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4. The art of Web-based learning : past achievements, present objectives and future strategies

Author

Cheung, Helen, Ko, Robert K.M., Yim, T. K. Bobby, Cheung, Helen, Ko, Robert K.M., and Yim, T. K. Bobby

Abstract

The traditional pedagogical teaching approach has been the continuous subject of scrutiny among educationalists worldwide. Recently, the escalating recognition of educational constructivism and progressivism has highlighted the inadequacies of the conventional didactic system in knowledge delivery. The ongoing evolution from the conventional practice of ‘chalk-and-talk’ teaching toward the innovative execution of 'click-and-tick' learning has led to a further step in the accomplishment of outcomebased, self-directed learning. Exploitation of web-based learning has established a significant advancement in areas where mechanistic and conceptual understanding is critical. Identification of well-defined learning objectives and the appreciation of technological capabilities have initiated the pioneering development of the online learning enhancement, WEBCT for BICH172/182, in basic biochemistry. WEBCT for BICH172/182 can be regarded as the progeny of an exploratory effort to support conceptual understanding as well as to instigate a dynamic approach in reciprocal learning. Subsequent enthusiastic user acceptance of the preliminary output has encouraged further moves toward the endeavor of formulating a high quality of learning environments with outcome objectives in mind. The recent launching of WEBCT for BICH122 represents a second generation of technological development targeted for self-instructional reflective learning. Undoubtedly, the current availability of technological enrichment has contributed a great deal toward the reinforcement of integration between the classical and technological approaches to learning; relentless pursuit must be sustained to encourage active learning and high-level thinking. Such strategies will certainly be the essential criteria to be considered in the continual development of future generations of technological-based learning environments.

Published
2004

5. Does it work for biochemistry teaching : a personal account of a model one online course development

Author

Ho, W. Y. Joanna, Yim, T. K. Bobby, Ko, Robert K.M., Fang, W. Mei Yeung, Li, Wing Sze Wanze, Lai, C. L. Rambo, Ho, W. Y. Joanna, Yim, T. K. Bobby, Ko, Robert K.M., Fang, W. Mei Yeung, Li, Wing Sze Wanze, and Lai, C. L. Rambo

Abstract

WebCT development was initially targeted to realize my own teaching goals. However, my own initiatives became joint initiatives and collaborations with others, which further enriched the whole course. We had a clear goal for our phase one development, and we also formed a dedicated team in collaboration with CELT. After some intensive work, and within just a few short months, WebCT for BICH172/182 was lunched as scheduled in the beginning of the Fall semester, 2001. Clearly, it provides a good anchor for both teaching and learning. It is not only a convenient contact point between instructors and students, but also a good place for course materials. At the moment, there are four videos and ten animations, as well as other course materials available in our WebCT. Although we are only at phase-one of the course development with WebCT, I’d say this online tool for teaching has certainly been helpful to my course delivering, and that I wouldn’t do without it. This paper is not aimed at answering the ambitious question posed in the title, but is intended to give a personal account of a still on going attempt to develop a model one online course (BICH172 and BICH182).

Published
2001

8. Hepatoprotective action of an oleanolic acid‐enriched extract ofLigustrum lucidumfruits is mediated through an enhancement on hepatic glutathione regeneration capacity in mice

Author

Yim, T. K., Wu, W. K., Pak, W. F., and Ko, K. M.

