Fisher, J, Hu, XQ, Stewart, TD, Williams, S, Tipper, JL, Ingham, E, Stone, MH, Davies, C, Hatto, P, Bolton, J, Riley, M, Hardaker, C, Isaac, GH & BERRY, G 2004, 'Wear of surface engineered metal-on-metal hip prostheses', Journal of Materials Science: Materials in Medicine, vol. 15, no. 3, pp. 225-235.
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Hutvágner, G, Simard, MJ, Mello, CC & Zamore, PD 2004, 'Sequence-Specific Inhibition of Small RNA Function', PLoS Biology, vol. 2, no. 4, pp. e98-e98.
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Hundreds of microRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) have been identified from both plants and animals, yet little is known about their biochemical modes of action or biological functions. Here we report that 2′-O-methyl oligonucleotides can act as irreversible, stoichiometric inhibitors of small RNA function. We show that a 2′-O-methyl oligonucleotide complementary to an siRNA can block mRNA cleavage in Drosophila embryo lysates and HeLa cell S100 extracts and in cultured human HeLa cells. In Caenorhabditis elegans, injection of the 2′-O-methyl oligonucleotide complementary to the miRNA let-7 can induce a let-7 loss-of-function phenocopy. Using an immobilized 2′-O-methyl oligonucleotide, we show that the C. elegans Argonaute proteins ALG-1 and ALG-2, which were previously implicated in let-7 function through genetic studies, are constituents of a let-7-containing protein-RNA complex. Thus, we demonstrate that 2′-O-methyl RNA oligonucleotides can provide an efficient and straightforward way to block small RNA function in vivo and furthermore can be used to identify small RNA-associated proteins that mediate RNA silencing pathways.
Khosroshahi, ME, Valanezhad, A & Tavakoli, J 2004, 'Evaluation of mid-IR laser radiation effect on 316L stainless steel corrosion resistance in physiological saline', Amirkabir (Journal of Science and Technology), vol. 15, no. 58 B, pp. 107-115.
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The effects of a short pulsed (∼ 400 ns) multiline hydrogen fluoride (HF) laser radiation operating on average at 2.8 μm has been studied on 316L stainless steel in terms of optical and physical parameters. At low fluences ≤ 8 Jcm -2 (phase I) no morphological changes occurred at the surface and melting began at ∼ 8.8 Jcm -2 (phase II) which continued up to about 30 Jcm -2. In this range the melting zone was effectively produced by high temperature surface centres growth which subsequently joined these centres together. Thermal ablation via surface vaporization began at ∼ 33 Jcm -2 (phase III). The results of SEM evaluation and corrosion resistance experiment which was carried out using EG&G device with cyclic potentiodynamic polarization method in a physiological (Hank's) solution indicated that pitting corrosion sensitivity was decreased ie. enhancement of corrosion resistance. Also, the XRD results showed a double increase of γ(111) at microstructure, thus in effect a superaustenite stainless steel was obtained at an optimized melting fluence.
Lee, DK, Lança, AJ, Cheng, R, Nguyen, T, Ji, XD, Gobeil, F, Chemtob, S, George, SR & O'Dowd, BF 2004, 'Agonist-independent Nuclear Localization of the Apelin, Angiotensin AT1, and Bradykinin B2 Receptors', Journal of Biological Chemistry, vol. 279, no. 9, pp. 7901-7908.
