Browse publications by year: 2012

Fulltext Degradability enhancement of poly(lactic acid) by stearate-Zn(3)Al LDH nanolayers

Eili M, Shameli K, Ibrahim NA, Wan Yunus WMZ

Int J Mol Sci, 2012;13(7):7938-7951.
PMID: 22942682 DOI: 10.3390/ijms13077938

Recent environmental problems and societal concerns associated with the disposal of petroleum based plastics throughout the world have triggered renewed efforts to develop new biodegradable products compatible with our environment. This article describes the preparation, characterization and biodegradation study of poly(lactic acid)/layered double hydroxide (PLA/LDH) nanocomposites from PLA and stearate-Zn(3)Al LDH. A solution casting method was used to prepare PLA/stearate-Zn(3)Al LDH nanocomposites. The anionic clay Zn(3)Al LDH was firstly prepared by co-precipitation method from a nitrate salt solution at pH 7.0 and then modified by stearate anions through an ion exchange reaction. This modification increased the basal spacing of the synthetic clay from 8.83 Å to 40.10 Å. The morphology and properties of the prepared PLA/stearate-Zn(3)Al LDH nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), tensile tests as well as biodegradation studies. From the XRD analysis and TEM observation, the stearate-Zn(3)Al LDH lost its ordered stacking-structure and was greatly exfoliated in the PLA matrix. Tensile test results of PLA/stearate-Zn(3)Al LDH nanocomposites showed that the presence of around 1.0-3.0 wt % of the stearate-Zn(3)Al LDH in the PLA drastically improved its elongation at break. The biodegradation studies demonstrated a significant biodegradation rate improvement of PLA in the presence of stearate-Zn(3)Al LDH nanolayers. This effect can be caused by the catalytic role of the stearate groups in the biodegradation mechanism leading to much faster disintegration of nanocomposites than pure PLA.

MeSH terms: Enzymes, Immobilized/chemistry; Hydrogen-Ion Concentration; Hydroxides/chemistry*; Nitrates/chemistry*; Oxidation-Reduction; Polyesters; Polymers/chemistry*; Stearates/chemistry*; Tensile Strength; Thermogravimetry; X-Ray Diffraction; Aluminum Compounds/chemistry*; Zinc Compounds/chemistry*; Lactic Acid/chemistry*; Environmental Restoration and Remediation; Nanocomposites/chemistry; Elastic Modulus
Fulltext Green formation of spherical and dendritic silver nanostructures under microwave irradiation without reducing agent

Noroozi M, Zakaria A, Moksin MM, Wahab ZA, Abedini A

Int J Mol Sci, 2012;13(7):8086-96.
PMID: 22942691 DOI: 10.3390/ijms13078086

The rapid and green formation of spherical and dendritic silver nanostructures based on microwave irradiation time was investigated. Silver nanoparticles were successfully fabricated by reduction of Ag(+) in a water medium and using polyvinylpyrrolidone (PVP) as the stabilizing agent and without the use of any other reducing agent, and were compared with those synthesized by conventional heating method. UV-vis absorption spectrometry, transmission electron microscopy (TEM), atomic absorption spectroscopy (AAS) and photon correlation spectroscopy (PCS) measurements, indicated that increasing the irradiation time enhanced the concentration of silver nanoparticles and slightly increased the particle size. There was a lack of large silver nanoparticles at a high concentration, but interestingly, the formation and growth of silver dendrite nanostructures appeared. Compared to conventional heating methods, the silver nanoparticle suspension produced by irradiated microwaves was more stable over a six-month period in aqueous solution without any signs of precipitation.

MeSH terms: Microwaves; Silver Nitrate/chemistry*; Reducing Agents/chemistry; Dendrimers/chemical synthesis*; Green Chemistry Technology
Fulltext Production of defatted palm kernel cake protein hydrolysate as a valuable source of natural antioxidants

Zarei M, Ebrahimpour A, Abdul-Hamid A, Anwar F, Saari N

Int J Mol Sci, 2012;13(7):8097-111.
PMID: 22942692 DOI: 10.3390/ijms13078097

The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential.