Abstract

The fruits of Ligustrum lucidum Ait.(FLL) were fractionated into petroleum ether (FLL‐Pe), chloroform (FLL‐Ch), butanol (FLL‐Bu) and aqueous (FLL‐Aq) fractions, of which FLL‐Ch and FLL‐Bu were found to be enriched with oleanolic acid (OLA). The in vivoantioxidant activities of various FLL fractions and OLA were assessed by examining the effect on carbon tetrachloride (CCl4)‐induced hepatotoxicity in mice. Pretreatment of animals with various FLL fractions could protect against CCl4‐induced hepatotoxicity to a varying degree, with OLA‐enriched FLL‐Bu and FLL‐Ch being more potent. However, a mortality rate of 60% was observed in the FLL‐Ch pretreated and CCl4‐intoxicated mice. OLA pretreatment also produced a dose‐dependent protection against CCl4hepatotoxicity. The hepatoprotection afforded by FLL‐Bu or OLA pretreatment was associated with an enhancement of hepatic­glutathione regeneration capacity (GRC). In contrast, the inability of FLL‐Aq pretreatment to enhance hepatic GRC resulted in a failure to prevent CCl4‐induced hepatic injury. The results suggest that the hepatoprotective action afforded by OLA‐enriched FLL‐Bu or OLA pretreatment may be mainly mediated by the enhancement of hepatic GRC, particularly under conditions of CCl4‐induced oxidative stress. Copyright © 2001 John Wiley & Sons, Ltd.

Published
2001
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9. Myocardial protection against ischaemia‐ reperfusion injury by aPolygonum multiflorumextract supplemented ‘Dang‐Gui decoction for enriching blood’, a compound formulation,ex vivo

Author

Yim, T. K., Wu, W. K., Pak, W. F., Mak, D. H. F., Liang, S. M., and Ko, K. M.

Abstract

‘Dang‐Gui Decoction for Enriching the Blood’ (BE), a traditional Chinese formulation comprising Angelica sinensisand Astragalus membranaceus, is used for stimulating red blood cell production as well as enhancing cardiovascular function. In the present study, we have demonstrated the myocardial protection afforded by BE pretreatment against ischaemia‐reperfusion (IR) injury in isolated‐perfused rat hearts. A more complete and potent myocardial protection against IR injury was also shown by a Polygonum multiflorumextract supplemented BE preparation (BEA). The results suggest that the more potent cardioprotective action of BEA may be related to its ability to sustain the myocardial glutathione antioxidant status under conditions of IR‐induced oxidative stress, which may possibly in turn result from the synergistic interaction between the BE and Polygonum extract. Copyright © 2000 John Wiley & Sons, Ltd.

Published
2000
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10. Myocardial protection against ischaemia- reperfusion injury by a<TOGGLE> Polygonum multiflorum</TOGGLE> extract supplemented ‘Dang-Gui decoction for enriching blood’, a compound formulation,<TOGGLE> ex vivo</TOGGLE>

Author

Yim, T. K., Wu, W. K., Pak, W. F., Mak, D. H. F., and Liang, S. M.

Abstract

‘Dang-Gui Decoction for Enriching the Blood’ (BE), a traditional Chinese formulation comprising Angelica sinensis and Astragalus membranaceus, is used for stimulating red blood cell production as well as enhancing cardiovascular function. In the present study, we have demonstrated the myocardial protection afforded by BE pretreatment against ischaemia-reperfusion (IR) injury in isolated-perfused rat hearts. A more complete and potent myocardial protection against IR injury was also shown by a Polygonum multiflorum extract supplemented BE preparation (BEA). The results suggest that the more potent cardioprotective action of BEA may be related to its ability to sustain the myocardial glutathione antioxidant status under conditions of IR-induced oxidative stress, which may possibly in turn result from the synergistic interaction between the BE and Polygonum extract. Copyright © 2000 John Wiley & Sons, Ltd.

Published
2000

12. Schisandrin B protects against myocardial ischemia-reperfusion injury by enhancing myocardial glutathione antioxidant status.

