Browse publications by year: 2015

  1. De Bolle M, De Fruyt F, McCrae RR, Löckenhoff CE, Costa PT, Aguilar-Vafaie ME, et al.
    J Pers Soc Psychol, 2015 Jan;108(1):171-185.
    PMID: 25603371 DOI: 10.1037/a0038497
    Although large international studies have found consistent patterns of sex differences in personality traits among adults (i.e., women scoring higher on most facets), less is known about cross-cultural sex differences in adolescent personality and the role of culture and age in shaping them. The present study examines the NEO Personality Inventory-3 (McCrae, Costa, & Martin, 2005) informant ratings of adolescents from 23 cultures (N = 4,850), and investigates culture and age as sources of variability in sex differences of adolescents' personality. The effect for Neuroticism (with females scoring higher than males) begins to take on its adult form around age 14. Girls score higher on Openness to Experience and Conscientiousness at all ages between 12 and 17 years. A more complex pattern emerges for Extraversion and Agreeableness, although by age 17, sex differences for these traits are highly similar to those observed in adulthood. Cross-sectional data suggest that (a) with advancing age, sex differences found in adolescents increasingly converge toward adult patterns with respect to both direction and magnitude; (b) girls display sex-typed personality traits at an earlier age than boys; and (c) the emergence of sex differences was similar across cultures. Practical implications of the present findings are discussed. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
    MeSH terms: Adolescent; Adult; Age Factors; Aged; Child; Cross-Sectional Studies; Cross-Cultural Comparison; Culture*; Female; Humans; Male; Middle Aged; Personality/physiology*; Sex Characteristics*; Sex Factors; Adolescent Development/physiology*; Young Adult
  2. Hashim HA, Zainol NA
    Psychol Health Med, 2015;20(5):623-8.
    PMID: 25603900 DOI: 10.1080/13548506.2014.1002851
    This study compared the effects of 6 and 12 sessions of relaxation training on emotional distress, short-term memory, and sustained attention in primary school children.
    MeSH terms: Anxiety/therapy*; Attention/physiology*; Autogenic Training/methods*; Child; Depression/therapy*; Female; Humans; Male; Memory, Short-Term/physiology*; Stress, Psychological/therapy*; Treatment Outcome
  3. Marufuzzaman M, Reaz MB, Ali MA, Rahman LF
    Methods Inf Med, 2015;54(3):262-70.
    PMID: 25604028 DOI: 10.3414/ME14-01-0061
    OBJECTIVES: The goal of smart homes is to create an intelligent environment adapting the inhabitants need and assisting the person who needs special care and safety in their daily life. This can be reached by collecting the ADL (activities of daily living) data and further analysis within existing computing elements. In this research, a very recent algorithm named sequence prediction via enhanced episode discovery (SPEED) is modified and in order to improve accuracy time component is included.

    METHODS: The modified SPEED or M-SPEED is a sequence prediction algorithm, which modified the previous SPEED algorithm by using time duration of appliance's ON-OFF states to decide the next state. M-SPEED discovered periodic episodes of inhabitant behavior, trained it with learned episodes, and made decisions based on the obtained knowledge.

    RESULTS: The results showed that M-SPEED achieves 96.8% prediction accuracy, which is better than other time prediction algorithms like PUBS, ALZ with temporal rules and the previous SPEED.

    CONCLUSIONS: Since human behavior shows natural temporal patterns, duration times can be used to predict future events more accurately. This inhabitant activity prediction system will certainly improve the smart homes by ensuring safety and better care for elderly and handicapped people.

    MeSH terms: Activities of Daily Living*; Algorithms*; Forecasting; Housing*; Humans; Software Design; Monitoring, Ambulatory/instrumentation*
  4. Keshavarzifard M, Zakaria MP, Hwai TS, Yusuff FM, Mustafa S
    Environ Sci Pollut Res Int, 2015 Jun;22(12):9424-37.