MeSH terms: Biphenyl Compounds/chemistry; Free Radicals/chemistry; Hydrolysis; Papain/chemistry; Peptide Fragments/isolation & purification; Peptide Fragments/chemistry*; Picrates/chemistry; Plant Oils/chemistry; Plant Proteins/isolation & purification; Plant Proteins/chemistry*; Protein Hydrolysates/chemistry; Free Radical Scavengers/isolation & purification; Free Radical Scavengers/chemistry*; Arecaceae/chemistry; Proteolysis
Fulltext Reflection and transmission coefficient of yttrium iron garnet filled polyvinylidene fluoride composite using rectangular waveguide at microwave frequencies

Soleimani H, Abbas Z, Yahya N, Shameli K, Soleimani H, Shabanzadeh P

Int J Mol Sci, 2012;13(7):8540-8.
PMID: 22942718 DOI: 10.3390/ijms13078540

The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer.

MeSH terms: Iron/chemistry*; Microscopy, Electron, Scanning; Microwaves; Particle Size; Polyvinyls/chemistry*; Surface Properties; X-Ray Diffraction; Yttrium/chemistry*; Spectroscopy, Fourier Transform Infrared; Powder Diffraction; Nanocomposites/ultrastructure; Nanocomposites/chemistry*
Fulltext Effects of brown rice and white rice on expression of xenobiotic metabolism genes in type 2 diabetic rats

Imam MU, Ismail M

Int J Mol Sci, 2012;13(7):8597-608.
PMID: 22942722 DOI: 10.3390/ijms13078597

Xenobiotics constantly influence biological systems through several means of interaction. These interactions are disturbed in type 2 diabetes, with implications for disease outcome. We aimed to study the implications of such disturbances on type 2 diabetes and rice consumption, the results of which could affect management of the disease in developing countries. In a type 2 diabetic rat model induced through a combination of high fat diet and low dose streptozotocin injection, up-regulation of xenobiotic metabolism genes in the diabetic untreated group was observed. Xenobiotic metabolism genes were upregulated more in the white rice (WR) group than the diabetic untreated group while the brown rice (BR) group showed significantly lower expression values, though not as effective as metformin, which gave values closer to the normal non-diabetic group. The fold changes in expression in the WR group compared to the BR group for Cyp2D4, Cyp3A1, Cyp4A1, Cyp2B1, Cyp2E1, Cyp2C11, UGT2B1, ALDH1A1 and Cyp2C6 were 2.6, 2, 1.5, 4, 2.8, 1.5, 1.8, 3 and 5, respectively. Our results suggest that WR may upregulate these genes in type 2 diabetes more than BR, potentially causing faster drug metabolism, less drug efficacy and more toxicity. These results may have profound implications for rice eating populations, constituting half the world's population.

MeSH terms: Animals; Aryl Hydrocarbon Hydroxylases/genetics; Aryl Hydrocarbon Hydroxylases/metabolism*; Diabetes Mellitus, Experimental/enzymology*; Diabetes Mellitus, Type 2/enzymology*; Diet; Liver/enzymology; Male; Oryza/metabolism*; Gene Expression; Rats, Sprague-Dawley; Glycemic Index
Fulltext Infrared study of Er(3+)/Yb(3+) Co-Doped GeO(2)-PbO-Bi(2)O(3) glass

Bahari HR, Sidek HA, Adikan FR, Yunus WM, Halimah MK

Int J Mol Sci, 2012;13(7):8609-14.
PMID: 22942723 DOI: 10.3390/ijms13078609

Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO(2)-PbO-Bi(2)O(3) glass host doped with Er(3+)/Yb(3+) ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi(2)O(3) participate with PbO(4) tetragonal pyramids and strongly distort BiO(6) octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.

MeSH terms: Bismuth/chemistry*; Erbium/chemistry*; Germanium/chemistry*; Glass/chemistry*; Lead/chemistry*; Oxides/chemistry*; Ytterbium/chemistry*; Spectroscopy, Fourier Transform Infrared
Fulltext Antioxidant property enhancement of sweet potato flour under simulated gastrointestinal pH

