Biomedical subjects

Jin-Hui Wang

Publications and source records attributed to Jin-Hui Wang.

At least 19 recordsLinked to original sources

PubMed2006

Sodium channel-mediated intrinsic mechanisms underlying the differences of spike programming among GABAergic neurons.

Neural codes to guide well-organized behavior are thought to be the programmed patterns of sequential spikes at central neurons, in which the coordinative activities of voltage-gated ion channels are involved. The attention has been paid to study the role of potassium channels in spike pattern; but it is not clear how the intrinsic mechanism mediated by voltage-gated sodium channels (VGSC) influences the programming of sequential spikes, which we investigated at GABAergic cerebellar Purkinje cells and hippocampal interneurons by patch-clamp recording in brain slices. Spike capacity is higher at Purkinje cells than interneurons in response to the given intensities of inputs, and is dependent on input intensity. Compared to interneurons, Purkinje cells express the lower threshold potentials and the shorter refractory periods of sequential spikes. The increases of input intensities shorten spike refractory periods significantly. The threshold potentials for VGSC activation and the refractory periods for its reactivation are lower at Purkinje cells, and are reduced by the strong depolarization. We suggest that the VGSC-mediated threshold potentials and refractory periods are regulated by synaptic inputs, and navigate the programming of sequential spikes at the neurons.

Action Potentials↗

PubMed2006

A new nor-lignan from the seeds of Descurainia sophia.

A new aryldihydronaphthoic acid, descuraic acid (1), was isolated from the seeds of Descurainia sophia (L.) Webb ex Prantl. The structure of 1 was elucidated by means of physico-chemical properties and spectroscopic methods (1D and 2D NMR, MS). 1 was a new nor-lignan.

Brassicaceae↗

PubMed2006

The intrinsic mechanisms underlying the maturation of programming sequential spikes at cerebellar Purkinje cells.

Cerebellum is involved in the motion coordination and working memory, to which the programming of sequential spikes at Purkinje cells is essential. It is not clear about the intrinsic mechanisms underlying spike capacity and timing precision as well as their postnatal maturation. We investigated the programming and intrinsic property of sequential spikes at Purkinje neurons during postnatal development by whole-cell recording in cerebellar slices. Cerebellar Purkinje neurons demonstrate the increasing of spike capacity and timing precision, as well as the lowering of refractory periods and threshold potentials during the postnatal maturation. In addition, the correlation between spike parameters and intrinsic properties converts to be more linear. This postnatal plasticity of neuronal intrinsic properties improves the timing precision and capacity of spike programming at cerebellar Purkinje neurons.

Action Potentials↗

PubMed2006

A new cycloartane glycoside from Camptosorus sibiricus Rupr.

A new cycloartane glycoside was isolated from the dried aerial parts of Camptosorus sibiricus Rupr. By means of chemical and spectroscopic methods (IR, 1D and 2D NMR, ESI-MS), the structure was established as 3beta, 7beta, 24beta, 25, 30-pentahydroxycycloartane-3-O-beta-D-glucopyranoside-24-O-beta-D-glucopyranosyl(1 --> 2)-D-glucopyranoside (1).

China↗

PubMed2006

A new cerebroside from fruits of Ailanthus altissima Swingle.

A new cerebroside and three known cycloartan triterpenes were isolated from fruits of Ailanthus altissima Swingle. Their structures were identified as 1-O-beta-D-glucopyranosyl-(2S, 3R, 4E, 9E)-2-(2'R-hydroxyhexadecenoy)-4, 9-octadecadiene-1, 3-diol (1), 9, 19-cyclolanost-23 (Z)-ene-3beta, 25-diol (2), cycloart-25-ene-3beta, 24R-diol (3), and cycloart-25-ene-3beta, 24S-diol (4) by means of chemical and spectroscopic analysis. Compounds 2, 3, and 4 were isolated from genus Ailanthus for the first time. The analgesic activity of 1 was also evaluated.

Ailanthus↗

PubMed2006

A new anthraquinone from Galium verum L.

A new anthraquinone (4) and three known anthraquinones (1-3) were isolated from Galium verum L. Their structures were identified as 1,3-dihydroxy-2-methylanthraquinone (1), physcion (2), 2-hydroxy-1,3-dimethoxyanthraquinone (3), 2,5-dihydroxy-1,3-dimethoxyanthraquinone (4) by means of chemical and spectroscopic analysis. Compound 2 was isolated from the genus Galium for the first time. In addition, compound 4 was assayed for antimicrobial activity in vitro.

