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Biomedical subjects

B Yang

Publications and source records attributed to B Yang.

At least 433 records · Page 24Linked to original sources
PubMed1989

[Effects of noradrenaline,glycine, gamma-aminobutyric acid and L-glutamic acid on spinal field potentials in the rat].

Noradrenaline (NE), glucine (GLY), gamma-aminobutyric acid (GABA) and L-glutamic acid (L-GLU) were locally applied to the dorsal surface of lumbar spinal cord on anesthetized and immobilized rats and their effects on segmental (SP) and descending (DP) spinal field potentials were examined. Both waves N and P of SP and DP were reduced markedly in amplitudes following local application of NE. A significant decrease in amplitude of wave N and a remarkable increase in wave P in both SP and DP were shown during the application of GLY, GABA and L-GLU. The results suggest that these neurotransmitters may be involved in the generation of waves N and P, particularly affecting the activities of interneurons in the spinal dorsal horn.

Animals↗
PubMed1982

The role of the human caudate nucleus in acupuncture analgesia.

The role of the caudate nucleus in acupuncture analgesia was studied in 17 patients receiving caudate stimulation through chronic implanted electrodes to relieve intractable pain caused by late malignancy. Electrical stimulation of the head of the caudate nucleus provided relief from intractable pain in all 17 patients. The pain and pain tolerance threshold were elevated, the alteration in skin galvanic activity, respiratory movement and fingertip plethysmography elicited by a given painful stimulus were depressed. The analgesia required a period of induction and persisted for some time after cessation of stimulation; it showed no obvious segmental topography. These characteristics are similar to those observed in acupuncture analgesia. The effect of caudate stimulation was similar to that of electric needling in depressing the late component of the somatosensory evoked potentials (SEPs) recorded over the scalp and from the centrum medianum of the thalamus. Evoked potentials could be recorded from the caudate nucleus when an acupuncture point was electrically stimulated. The evoked potential record was a complex wave of positive and negative components, the peak latencies of main components being 100-180 msec for positive wave and 148-332 msec for negative wave components. The present study supports the supposition that the caudate nucleus may play a role in acupuncture analgesia. The possibility that the effect of caudate stimulation is brought on by inhibiting the activity of the medial thalamus is discussed.

Acetylcholine↗
PubMedDate not supplied

Separation and identification of proteins obtained from Agkistrodon acutus snake venom by capillary zone electrophoresis and laser desorption/ionization mass monitoring.

Fractions of seven protein principles with fibrinolytic or thrombin-like activities obtained from Agkistrodon acutus snake venom purified by two steps of normal pressure chromatography were separated further by capillary zone electrophoresis (CZE). Mass determination for these fractions were achieved by performing laser desorption/ionization mass monitoring (LDIM). The comparative study between CZE and LDIM on the separation of these fractions was made.

Agkistrodon↗
PubMedDate not supplied

Photodynamic therapy for upper gastrointestinal tumours over the past 10 years.

A total of 207 patients with advanced upper gastrointestinal tumors were treated with photodynamic therapy (PDT) from 1982 to 1992. This paper reports on the effectiveness and evaluates the follow-up survey of the results. The patients were aged 29-91 years, of whom 189 were men and 18 women. Forty-eight to 72 hr prior to irradiation, 5 mg/kg of HpD was injected intravenously. An argon pumped dye laser was used with an output beam of 630 nm. The entire tumour received an estimated energy dose of 200-250 J/cm2. The diagnosis of cancer was confirmed by biopsy and histological examination. Of the 207 cases treated, 45 had cancer of the esophagus, 123 had cancer of the cardia, and 39 had cancer of the stomach. Response to PDT was seen in 146 patients (70.5%), with CR in 31 patients who were followed up for 6 months to 10 years. Seven of the latter patients (22.6%) survived more than 5 years and are still under close follow-up.

Adult↗
PubMedDate not supplied

High-dose mitomycin C-containing regimens in the treatment of advanced gastric cancer.

In 136 patients (115 males and 21 females) with advanced gastric cancer confirmed histologically, a regimen of high-dose mitomycin C plus tegafur or UFT was administered. Dosage of agents used and schedules were as follows: MMC 20 mg i.v. once a week up to a total of 60 mg, followed either by tegafur 600 mg/day p.o. to a total dosage of 20-40 g, or by UFT 450 mg/day p.o., to a total dosage of 30 g. Patients' ages ranged from 24 to 75 years. Of this series, 70 patients were deemed inoperable, 21 patients underwent nonradical surgical operation, and the other 45 patients had postoperative recurrent disease. Of the 136 patients, 78 achieved complete tumour remission (CR) (21/136) and partial remission (PR) (57/136), yielding a response rate of 57.4%. The median duration of remission and survival was 5.2 (range 2-16+) and 10.1 (range 3-48+) months. The main side effects were leukopenia and thrombocytopenia. None of these patients had liver or kidney function damage.

Adult↗
PubMedDate not supplied

The membrane disordering effect of ethanol on neural crest cells in vitro and the protective role of GM1 ganglioside.

The teratogenic effect of ethanol appears to be related to excessive cell death in selected cell populations including craniofacial neural crest. Because there is a large body of evidence suggesting that a primary site of action of ethanol is at the membrane level, the current study was designed to examine and attempt to ameliorate ethanol-induced neural crest cell membrane changes that proceed cell death. To this end, neural crest cells were grown as primary cultures from mouse cranial neural tube be explants. In these cultured cells, the relationships between changes in membrane lipid lateral mobility (a measure of membrane fluidity) as determined using the technique of fluorescence recovery after photobleaching (FRAP), ethanol-induced cell death, and the protective role of GM1 ganglioside were examined. A dose-response study showed that treatment with 50, 100, 150, or 200 mM ethanol respectively, for 24 h was positively correlated with membrane lipid lateral mobility and negatively correlated with cell viability. Pre- or co-treatment of the cells with GM1 ganglioside diminished the ethanol-induced increases in membrane fluidity and decreases in cell viability. The results of this study suggest that change in membrane fluidity can account, in part, for ethanol-induced neural crest cell death and that the protection conferred by GM1 ganglioside may result from membrane stabilization and subsequent preservation of the biophysical properties and biological function of the ethanol-exposed cell membranes.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Validation of conductance catheter system for quantification of murine pressure-volume loops.

The purpose of this study was to define the validation methods and outcomes of a conductance catheter system specifically for in vivo murine cardiac hemodynamic analysis. To express the relationship between conductance and blood volumes, we used an in vitro model to derive a volume-conductance line. The volume-conductance line was used to compute raw volume from the modified conductance signals. The parallel volume was calibrated with hypertonic (15%) saline injected from extrajugular vein. The ventricular volume was computed by raw volume minus parallel volume. The accuracy of conductance volumetric measurements was validated with a static in situ infusion of calibrated volumes of whole blood injected into arrested left ventricles. In vivo dynamic measurements were performed with 24 C57B1/6 mice, 6 months old; for comparison of established values. The in situ model showed that after calibration, the experimental coefficient, alpha, was equal to 1 and the measured volume by conductance catheter was equal to the true volume of the left ventricle (y = 0.982x + 0.513, p < .0001). For the in vivo models, the end-diastolic volumes and the stroke volumes and cardiac output determined with the conductance catheter system were 17.3 +/- 1.0 microL, 10.6 +/- 0.9 microL, and 6.0 +/- 0.5 mL/min, respectively. We validated the relationship between measured volume by conductance catheter and the true volume and demonstrated the accuracy of the volume-conductance line for conversion of conductance to volume.

Animals↗