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Signaling of the apelin, angiotensin, and bradykinin peptides is mediated by G protein-coupled receptors related through structure and similarities of physiological function. We report nuclear expression as a characteristic of these receptors, including a nuclear localization for the apelin receptor in brain and cerebellum-derived D283 Med cells and the AT1 and bradykinin B2 receptors in HEK-293T cells. Immunocytochemical analyses revealed the apelin receptor with localization in neuronal nuclei in cerebellum and hypothalamus, exhibiting expression in neuronal cytoplasm or in both nuclei and cytoplasm. Confocal microscopy of HEK-293T cells revealed the majority of transfected cells displayed constitutive nuclear localization of AT1 and B2 receptors, whereas apelin receptors did not show nuclear localization in these cells. The majority of apelin receptor-transfected cerebellum D283 Med cells showed receptor nuclear expression. Immunoblot analyses of subcellular-fractionated D283 Med cells demonstrated endogenous apelin receptor species in nuclear fractions. In addition, an identified nuclear localization signal motif in the third intracellular loop of the apelin receptor was disrupted by a substituted glutamine in place of lysine. This apelin receptor (K242Q) did not exhibit nuclear localization in D283 Med cells. These results demonstrate the following: (i) the apelin receptor exhibits nuclear localization in human brain; (ii) distinct cell-dependent mechanisms for the nuclear transport of apelin, AT 1, and B2 receptors; and (iii) the disruption of a nuclear localization signal sequence disrupts the nuclear translocation of the apelin receptor. This discovery of apelin, AT1, and B2 receptors with agonist-independent nuclear translocation suggests major unanticipated roles for these receptors in cell signaling and function.
Li, QF, Li, L, Liu, EB, Wang, J, Xu, XX & Wang, YB 2004, 'Study of reverse temper embrittlement NGS mechanism in steel 12CrlMoV', Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University, vol. 25, no. 4, pp. 451-456.
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According to the non-equilibrium grain-boundary segregation kinetics curves of phosphorus in steel 12CrlMoV was found recently in an experimental investigation, a series of Charpy impact tests were performed on specimens at the segregation process, the critical time and the desegregation process. The DBTT values of different holding time specimens were measured. Experimental results show that overaging appears in this steel. That is, the degree of embrittlement increases first and then decreases with isothermal aging time. The reverse temper embrittlement non-equilibrium grain-boundary segregation (NGS) mechanism was analyzed, and a reverse temper embrittlement NGS mechanism for steel 12CrlMoV was built, which proved a method for brittle fracture forecast and control of steel.
Livshits, G, Deng, H-W, Nguyen, TV, Yakovenko, K, Recker, RR & Eisman, JA 2004, 'Genetics of Bone Mineral Density: Evidence for a Major Pleiotropic Effect From an Intercontinental Study', Journal of Bone and Mineral Research, vol. 19, no. 6, pp. 914-923.
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Abstract BMD is a primary predictor of osteoporotic fracture, and its genetic determination is still unclear. This study showed that the correlation between BMD at different skeletal sites is caused by an underlying genetic structure of common genetic effects. In addition to possible shared (pleiotropic) genetic and environmental effects, each of the BMD variables may also be determined by site-specific genetic factors. Introduction: BMD is a primary predictor of osteoporotic fracture and a key phenotype for the genetic study of osteoporosis. The interindividual variation in BMD measured at a given skeletal site is largely regulated by genetic factors. A strong phenotypic covariation exists for BMD at different skeletal sites. This study tests the hypothesis that the covariation is in fact caused by an underlying genetic structure of common genetic effects and that, in addition to possible shared (pleiotropic) genetic effects, each of the BMD variables may also be determined by site-specific genetic factors Materials and Methods: A bivariate complex segregation analysis as implemented in statistical package PAP was conducted to explore various models of pleiotropic genetic and environmental transmission in lumbar spine and femoral neck BMD, as well as in compact and spongious segments of hand phalanges. The BMD was obtained in three ethnically, culturally, and socially heterogeneous samples of white pedigrees, with 2549 individuals between 18 and 100 years of age, from Australia, Europe, and North America. Results and Conclusions: The genetic correlation between BMD measures ranged between 0.50 ± 0.09 and 0.79 ± 0.04 in the three samples. In each sample, the model incorporated a major locus pleiotropic effect, and residual correlation was found to be the most parsimonious model. Estimated parameters from the mod...
Nguyen, ND, Ahlborg, HG & Nguyen, TV 2004, 'Does hip strength measures account for the difference in hip fracture incidence between the Chinese and Caucasian populations?', Bone, vol. 35, no. 4, pp. 998-999.