    PMID: 25604562 DOI: 10.1007/s11356-015-4093-7
    In this study, the distributions and sources of sediment-associated polycyclic aromatic hydrocarbons (PAHs) and hopanes in the Malaysian rivers and estuaries were evaluated. The concentrations of 16 USEPA PAHs varied from 225.5 to 293.9 (Perlis River), 195.2 to 481.2 (Kedah River), 791.2 to 1995.4 (Merbok River), 231.2 to 426.7 (Perak River), and 3803.2 to 7442.7 ng g(-1) (Klang River) dry weight. PAHs can be classified as moderate in the Perlis, Kedah, and Perak Rivers, moderate to high in the Merbok River, and high to very high in the Klang River. The comparison of PAHs with sediment quality guidelines (SQGs) indicates that occasionally adverse biological effects may occur from total PAHs, low molecular weight (LMW), and high molecular weight (HMW) PAHs at stations 1, 2, and 3 of the Klang River and from total PAHs at station 2 of the Merbok River. The diagnostic ratios of individual PAHs indicate both petrogenic and pyrogenic origin PAHs with significant dominance of pyrogenic sources in the study areas. The results suggest that Malaysian sediments had hopane ratios (C29/C30) similar to MECO suggesting MECO as a major source of the petroleum hydrocarbons found in the sediments, which is consistent with results reported in previous studies. These findings demonstrate that effective and improved environmental regulations in Malaysia have shifted the source of petroleum hydrocarbons from petrogenic to pyrogenic origin.
    MeSH terms: Environmental Monitoring; Malaysia; Polycyclic Hydrocarbons, Aromatic/chemistry*; Triterpenes/chemistry*; Water Pollutants, Chemical/chemistry*; Geologic Sediments*; Rivers/chemistry*; Estuaries*
  5. Sachithanandan A
    Interact Cardiovasc Thorac Surg, 2015 Feb;20(2):221.
    PMID: 25605822 DOI: 10.1093/icvts/ivu415
    MeSH terms: Humans; Lung Neoplasms/mortality*; Colorectal Neoplasms/mortality*; Metastasectomy/mortality*
  6. Dalaba MA, Akweongo P, Aborigo RA, Saronga HP, Williams J, Aninanya GA, et al.
    BMC Health Serv Res, 2015;15:34.
    PMID: 25608609 DOI: 10.1186/s12913-014-0659-1
    The cost of treating maternal complications has serious economic consequences to households and can hinder the utilization of maternal health care services at the health facilities. This study estimated the cost of maternal complications to women and their households in the Kassena-Nankana district of northern Ghana.
    MeSH terms: Adult; Cross-Sectional Studies; Health Expenditures/statistics & numerical data*; Female; Ghana; Humans; Maternal Health Services/economics*; Maternal Health Services/utilization*; Maternal Health Services/statistics & numerical data; Pregnancy; Pregnancy Complications/economics*; Pregnancy Complications/therapy*; Socioeconomic Factors; Young Adult
  7. Park JY, Ngan HY, Park W, Cao Z, Wu X, Ju W, et al.
    J Gynecol Oncol, 2015 Jan;26(1):68-74.
    PMID: 25609163 DOI: 10.3802/jgo.2015.26.1.68
    The Asian Society of Gynecologic Oncology International Workshop 2014 on gynecologic oncology was held in Asan Medical Center, Seoul, Korea on the 23rd to 24th August 2014. A total of 179 participants from 17 countries participated in the workshop, and the up-to-date findings on the management of gynecologic cancers were presented and discussed. This meeting focused on the new trends in the management of cervical cancer, fertility-sparing management of gynecologic cancers, surgical management of gynecologic cancers, and recent advances in translational research on gynecologic cancers.
    MeSH terms: Uterine Cervical Neoplasms/therapy; Female; Genital Neoplasms, Female/therapy*; Humans; Ovarian Neoplasms/therapy; Translational Medical Research/methods; Fertility Preservation/methods
  8. Baskaran G, Salvamani S, Ahmad SA, Shaharuddin NA, Pattiram PD, Shukor MY
    Drug Des Devel Ther, 2015;9:509-17.