Author

Yim TK and Ko KM

Subjects
Animals, Cyclooctanes, Male, Myocardial Contraction, Rats, Rats, Sprague-Dawley, Antioxidants therapeutic use, Glutathione metabolism, Lignans, Myocardial Reperfusion Injury prevention & control, Myocardium metabolism, Polycyclic Compounds therapeutic use
Abstract

The effects of Schisandrin B (Sch B) and dimethyl-4,4'-dimethoxy-5,6,5',6'dimethylene-dioxy-biphenyl-2,2'-+ ++bicarboxylate (DDB) treatment on myocardial ischemia-reperfusion (IR) injury in isolated perfused rat hearts were examined under both in vitro and ex vivo conditions. In vitro administration of liposome-entrapped Sch B or DDB during reperfusion did not protect against myocardial IR injury, whereas ascorbic acid or Trolox supplemented perfusate produced protective effect, as evidenced by the significant decrease in the extent of lactate dehydrogenase leakage as well as an improvement in contractile force recovery. Myocardial protection afforded by N-acetyl-L-cysteine supplemented perfusate was not accompanied by the enhancement in contractile force recovery. In ex vivo experiment, pretreatment of Sch B (0.6/1.2 mmol/kg/day x 3) protected against IR-induced myocardial damage in a dose-dependent manner. The myocardial protection was associated with an enhancement in myocardial glutathione antioxidant status, as indicated by significant reductions in both the extent of IR-induced reduced glutathione depletion and inhibition of Se-glutathione peroxidase and glutathione reductase activities. In contrast, the inability of DDB pretreatment to enhance myocardial glutathione antioxidant status resulted in a failure in preventing IR injury. The ensemble of results suggests that the myocardial protection afforded by Sch B pretreatment, which was unlikely due to free radical scavenging action, may be mainly mediated by the enhancement of myocardial glutathione antioxidant status, particularly under oxidative stress conditions.

Published
1999

13. Methylenedioxy group and cyclooctadiene ring as structural determinants of schisandrin in protecting against myocardial ischemia-reperfusion injury in rats.

Author

Yim TK and Ko KM

Subjects
Animals, Antioxidants chemistry, Drugs, Chinese Herbal chemistry, Drugs, Chinese Herbal pharmacology, Free Radical Scavengers chemistry, Glutathione metabolism, Glutathione Peroxidase metabolism, Glutathione Reductase metabolism, Glutathione Transferase metabolism, Heart drug effects, In Vitro Techniques, L-Lactate Dehydrogenase, Male, Molecular Conformation, Molecular Structure, Myocardium metabolism, Polycyclic Compounds chemistry, Rats, Rats, Sprague-Dawley, Antioxidants pharmacology, Cyclooctanes, Free Radical Scavengers pharmacology, Lignans, Myocardial Reperfusion Injury prevention & control, Polycyclic Compounds pharmacology
Abstract

As a preliminary investigation to exploring whether the methylenedioxy group and the cyclooctadiene ring of the dibenzo[a,c]cyclooctadiene (schisandrin) molecule plays an important role in the protection against myocardial ischemia-reperfusion (IR) injury, we examined the effects of three schisandrins, namely schisandrin A (Sch A), schisandrin B (Sch B), and schisandrin C (Sch C), and the effect of dimethyl-4,-4'-dimethoxy-5,6,5',6'-dimethylene-dioxy-biphenyl-2,2' -bicarboxylate (DDB), an intermediate compound derived from the synthesis of Sch C, on myocardial IR injury in isolated Langendorff-perfused rat hearts. While pretreating rats with Sch A or DDB at a daily oral dose of 1.2 mmol/kg for 3 days did not protect the isolated-perfused hearts against IR-induced damage, pretreatment with Sch B or Sch C at the same dosage regimen produced cardioprotective action. The extent of cardioprotection afforded by Sch B or Sch C pretreatment correlated well with the degree of enhancement in myocardial glutathione antioxidant status, as indicated by significant increases in the tissue-reduced glutathione level and Se-glutathione peroxidase (EC 1.11.1.9), glutathione transferases (EC 2.5.1.18), and glutathione reductase (EC 1.6.4.2) activities in ischemic-reperfused hearts when compared with the unpretreated IR control. Our results indicate that both the methylenedioxy group and the cyclooctadiene ring of the schisandrin molecule are important structural determinants in mediating the protection against myocardial IR injury.

Published
1999
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