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Biomedical subjects

W Gao

Publications and source records attributed to W Gao.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Comparative study on the erect and fallen types of Platycodon grandiflorum (Jacq.) DC].

Based on botanica characters, phenophase, yield and content of active constituents, the erect and fallen types of platycodon grandiflorum were compared. The results show that the comprehensive characters of erect type are better than those of fallen type and the erect type is therefore good for popularization. Some specific characters of the fallen type are better than those of the erect type, and the fallen type is therefore to be preserved as one of the germ plasm resources.

Glucose↗
PubMed1997

[Advancement on neurotransmitter transporters].

The neurotransmitter transporter (NTT), a kind of glycoprotein situating on the presynaptic membrane, glial membrane, or vesicle membrane, has become the focusing point of neuroscience research in recent years. They could combine selectively with transmitters released into synaptic cleft and carry them back into cells to aid the termination of synaptic transmission. In this way, NTT took an important part in modulation of information between neurons. Study on NTT has not been reported domestically. This article reviewed recent studies on molecular structure, classification, study methods, distribution, function, modulating factors and gene modulation, focus of study and also unresolved problems of NTT.

ATP-Binding Cassette Transporters↗
PubMed1997

[Isoesterase assay over the course of dormancy relieving with low temperature in the seed of Fritillaria thunbergii Miq. by electrophoresis].

In order to study the physiological basis of dormancy relieving with low temperature in the seed of Frit-illaria thunbergii isoesterase patterns were assaved by means of electrophoresis over the courses of dormancy relieving at 8-10 degrees C and 3-5 degrees C. The changes of isoesterase patterns are similar at the two different temperatures. Over the courses of dormancy relieving, some new bands are detected and some original bands are enhanced. These results show that the physiological basis may be similar over the courses of dormancy relieving at 8-10 degrees C and 3-5 degrees C.

Adaptation, Physiological↗
PubMed1997

[Changes of soluble protein contents in Fritillaria thunbergii Miq. over the course of dormancy relieving with low temperature].

The changes of soluble protein contents in bud, adaxial cortex and inner tissue in the scale of Fritillaria thunbergii were assayed over the course of dormancy relieving with low temperature. There was a peak in each of the three diagrams at 25 days or 35 days treated with low temperature. All of the soluble protein contents of bud, adaxial cortex and inner tissue in scale tended to increased in the stage before dormancy relieving.

Adaptation, Physiological↗
PubMed1997

[Diastase and reducing sugar in Fritillaria thunbergii Miq. during the process of dormancy relieving with low temperature].

The changes of diastase's activity and reducing sugar's content in Fritillaria thunbergii were studied during the process of relieving dormancy with low temperature. The results showed that the metabolism in bud and scale was changed, the diastase's activity and reducing sugar's content of the adaxial epiderm were higher than those of the inner store tissue in the scale, but were approximate to those of the bud.

Adaptation, Physiological↗
PubMed1997

[Peroxidase assay over the course of dormancy relieving with low temperature in Fritillaria thunbergii Miq. by electrophoresis].

In order to study the physiological basis of dormancy relieving with low temperature in Fritillaria thunbergii, isoperoxidase changes of bud, adaxial epiderm and inner tissues in scale were assayed by means of electrophoresis over the course of dormancy relieving. All the patterns in bud and different parts of scale change at different stages, and the peroxidase activity in bud and adaxial epiderm is higher than that in the inner tissue of scale. These results indicate both bud and scale join in the dormancy relieving.

Adaptation, Physiological↗
PubMed1997

[Electrophoresis assay on isoperoxidase in the course of seed dormancy relieving for Fritillaria thunbergii Miq. at two different low temperatures].

The relieving of seed dormancy for Fritillaria thunbergii required 50 days at 8-10 degrees C and 80 days at 3-5 degrees C. During the relieving process, isoperoxidase pattern changes were studied by means of electrophoresis. The results showed that some new bands were detected, some original bands enhanced as the seeds were treated with a low temperature, and the changes of lsoperoxidase patterns were similar at two different low temperatures.