    PMID: 25609924 DOI: 10.2147/DDDT.S75056
    The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases.
    MeSH terms: Chromatography, High Pressure Liquid; Hypercholesterolemia/drug therapy*; Gas Chromatography-Mass Spectrometry; Phytotherapy; Plant Extracts/pharmacology*; Plant Extracts/chemistry; Plants, Medicinal; Plant Leaves; Hydroxymethylglutaryl-CoA Reductase Inhibitors/isolation & purification; Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology*; Hydroxymethylglutaryl-CoA Reductase Inhibitors/chemistry; Tandem Mass Spectrometry; Chromatography, Reverse-Phase
  9. Mohaghegh Z, Abedi P, Dilgouni T, Namvar F, Ruzafza S
    Horm. Metab. Res., 2015 Apr;47(4):284-8.
    PMID: 25611206 DOI: 10.1055/s-0034-1395607
    The predisposing factors of preeclampsia may endanger the mother's heath as well as her neonate. One hypothesis related to preeclampsia is vitamin D deficiency or insufficiency. This study was conducted to evaluate the relationship between preeclampsia and the serum level of 25-hydroxyvitamin D (25-OH-D) in mothers and their neonates. In this case-control study, we recruited 41 preeclamptic and 50 healthy women from the Imam Khomeini Hospital in Ahvaz, Iran. Venous blood (2 ml) from mothers (in time of labor) and 2 ml of blood from the umbilical cord were taken, centrifuged, stored at -30°C and sent to a laboratory for analysis of 25-OH-D by ELISA. Vitamin D levels<20 ng/ml were regarded as deficiency, levels between 21-29 ng/ml were regarded as insufficiency, and if levels were higher than 30 ng/ml, these were considered normal. Independent t-test, chi-square, Spearman correlation coefficient and logistic regression were used to analyze data. Mean levels of 25-OH-D were significantly lower in preeclamptic women (15.2±13.6 vs. 23.3±15.3 ng/ml, p=0.001) and in their neonates (15.2±13.1 vs. 21.6±12.6 ng/ml, p=0.01) compared to normal pregnant women and their neonates. There was a significant relationship between the levels of vitamin D in preeclamptic women with levels of this vitamin in their neonates (r=0.901, p=0.0001). 25-OH-D deficiency that exist in preeclamptic mothers, may be a health risk for their infants, therefore, early use of vitamin D supplement with higher dose than 400 IU in Iranian women is recommended.
    MeSH terms: Adult; Female; Fetal Blood/chemistry*; Gestational Age; Humans; Infant, Newborn; Iran/epidemiology; Pre-Eclampsia/blood*; Pre-Eclampsia/etiology; Pregnancy; Pregnancy Complications/blood*; Vitamin D/administration & dosage; Vitamin D/analogs & derivatives*; Vitamin D/blood; Vitamin D Deficiency/blood; Vitamin D Deficiency/complications*; Vitamin D Deficiency/epidemiology; Case-Control Studies; Dietary Supplements
  10. Leong Abdullah MF, Nik Jaafar NR, Zakaria H, Rajandram RK, Mahadevan R, Mohamad Yunus MR, et al.
    Psychooncology, 2015 Aug;24(8):894-900.
    PMID: 25612065 DOI: 10.1002/pon.3740
    Positive and negative psychological reactions have been described in head and neck cancer patients. Nevertheless, the relationships between these responses across time need to be studied to understand the patients' strengths and vulnerabilities.
  11. Ahmadi H, Nilashi M, Ibrahim O
    Int J Med Inform, 2015 Mar;84(3):166-88.
    PMID: 25612792 DOI: 10.1016/j.ijmedinf.2014.12.004
    This study mainly integrates the mature Technology-Organization-Environment (TOE) framework and recently developed Human-Organization-Technology (HOT) fit model to identify factors that affect the hospital decision in adopting Hospital Information System (HIS).