Chan KW, Khong NM, Iqbal S, Umar IM, Ismail M

Int J Mol Sci, 2012;13(7):8987-97.
PMID: 22942747 DOI: 10.3390/ijms13078987

Sweet potato is known to be rich in healthful antioxidants, but the stability of its antioxidant properties under gastrointestinal pH is very much unknown. Hence, this study aimed to evaluate the changes in antioxidant properties (total contents of phenolics and flavonoids as well as antioxidant activity) of sweet potato flour (SPF) under simulated gastrointestinal pH conditions. It was found that the yield of SPF crude phenolic extract increased from 0.29 to 3.22 g/100 g SPF upon subjection to gastrointestinal pH conditions (p < 0.05). Also elevated significantly were the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of SPF (p < 0.05). In summary, the antioxidant properties of SPF were enhanced under gastrointestinal pH conditions, suggesting that SPF might possess a considerable amount of bound phenolic and other antioxidative compounds. The antioxidant properties of SPF are largely influenced by pH and thus might be enhanced during the in vivo digestive process.

MeSH terms: Antioxidants/chemistry*; Flour*; Gastric Juice/chemistry*; Hydrogen-Ion Concentration; Ipomoea batatas/chemistry*
Fulltext 3D structure elucidation of thermostable L2 lipase from Thermophilic Bacillus sp. L2

Abd Rahman RN, Shariff FM, Basri M, Salleh AB

Int J Mol Sci, 2012;13(7):9207-17.
PMID: 22942761 DOI: 10.3390/ijms13079207

The crystallization of proteins makes it possible to determine their structure by X-ray crystallography, and is therefore important for the analysis of protein structure-function relationships. L2 lipase was crystallized by using the J-tube counter diffusion method. A crystallization consisting of 20% PEG 6000, 50 mM MES pH 6.5 and 50 mM NaCl was found to be the best condition to produce crystals with good shape and size (0.5 × 0.1 × 0.2 mm). The protein concentration used for the crystallization was 3 mg/mL. L2 lipase crystal has two crystal forms, Shape 1 and Shape 2. Shape 2 L2 lipase crystal was diffracted at 1.5 Å and the crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 72.0, b = 81.8, c = 83.4 Å, α = β = γ = 90°. There is one molecule per asymmetric unit and the solvent content of the crystals is 56.9%, with a Matthew's coefficient of 2.85 Å Da(-1). The 3D structure of L2 lipase revealed topological organization of α/β-hydrolase fold consisting of 11 β-strands and 13 α-helices. Ser-113, His-358 and Asp-317 were assigned as catalytic triad residues. One Ca(2+) and one Zn(2+) were found in the L2 lipase molecule.

MeSH terms: Bacillus/enzymology*; Bacterial Proteins/chemistry*; Calcium/chemistry*; Lipase/chemistry*; Zinc/chemistry*; Protein Structure, Tertiary; Crystallography, X-Ray
Fulltext Molecular characterization and comparative sequence analysis of defense-related gene, Oryza rufipogon receptor-like protein kinase 1

Law YS, Gudimella R, Song BK, Ratnam W, Harikrishna JA

Int J Mol Sci, 2012;13(7):9343-9362.
PMID: 22942769 DOI: 10.3390/ijms13079343

Many of the plant leucine rich repeat receptor-like kinases (LRR-RLKs) have been found to regulate signaling during plant defense processes. In this study, we selected and sequenced an LRR-RLK gene, designated as Oryza rufipogon receptor-like protein kinase 1 (OrufRPK1), located within yield QTL yld1.1 from the wild rice Oryza rufipogon (accession IRGC105491). A 2055 bp coding region and two exons were identified. Southern blotting determined OrufRPK1 to be a single copy gene. Sequence comparison with cultivated rice orthologs (OsI219RPK1, OsI9311RPK1 and OsJNipponRPK1, respectively derived from O. sativa ssp. indica cv. MR219, O. sativa ssp. indica cv. 9311 and O. sativa ssp. japonica cv. Nipponbare) revealed the presence of 12 single nucleotide polymorphisms (SNPs) with five non-synonymous substitutions, and 23 insertion/deletion sites. The biological role of the OrufRPK1 as a defense related LRR-RLK is proposed on the basis of cDNA sequence characterization, domain subfamily classification, structural prediction of extra cellular domains, cluster analysis and comparative gene expression.