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Nguyen, TV, Center, JR & Eisman, JA 2004, 'Bone mineral density-independent association of quantitative ultrasound measurements and fracture risk in women', Osteoporosis International, vol. 15, no. 12, pp. 942-947.
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Nguyen, TV, Center, JR & Eisman, JA 2004, 'Osteoporosis: underrated, underdiagnosed and undertreated', Medical Journal of Australia, vol. 180, no. S5.
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Osteoporosis is: ■ Underrated Currently costs about $7 billion annually in Australia. Has high morbidity and 2-3-fold increase in risk of death after any major osteoporotic fracture. Genetic factors contribute highly to risk, modified by lifestyle and hormonal factors. ■ Underdiagnosed Bone density is a good predictor of subsequent risk. Anyone with a low-trauma fracture has osteoporosis unless proven otherwise. Every individual with a low trauma fracture should be investigated for exclusion of underlying osteoporosis and considered for effective treatment to reduce future fracture risk. More than 75% of women and about 90% of men with a high likelihood of osteoporosis are not investigated. ■ Undertreated More than 75% of those affected are not treated. Effective treatments (eg, hormone replacement therapy, selective oestrogen receptor modifiers and bisphosphonates) reduce fracture risk by 30%-60%. Simple measures like vitamin D and calcium supplementation and use of hip protectors can reduce hip fractures, particularly in institutionalised and housebound elderly people.
Nguyen, TV, Center, JR, Pocock, NA & Eisman, JA 2004, 'Limited utility of clinical indices for the prediction of symptomatic fracture risk in postmenopausal women', Osteoporosis International, vol. 15, no. 1, pp. 49-55.
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Pongchaiyakul, C, Nguyen, ND, Pongchaiyakul, C & Nguyen, TV 2004, 'Development and validation of a new clinical risk index for prediction of osteoporosis in Thai women.', J Med Assoc Thai, vol. 87, no. 8, pp. 910-916.
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The objective of this study was to develop and validate a new simple tool for identifying Thai women who are at high risk of having osteoporosis. A total of 322 women, aged > or = 45 years, were randomly divided into two cohorts: a development (n = 130) and a validation cohort (n = 192). Femoral neck and lumbar spine BMD were measured by LUNAR DPX-IQ densitometer. The prevalence of osteoporosis (defined by BMD T-scores < or = -2.5) was 33 per cent by either femoral neck or lumbar spine BMD. Khon Kaen Osteoporosis Study (KKOS), scoring based on age and weight was calculated and applied to the development cohort. Individuals with KKOS score < or = -1 were defined as 'high risk'; otherwise a 'low risk' was defined. In the validation cohort, the sensitivity and specificity of KKOS was 70 and 73 per cent, respectively. Furthermore, if the high risk individuals identified by KKOS are to be treated, and if the treatment reduces fracture incidence by 50 per cent and assuming that treatment cost is 10 bahts per day, then the cost to prevent one fracture is estimated to be 466,695 bahts per year. These data suggest that although age and body weight can be used to identify Thai women who are at high risk of having osteoporosis, its application to the general population requires further research to arrive at the optimal cost-benefit for the community.
Pongchaiyakul, C, Nguyen, TV, Kosulwat, V, Rojroongwasinkul, N, Charoenkiatkul, S, Eisman, JA & Rajatanavin, R 2004, 'Effects of physical activity and dietary calcium intake on bone mineral density and osteoporosis risk in a rural Thai population', Osteoporosis International, vol. 15, no. 10, pp. 807-813.
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Zochling, J, Nguyen, TV, March, LM & Sambrook, PN 2004, 'Quantitative ultrasound measurements of bone: measurement error, discordance, and their effects on longitudinal studies', Osteoporosis International, vol. 15, no. 8, pp. 619-624.