    MeSH terms: Decision Making, Organizational*; Diffusion of Innovation; Health Policy; Hospital Information Systems*; Hospitals, Public; Humans; Malaysia; Organizational Innovation*; Surveys and Questionnaires
  12. Tan MP, Kamaruzzaman SB, Zakaria MI, Chin AV, Poi PJ
    Geriatr Gerontol Int, 2015 Jan 22.
    PMID: 25613422 DOI: 10.1111/ggi.12446
    METHODS: Information on sociodemographics, dependency using the Barthel index and fall characteristics were collected from consecutive patients attending the ED over a 6-month period. Barthel score was reassessed at 12 months. Ten-year mortality data were obtained through the National Registry Department.
    RESULTS: A total of 198 participants, with a mean age (standard deviation) of 76.2 years (6.3 years) and 74% women, were recruited. Of these, 70% sustained falls indoors, while 49% of falls occurred between 06.00 to 12.00 hours. Total Barthel scores were significantly lower at 1-year follow up compared with baseline (median [interquartile range], 20 [2] vs 18 [5], P 
    MeSH terms: Accidental Falls*; Aged*; Emergency Service, Hospital; Hospitals, University; Humans; Malaysia; Mortality*; Cohort Studies
  13. Lim JC, Jeyaraj EJ, Sagineedu SR, Wong WS, Stanslas J
    Pharmacology, 2015;95(1-2):70-7.
    PMID: 25613753 DOI: 10.1159/000370313
    Andrographolide has been reported with anticancer and anti-inflammatory properties through the inhibition of the activity of signaling molecules such as v-Src, nuclear factor-κB (NF-κB), STAT3, and PI3K. NF-κB has been proven to promote cancer cell survival, and targeting this pathway will halt the growth of cancer cells. Efforts have been made to produce semisynthetic derivatives of andrographolide with improved anticancer potency and selectivity. Subsequently, the effect of a selected derivative, 3,14,19-tripropionylandrographolide (SRS06), was tested for its action against NF-κB.
    MeSH terms: Antineoplastic Agents/pharmacology*; Carcinoma, Non-Small-Cell Lung/metabolism*; Cell Survival/drug effects; Diterpenes/pharmacology*; Humans; Lung Neoplasms/metabolism*; Signal Transduction/drug effects; NF-kappa B/antagonists & inhibitors*; Cell Line, Tumor; DNA Fragmentation
  14. Ahmed A, Masud MM, Al-Amin AQ, Yahaya SR, Rahman M, Akhtar R
    Environ Sci Pollut Res Int, 2015 Jun;22(12):9494-504.
    PMID: 25613801 DOI: 10.1007/s11356-015-4110-x
    This study empirically estimates farmers' willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in Pakistan's agricultural sectors. The contingent valuation method (CVM) was employed to determine a monetary valuation of farmers' preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues. The survey was conducted by distributing structured questionnaires among Pakistani farmers. The study found that 67 % of respondents were willing to pay for a planned adaptation programme. However, several socioeconomic and motivational factors exert greater influence on their willingness to pay (WTP). This paper specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support attempts by policy makers to design an efficient adaptation framework for mitigating and adapting to the adverse impacts of climate change.
    MeSH terms: Acclimatization; Agriculture/economics*; Agriculture/methods*; Humans; Motivation; Pakistan; Surveys and Questionnaires; Socioeconomic Factors; Climate Change*
  15. Mohd Zahid AZ, Ismail Z, Abdullah B, Daud S
    PMID: 25614093 DOI: 10.1016/j.ejogrb.2014.12.018
    OBJECTIVE: To investigate the experience of medical students during a clinical attachment in obstetrics and gynaecology (O&G).
    STUDY DESIGN: A questionnaire was distributed to medical students who completed their O&G posting between August 2012 and August 2013. The first part included basic demographic details (age, gender, and ethnicity) and frequency of actual clinical experience; the second part explored students' perception of their training and their relationship with other staff, in particular feeling of discrimination by specified groups of medical personnel. The responses were recorded using a Likert scale and were recategorised during analysis.