MeSH terms: Base Sequence; Exons/physiology*; Molecular Sequence Data; Plant Proteins/genetics*; Protein Kinases/genetics*; Oryza/genetics*; Genes, Plant/physiology*; Polymorphism, Single Nucleotide*
De-novo mutations and genetic variation in the SCN1A gene in Malaysian patients with generalized epilepsy with febrile seizures plus (GEFS+)

Tan EH, Razak SA, Abdullah JM, Mohamed Yusoff AA

Epilepsy Res, 2012 Dec;102(3):210-5.
PMID: 22944210 DOI: 10.1016/j.eplepsyres.2012.08.004

Generalized epilepsy with febrile seizures plus (GEFS+) comprises a group of clinically and genetically heterogeneous epilepsy syndrome. Here, we provide the first report of clinical presentation and mutational analysis of SCN1A gene in 36 Malaysian GEFS+ patients. Mutational analysis of SCN1A gene revealed twenty seven sequence variants (missense mutation and silent polymorphism also intronic polymorphism), as well as 2 novel de-novo mutations were found in our patients at coding regions, c.5197A>G (N1733D) and c.4748A>G (H1583R). Our findings provide potential genetic insights into the pathogenesis of GEFS+ in Malaysian populations concerning the SCN1A gene mutations.

MeSH terms: Seizures, Febrile/complications; Seizures, Febrile/genetics*; DNA Mutational Analysis; Electroencephalography; Epilepsy, Generalized/complications; Epilepsy, Generalized/genetics*; Female; Humans; Malaysia; Male; Mutation/genetics*; Polymorphism, Single Nucleotide/genetics; NAV1.1 Voltage-Gated Sodium Channel/genetics*
Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA)

Idris SS, Rahman NA, Ismail K

Bioresour Technol, 2012 Nov;123:581-91.
PMID: 22944493 DOI: 10.1016/j.biortech.2012.07.065

The combustion characteristics of Malaysia oil palm biomass (palm kernel shell (PKS), palm mesocarp fibre (PMF) and empty fruit bunches (EFB)), sub-bituminous coal (Mukah Balingian) and coal/biomass blends via thermogravimetric analysis (TGA) were investigated. Six weight ratios of coal/biomass blends were prepared and oxidised under dynamic conditions from temperature 25 to 1100°C at four heating rates. The thermogravimetric analysis demonstrated that the EFB and PKS evolved additional peak besides drying, devolatilisation and char oxidation steps during combustion. Ignition and burn out temperatures of blends were improved in comparison to coal. No interactions were observed between the coal and biomass during combustion. The apparent activation energy during this process was evaluated using iso-conversional model free kinetics which resulted in highest activation energy during combustion of PKS followed by PMF, EFB and MB coal. Blending oil palm biomass with coal reduces the apparent activation energy value.

MeSH terms: Atmosphere; Coal/analysis*; Hot Temperature*; Kinetics; Malaysia; Oxidation-Reduction; Plant Oils/chemistry*; Temperature; Thermogravimetry/methods*; Time Factors; Biomass*
Fulltext Epithelial fusion during neural tube morphogenesis

Pai YJ, Abdullah NL, Mohd-Zin SW, Mohammed RS, Rolo A, Greene ND, et al.

Birth Defects Res. Part A Clin. Mol. Teratol., 2012 Oct;94(10):817-23.
PMID: 22945349 DOI: 10.1002/bdra.23072

Adhesion and fusion of epithelial sheets marks the completion of many morphogenetic events during embryogenesis. Neural tube closure involves an epithelial fusion sequence in which the apposing neural folds adhere initially via cellular protrusions, proceed to a more stable union, and subsequently undergo remodeling of the epithelial structures to yield a separate neural tube roof plate and overlying nonneural ectoderm. Cellular protrusions comprise lamellipodia and filopodia, and studies in several different systems emphasize the critical role of RhoGTPases in their regulation. How epithelia establish initial adhesion is poorly understood but, in neurulation, may involve interactions between EphA receptors and their ephrinA ligands. Epithelial remodeling is spatially and temporally correlated with apoptosis in the dorsal neural tube midline, but experimental inhibition of this cell death does not prevent fusion and remodeling. A variety of molecular signaling systems have been implicated in the late events of morphogenesis, but genetic redundancy, for example among the integrins and laminins, makes identification of the critical players challenging. An improved understanding of epithelial fusion can provide insights into normal developmental processes and may also indicate the mode of origin of clinically important birth defects.

