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991.
EF Magann NS Whitworth PG Rhodes JD Bass SP Chauhan JC Morrison 《Canadian Metallurgical Quarterly》1998,91(10):942-945
PROBLEM: We assessed neonatal outcome of normal diamniotic twin pregnancies with known amniotic fluid (AF) volume. METHOD: The AF volume was empirically determined in 39 diamniotic twin gestations. The neonates were stratified by AF volume and evaluated for clinical outcome, gestational age, lecithin-sphingomyelin (L/S) ratio, and birth weight. RESULTS: Neonatal complications did not significantly differ among infants delivered from pregnancies with low (155 to 404 mL), moderate (405 to 807 mL), or high (808 to 5,430 mL) volumes of AF. Relatively constant volumes of AF were maintained throughout the 27 to 38 week range of gestational age, with no apparent correlation between AF volume and gestational age. Variations in the L/S ratio and newborn birth weights were also independent of AF volume. Gestational age was the only significant determinant of the frequency of neonatal complications. CONCLUSION: Amniotic fluid volume does not greatly affect neonatal outcome in normal diamniotic twin pregnancies. 相似文献
992.
DA Gilbert KZ Altshuler WV Rago SP Shon ML Crismon MG Toprac AJ Rush 《Canadian Metallurgical Quarterly》1998,59(7):345-351
BACKGROUND: The Texas Medication Algorithm Project (TMAP), a public-academic collaborative effort, is a 3-phase project to develop, implement, and evaluate medication treatment algorithms for public sector patients with schizophrenia, major depressive disorders, or bipolar disorders. DISCUSSION: This paper, the first in a series describing the activities of the TMAP, focuses on the various definitions and reasons why guidelines have gained popularity. Also discussed are their strengths, the limitations of the various methods used to develop them, and potential barriers to their implementation. 相似文献
993.
A Smine X Xu K Nishiyama T Katada P Gambetti SP Yadav X Wu YC Shi S Yasuhara V Homburger T Okamoto 《Canadian Metallurgical Quarterly》1998,273(26):16281-16288
To investigate a possible association between G-proteins and presenilin-1 (PS-1), a series of glutathione S-transferase-fusion proteins containing portions of PS-1 were prepared and used in vitro in binding experiments with tissue and recombinant G-proteins. The results demonstrate that the 39 C-terminal amino acids of PS-1 selectively bind the brain G-protein, Go. Addition of guanosine 5'-3-O-(thio)triphosphate promoted Go dissociation from PS-1, indicating that this domain mimics the function of G-protein-coupling domains found in receptors. The 39-amino acid synthetic polypeptide activated Go in a magnesium ion-dependent manner. Physical interaction of full-length PS-1 and Go was also demonstrated. Following transfection of Goalpha and N-terminally FLAG-tagged PS-1 in COS-7 cells, Go was immunoprecipitated by FLAG antibodies. In addition, endogenous PS-1 and Goalpha were colocalized immunocytochemically in human glioma cell lines. The results indicate that PS-1 regulates Go activities in living cells. 相似文献
994.
MC Weinrich SJ Jacobsen SP Weinrich JW Moul JE Oesterling D Jacobson R Wise 《Canadian Metallurgical Quarterly》1998,52(6):967-973
OBJECTIVES: To determine the age- and race-specific prostate-specific antigen (PSA) distributions in healthy men in central South Carolina and to compare these to data from other studies. METHODS: Two thousand ninety-two black men aged 40 to 69 years and white men aged 50 to 69 years from the general population in 11 counties of central South Carolina participated in a prostate cancer educational program. Seventy-two percent of the participants were black-about double the proportion in the general population-and 63% of the men (1319 of 2092) subsequently obtained a PSA determination from their own physician. The distribution of serum PSA was compared with distributions from the Olmsted County study and from the Walter Reed Army Medical Center/Center for Prostate Disease Research study. RESULTS: Older men without cancer had higher PSA levels. Regression analyses yielded an associated increase of about 3.3% per year. Reference ranges for normal PSA in men without cancer (based on their sample 95th percentiles) were zero to 1.9, 3.8, and 5.7 ng/mL in black men aged 40 to 49, 50 to 59, and 60 to 69 years, and zero to 2.7 and 4.9 mg/mL in white men aged 50 to 59 and 60 to 69 years, respectively. CONCLUSIONS: Reference ranges for normal serum PSA levels should take into account the population from which they are derived and to which they will be applied. Reference ranges that are useful in the general population can differ from those that are appropriate in a hospital setting. For the general population in central South Carolina, reference ranges for serum PSA levels are lower than previously published reference ranges, particularly among black men. 相似文献
995.
996.
The effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and four novel synthetic analogues (EB1089, KH1060, KH1230 and CB1093) on IGF-I-stimulated growth of MCF-7 human breast cancer cells have been determined. A significant time- and dose-dependent inhibition of IGF-I-stimulated cell growth was seen with EB1089, such that after 7 days of treatment with 10(-8) M EB1089, the mitogenic effect of IGF-I (30 ng/ml) was negated. Comparison with 1,25(OH)2D3 showed the synthetic analogues to be more potent. The anti-oestrogen ICI 182,780 similarly inhibited IGF-I-stimulated growth of these cells and in combination with EB1089 exerted additional inhibitory effects. Retinoids (all-trans-retinoic acid or the isomer 9-cis-retinoic acid) were less effective in limiting MCF-7 cell responsiveness to IGF-I but, in combination with EB1089, a co-operative effect was achieved. Using radioligand-binding techniques, we observed that 1,25(OH)2D3 and EB1089 down-regulated the levels of 125I-IGF-I binding to MCF-7 cell membranes. Scatchard analysis showed that EB1089 decreased maximal binding approximately 2-fold. Vitamin D derivatives were also demonstrated to reduce IGF-I receptor expression in MCF-7 cells by Western analysis. Our findings demonstrate that vitamin D derivatives limit responsiveness of MCF-7 cells to the mitogenic effects of IGF-I, which may be mediated by reduction of IGF-I receptor expression. 相似文献
997.
Sastry R. Ranganathan N. Jain R.C. 《IEEE transactions on pattern analysis and machine intelligence》1995,17(9):894-899
Depth recovery from gray-scale images is an important topic in the field of computer and robot vision. Intensity gradient analysis (IGA) is a robust technique for inferring depth information from a sequence of images acquired by a sensor undergoing translational motion. IGA obviates the need for explicitly solving the correspondence problem and hence is an efficient technique for range estimation. Many applications require real time processing at very high frame rates. The design of special purpose hardware could significantly speed up the computations in IGA. In this paper, we propose two VLSI architectures for high-speed range estimation based on IGA. The architectures fully utilize the principles of pipelining and parallelism in order to obtain high speed and throughput. The designs are conceptually simple and suitable for implementation in VLSI 相似文献
998.
999.
This article describes an overall video network architecture with primary focus on the ATM subnetwork. The ATM subnetwork provides efficient switching capability for providing constant bit rate and variable bit rate video communication services. The ATM subnetwork can support multiple access networks like hybrid fiber coax (HFC), asymmetric digital subscriber line (ADSL), and fiber to the curb (FTTC). A broadband network controller is presented as the external controller for the ATM subnetwork which performs the functions of the session/network manager and the ATM-based connection management. The initial deployment of video is likely to be permanent virtual connection (PVC)-based, so a dynamic PVC-based scenario is described. The ATM switch architecture presented here has been optimized to support video applications. An evolution to the switched virtual connection environment and support of multiple services over the ATM subnetwork is also addressed. Traffic management schemes are discussed which provide the negotiated quality of service to the connections 相似文献
1000.
SP Mackessy 《Canadian Metallurgical Quarterly》1996,34(11-12):1277-1285
Rattlesnake venoms typically contain several different metalloproteases, some of which are hemorrhagic toxins. Metalloproteases contribute significantly to the often severe necrotic changes in tissues following envenomation, and these prominent components are important to the predigestive role of venoms. Venom of the northern Pacific rattlesnake (Crotalus viridis oreganus) contains at least five distinct metalloproteases, and the dominant protease (trivial name, CVO protease V) has been isolated and characterized as being a single polypeptide chain acidic protein with a molecular mass of 61 kDa and a pH optimum of approximately 9.0. It catalyzes the hydrolysis of several protein substrates, including casein, and is inhibited by metal chelators such as EDTA, EGTA and 1,10-phenanthroline but not by serine protease inhibitors such as PMSF. Calcium is present at a molar ratio of approximately 1:1, but, unlike other described venom metalloproteases, this protease does not appear to contain zinc. Caseinolytic activity is not significantly inhibited by citrate (at pH 9.0) at levels up to 2.0 mM; at 100 mM citrate (at pH 9.0) more than 65% of activity is retained. It is partially inhibited by nanomolar concentrations of ATP, but higher amounts (micromolar) do not result in further inhibition of activity. The protease shows fibrinolytic and fibrinogenolytic activity, but is only weakly hemorrhagic in rats. When stored in solution for long periods it undergoes autolytic degradation. This protease or a homolog appears to be present in venoms from several rattlesnake species but is not present in venoms from juvenile C.v. oreganus. The presence of this component in venoms from adult Pacific rattlesnakes is responsible for the age-related increase in metalloprotease activity of the crude venom. 相似文献