    RESULTS: A total of 370 questionnaires were distributed, and 262 completed questionnaires were returned, giving a response rate of 71%. Female students had a significantly higher median (IqR) number of vaginal examinations performed 0.25(0.69) (p=0.002) compared to male students. Male students experienced a higher proportion of patient rejections during medical consultation, 87% vs. 32% of female students (p<0.001), a higher rate of refusal for clerking (71.4% vs. 57.5% of females, p=0.035) and a higher rate of patients declining consent for internal examination (93.3% vs. 67.6% of females, p<0.001). The majority of male students felt that their gender negatively affected their learning experience (87% vs. 27.4% of the female students, p<0.001). Male students reported a significantly higher proportion of discrimination against their gender by medical officers (p=0.018) and specialists/consultants (p<0.001) compared to females but there was no discrimination between genders by staff nurses or house officers. A majority (58%) of female students stated an interest in pursuing O&G as a future career compared to 31.2% of male students.
    CONCLUSIONS: Our study confirmed that gender bias exists in our clinical setting as male students gain significantly less experience than female students in pelvic examination skills. We also demonstrated that compared to female students, male students experience higher levels of discrimination against their gender by trainers who are medical officers and specialists/consultants. Trainers must improve their attitudes towards male students, to encourage them and make them feel welcome in the clinical area. We must minimize gender discrimination and educational inequities experienced by male students, in order to improve their learning experience.
    KEYWORDS: Gender discrimination; Obstetrics and gynaecology; Training
    MeSH terms: Attitude of Health Personnel*; Career Choice; Clinical Clerkship; Female; Gynecology/education*; Humans; Male; Nursing Staff; Obstetrics/education*; Physicians; Surveys and Questionnaires; Students, Medical*; Treatment Refusal; Gynecological Examination; Sexism*
  16. Ragavan AD, Govind SK
    Parasitol Res, 2015 Mar;114(3):1163-6.
    PMID: 25614298 DOI: 10.1007/s00436-014-4296-8
    Dientamoeba fragilis, a trichomonad parasite is usually found in the gastrointestinal tract of human, and it is known to be the cause for gastrointestinal disease. The parasite is globally distributed and mostly found in rural and urban areas. The parasite is found in humans and nonhuman primates such as the macaques, baboons, and gorillas. Often, the parasite is confused with another largely found organism in stools called Blastocystis sp. especially when seen directly under light microscopy on culture samples containing both parasites. Both sometimes are seen with two nuclei with sizes tending to be similar which complicates identification. Stools were collected fresh from nine previously diagnosed persons infected with D. fragilis who also were found to be positive for Blastocystis sp. Samples were then cultured in Loeffler's medium and were stained with Giemsa, iron hematoxylin, and modified Fields' (MF) stain, respectively. D. fragilis was differentiated from Blastocystis sp. when stained with MF stain by the presence of a thinner outer membrane with clearly demarcated nuclei in the center of the cell whilst Blastocystis sp. had a darker and thicker stained outer membrane with the presence of two nuclei. The staining contrast was more evident with modified Fields' stain when compared with the other two. The simplicity in preparing the stain as well as the speed of the staining procedure make MF stain an ideal alternate. The modified Fields' stain is faster and easier to prepare when compared to the other two stains. MF stain provides a better contrast differentiating the two organisms and therefore provides a more reliable diagnostic method to precisely identify one from the other especially when cultures show mixed infections.
    MeSH terms: Animals; Azure Stains; Cell Nucleus; Dientamoeba/cytology*; Dientamoeba/isolation & purification; Dientamoebiasis/diagnosis*; Dientamoebiasis/parasitology; Coloring Agents; Feces/parasitology; Hematoxylin; Humans; Microscopy; Staining and Labeling/methods*; Blastocystis Infections/diagnosis*; Blastocystis Infections/parasitology; Blastocystis/cytology*; Blastocystis/isolation & purification
  17. Harreld JH, Mohammed N, Goldsberry G, Li X, Li Y, Boop F, et al.
    AJNR Am J Neuroradiol, 2015 May;36(5):993-9.
