MyMedR

Displaying publications 81 - 100 of 1075 in total

Abstract:

Sort:

Comparative cohorts of retinopathy of prematurity outcomes of differing oxygen saturation: real-world outcomes

Choo MM, Grigg J, Barnes EH, Khaliddin N, Kamalden TA, Ahmad Kamar A, et al.

BMJ Open Ophthalmol, 2021;6(1):e000626.
PMID: 33768163 DOI: 10.1136/bmjophth-2020-000626

Objective: An ongoing third epidemic of retinopathy of prematurity (ROP) is contributed largely by developing nations. We describe a cohort of infants in a single neonatal unit where two limits of oxygen saturation were administered, to show real-world outcomes from trend in neonatology for higher oxygen to improve survival.
Methods and analysis: This retrospective, comparative study of prospectively collected data in an ROP screening programme included infants indicated by gestational age ≤32 weeks, birth weight <1501 g, ventilation for 7 days or requiring oxygen >1 month, who underwent dilated fundoscopic examination from age 4 weeks, every 2 weeks until full retinal vascularisation. Infants with ROP were examined weekly and treated where indicated. Data were divided into two epochs. Epoch 1 oxygen saturation targets were [88-92%], epoch 2 targets [90-95% (99%)] with allowance of increase to 20% for several hours after procedures. Outcome measures included development of ROP, treatment, mortality, sepsis and intraventricular haemorrhage.
Results: A total of 651 infants underwent examination between 2003 and 2016. The incidence of ROP in epoch 1 was 29.1% and epoch 2 was 29.3% (p=0.24). ROP progression doubled in epoch 2 (5 vs 11%, p=0.006), proportion of cases treated halved (14% vs 6%, p=0.0005), sepsis was halved (78.5% vs 41.2%, p<0.0001) and intraventricular haemorrhage doubled (20.2% vs 43.8%, p=0.0001) in epoch 2. Mortality was 4% and 0% in epochs 1 and 2, respectively.
Conclusion: Incidence of ROP did not differ, although ROP cases that worsened doubled with higher oxygen targets. ROP cases requiring treatment decreased, as did sepsis and mortality. Intraventricular haemorrhage cases doubled.

Matched MeSH terms: Oxygen
Fulltext Impact of prolonged nicotine administration on myocardial function and susceptibility to ischaemia-reperfusion injury in rats

Ramalingam A, Mohd Fauzi N, Budin SB, Zainalabidin S

Basic Clin Pharmacol Toxicol, 2021 Feb;128(2):322-333.
PMID: 32991780 DOI: 10.1111/bcpt.13500

This study investigated the impact of prolonged nicotine administration on myocardial susceptibility to ischaemia-reperfusion (I/R) injury in a rat model and determined whether nicotine affects mitochondrial reactive oxygen species (ROS) production and permeability transition in rat hearts. Sprague-Dawley rats were administered 0.6 or 1.2 mg/kg nicotine for 28 days, and their hearts were isolated at end-point for assessment of myocardial susceptibility to I/R injury ex vivo. Rat heart mitochondria were also isolated from a subset of rats for analysis of mitochondrial ROS production and permeability transition. Compared to the vehicle controls, rat hearts isolated from nicotine-administered rats exhibited poorer left ventricular function that worsened over the course of I/R. Coronary flow rate was also severely impaired in the nicotine groups at baseline and this worsened after I/R. Nicotine administration significantly increased mitochondrial ROS production and permeability transition relative to the vehicle controls. Interestingly, pre-incubation of isolated mitochondria with ROS scavengers (superoxide dismutase and mitoTEMPO) significantly abolished nicotine-induced increase in mitochondria permeability transition in isolated rat heart mitochondria. Overall, our data showed that prolonged nicotine administration enhances myocardial susceptibility to I/R injury in rats and this is associated with mitochondrial ROS-driven increase in mitochondrial permeability transition.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage

Guarini G, Kiyooka T, Ohanyan V, Pung YF, Marzilli M, Chen YR, et al.

