8.
    PMID: 16509831
    Many plant-derived natural compounds have been reported previously to inhibit the production of important pro-inflammatory mediators such as nitric oxide, prostaglandin E2, TNF-alpha and reactive oxygen species by suppressing inducible enzyme expression via inhibition of the mitogen-activated protein kinase pathway and nuclear translocation of critical transcription factors. This study evaluates the effects of atrovirinone [2-(1-methoxycarbonyl-4,6-dihydroxyphenoxy)-3-methoxy-5,6-di-(3-methyl-2-butenyl)-1,4-benzoquinone)], a benzoquinone that we have previously isolated from Garcinia atroviridis, on two cellular systems that are repeatedly used in the analysis of anti-inflammatory bioactive compounds, namely, RAW 264.7 macrophage cells and whole blood. Atrovirinone inhibited the production of both nitric oxide and prostaglandin E2 from LPS-induced and IFN-gamma-induced RAW 264.7 cells and whole blood, with inhibitory concentration (IC)50 values of 4.62 +/- 0.65 and 9.33 +/- 1.47 micromol/L, respectively. Analysis of thromboxane B2 (TXB2) secretion from whole blood stimulated by either the cyclooxygenase (COX)-1 or the COX-2 pathway showed that atrovirinone inhibits the generation of TXB2 by both pathways, with IC50 values of 7.41 +/- 0.92 and 2.10 +/- 0.48 micromol/L, respectively. Analysis of IC50 ratios showed that atrovirinone was more COX-2 selective in its inhibition of TXB2, with a ratio of 0.32. Atrovirinone also inhibited the generation of intracellular reactive oxygen species and the secretion of TNF-alpha from RAW 264.7 cells in a dose-responsive manner, with IC50 values of 5.99 +/- 0.62 and 11.56 +/- 0.04 micromol/L, respectively. Lipoxygenase activity was also moderately inhibited by atrovirinone. Our results suggest that atrovirinone acts on important pro-inflammatory mediators possibly by the inhibition of the nuclear factor-kappaB pathway and also by the inhibition of the COX/lipoxygenase enzyme activity.
    Matched MeSH terms: Nitrites/metabolism
  9. 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: Nitrites/metabolism
  10. 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: Nitrites/metabolism
  11. Suhaimi Suratman, Azyyati Abdul Aziz, Norhayati Mohd Tahir, Lee HL
    Sains Malaysiana, 2018;47:651-659.
    A study was carried out to determine the distribution and behaviour of nitrogen (N) compounds (nitrite, nitrate, ammonia,
    dissolved and particulate organic nitrogen) in Sungai Terengganu estuary (TRE). Surface water samples were collected
    during ebb neap and spring tides for the longitudinal survey along the salinity gradient. The results indicated that all N
    compounds behave non-conservatively with addition during both tidal cycles, except for nitrate which exhibited removal
    behaviour during spring tide. In general, higher concentration of N compounds was observed during spring tide compared
    to neap tide. It is suggested that during spring tide, stronger water turbulence resulted in resuspension of nutrients in
    bottom sediment and lead to the increase in N compounds concentrations in the surface water. The diurnal survey for the
    freshwater station showed that the concentrations of N compounds follow the ebb and flood variations, whereas for the
    coastal station the reverse trend was observed. Comparisons with a previous study under similar tidal conditions show
    there was an increase in nitrite and ammonia concentrations in TRE, which was probably due to increase in discharge
    from the rapid development activities around this area. In addition, the presence of a breakwater at the lower part of
    the estuary may also contribute to the high nutrient content in the estuary due to restricted outflow of nutrients to the
    coastal area. Overall, the results from this study highlighted the importance of monitoring the N compounds for future
    protection of the estuary.
    Matched MeSH terms: Nitrites
  12. Sosroseno W, Bird PS, Seymour GJ
    Anaerobe, 2011 Oct;17(5):246-51.