MeSH terms: Animals; Cell Adhesion/genetics; Cell Adhesion/physiology; Cell Fusion; Epithelial Cells/cytology; Epithelial Cells/metabolism; Epithelial Cells/physiology*; Humans; Models, Biological; Morphogenesis/genetics; Morphogenesis/physiology*; Neural Crest/cytology; Neural Crest/embryology*; Neural Crest/metabolism; Apoptosis/genetics; Apoptosis/physiology; Neural Tube/embryology*; Neural Tube/metabolism; Neural Tube/physiology; Neurulation/genetics; Neurulation/physiology
Tocotrienol research: past into present

Wong RS, Radhakrishnan AK

Nutr Rev, 2012 Sep;70(9):483-90.
PMID: 22946849 DOI: 10.1111/j.1753-4887.2012.00512.x

The vitamin E family consists of eight isomers known as alpha-, beta-, gamma-, and delta-tocopherols and alpha-, beta-, gamma-, and delta-tocotrienols. Numerous studies focused on the health benefits of these isomers have been performed since the discovery of vitamin E in 1922. Recent discoveries on the potential therapeutic applications of tocotrienols have revolutionized vitamin E research. Nevertheless, despite the abundance of literature, only 1% of vitamin E research has been conducted on tocotrienols. Many new advances suggest that the use of tocotrienols for health improvement or therapeutic purposes is promising. Although the mechanisms of action of tocotrienols in certain disease conditions have been explored, more detailed investigations into the fundamentals of the health-promoting effects of these molecules must be elucidated before they can be recommended for health improvement or for the treatment or prevention of disease. Furthermore, many of the studies on the effects of tocotrienols have been carried out using cell lines and animal models. The effects in humans must be well established before tocotrienols are used as therapeutic agents in various disease conditions, hence the need for more evidence-based human clinical trials.

MeSH terms: Animals; Antioxidants/physiology*; Antioxidants/therapeutic use; Diet*; Heart Diseases/prevention & control; Humans; Neoplasms/prevention & control; Vitamin E/physiology*; Vitamin E/therapeutic use; Evidence-Based Medicine; Tocotrienols/therapeutic use*
Differentiating Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii using nested polymerase chain reaction (PCR) in rural communities in Malaysia

Ngui R, Angal L, Fakhrurrazi SA, Lian YL, Ling LY, Ibrahim J, et al.

Parasit Vectors, 2012;5:187.
PMID: 22947430

In this study, a total of 426 human faecal samples were examined for the presence of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii infection via a combination of microscopic examination and nested polymerase chain reaction (PCR) targeting 16S ribosomal RNA of Entamoeba species.

MeSH terms: Adolescent; Adult; Child; Entamoeba/classification*; Entamoeba/genetics; Entamoeba/isolation & purification; Entamoebiasis/epidemiology*; Entamoebiasis/parasitology*; Feces/parasitology; Female; Humans; Malaysia/epidemiology; Male; Microscopy*; Parasitology; RNA, Ribosomal, 16S/genetics; Rural Population; Prevalence; RNA, Protozoan/genetics; Polymerase Chain Reaction*; Age Distribution; Sex Distribution; Molecular Diagnostic Techniques; Young Adult
Fulltext The epiphytic microbiota of the globally widespread macroalga Cladophora glomerata (Chlorophyta, Cladophorales)

Zulkifly S, Hanshew A, Young EB, Lee P, Graham ME, Graham ME, et al.

Am J Bot, 2012 Sep;99(9):1541-52.
PMID: 22947483 DOI: 10.3732/ajb.1200161

The filamentous chlorophyte Cladophora produces abundant nearshore populations in marine and freshwaters worldwide, often dominating periphyton communities and producing nuisance growths under eutrophic conditions. High surface area and environmental persistence foster such high functional and taxonomic diversity of epiphytic microfauna and microalgae that Cladophora has been labeled an ecological engineer. We tested the hypotheses that (1) Cladophora supports a structurally and functionally diverse epiphytic prokaryotic microbiota that influences materials cycling and (2) mutualistic host-microbe interactions occur. Because previous molecular sequencing-based analyses of the microbiota of C. glomerata found as western Lake Michigan beach drift had identified pathogenic associates such as Escherichia coli, we also asked if actively growing lentic C. glomerata harbors known pathogens.