Basic Res Cardiol, 2016 May;111(3):29.
PMID: 27040114 DOI: 10.1007/s00395-016-0547-4

Mitochondrial dysfunction in obesity and diabetes can be caused by excessive production of free radicals, which can damage mitochondrial DNA. Because mitochondrial DNA plays a key role in the production of ATP necessary for cardiac work, we hypothesized that mitochondrial dysfunction, induced by mitochondrial DNA damage, uncouples coronary blood flow from cardiac work. Myocardial blood flow (contrast echocardiography) was measured in Zucker lean (ZLN) and obese fatty (ZOF) rats during increased cardiac metabolism (product of heart rate and arterial pressure, i.v. norepinephrine). In ZLN increased metabolism augmented coronary blood flow, but in ZOF metabolic hyperemia was attenuated. Mitochondrial respiration was impaired and ROS production was greater in ZOF than ZLN. These were associated with mitochondrial DNA (mtDNA) damage in ZOF. To determine if coronary metabolic dilation, the hyperemic response induced by heightened cardiac metabolism, is linked to mitochondrial function we introduced recombinant proteins (intravenously or intraperitoneally) in ZLN and ZOF to fragment or repair mtDNA, respectively. Repair of mtDNA damage restored mitochondrial function and metabolic dilation, and reduced ROS production in ZOF; whereas induction of mtDNA damage in ZLN reduced mitochondrial function, increased ROS production, and attenuated metabolic dilation. Adequate metabolic dilation was also associated with the extracellular release of ADP, ATP, and H2O2 by cardiac myocytes; whereas myocytes from rats with impaired dilation released only H2O2. In conclusion, our results suggest that mitochondrial function plays a seminal role in connecting myocardial blood flow to metabolism, and integrity of mtDNA is central to this process.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Dietary cocoa protects against colitis-associated cancer by activating the Nrf2/Keap1 pathway

Pandurangan AK, Saadatdoust Z, Esa NM, Hamzah H, Ismail A

Biofactors, 2015 Jan-Feb;41(1):1-14.
PMID: 25545372 DOI: 10.1002/biof.1195

Colorectal cancer (CRC) is the third most common malignancy in males and the second most common cancer worldwide. Chronic colonic inflammation is a known risk factor for CRC. Cocoa contains many polyphenolic compounds that have beneficial effects in humans. The objective of this study is to explore the antioxidant properties of cocoa in the mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated cancer, focusing on the activation of Nrf2 signaling. Mice were treated with AOM/DSS and randomized to receive either a control diet or a 5 and 10% cocoa diet during the study period. On day 62 of the experiment, the entire colon was processed for biochemical and histopathological examination and further evaluations. Increased levels of malondialdehyde (MDA) were observed in AOM/DSS-induced mice; however, subsequent administration of cocoa decreased the MDA. Enzymatic and nonenzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were decreased in the AOM/DSS mice. Cocoa treatment increases the activities/levels of enzymatic and nonenzymatic antioxidants. Inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were elevated during AOM/DSS-induction, and treatment with 5 and 10% cocoa effectively decreases the expression of iNOS and COX-2. The NF-E2-related factor 2 and its downstream targets, such as NQO1 and UDP-GT, were increased by cocoa treatment. The results of our study suggest that cocoa may merit further clinical investigation as a chemopreventive agent that helps prevent CAC.

Matched MeSH terms: Reactive Oxygen Species/antagonists & inhibitors; Reactive Oxygen Species/metabolism
Fulltext Enhancement of oxygen mass transfer and gas holdup using palm oil in stirred tank bioreactors with xanthan solutions as simulated viscous fermentation broths

Mohd Sauid S, Krishnan J, Huey Ling T, Veluri MV

Biomed Res Int, 2013;2013:409675.
PMID: 24350269 DOI: 10.1155/2013/409675

Volumetric mass transfer coefficient (kLa) is an important parameter in bioreactors handling viscous fermentations such as xanthan gum production, as it affects the reactor performance and productivity. Published literatures showed that adding an organic phase such as hydrocarbons or vegetable oil could increase the kLa. The present study opted for palm oil as the organic phase as it is plentiful in Malaysia. Experiments were carried out to study the effect of viscosity, gas holdup, and kLa on the xanthan solution with different palm oil fractions by varying the agitation rate and aeration rate in a 5 L bench-top bioreactor fitted with twin Rushton turbines. Results showed that 10% (v/v) of palm oil raised the kLa of xanthan solution by 1.5 to 3 folds with the highest kLa value of 84.44 h(-1). It was also found that palm oil increased the gas holdup and viscosity of the xanthan solution. The kLa values obtained as a function of power input, superficial gas velocity, and palm oil fraction were validated by two different empirical equations. Similarly, the gas holdup obtained as a function of power input and superficial gas velocity was validated by another empirical equation. All correlations were found to fit well with higher determination coefficients.