    PMID: 25614472 DOI: 10.3174/ajnr.A4221
    Postoperative intraspinal subdural collections in children after posterior fossa tumor resection may temporarily hinder metastasis detection by MR imaging or CSF analysis, potentially impacting therapy. We investigated the incidence, imaging and clinical features, predisposing factors, and time course of these collections after posterior fossa tumor resection.
    MeSH terms: Child; Child, Preschool; Female; Humans; Magnetic Resonance Imaging; Male; Postoperative Period; Retrospective Studies; Spinal Cord/pathology*; Spinal Cord Diseases/etiology*; Spinal Cord Diseases/epidemiology*; Spinal Cord Diseases/pathology; Infratentorial Neoplasms/surgery*; Incidence; Neurosurgical Procedures/adverse effects*
  18. Wan Ahmad WN, Sakri F, Mokhsin A, Rahman T, Mohd Nasir N, Abdul-Razak S, et al.
    PLoS One, 2015;10(1):e0116867.
    PMID: 25614985 DOI: 10.1371/journal.pone.0116867
    BACKGROUND: Inflammation, endothelial activation and oxidative stress have been established as key events in the initiation and progression of atherosclerosis. High-density lipoprotein cholesterol (HDL-c) is protective against atherosclerosis and coronary heart disease, but its association with inflammation, endothelial activation and oxidative stress is not well established.

    OBJECTIVES: (1) To compare the concentrations of biomarkers of inflammation, endothelial activation and oxidative stress in subjects with low HDL-c compared to normal HDL-c; (2) To examine the association and correlation between HDL-c and these biomarkers and (3) To determine whether HDL-c is an independent predictor of these biomarkers.

    METHODS: 422 subjects (mean age±SD = 43.2±11.9 years) of whom 207 had low HDL-c concentrations (HDL-c <1.0 mmol/L and <1.3 mmol/L for males and females respectively) and 215 normal controls (HDL-c ≥1.0 and ≥1.3 mmol/L for males and females respectively) were recruited in this study. The groups were matched for age, gender, ethnicity, smoking status, diabetes mellitus and hypertension. Fasting blood samples were collected for analysis of biomarkers of inflammation [high-sensitivity C-reactive protein (hsCRP) and Interleukin-6 (IL-6)], endothelial activation [soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1), soluble Intercellular Adhesion Molecule-1 (sICAM-1) and E-selectin)] and oxidative stress [F2-Isoprostanes, oxidized Low Density Lipoprotein (ox-LDL) and Malondialdehyde (MDA)].

    RESULTS: Subjects with low HDL-c had greater concentrations of inflammation, endothelial activation and oxidative stress biomarkers compared to controls. There were negative correlations between HDL-c concentration and biomarkers of inflammation (IL-6, p = 0.02), endothelial activation (sVCAM-1 and E-selectin, p = 0.029 and 0.002, respectively), and oxidative stress (MDA and F2-isoprostane, p = 0.036 and <0.0001, respectively). Multiple linear regression analysis showed HDL-c as an independent predictor of IL-6 (p = 0.02) and sVCAM-1 (p<0.03) after correcting for various confounding factors.

    CONCLUSION: Low serum HDL-c concentration is strongly correlated with enhanced status of inflammation, endothelial activation and oxidative stress. It is also an independent predictor for enhanced inflammation and endothelial activation, which are pivotal in the pathogenesis of atherosclerosis and atherosclerosis-related complications.

    MeSH terms: Adult; Aged; C-Reactive Protein/metabolism; Endothelium, Vascular/metabolism*; Female; Humans; Inflammation/metabolism*; Cholesterol, LDL/blood*; Malaysia; Male; Middle Aged; Biomarkers/blood; Interleukin-6/metabolism; Oxidative Stress*; Vascular Cell Adhesion Molecule-1/metabolism; Young Adult
  19. Fung SY, Lee ML, Tan NH
    Toxicon, 2015 Mar;96:38-45.