Anthraquinones↗

PubMed2005

Antibacterial constituents from fruit bodies of ascomyce Bulgaria inquinans.

Two ergosterins and two triterpenoids were isolated from the dried fruit bodies of Ascomyce Bulgaria inquinans. By means of chemical (hydrolysis) and spectroscopic methods (NMR, El-MS), their structures were established as betuinic acid (1), cerevisterol (2), (24R)ergosta-7, 22E-diene-3beta, 5alpha, 6beta-triol-3-O-palmitate (3) and ursolic acid (4). Compound 3 is a new compound.

Anti-Bacterial Agents↗

PubMed2005

A new phytosterone from Achyranthes bidentata B1.

A new phytosterone named achyranthesterone A (1), along with the three known compounds stachysterone D (2), beta-ecdysone (3) and polypodine B (4) have been isolated from the roots of Achyranthes bidentata Bl. The structure of the new compound was determined as 2beta,3beta,14alpha,20S,21,22R,25-heptahydroxycholest-7-en-6-one on the basis of physico-chemical properties and spectral methods.

Achyranthes↗

PubMed2005

A new sesquiterpene ester from the fruits of Celastrus orbiculatus.

From the fruits of Celastrus orbiculatus Thunb. a new beta-dihydroagarofuran sesquiterpene ester named 1beta,2beta,13-triacetoxy-9alpha-cinnamoyloxy-beta-dihydroagarofuran (1) has been isolated along with two known compounds, 6alpha-acetoxy-1beta,9beta-dibenzoyloxy-8beta-hydroxy-beta-dihydroagarofuran (2), and 1beta, 6alpha-diacetoxy-9beta-benzoyloxy-8beta-hydroxy-beta-dihydroagarofuran (3). Their structures were elucidated on the basis of spectroscopic data.

Celastrus↗

PubMed2005

A new cycloartane glycoside from Comptosorus sibiricus rupr.

The structure of a new cycloartane glycoside isolated from the whole herbs of Comptosorus sibiricus Rupr. has been established, by chemical and spectroscopic methods (IR, 1D and 2D NMR, HRMS, ESI-MS), as 3beta,7beta,24beta,25,30-pentahydroxycycloartane 24-O-beta-D-glucopyranoside (1).

Chromatography, Gel↗

PubMed2005

Sterols from the pericarp of Sphaerophysa salsula DC.

A new stigmasterol, (24S)-stigmast-5-en-7beta-ethoxy-3beta-ol (2) together with three known sterols have been isolated from the ethanolic extract of the pericarp of Sphaerophysa salsula (Pall.) DC, and their structures elucidated mainly on the basis of the spectral data and comparison with the literature.

China↗

PubMed2005

A new flavonoside from Leonurus heterophyllus.

In a chemical investigation on the flavone composition of Leonurus heterophyllus a new flavonoside has been isolated. By means of physico-chemical evidences and spectral analysis its structure has been established as quercetin-3-O-[3-(4-hydroxy-3,5-dimethoxybenzyl)-alpha-L-rhamnopyranosyl]-(1-->6)-beta-D-galactopyranoside (1).

Flavones↗

PubMed2005

Two new compounds from the seeds of Descurainia sophia.

Two new compounds, descurainin A (1) and descurainoside B (2), were isolated from the seeds of Descurainia sophia (L.) Webb ex Prantl. Their structures were elucidated by spectroscopic methods (MS, 1H, 13C and 2D NMR).

Brassicaceae↗

PubMed2004

HSF1 blockade-induced tumor thermotolerance abolishment is mediated by JNK-dependent caspase-3 activation.

We previously blocked the heat shock transcription factor 1 function with a dominant-negative mutant (mHSF1) in breast cancer cell line Bcap37, and found that mHSF1 sensitizes Bcap37 cells to hyperthermia by promoting the apoptotic process. Here we studied the mechanism of this abolishing process and how thermotolerance develops in Bcap37 cells. The results indicated that mHSF1 abolished acquired or intrinsic thermotolerance in Bcap37 cells by enhancing JNK and caspase-3 pathways, two stress-induced apoptotic pathways, after hyperthermia, and interference with either one of them attenuated hyperthermia-induced apoptosis. Furthermore, epistasis assay of these two pathways suggested that JNK was upstream of the caspase-3 pathway. Conversely, other hyperthermia-induced kinases implicated in cell survival and death, Akt, ERK or p38, did not influence the effect of mHSF1, indicating that these kinases were not implicated in this abolishing process. In addition, we found that the development of acquired thermotolerance of Bcap37 cells was associated with the suppression of JNK activation after mild preheat treatment and was not reduced by Akt, ERK or p38 inhibition. In contrast, the intrinsic thermotolerance of Bcap37 cells was due to the intrinsic high levels of Akt and ERK activities since Akt or ERK inhibition resulted in increased thermosensitivity of Bcap37 cells. Our results suggest that mHSF1 plays a valuable role in the thermotolerance abolishment of Bcap37 cells, which likely contributes to tumor therapy in combination with hyperthermia.