Matched MeSH terms: Oxygen/metabolism*
Fulltext Sundarban Honey Confers Protection against Isoproterenol-Induced Myocardial Infarction in Wistar Rats

Afroz R, Tanvir EM, Karim N, Hossain MS, Alam N, Gan SH, et al.

Biomed Res Int, 2016;2016:6437641.
PMID: 27294126 DOI: 10.1155/2016/6437641

The present study was designed to investigate the cardioprotective effects of Sundarban honey (SH) in rats with isoproterenol- (ISO-) induced myocardial infarction. Adult male Wistar Albino rats were pretreated with Sundarban honey (5 g/kg) daily for a period of 6 weeks. After the treatment period, ISO (85 mg/kg) was subcutaneously injected into the rats at 24 h intervals for 2 days. ISO-induced myocardial damage was indicated by increased serum cardiac specific troponin I levels and cardiac marker enzyme activities including creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, and alanine transaminase. Significant increases in serum total cholesterol, triglycerides, and low-density lipoprotein-cholesterol levels were also observed, along with a reduction in the serum high-density lipoprotein-cholesterol level. In addition to these diagnostic markers, the levels of lipid peroxide products were significantly increased. The activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase were significantly decreased in the hearts after ISO-induced myocardial infarction. However, pretreatment of ischemic rats with Sundarban honey brought the biochemical parameters to near normalcy, indicating the protective effect of Sundarban honey against ISO-induced ischemia in rats. Histopathological findings of the heart tissues further confirmed the biochemical findings, indicating that Sundarban honey confers protection against ISO-induced oxidative stress in the myocardium.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor

Wang J, Mahmood Q, Qiu JP, Li YS, Chang YS, Li XD

Biomed Res Int, 2015;2015:398028.
PMID: 26167485 DOI: 10.1155/2015/398028

Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM) dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m(3) of biogas per m(3) of POME which was utilized for electricity generation.

Matched MeSH terms: Biological Oxygen Demand Analysis
Fulltext Nanotoxic profiling of novel iron oxide nanoparticles functionalized with perchloric acid and SiPEG as a radiographic contrast medium

Mohamed MI, Mohammad MK, Abdul Razak HR, Abdul Razak K, Saad WM

Biomed Res Int, 2015;2015:183525.
PMID: 26075217 DOI: 10.1155/2015/183525

Emerging syntheses and findings of new metallic nanoparticles (MNPs) have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs) with silane-polyethylene glycol (SiPEG) and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS), lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM). The hematological analysis and liver function test (LFT) revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups (P < 0.05). ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA), also showed significant reductions in comparison with iodine group (P < 0.05). TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Secondary Metabolites Profiling of Acinetobacter baumannii Associated with Chili (Capsicum annuum L.) Leaves and Concentration Dependent Antioxidant and Prooxidant Properties

Monowar T, Rahman MS, Bhore SJ, Raju G, Sathasivam KV

Biomed Res Int, 2019;2019:6951927.
PMID: 30868071 DOI: 10.1155/2019/6951927

Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents.

