16,224 research outputs found
Alterations in Monoclonal Antibody Affinity and Antigenic Receptor Site Expression on Mycoplasma-Infected Human Colorectal Cancer Cells
No full textThe affinity of MoAb CO 17–1A and expression of its antigenic target were studied on uninfected and mycoplasma-infected colorectal cancer cell lines SW 1116 and SW 948. Binding of 125I-labeled CO 17–1A to SW 1116 cells was quantified at 37°C by determination of the affinity constant (Ka) and the number of antigenic receptor sites (r) per cell using Scatchard plots. When mycoplasma-free SW 1116 cells were used as targets, Ka was 0.92 ± 0.06 × 108M -1 and r = 1.32 ± 0.14 × 106 at 37°C. One batch of unspeciated, mycoplasma-infected SW 1116 cells had reduced affinity and a decreased number of antigenic receptor sites per cell for 125I-labeled 17–1A, while another batch of infected SW 1116 cells had a 4- to 5-fold increase in r and diminished Ka for the antibody compared with uninfected cells. When unspeciated, mycoplasma-infected SW 948 cells were exposed to 125I-labeled 17–1A and the data subjected to Scatchard analysis, the affinity of the antibody deviated markedly from linearity and rendered analysis for Ka and r meaningless. These data indicate that mycoplasma infection can produce variable effects on the cellular expression of antigenic receptor sites and the affinity of antibody for its target, and emphasize the importance of using mycoplasma-free cell lines in studies of these parameters. © 1990, SAGE Publications. All rights reserved
Effects of swimming exercise on learning and memory in the kainate-lesion model of temporal lobe epilepsy
No full textIntroduction: An aerobic exercise (Ex) augments neurogenesis and may ameliorate learning and memory deficits in the rat Kainic Acid (KA) model of temporal lobe epilepsy in the short-term but whether it reverses learning and memory deficits after a substantial period of delay remains unclear. Aim: This study tests the hypothesis that aerobic Ex attenuates the learning and memory deficits associated with kainate seizures in the long-term. Materials and Methods: A total of 60 rats were subjected to chemical lesioning using KA and to an Ex intervention consisting of a 30 days period of daily swimming for 15 min, immediately after KA lesioning (immediate exposure) or after a 60 days period of normal activity (delayed exposure). We evaluated spatial learning on a T-maze test, expressed as percentage of correct responses. We evaluated memory on a passive-avoidance test, expressed as time spent in a compartment in which the rats were previously exposed to an aversive stimulus. Results: Ex increases the percentage of correct responses, percentage bias, and number of alternations, associated with the T-maze testing for the normal control, sham-operated control and kainate-lesioned animals after both immediate and delayed exposures to Ex. Ex decreased the time exposed to the aversive stimulus in the smaller compartment of the two-compartment passive-avoidance test, also for the normal control, sham-operated control and kainate-lesioned animals after both immediate and delayed exposures to Ex. Conclusion: These finding suggest that, after temporal lobe epileptic seizures in rats, swimming exercise may attenuate the learning and memory deficits, even if the exercise treatment is delayed
Religious pathways to coping with personal death anxiety among older adult British Christians and Chinese Buddhists: afterlife beliefs, psychosocial maturity and regret management
No full textReligion was proposed to account for the relatively low personal death anxiety found among older adults. This dissertation sought to examine the influence of religious afterlife beliefs, religiously enhanced psychosocial maturity and religious management of a past major regret on personal death anxiety in later life. Terror Management Theory and Erikson’s Psychosocial Theory were used to describe these three religious pathways to coping with personal death anxiety in later life. The cross-sectional postal survey samples consisted of 143 older adult British Christians and 141 older adult Chinese Buddhists. Structural Equation Modelling results from the British Christian survey study showed that intrinsic religiosity predicted lower personal death anxiety through: (a) fostering more benign afterlife beliefs; (b) enhancing psychosocial maturity; and (c) promoting emotional stability. No significant relationship between belief in reincarnation and personal death anxiety was found in the Chinese Buddhist survey study. Both survey studies failed to support the personal death anxiety buffering power of religious management of a past major life regret, although some religious coping strategies were associated with lower negative emotional appraisal towards the major life regret among older adults. The British survey study has been the first to demonstrate both the personal death anxiety buffering and psychosocial maturity enhancing power of religion in an increasingly secular society. The lack of relationship between Buddhist reincarnation beliefs and personal death anxiety suggests that not all religious afterlife beliefs have death anxiety buffering power as proposed by Terror Management Theory. The development of Buddhist reincarnation belief and Buddhist coping scales is a pioneering step towards developing research on under-explored Eastern non-theistic afterlife beliefs and coping measures. Implications for ways that help religious older adults cope with their personal death anxiety were discussed. Prospective cross cultural and cross-religion studies were recommended to replicate the present survey findings. Finally, self detachment (self negation) was proposed as the basis of an alternative death transcendence theory to be researched in future studies on personal death anxiety
Una interpretación de a-ka-na-jo ( a3-ka-na-jo)
