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Biomedical subjects

S Z Yao

Publications and source records attributed to S Z Yao.

At least 19 recordsLinked to original sources
PubMed1992

The anteroventral wall of the third ventricle and the angiotensinergic component of need-induced sodium intake in the rat.

Because the anteroventral wall of the third ventricle (AV3V) has been implicated in the control of sodium intake it was studied in rats with damage of the AV3V region in the sodium-replete and sodium-deplete states, and when they were treated with either pulse intracerebroventricular (pICV) injection of renin to activate brain angiotensin or daily subcutaneous injections of deoxycorticosterone (DOCA). The response of rats with AV3V damage to sodium depletion was retarded and the excess sodium intake that is induced by pICV renin was absent, but their daily need-free sodium intake and the sodium intake that is induced by DOCA were essentially normal. The results suggest that the AV3V is responsible for the angiotensinergic, but not the aldosteronergic, component of the ANG II/ALDO synergy that controls need-induced sodium appetite in the rat. The integrity of the AV3V is not necessary for daily need-free sodium intake or for its enhancement by sodium depletions, suggesting that ANG II is probably not important for these phenomena. But ANG II action within the AV3V might be important for the rapid burst of sodium intake that immediately follows a period of depletion.

Aldosterone↗
PubMed1992

Deficits in NaCl ingestion after damage to the central nucleus of the amygdala in the rat.

These studies examined the NaCl intake behaviors of rats with bilateral electrolytic lesions of the central nucleus of the amygdala (CeAX). Daily need-free intake of 3% NaCl was abolished by CeAX even in rats in which it had been enhanced preoperatively by a history of repeated sodium depletions but was slightly restored by three successive postoperative sodium depletions. CeAX rats drank water but not 3% NaCl to high doses of DOCA and to the activation of cerebral angiotensin II, and expressed small but reliable salt intake (need-induced salt intake or salt appetite) after postoperative sodium depletions. Other ingestive behaviors (water drinking, intake of food and 5% sucrose) were normal. When given decreasing concentrations of NaCl solution the CeAX rats rejected them until the concentration reached 0.2%. These findings suggest that lesions to the central nucleus of the amygdala produce a global impairment in salt intake behaviors that is possibly due to an alteration in the central processing of the salt taste signal.

Amygdala↗
PubMed1991

Extraction-frequencymetric method. A new measurement technique for determination of micro amounts of chlorpheniramine.

A new measurement technique has been proposed and applied to the determination of chlorpheniramine as an example of its application. It is based on the extraction of free chlorpheniramine into carbon tetrachloride after neutralization with a basic agent, followed by measurement of the frequency change of the specially designed ring-coated piezoelectric sensor after evaporation of the extractant from the crystal surface. The frequency change is proportional to the chlorpheniramine amount in the range 0.025-1.2 microgram. The method has been applied to the determination of chlorpheniramine maleate in pharmaceutical preparations.

Calibration↗
PubMed1991

[Use of extraction-frequency metric method for the determination of microquantities of ephedrine and its application in pharmaceutical analysis].

A new extraction--frequency metric method has been proposed for the determination of ephedrine, which can not be determined by the conventional extraction--weighing method due to its volatility. The method is based on extraction of the free alkaloid followed by measuring the frequency shift of a specially constructed ring--coated piezoelectric crystal at room temperature. The frequency shift is in linear relationship with the content of ephedrine hydrochloride over a range 0.05-1.2 micrograms with a correlation coefficient of 0.999 and a detection limit of 0.02 micrograms. Methods for the assay of ephedrine hydrochloride tablet and nasal solution have been proposed.

Chemistry Techniques, Analytical↗
PubMed1991

Transfer mechanism of quinine drug across the oil/water (O/W) interface.

The transfer phenomena of quinine drug at the aqueous 1,2-dichloroethane (DCE) interface have been studied by the current-scanning polarography. The relationships between the wave height and pH of aqueous phase, concentration of quinine as well as the rate of water drop are discussed. The effect of supporting electrolyte, buffer solution and the nature of organic solvent on the polarographic wave is studied. The transfer characteristics of quinine in aqueous phase and in organic phase are compared. The mono-protonated and diprotonated quinines can both transfer at the interface so as to produce two polarographic waves. The transfer process of quinine at the interface is simultaneously controlled by diffusion and reestablishment of the disturbed protonated equilibrium of quinine. A further investigation is made by chronopotentiometry. On the basis of the theoretical analysis, the formulae of the limiting current are derived and discussed. The theoretical results are in agreement with the experimental ones. The transfer mechanism of quinine is put forward.

Mathematics↗
PubMed1990

[Surgical treatment of benign tracheoesophageal fistula and bronchoesophageal fistula in the adults].

This article deals with experiences of surgical treatment of benign tracheoesophageal fistula and bronchoesophageal fistula in seven adults. Among them 2 cases were congenital, 2 cases were infective and 3 cases were traumatic. There were 5 males and 2 females. Their average age ranged from 24 to 53 years. The modes of operation were as follows: (1) resection of fistula, and repairing of leak in 3 cases; (2) pneumonectomy and repairing of leak in 2 cases; (3) esophagectomy through right thoracotomy and cervical reconstruction of the retrosternal esophagogastrostomy was performed in one case; (4) repairing of leak with pedicled esophagus wall in one case. Follow-up shows that the surgical treatment gives satisfactory results in these patients.