Matched MeSH terms: Reactive Oxygen Species/metabolism; Reactive Oxygen Species/chemistry
Fulltext Cytotoxicity of snake venom enzymatic toxins: phospholipase A2 and l-amino acid oxidase

Hiu JJ, Yap MKK

Biochem Soc Trans, 2020 04 29;48(2):719-731.
PMID: 32267491 DOI: 10.1042/BST20200110

The phospholipase A2 (PLA2) and l-amino acid oxidase (LAAO) are two major enzymes found in the venoms from most snake species. These enzymes have been structurally and functionally characterised for their pharmacological activities. Both PLA2 and LAAO from different venoms demonstrate considerable cytotoxic effects on cancer cells via induction of apoptosis, cell cycle arrest and suppression of proliferation. These enzymes produce more pronounced cytotoxic effects in cancer cells than normal cells, thus they can be potential sources as chemotherapeutic agents. It is proposed that PLA2 and LAAO contribute to an elevated oxidative stress due to their catalytic actions, for instance, the ability of PLA2 to produce reactive oxygen species during lipolysis and formation of H2O2 from LAAO catalytic activity which consequently lead to cell death. Nonetheless, the cell-death signalling pathways associated with exposure to these enzymatic toxins are not fully elucidated yet. Here in this review, we will discuss the cytotoxic effects of PLA2 and LAAO in relationship to their catalytic mechanisms and the underlying mechanisms of cytotoxic actions.

Matched MeSH terms: Reactive Oxygen Species
Impact of low oxygen tension on stemness, proliferation and differentiation potential of human adipose-derived stem cells

Choi JR, Pingguan-Murphy B, Wan Abas WA, Noor Azmi MA, Omar SZ, Chua KH, et al.

Biochem Biophys Res Commun, 2014 May 30;448(2):218-24.
PMID: 24785372 DOI: 10.1016/j.bbrc.2014.04.096

Adipose-derived stem cells (ASCs) have been found adapted to a specific niche with low oxygen tension (hypoxia) in the body. As an important component of this niche, oxygen tension has been known to play a critical role in the maintenance of stem cell characteristics. However, the effect of O2 tension on their functional properties has not been well determined. In this study, we investigated the effects of O2 tension on ASCs stemness, differentiation and proliferation ability. Human ASCs were cultured under normoxia (21% O2) and hypoxia (2% O2). We found that hypoxia increased ASC stemness marker expression and proliferation rate without altering their morphology and surface markers. Low oxygen tension further enhances the chondrogenic differentiation ability, but reduces both adipogenic and osteogenic differentiation potential. These results might be correlated with the increased expression of HIF-1α under hypoxia. Taken together, we suggest that growing ASCs under 2% O2 tension may be important in expanding ASCs effectively while maintaining their functional properties for clinical therapy, particularly for the treatment of cartilage defects.

Matched MeSH terms: Oxygen/metabolism*
Studies of oxygen binding energy to hemoglobin molecule

Chow YW, Pietranico R, Mukerji A

Biochem Biophys Res Commun, 1975 Oct 27;66(4):1424-31.
PMID: 6
Matched MeSH terms: Oxygen/blood*
Boldine protects endothelial function in hyperglycemia-induced oxidative stress through an antioxidant mechanism

Lau YS, Tian XY, Huang Y, Murugan D, Achike FI, Mustafa MR

Biochem Pharmacol, 2013 Feb 1;85(3):367-75.
PMID: 23178655 DOI: 10.1016/j.bcp.2012.11.010

Increased oxidative stress is involved in the pathogenesis and progression of diabetes. Antioxidants are therapeutically beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1,10-dimethoxyaporphine) is a major alkaloid present in the leaves and bark of the boldo tree (Peumus boldus Molina), with known an antioxidant activity. This study examined the protective effects of boldine against high glucose-induced oxidative stress in rat aortic endothelial cells (RAEC) and its mechanisms of vasoprotection related to diabetic endothelial dysfunction. In RAEC exposed to high glucose (30 mM) for 48 h, pre-treatment with boldine reduced the elevated ROS and nitrotyrosine formation, and preserved nitric oxide (NO) production. Pre-incubation with β-NAPDH reduced the acetylcholine-induced endothelium-dependent relaxation; this attenuation was reversed by boldine. Compared with control, endothelium-dependent relaxation in the aortas of streptozotocin (STZ)-treated diabetic rats was significantly improved by both acute (1 μM, 30 min) and chronic (20mg/kg/daily, i.p., 7 days) treatment with boldine. Intracellular superoxide and peroxynitrite formation measured by DHE fluorescence or chemiluminescence assay were higher in sections of aortic rings from diabetic rats compared with control. Chronic boldine treatment normalized ROS over-production in the diabetic group and this correlated with reduction of NAD(P)H oxidase subunits, NOX2 and p47(phox). The present study shows that boldine reversed the increased ROS formation in high glucose-treated endothelial cells and restored endothelial function in STZ-induced diabetes by inhibiting oxidative stress and thus increasing NO bioavailability.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Activation of autophagy by stress-activated signals as a cellular self-defense mechanism against the cytotoxic effects of MBIC in human breast cancer cells in vitro