    PMID: 25615711 DOI: 10.1016/j.toxicon.2015.01.012
    Snake venom LAAOs have been reported to exhibit a wide range of pharmacological activities, including cytotoxic, edema-inducing, platelet aggregation-inducing/platelet aggregation-inhibiting, bactericidal and antiviral activities. A heat-stable form of l-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom (OH-LAAO) has been shown to exhibit very potent cytotoxicity against human tumorigenic cells but not in their non-tumorigenic counterparts, and the cytotoxicity was due to the apoptosis-inducing effect of the enzyme. In this work, the molecular mechanism of cell death induced by OH-LAAO was investigated. The enzyme exerts its apoptosis-inducing effect presumably via both intrinsic and extrinsic pathways as suggested by the increase in caspase-8 and -9 activities. Oligonucleotide microarray analysis showed that the expression of a total of 178 genes was significantly altered as a result of oxidative stress induced by the hydrogen peroxide generated by the enzyme. Of the 178 genes, at least 27 genes are involved in apoptosis and cell death. These alterations of gene expression was presumably caused by the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidative modifications of signaling molecules that eventually lead to apoptosis and cell death. The very substantial up-regulation of cytochrome P450 genes may also contribute to the potent cytotoxic action of OH-LAAO by producing excessive reactive oxygen species (ROS). In conclusion, the potent apoptosis inducing activity of OH-LAAO was likely due to the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidation of signalling molecules.
    MeSH terms: Analysis of Variance; Animals; Cobra Venoms/toxicity*; Gene Expression Regulation/drug effects*; Humans; Hydrogen Peroxide/metabolism*; Oxidation-Reduction/drug effects; Cell Death/drug effects*; Reactive Oxygen Species/metabolism; Elapidae/metabolism*; Gene Expression Profiling; Microarray Analysis; L-Amino Acid Oxidase/toxicity*; Caspase 8/metabolism; Caspase 9/metabolism; Real-Time Polymerase Chain Reaction; MCF-7 Cells
  20. Choi JR, Pingguan-Murphy B, Wan Abas WA, Yong KW, Poon CT, Noor Azmi MA, et al.
    PLoS One, 2015;10(1):e0115034.
    PMID: 25615717 DOI: 10.1371/journal.pone.0115034
    Adipose tissue-derived stromal cells (ASCs) natively reside in a relatively low-oxygen tension (i.e., hypoxic) microenvironment in human body. Low oxygen tension (i.e., in situ normoxia), has been known to enhance the growth and survival rate of ASCs, which, however, may lead to the risk of tumourigenesis. Here, we investigated the tumourigenic potential of ASCs under their physiological condition to ensure their safe use in regenerative therapy. Human ASCs isolated from subcutaneous fat were cultured in atmospheric O2 concentration (21% O2) or in situ normoxia (2% O2). We found that ASCs retained their surface markers, tri-lineage differentiation potential, and self-renewal properties under in situ normoxia without altering their morphology. In situ normoxia displayed a higher proliferation and viability of ASCs with less DNA damage as compared to atmospheric O2 concentration. Moreover, low oxygen tension significantly up-regulated VEGF and bFGF mRNA expression and protein secretion while reducing the expression level of tumour suppressor genes p16, p21, p53, and pRb. However, there were no significant differences in ASCs telomere length and their relative telomerase activity when cultured at different oxygen concentrations. Collectively, even with high proliferation and survival rate, ASCs have a low tendency of developing tumour under in situ normoxia. These results suggest 2% O2 as an ideal culture condition for expanding ASCs efficiently while maintaining their characteristics.
    MeSH terms: Adipose Tissue/cytology; Adult; Cells, Cultured; Female; Humans; Oxygen/metabolism*; Cell Hypoxia; Telomerase/metabolism; Tumor Suppressor Proteins/genetics; Tumor Suppressor Proteins/metabolism; Vascular Endothelial Growth Factor A/genetics; Vascular Endothelial Growth Factor A/metabolism; Cell Proliferation*; Telomere Homeostasis; Mesenchymal Stromal Cells/cytology; Mesenchymal Stromal Cells/metabolism*; Mesenchymal Stromal Cells/physiology; Carcinogenesis*
External Links