Apoptosis↗

PubMed2004

Differential modulation of glutamatergic and cholinergic synapses by calcineurin in hippocampal CA1 fast-spiking interneurons.

How signaling molecules in inhibitory interneurons modulate and coordinate the integration of synaptic inputs remains largely unknown. We investigated the kinetics and modulation of glutamatergic and cholinergic synapses on CA1 fast-spiking interneurons in hippocampal slices by using whole-cell clamp recording. Spontaneous synaptic currents mediated by either AMPA-type glutamate or nicotinic acetylcholine receptors on the interneurons can be classified into fast, slow and fast-slow based on their duration and decay phase. Effects of calcineurin, calmodulin-dependent protein phosphatase, on these two groups of synapses were examined by infusing an autoinhibitory peptide of calcineurin (CaN-AIP) into the recording neurons. CaN-AIP enhanced the amplitude of glutamatergic fast-EPSCs, as well as both amplitude and frequency of cholinergic fast-EPSCs. No significant changes in slow-EPSCs were observed during the infusion of CaN-AIP. Our results indicate that signal transmission at synapses, which are mediated by either AMPA-type glutamate or nicotinic acetylcholine receptors, appears different in the kinetics. The selective influence of calcineurin on different synapses in fast-spiking interneurons may play an important role in coordinating thousands of synaptic inputs in order to set neuronal excitability at proper levels.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed2004

Calcium signal-dependent plasticity of neuronal excitability developed postnatally.

Neuronal plasticity and its development were investigated at pyramidal neurons in the cortical slices of rats. The threshold and probability of firing spikes were measured by using whole-cell recording to assess neuronal excitability. Postsynaptic high frequency activity (HFA) at the pyramidal neurons, evoked by 20 trains (250-ms interval) of five depolarization-pulses (1 ms) at 100 Hz, persistently lowered the threshold and increased the probability of firing spikes. After long-term enhancement of neuronal excitability by HFA was stable, another HFA induced further enhancement. Infusing 1 mM 1,2-bis(2-aminophenoxy)-ethane-N, N,N',N'-tetraacetic acid or 100 microM CaMKII(281-301) into the recording neurons prevented HFA-induced long-term enhancement of neuronal excitability. The infusion of 40 microM calcineurin autoinhibitory peptide enhanced neuronal excitability, which occluded HFA effect. HFA-induced long-term enhancement of intrinsic excitability expressed at most pyramidal neurons after postnatal day (PND) 14, but not at those before PND 9. Our results show a new type of neuronal plasticity induced by physiological activity at cortical neurons, which requires calcium-dependent protein phosphorylation and develops during postnatal period. An upregulation of intrinsic excitability at cortical neurons facilitates their activity and broadens signal codes; consequently, their computational ability is upgraded.

Action Potentials↗

PubMed2004

A new cycloartane glycoside from Camptosorus sibiricus Rupr.

A new cycloartane glycoside was isolated from the dried whole herbs of Camptosorus sibiricus Rupr By means of chemical (hydrolysis) and spectroscopic methods (IR, 1D, and 2D NMR, ESI-MS), the structure was established as 3beta, 7beta, 24beta, 25, 30-pentahydroxycycloartane-3-omicron-beta-D-glucopyranoside-24-omicron-beta-D-glucopyranoside (1).

Glycosides↗

PubMed2004

Roles of ginsenosides on morphine-induced hyperactivity and rewarding effect in mice.

Ginsenosides, the main effective components of the root of Panax ginseng, have been reported to modulate morphine action. In the present study, ginsenosides Rd, Rb2, Rgl and Re were divided into two groups according to their effects in mice on morphine-induced hyperactivity and conditioned place preference (CPP). Ginsenosides Rd, Rb2, Rgl had no effect on morphine-induced hyperactivity, but antagonized morphine-induced CPP. On the contrary, ginsenoside Re increased morphine-induced hyperactivity whereas it showed no effect on morphine-induced CPP.Furthermore, Re antagonized the inhibitory effect of the mixture involving Rd, Rb2 and Rgl on the morphine action. These results suggest that ginsenosides with different structures have antagonizing properties in the regulation of morphine-induced reinforcement.

Animals↗