Hasanpourghadi M, Majid NA, Mustafa MR

Biochem Pharmacol, 2018 06;152:174-186.
PMID: 29608909 DOI: 10.1016/j.bcp.2018.03.030

We recently reported that methyl 2-(-5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) is a microtubule targeting agent (MTA) with multiple mechanisms of action including apoptosis in two human breast cancer cell-lines MCF-7 and MDA-MB-231. In the present study, investigation of early molecular events following MBIC treatment demonstrated the induction of autophagy. This early (<24 h) response to MBIC was characterized by accumulation of autophagy markers; LC3-II, Beclin1, autophagic proteins (ATGs) and collection of autophagosomes but with different variations in the two cell-lines. MBIC-induced autophagy was associated with generation of reactive oxygen species (ROS). In parallel, an increased activation of SAPK/JNK pathway was detected, as an intersection of ROS production and induction of autophagy. The cytotoxic effect of MBIC was enhanced by inhibition of autophagy through blockage of SAPK/JNK signaling, suggesting that MBIC-induced autophagy, is a possible cellular self-defense mechanism against toxicity of this agent in both breast cancer cell-lines. The present findings suggest that inhibition of autophagy eliminates the cytoprotective activity of MDA-MB-231 and MCF-7 cells, and sensitizes both the aggressive and non-aggressive human breast cancer cell-lines to the cytotoxic effects of MBIC.

Matched MeSH terms: Reactive Oxygen Species
Dihydroorotate dehydrogenase (DHODH) inhibitors affect ATP depletion, endogenous ROS and mediate S-phase arrest in breast cancer cells

Mohamad Fairus AK, Choudhary B, Hosahalli S, Kavitha N, Shatrah O

Biochimie, 2017 Apr;135:154-163.
PMID: 28196676 DOI: 10.1016/j.biochi.2017.02.003

Dihydroorotate dehydrogenase (DHODH) is the key enzyme in de novo biosynthesis of pyrimidine in both prokaryotes and eukaryotes. The de novo pathway of pyrimidine biosynthesis is essential in cancer cells proliferation. Leflunomide is an approved DHODH inhibitor that has been widely used for the treatment of arthritis. Similarly, brequinar sodium is another DHODH inhibitor that showed anti-tumour effect in MC38 colon carcinoma cells when used in combination with fluorouracil. Despite the potential role of DHODH inhibitors in cancer therapy, their mechanisms of action remain obscure and await further elucidation. Here, we evaluated the effect of DHODH inhibitors on the production of ATP and ROS in sensitive and non-sensitive breast cancer cells. Subsequently, the effects of DHODH inhibitors on cell cycle as well as on signalling molecules such as p53, p65 and STAT6 were evaluated in sensitive T-47D and non-sensitive MDAMB-436 cells. The correlations between DHODH protein expression, proliferation speed and sensitivity to DHODH inhibitors were also investigated in a panel of cancer cell lines. DHODH inhibitors-sensitive T-47D and MDAMB-231 cells appeared to preserve ROS production closely to endogenous ROS level whereas the opposite was observed in non-sensitive MDAMB-436 and W3.006 cells. In addition, we observed approximately 90% of intracellular ATP depletion in highly sensitive T-47D and MDAMB-231 cells compared to non-sensitive MDAMB-436 cells. There was significant over-expression of p53, p65 and STAT6 signalling molecules in sensitive cells which may be involved in mediating the S-phase arrest in cell cycle progression. The current study suggests that DHODH inhibitors are most effective in cells that express high levels of DHODH enzyme. The inhibition of cell proliferation by these inhibitors appears to be accompanied by ROS production as well as ATP depletion. The increase in expression of signalling molecules observed may be due to pyrimidine depletion which subsequently leads to cell cycle arrest at S-phase.

