Osteoprotective effects of Fructus Ligustri Lucidi aqueous extract in aged ovariectomized rats

<p>Abstract</p> <p>Background</p> <p><it>Fructus Ligustri Lucidi </it>(FLL) is a commonly used herb for treating bone disorders in Chinese medicine. The present study investigates the anti-osteoporotic activity of FLL aqueous extract in the model of postmenopausal bone loss in aged ovariectomized (OVX) female rats.</p> <p>Methods</p> <p>After eight weeks of treatment of FLL or water, the lumbar spine was scanned by peripheral quantitative computed tomography (pQCT). Effects of FLL water extract on osteogenic and adipogenic differentiations in rat mesenchymal stem cells (MSCs) were assessed by biochemical methods and staining.</p> <p>Results</p> <p>FLL aqueous extract significantly inhibited bone mineral density (BMD) loss in total, trabecular and cortical bones without affecting body weight and uterus wet weight. FLL extract significantly promoted osteogenesis and suppressed adipogenesis in MSCs as indicated by the elevated alkaline phosphatase activity, calcium deposition levels and decreased adipocyte number in a dose-dependent manner without cytotoxic effects. Real-time PCR analysis revealed significant increase of osteoprotegerin (OPG)-to-receptor activator for nuclear factor-κB ligand (RANKL) mRNA, indicating a decrease in osteoclastogenesis.</p> <p>Conclusion</p> <p>The present study demonstrates the osteoprotective effects of FLL aqueous extract on aged OVX rats, stimulation of osteogenesis, inhibition of adipogenesis and osteoclastogenesis in MSCs.</p

Old Technique -New Evidence: Topical agents for musculo-skeletal injuries

The popular use of topical agents for the treatment of musculoskeletal injuries has persisted for centuries but not much scientific evaluations have been done. Since medicinal herbs are particularly popular in Asia, we started a systematic exploration on their choices, and their pharmacological activities; whether transcutaneous transport of bioactive components occur and above all, whether quality clinical evidences could be generated. We found that a search on the vast literature pool would reveal the favourable choices of herbal agents. Biological screening of those selected herbs showed that they probably follow three major common pathways to help with healing after injury, viz, anti-inflammation, pro-angiogenesis and cellular proliferation. Using a simple formula of selected herbs with the ideal bioactivities, evidence based clinical trials could be organized to further prove the efficacy. We have created two such formulae to be put on clinical trial. Our early pilot clinical trials on two minor injuries on the foot and one chronic inflammatory condition have yielded positive data on the value of such topical agents on pain and oedema control, as well as functional maintenance. There was also suggestion of more rapid bone healing. Although limitations exist clear with the small number of study subjects, the positive data and safe application support more studies

Serial overshadowing in long-delay taste aversion learning

Taste aversion learning (conditioned taste aversions; CTA) can occur even when there is delay of some hours between experience of the taste and the subsequent onset of illness. This property of CTA is quite distinct from other forms of associative learning, where typically no association between two events is acquired if they are separated by more than a minute. Through a series of experiments based on the assumption that long-delay CTA is possible only when no potentially overshadowing – or ‘concurrently interfering’ (Revusky, 1971) – events occur during the delay, this thesis investigates the mechanisms and parameters involved in serial overshadowing to gain a better understanding of long-delay CTA. The general method was a conditioning session in which rats were first given 8% sucrose and later injected with lithium chloride at a dose that produces mild and transient malaise. What varied across experiments was the potentially interfering events that occurred during the delay period. When the interfering event was a second, and quite different taste, namely sour-tasting hydrochloric acid solution (HCl), one-trial overshadowing of the sucrose aversion was observed, to a degree that was greater when HCl was given late in the delay period and greater when HCl had not been pre-exposed. Other intervening events were also found to overshadow sucrose aversion learning. These included placement into a novel context, as long as this occurred immediately before injection, and even stimuli that evoked memories of food-related experiences. Events that occurred outside the delay period can also proactively overshadow the acquisition of a sucrose aversion, though this was only found following two conditioning sessions, but not after a single conditioning session. No evidence was found for release from overshadowing following extinction of the aversion to the overshadowing taste. Whether the findings observed in CTA would be relevant and applicable to general features of learning observed in other conditioning preparations was tested. Two experiments involving fear conditioning assessed whether the amount of overshadowing depended on the temporal location of the overshadowing cue and whether overshadowing produced inverse fear of the context after a single trial. Critically, the results were similar to those for taste aversion. Overall, the results of these various experiments suggest that Revusky’s account provides a simple and effective framework for understanding why taste aversion learning can tolerate long delays between the taste and subsequent illness

Partial differential equation based methods in medical image processing

abstractpublished_or_final_versionElectrical and Electronic EngineeringDoctoralDoctor of Philosoph

Hypergraph: An alternative graphical model for computing transfer functions in circuits and systems

Hypergraphs are generalization of graphs with applications in many areas, such as VLSI design and data mining. In this paper, we propose the use of hypergraphs, as an alternative model to signal flow graphs, to provide graphical intuition on the relationships among variables in the area of circuits and systems. To demonstrate its effectiveness, the exact computation of a multiple-stage feedback amplifier, namely the damping-factor-control frequency compensation (DFCFC) amplifier, is considered. © 2005 IEEE

A binary-search switched-current sensing scheme for 4-state MRAM

A current-mode binary-search sensing scheme for a 4-state one-transistor one-magnetic tunnel junction (1T1MTJ) magneto-resistive random access memory (MRAM) is proposed. By using the switched-current technique, it is able to read data non-destructively with a magneto-resistive (MR) ratio of as low as 5%. The circuit is designed using a 0.18μm CMOS process and the performance is verified by HSPICE. Compared to the parallel sensing approach, the proposed sensing scheme consumes less power and chip area and requires fewer comparison steps. Compared to the serial sensing approach, it allows a shorter read access time while requiring the same number of comparisons

A novel current-mode sensing scheme for magnetic tunnel junction MRAM

In this paper, we present two integrated circuits for sensing data nondestructively from one-transistor one-magnetic tunnel junction (1T-1MTJ) magnetoresistive random access memory (MRAM). The first one is a low-power sensing circuit for MTJs with a magnetoresistance (MR) ratio larger than 10\%, and the second one is a high-sensitivity switched-current sensing circuit for MTJs with an MR ratio as low as 5\%. The circuits are designed using 0.60- and 0.18-mum CMOS processes, and their performance is verified using HSPICE. Compared with existing sensing circuits at a power supply of 3.0 V, their read access time is 1.46-3.33 times faster and power consumption is 2.67-3.85 times smaller