    PMID: 21736946 DOI: 10.1016/j.anaerobe.2011.06.006
    Nitric oxide (NO) may play a crucial role in the pathogenesis of periodontal disease and, hence, the aim of the present study was to test the hypothesis that Aggregatibacter actinomycetemcomitans surface-associated material (SAM) stimulates inducible nitric oxide synthase (iNOS) activity and NO production by the murine macrophage cell line RAW264.7. Cells were stimulated with untreated or heat-treated A. actinomycetemcomitans SAM and with or without pre-treatment with L-N(6)-(1-Iminoethyl)-lysine (L-NIL) (an iNOS inhibitor), polymyxin B, interferon-gamma (IFN-γ) and Interleukin-4 (IL-4), IL-10, genistein [a protein tyrosine kinase (PTK) inhibitor], bisindolylmaleimide [a protein kinase C (PKC) inhibitor], bromophenacyl bromide (BPB) [a phospholipase A(2) (PLA2) inhibitor] or wortmannin [phosphatidylinositol 3-kinase (PI-3K) inhibitor]. The iNOS activity and nitrite production in the cell cultures were determined. Untreated but not heat-treated A. actinomycetemcomitans SAM-stimulated both iNOS activity and nitrite production in RAW264.7 cells. L-NIL, IL-4, IL-10, genistein, bisindolylmaleimide, or BPB, suppressed but IFN-γ enhanced both iNOS activity and nitrite production by A. actinomycetemcomitans SAM-stimulated cells. Wortmannin and polymyxin B failed to alter both iNOS activity or nitrite production by A. actinomycetemcomitans SAM treated cells. Therefore, the present study suggests that a heat-sensitive protein constituent(s) of A. actinomycetemcomitans SAM stimulates both iNOS activity and nitrite production by RAW264.7 cells in a cytokine, PTK, PKC, and PLA(2) but not PI-3K-dependent fashion.
    Matched MeSH terms: Nitrites/metabolism
  13. Sosroseno W, Sugiatno E, Samsudin AR, Ibrahim F
    J Oral Implantol, 2008;34(4):196-202.
    PMID: 18780564 DOI: 10.1563/0.910.1
    The aim of the present study was to test the hypothesis that the proliferation of a human osteoblast cell line (HOS cells) stimulated with hydroxyapatite (HA) may be regulated by nitric oxide (NO). The cells were cultured on the surface of HA. Medium or cells alone were used as controls. L-arginine, D-arginine, 7-NI (an nNOS inhibitor), L-NIL (an iNOS inhibitor), L-NIO (an eNOS inhibitor) or carboxy PTIO, a NO scavenger, was added in the HA-exposed cell cultures. The cells were also precoated with anti-human integrin alphaV antibody. The levels of nitrite were determined spectrophotometrically. Cell proliferation was assessed by colorimetric assay. The results showed increased nitrite production and cell proliferation by HA-stimulated HOS cells up to day 3 of cultures. Anti-integrin alphaV antibody, L-NIO, or carboxy PTIO suppressed, but L-arginine enhanced, nitrite production and cell proliferation of HA-stimulated HOS cells. The results of the present study suggest, therefore, that interaction between HA and HOS cell surface integrin alphaV molecule may activate eNOS to catalyze NO production which, in turn, may regulate the cell proliferation in an autocrine fashion.
    Matched MeSH terms: Nitrites/analysis
  14. Soh SC, Abdullah MP
    Environ Monit Assess, 2007 Jan;124(1-3):39-50.
    PMID: 16967208
    A field investigation was conducted at all water treatment plants throughout 11 states and Federal Territory in Peninsular Malaysia. The sampling points in this study include treatment plant operation, service reservoir outlet and auxiliary outlet point at the water pipelines. Analysis was performed by solid phase micro-extraction technique with a 100 microm polydimethylsiloxane fibre using gas chromatography with mass spectrometry detection to analyse 54 volatile organic compounds (VOCs) of different chemical families in drinking water. The concentration of VOCs ranged from undetectable to 230.2 microg/l. Among all of the VOCs species, chloroform has the highest concentration and was detected in all drinking water samples. Average concentrations of total trihalomethanes (THMs) were almost similar among all states which were in the range of 28.4--33.0 microg/l. Apart from THMs, other abundant compounds detected were cis and trans-1,2-dichloroethylene, trichloroethylene, 1,2-dibromoethane, benzene, toluene, ethylbenzene, chlorobenzene, 1,4-dichlorobenzene and 1,2-dichloro - benzene. Principal component analysis (PCA) with the aid of varimax rotation, and parallel factor analysis (PARAFAC) method were used to statistically verify the correlation between VOCs and the source of pollution. The multivariate analysis pointed out that the maintenance of auxiliary pipelines in the distribution systems is vital as it can become significant point source pollution to Malaysian drinking water.