No full textThe author studies the word a-ka-na-jo in the PY Cn 328 tablet and taking into account some factors she proposes αγναιος as the reading of this word.The author studies the word a-ka-na-jo in the PY Cn 328 tablet and taking into account some factors she proposes αγναιος as the reading of this word
Environmental influences over the last 16 ka on compound-specific δ13C variations of leaf wax n-alkanes in the Hani peat deposit from northeast China
No full textCompound-specific carbon isotope ratios (δ13C) of leaf wax n-alkanes (C21-C33 odd carbon numbered n-alkanes) were measured in the Hani peat sequence from northeast China. These data were compared with lipid biomarker compositions to assess changes in local vegetation and paleoclimate for the last 16 ka The δ13C values of n-alkanes range between -36.6 and -30.7‰, showing that the compounds originate from C3 plants. Much larger variations (∼5.4‰) in the n-alkane δ13C values than those of atmospheric CO2 during the last 16 ka (< 0.5‰) indicate that the isotopic values were affected by environmental factors in addition to the postglacial δ13C variations in the atmospheric reservoir. The stratigraphic records of δ13C reveal decoupled fluctuations among the individual n-alkanes, particularly between 15.5 to 11.4 ka. Synchronous excursions in the δ13C offsets among individual n-alkanes (Δδ13C) and lipid biomarker paleoplant proxies (Paq, and C23/C31 and C27/C31) from 14.9 to 13.2 ka and 12.7 to 11.6 ka suggest that vegetational changes are the most likely causes for the decoupled δ13C variations. Parallel fluctuations of the δ13C values of terrestrial higher plant-derived C29 and C31 n-alkanes and the n-alkane average chain-length (ACL) from 11 to 6 ka indicate that the δ13C variations responded to net evaporation changes. Negative shifts in the n-alkane δ13C values coinciding with the ACL decreases at 10.5-9.3 ka and 8.1 ka indicate the short-term onset and fluctuations of the summer monsoon strength in eastern China during the early Holocene
NRF2 and chemoprevention: signaling, epigenetics and role in intestinal carcinogensis
No full textPrevention is better than cure. The carcinogenesis could take as long as 20 to 30 years to develop from initiated cells to malignant tumor, therefore providing us various opportunities to prevent the appearance of tumors with the use of chemopreventive compounds in the early stage. Chemoprevention becomes an increasing important concept and has led to the intense research about the mechanisms of actions of various chemopreventive compounds. They can be generally classified into blocking agents and suppressing agents. The chemopreventive compounds usually prevent or slow progression of cancer by maintaining a low oxidative stress and inflammatory environment in cells. This is brought about by the activation of Nrf2, the key protein being investigated in our lab. In this dissertation, I will be discussing the use of compounds as suppressing agents and blocking agents, how compounds activates Nrf2 signaling, how novel Nrf2 interaction partner IQGAP1 mediates Nrf2-Keap1 signaling axis, how expression level of Nrf2 could be regulated epigenetically, apart from the well-known post-translational control by Keap1-Ubiquitinase-Protesome axis and finally how loss of Nrf2 could enhance intestinal tumorigenesis in Apc(min/+) mice.Ph.D.Includes bibliographical referencesIncludes vitaby Ka Lung Cheun
Nearby fibroblasts' response to multiple acupuncture needle revolutions on fibroblast populated collagen gels
No full textAcupuncture is an ancient Chinese healing practice, and an alternative therapy for alleviating pain and chronic disorders. For over twenty years, research is trying to understand the mechanisms that lead to its therapeutic effect. Our laboratory investigates the cellular and molecular events in the connective tissue that occur by acupuncture needling. An in vitro assay was developed to evaluate some of the potential contributors to acupuncture’s effects using a cellular collagen gel as a loose connective tissue mimic. It was hypothesized besides immediate changes to cells under mechanical loading from an acupuncture needle, there were chemical factors released to nearby cells in acupuncture. This thesis investigates whether mechanically stimulating collagen gels with fibroblasts at different revolutions would release chemical factors to nearby fibroblasts where flow cytometry was used to observe cell proliferation as an indicator. Results reveal mechanically stimulating cellular collagen gels at different revolutions does not cause any changes in cell proliferation to nearby cells. However, dead stained mechanically stimulated cellular collagen gels showed cell death occurs around the acupuncture needle. It is possible there were no effects in cell proliferation because when a cellular collagen gel was needle manipulated, some chemical factors were released into the nearby cells. Then as needle manipulation increased, more chemical factors were released, but restricted by the larger amount of cell death around the needle from the increasing rotation.M.S.Includes bibliographical referencesby Ka Po Ch
Oral History Interview with Howard Hunter: Conceptualising SMU
No full textThis is an abridged version of the original interview. Please contact the Library at [email protected] for access to the full version of the transcript and/or audio recording.</p
Duan wei xia mu xie lei de xin xing he nei DNA fen zi xi tong biao ji zhi jian ding
No full textLeung Ka Chun.Thesis M.Phil. Chinese University of Hong Kong 2013.Includes bibliographical references (leaves 100-110).Abstracts also in Chinese.Title from PDF title page (viewed on 21, September, 2016).Leung Ka Chun
San zhong chao jian dai teng hu dui gao wen de sheng li fan ying ji zhuan lu ti yan jiu
No full textWong, Ka Wing Karen.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 143-157).Abstracts also in Chinese.Title from PDF title page (viewed on 30, November, 2016).Wong, Ka Wing Karen
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