Establishment and application of experimental model of human fetal hepatocytes: protective effects of silybin and polyporus umbelalus polysaccharides on human fetal hepatocytes

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Good regulation of acupuncture in simple obesity patients with stomach-intestine excessive heat type

In order to investigate the regulatory effect of acupuncture on obesity patients with the Stomach-Intestine Excessive Heat Type, the pre-acupunctureal and post-acupunctural obesity index and biochemical indices of 718 simple obesity patients with Stomach-Intestine Excessive Heat Type were observed. It was showed that the marked weight loss effect was achieved in the cases by acupuncture, and the biochemical indices improved. It suggests that acupuncture had a optimal regulatory effect on the function of nerve, endocrine, digestion and energy metabolism.     

Microscale Transport and Sorting by Kinesin Molecular Motors

As biomolecular detection systems shrink in size, there is an increasing demand for systems that transport and position materials at micron- and nanoscale dimensions. Our goal is to combine cellular transport machinery-kinesin molecular motors and microtubules-with integrated optoelectronics into a hybrid biological/engineered microdevice that will bind, transport, and detect specific proteins, DNA/RNA molecules, viruses, or cells. For microscale transport, 1.5 microm deep channels were created with SU-8 photoresist on glass, kinesin motors adsorbed to the bottom of the channels, and the channel walls used to bend and redirect microtubules moving over the immobilized motors. Novel channel geometries were investigated as a means to redirect and sort microtubules moving in these channels. We show that DC and AC electric fields are sufficient to transport microtubules in solution, establishing an approach for redirecting microtubules moving in channels. Finally, we inverted the geometry to demonstrate that kinesins can transport gold nanowires along surface immobilized microtubules, providing a model for nanoscale directed assembly.     

Noninvasive Electrocardiographic Imaging (ECGI): Application of the Generalized Minimal Residual (GMRes) Method

Electrocardiographic imaging (ECGI) is a developing imaging modality for cardiac electrophysiology and arrhythmias. It reconstructs epicardial potentials, electrograms, and isochrones from electrocardiographic body-surface potentials noninvasively. Current ECGI methodology employs Tikhonov regularization, which imposes constraints on the reconstructed potentials or their derivatives. This approach can sometimes reduce spatial resolution by smoothing the solution. Accuracy depends on a priori knowledge of solution characteristics and determination of an optimal regularization parameter. These properties led us to implement an independent, iterative approach for ECGI—the generalized minimal residual (GMRes) method—which does not apply constraints. GMRes was applied to experimental data during activation/repolarization of normal and infarcted hearts. GMRes reconstructions were compared to Tikhonov reconstructions and to measured gold standards in isolated hearts. Overall, the accuracy of GMRes solutions was similar to Tikhonov regularization. However, in certain cases GMRes recovered localized potential features (e.g., multiple potential minima), which were lost in the Tikhonov solution. Simultaneous use of these two complementary methods in clinical ECGI will ensure reliability and maximal extraction of diagnostic information in the absence of a priori information about a patient's condition.© 2003 Biomedical Engineering Society. PAC2003: 8719Hh, 8757Gg     

Spontaneous waves in the dentate gyrus of slices from the ventral hippocampus

Spontaneous negative-going potentials occurring at an average frequency of 0.7 Hz were recorded from the dentate gyrus of slices prepared from the temporal hippocampus of young adult rats. These events (here termed "dentate waves") in several respects resembled the dentate spikes described for freely moving rats during immobile behaviors and slow-wave sleep. Action potentials were observed on the descending portion of the in vitro waves and, as expected from this, whole cell recordings established that the waves were composed of depolarizing currents. Dentate waves appeared to be locally generated within the granule cell layer and were greatly reduced by antagonists of AMPA-type glutamate receptors or by lesions to the entorhinal cortex. Simultaneous recordings indicated that the waves were often synchronized in the inner and outer blades of the dentate gyrus. Knife cuts through the perforant path and the commissural/associational system did not eliminate synchronization, leaving electrotonic propagation via gap junctions as its probable cause. In accord with this, cuts that separated the two blades of the dentate eliminated synchronization between them, and a compound that inhibits gap junctions reduced wave activity. Dentate waves were regularly accompanied by sharp waves in field CA3 and were reduced in size by the acetylcholinesterase inhibitor, physostigmine. It is hypothesized that dentate waves occur when spontaneous glutamate release from dentate afferents produces action potentials in neighboring granule cells that then summate electrotonically into a population event; once initiated, the waves propagate, again electrotonically, and thereby engage a significant portion of the granule cell population.     

Immunohistochemical analysis of centromere protein F expression in buccal and gingival squamous cell carcinoma

Centromere protein F (CENP-F) expression (localization and characteristics) in relation to tumor clinicopathological parameters was immunohistochemically examined and evaluated in 47 archival biopsy specimens of buccal and gingival squamous cell carcinomas (SCC). Centromere protein F expression was detected in 79% of the samples. An increase in the labeling index (LI) with WHO grading was obtained ( P  < 0.05). Correlations were obtained between the CENP-F LI and tumor size ( P  < 0.05). Immunoelectron microscopy showed CENP-F nuclear staining as punctate or fine dots. The present study shows that CENP-F expression and detection of a more specific cell subpopulation presents a theoretical advantage for the analysis of the precise cell cycle of G₂ to M cells, compared to Ki-67.     

4E-binding protein phosphorylation and eukaryotic initiation factor-4E release are required for airway smooth muscle hypertrophy

The molecular mechanisms of airway smooth muscle hypertrophy, a feature of severe asthma, are poorly understood. We previously established a conditionally immortalized human bronchial smooth muscle cell line with a temperature-sensitive SV40 large T antigen. Temperature shift and loss of large T cause G1-phase cell cycle arrest that is accompanied by increased airway smooth muscle cell size. In the present study, we hypothesized that phosphorylation of eukaryotic initiation factor-4E (eIF4E)-binding protein (4E-BP), which subsequently releases eIF4E and initiates cap-dependent mRNA translation, was required for airway smooth muscle hypertrophy. Treatment of cells with chemical inhibitors of PI 3-kinase and mammalian target of rapamycin blocked protein synthesis and cell growth while decreasing the phosphorylation of 4E-BP and increasing the binding of 4E-BP to eIF4E, consistent with the notion that 4E-BP1 phosphorylation and eIF4E function are required for hypertrophy. To test this directly, we infected cells with a retrovirus encoding a phosphorylation site mutant of 4E-BP1 (AA-4E-BP-1) that dominantly inhibits eIF4E. Upon temperature shift, cells infected with AA-4E-BP-1, but not empty vector, failed to undergo hypertrophic growth. We conclude that phosphorylation of 4E-BP, eIF4E release, and cap-dependent protein synthesis are required for hypertrophy of human airway smooth muscle cells.