    Matched MeSH terms: Nitrites/chemistry
  15. Siti HN, Kamisah Y, Mohamed S, Jaarin K
    Appl Physiol Nutr Metab, 2019 04;44(4):373-380.
    PMID: 30216735 DOI: 10.1139/apnm-2018-0175
    The prolonged intake of diet containing repeatedly heated vegetable oil can cause hypertension in the long run.
    In this study, the effects of citrus leaf extract (CLE) supplementation on vascular reactivity, plasma nitrite, and aortic structure in hypertensive rats were investigated by the consumption of repeatedly heated vegetable oil [corrected]. Male Sprague Dawley rats (n = 56) were divided into 7 groups corresponding to the respective diets. For 16 weeks, 1 group was given standard rat chow (control) while other groups were given diets containing 15% w/w of palm oil, fresh palm oil (FPO), palm oil heated 5 times (5HPO), and palm oil heated 10 times (10HPO), with or without the incorporation of 0.15% w/w CLE (FPO+CLE, 5HPO+CLE, or 10HPO+CLE). Plasma nitrite levels were measured before and at 16 weeks of treatment. After 16 weeks, the rats were sacrificed and aortae were harvested for measuring vascular reactivity and for microscopic study. CLE supplementation had significantly reduced the loss of plasma nitrite and attenuated the vasoconstriction response to phenylephrine in the 5HPO group but not in the 10HPO group. However, CLE had no significant effect on the vasorelaxation response to acetylcholine and sodium nitroprusside. The elastic lamellae of tunica media in 5HPO, 10HPO, and 10HPO+CLE groups appeared disorganised and disrupted. Obtained findings suggested that CLE was able to enhance nitric oxide bioavailability that might dampen the vasoconstriction effect of phenylephrine.
    Matched MeSH terms: Nitrites/blood
  16. Shukor MY, Dahalan FA, Jusoh AZ, Muse R, Shamaan NA, Syed MA
    J Environ Biol, 2009 Jan;30(1):145-50.
    PMID: 20112877
    A diesel-degrading bacterium has been isolated from a diesel-polluted site. The isolate was tentatively identified as Staphylococcus aureus strain DRY11 based on partial 16S rDNA molecular phylogeny and Biolog GP microplate panels and Microlog database. Isolate 11 showed an almost linear increase in cellular growth with respect to diesel concentrations with optimum growth occurring at 4% (v/v) diesel concentration. Optimization studies using different nitrogen sources showed that the best nitrogen source was potassium nitrite. Sodium nitrite was optimum at 1.2 g l(-1) and higher concentrations were strongly inhibitory to cellular growth. The optimal pH that supported growth of the bacterium was between 7.5 to 8.0 and the isolate exhibited optimal broad temperature supporting growth on diesel from 27 to 37 degrees C. An almost complete removal of diesel components was seen from the reduction in hydrocarbon peaks observed using Solid Phase Microextraction Gas Chromatography analysis after 5 days of incubation. The characteristics of this bacterium suggest that it is suitable for bioremediation of diesel spills and pollutions in the tropics.
    Matched MeSH terms: Nitrites/metabolism; Nitrites/chemistry
  17. Shen TC
    Plant Physiol, 1972 Apr;49(4):546-9.
    PMID: 16657998
    Nitrate simultaneously induced NADH- and NADPH-nitrate reductase activities in rice seedlings. Chloramphenicol, other organic nitro-compounds such as o-nitroaniline and 2,4-dinitrophenol and nitrite also induced nitrate reductase in rice seedlings. The nitrate- or nitrite-induced nitrate reductase could accept electrons more efficiently from NADH than NADPH. However, when this enzyme was induced by organic nitro-compounds, it could accept electrons more efficiently from NADPH than NADH.
    Matched MeSH terms: Nitrites
  18. Shen TC
    Plant Physiol, 1969 Nov;44(11):1650-5.