MeSH terms: Chlorophyta/microbiology*; Bacteria/classification; Bacteria/genetics; Bacteria/ultrastructure; Base Sequence; Genotype; Phylogeny; RNA, Ribosomal, 16S/genetics; Seaweed/microbiology*; Wisconsin; Metagenome/genetics*
Redness enhances perceived aggression, dominance and attractiveness in men's faces

Stephen ID, Oldham FH, Perrett DI, Barton RA

Evol Psychol, 2012 Aug 17;10(3):562-72.
PMID: 22947678

In a range of non-human primate, bird and fish species, the intensity of red coloration in males is associated with social dominance, testosterone levels and mate selection. In humans too, skin redness is associated with health, but it is not known whether--as in non-human species--it is also associated with dominance and links to attractiveness have not been thoroughly investigated. Here we allow female participants to manipulate the CIELab a* value (red-green axis) of skin to maximize the perceived aggression, dominance and attractiveness of photographs of men's faces, and make two findings. First, participants increased a* (increasing redness) to enhance each attribute, suggesting that facial redness is perceived as conveying similar information about a male's qualities in humans as it does in non-human species. Second, there were significant differences between trial types: the highest levels of red were associated with aggression, an intermediate level with dominance, and the least with attractiveness. These differences may reflect a trade-off between the benefits of selecting a healthy, dominant partner and the negative consequences of aggression.

MeSH terms: Aggression/psychology*; Beauty*; Color*; Face*; Female; Humans; Image Processing, Computer-Assisted; Male; Photography; Social Dominance*; Young Adult
Serum testosterone, sex hormone-binding globulin and total calcium levels predict the calcaneal speed of sound in men

Chin KY, Soelaiman IN, Mohamed IN, Ngah WZ

Clinics (Sao Paulo), 2012 Aug;67(8):911-6.
PMID: 22948459

OBJECTIVES: Variations in sex hormones and the calcium balance can influence bone health in men. The present study aimed to examine the relationship between the calcaneal speed of sound and biochemical determinants of bone mass, such as sex hormones, parathyroid hormones and serum calcium.
METHODS: Data from 549 subjects from the Malaysian Aging Male Study, which included Malay and Chinese men aged 20 years and older residing in the Klang Valley, were used for analysis. The subjects' calcaneal speed of sound was measured, and their blood was collected for biochemical analysis. Two sets of multiple regression models were generated for the total/bioavailable testosterone and estradiol to avoid multicollinearity.
RESULTS: The multiple regression results revealed that bioavailable testosterone and serum total calcium were significant predictors of the calcaneal speed of sound in the adjusted model. After adjustment for ethnicity and body mass index, only bioavailable testosterone remained significant; the total serum calcium was marginally insignificant. In a separate model, the total testosterone and sex hormone-binding globulin were significant predictors, whereas the total serum calcium was marginally insignificant. After adjustment for ethnicity and body mass index (BMI), the significance persisted for total testosterone and SHBG. After further adjustment for age, none of the serum biochemical determinants was a significant predictor of the calcaneal speed of sound.
CONCLUSION: There is a significant age-dependent relationship between the calcaneal speed of sound and total testosterone, bioavailable testosterone and sex hormone-binding globulin in Chinese and Malay men in Malaysia. The relationship between total serum calcium and calcaneal speed of sound is ethnicity-dependent.

MeSH terms: Adult; Aged; Aged, 80 and over; Calcaneus/physiology*; Calcium/blood*; China; Estradiol/blood; Humans; Malaysia; Male; Middle Aged; Osteoporosis/blood; Osteoporosis/diagnosis*; Osteoporosis/physiopathology; Predictive Value of Tests; Sex Hormone-Binding Globulin/analysis*; Sound*; Testosterone/blood*; Bone Density/physiology; Body Mass Index; Statistics, Nonparametric; Young Adult
Upregulation of matrix synthesis in chondrocyte-seeded agarose following sustained bi-axial cyclic loading