Adult↗
PubMed1990

[Surgical treatment of multiple primary carcinoma of the alimentary tract: report of 15 cases].

From March 1964 to December 1986, 26 cases of multiple primary carcinomas were treated in our clinic. Among them 15 cases (57.7%) were multiple primary carcinomas of the alimentary tract including 9 cases of synchronous carcinomas and 6 cases of metachronous carcinomas. All the cases were confirmed by operation and pathological examination. There were 12 males and 3 females. Their ages ranged from 33 to 68 years and most (86.7%) were between 50 and 68 years. The combination of involved organs were mainly esophagus and gastric cardia (11 cases) and colon and gall bladder (2 cases). The pathological combinations were squamous carcinoma and adenocarcinoma (53.3%), adenocarcinoma and adenocarcinoma (26.7%), and squamous carcinoma and carcinoma in situ (6.7%). The follow-up data showed that treatment results of multiple carcinomas of the alimentary tract were poor.

Adenocarcinoma↗
PubMed1990

[Teratoma of the lung: report of 3 cases].

In this paper, 20 cases of teratoma of the lung (3 cases were presented and 17 reviewed) were analyzed. There were 13 males and 7 females, the age ranging from 16-47 years. The primary symptoms were: cough (19 cases, 95%), blood sputum or hemoptysis (16 cases, 80%), chest pain (12 cases, 60%), fever (7 cases, 35%) and expectoration of hair (4 cases, 20%) etc. The histogenesis, diagnosis and treatment of the disease were discussed.

Adult↗
PubMed1990

[Determination of microgram-amount pentoxyverine citrate using a piezoelectric detector and neutralization-extraction technique].

A new method for the rapid determination of microgram and submicrogram amounts of pentoxyverine citrate has been suggested using a ring-coated piezoelectric quartz crystal in combination with the neutralization extraction technique. The detection limit is 0.02 microgram. Frequency shift is directly proportional to the pentoxyverine citrate concentration in the range of 0.05-1.6 micrograms, with a correlation coefficient of 0.999 and a coefficient of variation of 2.3%. The new method suggests a number of advantages over the classical neutralization-extraction method.

Cyclopentanes↗
PubMed1990

Studies on response characteristics of drug ISE's (VII)--performance and theoretical treatment of microcells connected in series.

A new type of MCCS (microcells connected in series) has been constructed and its performances investigated. It has been applied to the determination of streptomycin. The sensitivity and accuracy have been increased significantly. A theoretical model for the error of determination using the MCCS has been suggested and proved experimentally using the Monte Carlo method, and the error model proposed in Ref. [1] revised.

Electrodes↗
PubMed1989

[Characteristics of ion selective electrodes with hetero-poly anion sites].

Drug ion-selective electrodes made with hetero-poly anion as exchange site exhibit better performances than the respective electrodes of conventional tetraphenylboron type, yielding low detection limits and fast responses. Functions of propantheline, berberine, dibazol, thiamine, streptomycin, moroxydine, tetracycline, oxytetracycline, doxycycline, erythromycin, carbetapentane, benzydamine, tetramisole and trifluoperazine electrodes are reported. The electrodes can be used in potentiometric determinations of the respective drugs in aqueous solutions, urine and mixture of water and organic solvents.

Berberine↗
PubMed1989

Studies on response characteristics of drug ise's. (III)--Erythromycin electrodes and their selectivity toward quaternary ammoniums.

Erythromycin sensitive electrodes have been proposed. Their selectivity toward quaternary ammoniums is described in terms of induction effect and steric hindrance effect: logKij = a1I-a2Z/R + a0, where I is induction effect index, a1, a2 and a0 are coefficients which depend on the electro-active material. A general formula has been suggested to relate the electrode selectivity to the carbon atom number (n) of the alkyl of the quaternary ammonium; logKij = A/2.7n-B/(0.80+1.26n)+C, where A, B and C are coefficients which depend on the electro-active material. logKij tends to a limited value C when n increases.

Ammonia↗
PubMed1989

[Determination of micro-amount of dipyrone with a piezoelectric detector].

A new method for the determination of dipyrone (analgin) using a piezoelectric quartz crystal as detector has been proposed. An iodine-potassium iodide solution is added to the sample and the frequency shift of the crystal immersed in the sample solution with respect to the blank is directly proportional to the concentration of dipyrone over a range from 2 x 10(-7) to 3 x 10(-6) mol/L at pH 3.5-6.5 according to the equation C (mol/L) = 6.85 x 10(-9) delta F (Hz). No significant interferences were caused by commonly met inorganic substances, amino acids and a number of other organic substances. The method has been suggested for determining dipyrone at ppm level and in micro-samples of mg or microliters level.

Aminopyrine↗