    PMID: 16657253
    Nitrate reduotase is induced by nitrate in excised embryos and germinating intact seedlings of rice (Oryza sativa L.). The enzyme is induced 24 hr after imbibition. The rate of enzyme formation increases with the age of seedlings. There is a lag period of 30 to 40 min between the addition of substrate and the formation of nitrate reductase. Formation of the enzyme is promoted by the presence of ammonium. Chloramphenicol, actinomycin D and cycloheximide effectively inhibit the formation of nitrate reductase.Rice seedlings can assimilate nitrate from the beginning of germination. However, the utilization of nitrate is completely suppressed by the presence of ammonium. As soon as ammonium is depleted from the medium, nitrate utilization is resumed. Ammonium inhibits the first step of nitrate reduction, i.e., NO(-) (3) --> NO(-) (2), but does not inhibit the assimilation of nitrite. This provides an example of feedback inhibition in higher plants.
    Matched MeSH terms: Nitrites
  19. Shahnavaz Z, Zaharani L, Johan MR, Khaligh NG
    Curr Org Synth, 2020;17(2):131-135.
    PMID: 32013833 DOI: 10.2174/1570179417666200203121437
    BACKGROUND: In continuation of our previous work and the applications of saccharin, we encouraged to investigate the one-pot synthesis of the aryl iodides by the diazotization of the arene diazonium saccharin salts.

    OBJECTIVE: Arene diazonium salts play an important role in organic synthesis as intermediate and a wide variety of aromatic compounds have been prepared using them. A serious drawback of arene diazonium salts is their instability in a dry state; therefore, they must be stored and handled carefully to avoid spontaneous explosion and other hazard events.

    METHODS: The arene diazonium saccharin salts were prepared as active intermediates in situ through the reaction of various aryl amines with tert-butyl nitrite (TBN) in the presence of saccharin (Sac-H). Then, in situ obtained intermediates were used into the diazotization step without separation and purification in the current protocol.

    RESULTS: A variety of aryl iodides were synthesized at a greener and low-cost method in the presence of TBN, Sac-H, glacial acetic acid, and TEAI.

    CONCLUSION: In summary, a telescopic reaction is developed for the synthesis of aryl iodides. The current methodology is safe, cost-effective, broad substrate scope, and metal-free. All used reagents are commercially available and inert to moisture and air. Also, the saccharine and tetraethylammonium cation could be partially recovered from the reaction residue, which reduces waste generation, energy consumption, raw material, and waste disposal costs.

    Matched MeSH terms: Nitrites
  20. Shaha DC, Hasan J, Kundu SR, Yusoff FM, Salam MA, Khan M, et al.
    Sci Rep, 2022 Dec 05;12(1):20980.
    PMID: 36470973 DOI: 10.1038/s41598-022-24500-2
    The tropical estuarine ecosystem is fascinating for studying the dynamics of water quality and phytoplankton diversity due to its frequently changing hydrological conditions. Most importantly, phytoplankton is the main supplier of ω3 polyunsaturated fatty acids (PUFA) in the coastal food web for fish as they could not synthesize PUFA. This study evaluated seasonal variations of water quality parameters in the Meghna River estuary (MRE), explored how phytoplankton diversity changes according to hydro-chemical parameters, and identified the major phytoplankton groups as the main source of PUFA for hilsa fish. Ten water quality indicators including temperature, dissolved oxygen, pH, salinity, dissolved inorganic nitrogen (DIN = nitrate, nitrite, ammonia) and phosphorus, dissolved silica and chlorophyll-a were evaluated. In addition, phytoplankton diversity was assessed in the water and hilsa fish gut. Principal component analysis (PCA) was used to analyze the spatio-temporal changes in the water quality conditions, and the driving factors in the MRE. Four main components were extracted and explained 75.4% variability of water quality parameters. The most relevant driving factors were dissolved oxygen, salinity, temperature, and DIN (nitrate, nitrite and ammonia). These variabilities in physicochemical parameters and dissolved inorganic nutrients caused seasonal variations in two major groups of phytoplankton. Peak abundance of Chlorophyta (green algae) occurred in water in nutrient-rich environments (nitrogen and phosphorus) during the wet (36%) season, while Bacillariophyta (diatoms) were dominant during the dry (32%) season that depleted dissolved silica. Thus, the decrease of green algae and the increase of diatoms in the dry season indicated the potential link to seasonal changes of hydro-chemical parameters. The green algae (53.7%) were the dominant phytoplankton group in the hilsa gut content followed by diatoms (22.6%) and both are contributing as the major source of PUFAs for hilsa fish according to the electivity index as they contain the highest amounts of PUFAs (60 and 28% respectively).
    Matched MeSH terms: Nitrites/analysis
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