Matched MeSH terms: Reactive Oxygen Species
Fulltext Selection of various coagulants for sugar industry waste water treatment

Nur Shazweena Samsudin, Jami, Mohammed Saedi, Kabbashi, Nassereldeen Ahmed

Biological and Natural Resources Engineering Journal, 2019;2(1):1-9.
MyJurnal

sugar industry is one of the industries that produce a high amount of
pollutant since its wastewater contains high amount of organic material, biochemical
oxygen demand (bod) and chemical oxygen demand (cod). if this waste is
discharged without a proper treatment into the watercourse, it can cause problem to aquatic
life and environment. for the primary treatment process, sugar wastewater can be treated
by using chemical precipitation method which involves coagulation process. currently,
ferric chloride has been used as the coagulant but it consumes more alkalinity and
corrosive. in this study, the suitable coagulant to be used to treat the wastewater from sugar
industry and the optimum conditions to achieve high percentage removal of cod was
determined. the characteristic of the wastewater was firstly determined. then, the most
suitable coagulant to be used for the treatment was studied by determining their efficiency
to reduce cod and tss in the wastewater at different dosages. aluminium sulphate
(alum), ferric chloride and polyaluminium chloride (pac) were chosen to be studied for
suitable coagulant. The optimum condition of the coagulant (ph, coagulant dosage, fast
mixing speed) was determined by using design expert software. results showed that alum
can be used to effectively remove 42.9% of cod and 100% of tss at high dosage (50
mg/l). the optimum condition of alum was at ph 5.2, 10 mg/l of alum and 250 rpm of
mixing speed. this shows that at optimum condition, alum can be used to treat wastewater
from sugar industry.

Matched MeSH terms: Oxygen; Biological Oxygen Demand Analysis
Fulltext Treatment of river water of Sg. Pusu by using magnesium oxide (MGO) coated with chitosan

Nik Nur Syafika Pahri, Nur Huda Syazwani Jafri, Husna Ahmad Tajuddin, Yusilawati Ahmad Nor

Biological and Natural Resources Engineering Journal, 2019;2(1):10-25.
MyJurnal

Effective treatment of wastewater is crucial in order to achieve a sustainable development. For instance, highly efficient treatment processes with low capital requirements are the major prerequisite for implementation of the advanced wastewater treatment operations. Among various available treatment methods, the application of coagulation-flocculation process by using natural coagulant; chitosan has vast advantages such as low operating cost, environmental friendly and highly effective in the wastewater treatment operations. The application of nanotechnology in numerous treatment techniques are considered as the most significant advances in water and wastewater treatment practices. The utilization of magnesium oxide (MgO) as nano-adsorbent has recently gained attention as a potential treatment method in water remediation particularly for treating effluents with high amount of organic dyes and heavy metals due to its high treatment efficiency, low cost, versatility and environment compatibility. The purpose of this study was to determine the effectiveness of coagulation-flocculation process when using novel coagulant in which MgO coated with chitosan by investigating the percentage removal of several significant parameters which were turbidity, chemical oxygen demand (COD) and suspended solid. The removal efficiencies were determined throughout a series of experiments carried out using a standard jar test procedure in which three different coagulants; chitosan, MgO coated with chitosan and MgO were tested on water samples taken from Sg. Pusu. In addition, a set of experiments was designed using response surface methodology (RSM) in order to optimize adsorption of chitosan into MgO. The experiments were conducted at various concentrations of chitosan (10-30 mg/ml) and selected MgO dosage ranges (10-30 mg). From the obtained results, it was found that chitosan-MgO coagulant has good removal efficiencies of turbidity, chemical oxygen demand (COD) and suspended solids at 92%, 91%, and 98% respectively from the optimization of adsorption of chitosan-MgO. The MgO coated with chitosan is the best coagulant in this study compared to chitosan and MgO alone because of the ability of treating the river water with up to 90 % removal for all the main parameters. The results showed that coagulation-flocculation is effective as a treatment for treating river water.