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Center, JR, Nguyen, TV, Pocock, NA & Eisman, JA 1970, 'Volumetric Bone Density at the Femoral Neck as a Common Measure of Hip Fracture Risk for Men and Women', The Journal of Clinical Endocrinology & Metabolism, The Endocrine Society, pp. 2776-2782.
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Fisher, J, McEwen, HMJ, Tipper, JL, Galvin, AL, Ingram, J, Kamali, A, Stone, MH & Ingham, E 1970, 'Wear, Debris, and Biologic Activity of Cross-linked Polyethylene in the Knee', Clinical Orthopaedics & Related Research, Joint Annual Meeting of the Knee-Society/Association-of-Hip-and-Knee-Surgeons, Ovid Technologies (Wolters Kluwer Health), New Orleans, LA, pp. 114-119.
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Fisher, J, Stewart, TD, Tipper, JL, Hatton, A & Ingham, E 1970, 'Wear, debris and functional biocompatability of third and fourth generation ceramic on ceramic bearing couples', Transactions - 7th World Biomaterials Congress, p. 223.
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Wear, debris, and functional biocompatibility of third generation Biolox Forte and fourth generation Biolox Delta ceramic bearing couples under standard and micro separation simulator testing were discussed. Microseparation sub-luxation testing was found to be necessary to reproduce clinically relevant stripe wear on both materials. Under standard simulator conditions, the wear of both materials was very low with the wear of Biolox Delta being lower than the wear of Biolox Forte. The low wear, even under the most severe loading conditions, combined with good biocompatibility of the wear debris, indicate that third and fourth generation ceramic on ceramic bearing couples are a good choice for active, high demand patients.
Galvin, AL, Endo, MM, Tipper, JL, Ingham, E & Fisher, J 1970, 'Functional biological activity of non-crosslinked and crosslinked UHMWPE hip joint prostheses', Transactions - 7th World Biomaterials Congress, p. 145.
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The wear rates, debris and biological activity of non-crosslinked and crosslinked ultra high molecular weight polyethylene (UHMWPE) hip joint prostheses were studied. The non-crosslinked, slightly crosslinked and highly crosslinked samples of UHMWPE were gamma irradiated in nitrogen and were measurements were taken using a coordinate measuring machine. SEM was used for the analysis of the wear debris from the materials. It was found that the wear rate of the highly crosslinked UHMWPE was lower than for the other materials. While the wear rate of the highly crosslinked materials was low, it only generated a two fold reduction in functional biological activity and osteolytic potential.
Galvin, AL, Tipper, JL, McEwen, HMJ, Williams, S, Stone, MH, Ingham, E & Fisher, J 1970, 'Nanometre sized polyethylene wear debris in hip and knee prostheses', Transactions - 7th World Biomaterials Congress, p. 345.
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The nanometer sized wear debris of ultra high molecular weight polyethylene (UHMWPE) 1020 GVF generated in hip and knee prostheses was studied using a high resolution field emission gun scanning electron microscopy (FEGSEM). The samples were foil packed and irradiated with 4MRad gamma irradiation in a vacuum. A coordinate measuring machine (CMM) was used to measure the wear of the samples. All tests were carried out in 25% bovine serum diluted with 0.1% sodium azide and were run to 5 million cycles. It was observed that the UHMWPE debris from the knee prostheses was generally larger than the debris from the hip prostheses.
Pham, TD, Crane, DI, Tannock, D & Bock, D 1970, 'Kullback-Leibler dissimilarity of Markov models for phylogenetic tree reconstruction', Proceedings of 2004 International Symposium on Intelligent Multimedia, Video and Speech Processing, 2004., 2004 International Symposium on Intelligent Multimedia, Video and Speech Processing, 2004., IEEE, pp. 157-160.
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In this paper, we introduce the Kullback-Leibler dissimilarity measure of Markov-chain models for unaligned DNA sequences with application to the phylogenetic tree reconstruction of complete mammalian mitochondrial genomes. The tree obtained by our approach is generally in agreement with those obtained from other methods. Our proposed method is computationally efficient and very easy for computer implementation.