Pingguan-Murphy B, Nawi I

Clinics (Sao Paulo), 2012 Aug;67(8):939-44.
PMID: 22948463

OBJECTIVES: The promotion of extracellular matrix synthesis by chondrocytes is a requisite part of an effective cartilage tissue engineering strategy. The aim of this in vitro study was to determine the effect of bi-axial cyclic mechanical loading on cell proliferation and the synthesis of glycosaminoglycans by chondrocytes in three-dimensional cultures.
METHOD: A strain comprising 10% direct compression and 1% compressive shear was applied to bovine chondrocytes seeded in an agarose gel during two 12-hour conditioning periods separated by a 12-hour resting period.
RESULTS: The bi-axial-loaded chondrocytes demonstrated a significant increase in glycosaminoglycan synthesis compared with samples exposed to uni-axial or no loading over the same period (p<0.05). The use of a free-swelling recovery period prior to the loading regime resulted in additional glycosaminoglycan production and a significant increase in DNA content (p<0.05), indicating cell proliferation.
CONCLUSIONS: These results demonstrate that the use of a bi-axial loading regime results in increased matrix production compared with uni-axial loading.

MeSH terms: Animals; Cattle; Cells, Cultured; Extracellular Matrix/genetics; Extracellular Matrix/metabolism*; Glycosaminoglycans/biosynthesis*; Sepharose; Stress, Mechanical; Time Factors; Up-Regulation/physiology*; Compressive Strength; Chondrocytes/cytology; Chondrocytes/metabolism*; Tissue Engineering/methods; Cell Proliferation
Flow and sediment yield simulations for Bukit Merah Reservoir catchment, Malaysia: a case study

Hasan ZA, Hamidon N, Yusof MS, Ghani AA

Water Sci Technol, 2012;66(10):2170-6.
PMID: 22949248 DOI: 10.2166/wst.2012.432

Bukit Merah Reservoir is the main potable and irrigation water source for Kerian District, Perak State, Malaysia. For the past two decades, the reservoir has experienced water stress. Land-use activities have been identified as the contributor of the sedimentation. The Soil and Water Assessment Tool (SWAT) was used to simulate and quantify the impacts of land-use change in the reservoir watershed. The SWAT was calibrated and two scenarios were constructed representing projected land use in the year 2015 and hypothetical land use to represent extensive land-use change in the catchment area. The simulation results based on 17 years of rainfall records indicate that average water quantity will not be significantly affected but the ground water storage will decrease and suspended sediment will increase. Ground water decrease and sediment yield increase will exacerbate the Bukit Merah Reservoir operation problem.

MeSH terms: Malaysia; Models, Theoretical; Water Movements*; Water Pollutants, Chemical; Reproducibility of Results; Geologic Sediments*; Geographic Information Systems; Rivers/chemistry*
Fulltext Detection of differential levels of proteins in the urine of patients with endometrial cancer: analysis using two-dimensional gel electrophoresis and o-glycan binding lectin

Mu AK, Lim BK, Hashim OH, Shuib AS

Int J Mol Sci, 2012;13(8):9489-501.
PMID: 22949810 DOI: 10.3390/ijms13089489

Cancers can cause some proteins to be aberrantly excreted or released in the urine, which can be used as biomarkers. To screen for potential biomarkers for endometrial cancer (ECa), the urinary proteins from patients who were newly diagnosed with early stage ECa and untreated controls were separated using two-dimensional gel electrophoresis (2-DE) and followed by image analysis. The altered levels of zinc alpha-2 glycoprotein, alpha 1-acid glycoprotein, and CD59 were detected in the patients compared to the controls. In addition, the urine of the ECa patients was also found to contain relatively lower levels of a fragment of nebulin when the 2-DE separated urinary proteins were probed using champedak galactose binding (CGB) lectin. The different levels of the nebulin fragment were further validated by subjecting the urinary protein samples to CGB lectin affinity chromatography and analysis of the bound fractions by LC-MS/MS. Our data is suggestive of the potential use of the differentially expressed urinary proteins as biomarkers for ECa although this requires further extensive validation on clinically representative populations.

MeSH terms: Chromatography, Affinity; Endometrium/metabolism*; Female; Glycoproteins/urine; Glycosylation; Humans; Biomarkers, Tumor/urine*; Blotting, Western; Electrophoresis, Gel, Two-Dimensional/methods*; Case-Control Studies; Endometrial Neoplasms/urine*; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Proteome/analysis*; Lectins/metabolism; Proteomics/methods*; Tandem Mass Spectrometry/methods*

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