Matched MeSH terms: Oxygen; Biological Oxygen Demand Analysis
The value of maternal and fetal blood gas analysis in cesarean sections under general anesthesia

Thavarasah AS, Lobo RM

Biol Res Pregnancy Perinatol, 1987;8(2 2D Half):76-83.
PMID: 3427139

Maternal and fetal blood gas values were studied in 90 selected mothers of comparable age, weight, duration of pregnancy and hematocrit values undergoing cesarean section under balanced general anesthesia in four differing clinical situations: elective with and without placental dysfunction, and emergency with and without fetal distress in apparently normal mothers. Pre-induction (Fi O2 0.21) and pre-delivery (Fi O2 0.60) maternal blood gas analysis, along with umbilical cord blood gas analysis were performed in all cases. Apgar scoring was carried out at one minute and three minutes and correlated with the blood gas values. Out of the 90 cases studied, 36 neonates (40%) showed good apgar scores of greater than seven at one minute and three minutes and correlated well with maternal blood gas values which were within normal ranges. Of the remaining 54 cases (60%) with similar mean maternal gas values the neonates showed an apgar score of less than seven in the first minute. The score improved in three minutes in 35 of them (66%), and umbilical cord blood gas values showed a low pH (umbilical vein 7.22 +/- 0.02 units, umbilical arterial 7.21 +/- 0.01 units) but satisfactory pO2 (umbilical vein 39.4 +/- 1.9 torr, umbilical arterial 2.5 +/- 1.3 torr).(ABSTRACT TRUNCATED AT 250 WORDS)

Matched MeSH terms: Oxygen/blood*
Zinc and Metallothionein in the Development and Progression of Dental Caries

Rahman MT, Hossain A, Pin CH, Yahya NA

Biol Trace Elem Res, 2019 Jan;187(1):51-58.
PMID: 29744817 DOI: 10.1007/s12011-018-1369-z

Chronic oxidative stress and reactive oxygen species (ROS) in oral cavity as well as acidic pH on dental enamel surface due to the metabolic activities of bacterial plaque are the major contributors in the development and progression of dental caries. Along with other factors, deposition or dissolution Ca and Mg mostly determines the re- or demineralization of dental enamel. Zn plays an important role for both Ca and Mg bioavailability in oral cavity. Metallothionein (MT), a group of small molecular weight, cysteine-rich proteins (~ 7 kDa), is commonly induced by ROS, bacterial infection, and Zn. In the current review, we evaluated MT at the junction between the progression of dental caries and its etiologies that are common in MT biosynthesis.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Effects of Fiddler Crab Burrows on Sediment Properties in the Mangrove Mudflats of Sungai Sepang, Malaysia

Mokhtari M, Abd Ghaffar M, Usup G, Che Cob Z

Biology (Basel), 2016;5(1).
PMID: 26797647 DOI: 10.3390/biology5010007

In mangrove ecosystems, litter fall accumulates as refractory organic carbon on the sediment surface and creates anoxic sediment layers. Fiddler crabs, through their burrowing activity, translocate oxygen into the anoxic layers and promote aerobic respiration, iron reduction and nitrification. In this study, the effects of four species of fiddler crabs (Uca triangularis, Uca rosea, Uca forcipata and Uca paradussumieri) on organic content, water content, porosity, redox potential and solid phase iron pools of mangrove sediments were investigated. In each crab's habitat, six cores down to 30 cm depth were taken from burrowed and non-burrowed sampling plots. Redox potential and oxidized iron pools were highest in surface sediment, while porosity, water and organic content were higher in deeper sediment. Reduced iron (Fe (II)) and redox potential were significantly different between burrowed and non-burrowed plots. Crab burrows extend the oxidized surface layer down to 4 cm depth and through the oxidation effect, reduce the organic content of sediments. The effects of burrows varied between the four species based on their shore location. The oxidation effect of burrows enhance the decomposition rate and stimulate iron reduction, which are processes that are expected to play an important role in biogeochemical properties of mangrove sediments.

Matched MeSH terms: Oxygen

Filters

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

External Links