Adaptation, Physiological↗
PubMed1997

[Effect of environment on the teleutospore viability of Ustilago coicis].

The teleutospores of Ustilago coicis can retain their germinating power under indoor dry conditions for about five years. They can survive the winter in the fields in Beijing. Increase of soil humidity could reduce the number of teleutospores in soil. Rotation is an efficient method to control the head smut of Jobs-tears and the rotation cycle is two years minimum.

Ecology↗
PubMed1997

[Peroxidase and soluble protein in the leaves of Aloe vera L. var. chinensis (Haw.)Berger].

The peroxidase activity and soluble protein content in the leaves of Aloe vera var. chinensis were assayed by spectrophotometric method. The results show that the peroxidase activity in the upper most and lower parts of leaves is comparatively high. Soluble protein content decreases from top to bottom leaves. The results of electrophoresis of soluble protein show that the patterns of upper leaves have more and darker bands than those of lower leaves.

Drugs, Chinese Herbal↗
PubMed1997

[Evaluation of brain evoked potentials in the detection of subclinical hepatic encephalopathy in cirrhotics].

Brainstem auditory evoked potentials (BAEP), visual evoked potentials (VEP) and short latency somatosensory evoked potentials (SSEP) were examined in 30 nonalcoholic liver cirrhotics without clinically detectable hepatic encephalopathy and 30 healthy controls. In the cirrhotics, all peak latencies of the three kinds of evoked potentials, the interpeak latencies (IPLs) I-V, III-V of BAEP and the IPLs N13-N20, N13-P25 of SSEP were significantly prolonged compared with the controls, respectively. The amplitudes of P100, N125 of VEP were significantly lowered in the cirrhotics than those of the controls. Abnormal BAEP test and abnormal SSEP test results were found in both 60% of the cirrhotics, while VEP tests showed abnormalities in only 36.7%. In total, abnormal evoked potential test of one or more kinds were found in 90% of the cirrhotics. It is concluded that in cirrhotic patients, before the appearance of clinically encephalopathy, there were already brain evoked potential abnormalities or brain function changes. Our results argue in favor of the three kinds of evoked potential as the combined investigation for the sensitive and objective diagnosis of subclinical hepatic encephalopathy in patients with nonalcoholic cirrhosis.

Adult↗
PubMed1997

In vitro evaluation of sealing pits and fissures with newer glass-ionomer cements developed for the ART technique.

Four conventional glass-ionomer cements specifically developed for use with the atraumatic restorative treatment (ART) technique were compared with a resin-based sealant for marginal and surface dye penetration, material voids, and completeness of enamel fissure penetration. Thirty sound permanent mandibular molar teeth were randomly divided into five groups. After delayed placement of the glass-ionomer cement sealants using standardized finger pressure, and conventional placement of the resin-based sealant using a dental probe, the teeth were first thermocycled then the crowns immersed in methylene blue dye before being sectioned. There were no statistically significant differences found between any of the five materials, apart from less marginal dye leakage being present for the resin-based sealant than for one of the glass-ionomer cements. The cements, however, showed better fissure penetration than did the sealant. Despite the delayed placement and higher viscosity, all of the glass-ionomer cements showed satisfactory penetration of the enamel fissures and minimal marginal and surface dye penetration, and material voids, when placed using firm finger pressure. The cements could prove to be useful in the dental treatment of apprehensive children.

Analysis of Variance↗
PubMed1996

Force-frequency response in isoproterenol-induced hypertrophied rat heart.

Rate-dependent force production was investigated using small trabecular muscle from control and hypertrophied rat cardiac muscle. Cardiac hypertrophy was induced by daily subcutaneous injection of isoproterenol (0.3 mg/kg body weight) for 12 days. The force-frequency relationship, for the control rat myocardium, is clearly biphasic. A stepped increase in stimulation frequency from 0.1 to 0.5 Hz results in a decrease in contractile force (negative phase). However, at higher stimulation frequency above 0.5 Hz, an increased contractile force is revealed (positive phase). Membrane action potential duration (APD50) was used to reflect sarcolemmal Ca2+ influx. The frequency-dependent increase in APD50 and the ability of nifedipine, a sarcolemmal L-type Ca2+ channel blocker, to eliminate the positive-force frequency response, indicate that sarcolemmal Ca2+ influx is important for force development at high stimulation frequency. Relative Ca2+ content of sarcoplasmic reticulum is estimated from rapid cooling contractures. The parallel change of rapid cooling contractures and twitch force suggests that the sarcoplasmic reticulum Ca2+ content alters with varying frequencies of stimulation. Isoproterenol-induced hypertrophied muscle shows a greater contractile force, increased nifedipine-sensitive force development and prolonged APD50 compared to controls. These data suggest a greater availability of intracellular Ca2+ to activate contraction in hypertrophied muscle, possibly by amplified Ca2+ influx via L-type channel.

Action Potentials↗
PubMed1996

Destruction of Kupffer cells increases survival and reduces graft injury after transplantation of fatty livers from ethanol-treated rats.

This study investigated the role of Kupffer cells on survival and graft injury in transplanted fatty livers from rats treated acutely with ethanol. Donor rats were given ethanol (5 g/kg, by mouth) 20 hours before explantation, and liver grafts were preserved in University of Wisconsin cold storage solution for 24 to 42 hours prior to implantation. Blood samples were taken from the inferior vena cava for 3 hours after implantation. During this time, serum aspartate transaminase levels increased gradually from 122 U/L to 597 U/L in control rats, while ethanol treatment elevated values to 2,278 U/L. Gadolinium chloride (20 mg/kg, given intravenously to recipients 24 hours before explantation), a selective inactivator of Kupffer cells, minimized the increase in aspartate transaminase levels significantly. After implantation of grafts cold-stored for 42 hours, survival rates were 88% in control rats but only 33% in ethanol-treated rats. Gadolinium chloride improved survival nearly to control values. Ethanol nearly doubled white blood cell adhesion, an effect also largely blocked by gadolinium chloride. Further, alpha-(4-pyridyl 1-oxid)-N-tert-butylnitrone radical adducts detected in the bile were increased twofold by ethanol treatment. This effect was also reversed by gadolinium chloride. Taken together, these data indicate that survival is poorer and graft injury is greater in fatty livers from ethanol-treated rats. Inactivation of Kupffer cells minimized graft damage, most likely by improving hepatic microcirculation and diminishing lipid peroxidation.

Analysis of Variance↗
PubMed1996

Percutaneous balloon mitral valvuloplasty in patients with mitral restenosis after previous surgical commissurotomy. A matched comparative study.

BACKGROUND: Although the efficacy of percutaneous balloon mitral valvuloplasty in patients with unoperated mitral stenosis has been well documented, there exists less clear-cut data on its effectiveness in patients with mitral restenosis after previous surgical commissurotomy. Accordingly, the purpose of this study was to evaluate our immediate and midterm results of balloon mitral valvuloplasty in this subset of patients with previous mitral surgery. METHODS: Between October 1991 and August 1995, 29 consecutive patients with mitral restenosis after prior surgical commissurotomy (group 1) underwent Inoue balloon mitral valvuloplasty. They were matched on a patient-to-patient basis with regard to baseline mitral echocardiographic score mitral valve area, severity of angiographic mitral regurgitation and follow-up duration with 29 other patients with unoperated mitral stenosis (group 2) who underwent balloon mitral valvuloplasty during the same study period. RESULTS: Balloon mitral valvuloplasty yielded identical improvements in transmitral gradient and mitral valve area (from 0.8 to 1.6 cm2) determined echocardiographically, and similar changes in the severity of mitral regurgitation in both groups of patients. All procedures were successfully completed without major cardiac complications. Follow-up echocardiographic assessment in 73% of patients revealed equal mitral valve area (1.6 cm2) and a restenosis rate of 17%, with no difference in the restenosis rate between the two groups. CONCLUSION: Balloon mitral valvuloplasty in selected patients with mitral restenosis after past surgical commissurotomy can be performed safely and with similar immediate and midterm efficacy as in patients with de novo mitral stenosis.

Adult↗