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Biomedical subjects

C Zhang

Publications and source records attributed to C Zhang.

At least 361 records · Page 20Linked to original sources
PubMed1999

[Effect of fluoride-arsenic exposure on the neurobehavioral development of rats offspring].

In order to explain the effects of fluoride-arsenic exposure on the neurobehavioral development of rats, a two generations-one nest reproductive test was used. Wistar rats were exposed to fluoride and arsenic for two generations. The results demonstrated that: with the increasing concentrations of fluoride and arsenic, the positive rates of early physiological development and nerve reflex were decreased obviously, and the abilities of learning and memory of the offspring were decreased, the swimming and enduring anoxia time gradually shortened. The pathological changes of brain under electron microscope were as follows: decreased number of nerve cells, irregular cell nucleus, organellae degeneration, and obvious decreased number of synapses. It was demonstrated that fluoride-arsenic displayed distinct damage on the nerve system of the offspring.

Animals↗
PubMed1999

[A new method for repair of huge incisional hernia of abdominal wall].

OBJECTIVE: To repair the huge incisional hernia of abdominal wall, a new surgical method was introduced. METHODS: Eight cases of huge ventral incisional hernia, developed in 3 months to 12 months after operation, were treated in this new method with the defects ranged from 8 cm x 4 cm to 12 cm x 6 cm. RESULTS: They were followed up for 6 months to 18 months after operation. The clinical results showed that all of the 8 cases recovered satisfactorily without recurrence. CONCLUSION: The new method was recommendable for its advantages of easier manipulation, shortened time, no tissue reaction and less tissue trauma from operation.

Abdominal Wall↗
PubMed1999

[Anthraquinones in Eremurus chinensis Fedtsch].

OBJECTIVE: To investigate the chemical constituents in herbs of Eremurus chinensis METHOD: The chemical constituents were extracted with solvents and separated by column chromatography. RESULTS: The structures were identified by spectral analysis as chrysophanol, 10-(chrysophanol-7'-yl)-10-hydroxychrysophanol-9-anthrone and phthalic acid dibutyl ester. CONCLUSION: All the three compounds were separated from E. chinensis for the first time.

Anthraquinones↗
PubMed1999

[An investigation of immunoprotecting mechanism of macroencapsulated pancreatic islet xenograft].

Macroencapsulated islet xenografts in agarose are able to prevent rejection. This study was conducted to shed light on the immunoprotecting mechanism of macroencapsulated islet xenografts in agarose. There were four groups (n = 5 in each group): (1) macroencapsulated islet xenografts in agarose; (2) nonencapsulated islet xenografts; (3) agarose macroeencapsule without islet; (4) syngenic pancreatic islets. Mixed lymphocyte islet culture (MLIC) was used in the experiment. The results showed that stimulating index (SI) of MLIC and IL-2 level in the macroencapsulated islet xenografts in agarose group were similar to those of syngenic pancreatic islets group. The SI and IL-2 levels of nonencapsulated islet xenograft group were significant higher than those in macroencapsulated islet xenografts in agarose group and syngenic pancreatic islets group. These indicate that macroencapsulation is capable of reducing the immunogenicity of islet xenograft, and it is presumable that macroencapsulated islet xenografts in agarose be not recognized by the recipient's immune system because of being separated by the selectively permeable membrane made with agarose.

Animals↗
PubMed1999

[In vitro hepatic targeting tendency of galactosyl-anti CD3 McAb-TILS].

This study was undertaken to enhance the hepatic targeting tendency of tumor infiltrating lymphocytes (TILs) and hence to lower the recurrence rate of primary liver cancer after hepatectomy. Galactosyl-anti CD3McAb-TILs were prepared and then were incubated together with hepatocytes. Their interaction through asialoglycoprotein receptor-mediated mechanism was observed under the inverted phase contrast microscope. The carbohydrate density of galactosyl-anti CD3McAb and the combining rate of galactosyl-anti CD3McAb with TILs were measured. The results revealed that galactosyl-anti CD3 McAb-TIL obviously were adhered to hepatocytes. The carbohydrate density of galactosyl-anti CD3McAb was 62.18, and the combining rate of galactosyl-anti CD3McAb with TILs was 97.9%. The results suggested that in vitro hepatic targeting tendency of galactosyl-anti CD3McAb-TILs was satisfactory, and that the carbohydrate density of 62.18 and the combining rate of 97.9% ensured the effective use of TILs.

Animals↗
PubMed1999

[Leukocyte adhesion molecule expression and circulating ICAM-1, E-selectin levels during cardiopulmonary bypass in patients undergoing valve replacement].

The objectives of this study were to measure leukocyte adhesion molecule expression, assess the possibility of evaluating the serum levels of the soluble form of endothelium adhesion molecule as an alternative for endothelia cell activation, and analyze the correlation and regression between leukocyte adhesion molecule expression and soluble endothelium adhesion molecule levels during cardiopulmonary bypass (CPB) in patients undergoing valve replacement. Twelve adult patients were included in this study. The extracorporeal circuit was primed with Ringer's lactate. After systemic heparinization (300 IU/kg), CPB was initiated with a bubble oxygenator. Patients were cooled to about 28 degrees C, at that temperature, aorta was clamped and cold crystalloid cardioplegia was delivered into aortic root. The activatal clotting time was maintained at greater than 450 seconds. 1-1. 3 mg of protamine was administered for each 100 IU of heparin given prior to CPB. Peripheral blood was collected at the day prior to surgery and the morning of postoperative days 1, 2, 5, and 7 for determination of the expression of leukocyte CD11a, CD18, CD11a/CD18, CD11b, CD11b/CD18 (immunofluorescent flow cytometry) and the plasma soluble intercellular adhesion molecule-1(sICAM-1), soluble E-selectin (sE-selectin) (enzyme-linked immunoabsorbent assay). CPB caused a sustained increase in the leukocyte CD11a, CD18, CD11a/CD18, CD11b/CD18 expression and the plasma sICAM-1, sE-selectin levels in patients (P < 0.05). Upregulation of the leukocyte adhesion molecule expression and increase of the circulation endothelium adhesion molecule levels lasted at least 2 days after surgery (P < 0.05) except CD11a. There were correlation and regression between leukocyte adhesion molecule expression and soluble endothelium adhesion molecule levels (r = 0.91-0.99, P = 0.0322-0.0005; Y = -1377.06-44.64 + 1.49-14.78a to Y = 44.64 + 1.49a). These results suggest that CPB causes obvious leukocyte-endothelia interactions, that the expression of these adhesion molecules are presented by means of receptor-ligand form, and that the measurement of sICAM-1 and sE-selectin may well be used as a marker of endothelial cell activation.

Adult↗
PubMed1999

[Chemical constituents of Cynanchum chinense R. Br].

OBJECTIVE: To investigate the chemical constituents in the aerial part of Cynanchum chinense. METHOD: The chemical constituents were extracted with solvent and separated by column chromatography. The structures were identified by spectral methods: RESULT: The structures were identified as 7-O-alpha-L-rhamnopy-ranosyl-kaempferol-3-O-alpha-L-rhamnopyranoside, 7-O-alpha-L-rhamnopy-ranosyl-kaempferol-3-O-beta-D-glucopyranoside and 7-O-alpha-L-rhamnopyr-anosylkaempferol-3-O-beta-D-glucopyranosyl(1-->2)- beta-D-glucopyranoside. CONCLUSION: All the three compounds were separated from C. chinense for the first time.

Cynanchum↗
PubMed1999

[Determination of stilbene in radix Polygoni multiflori by HPLC and its stability study].

OBJECTIVE: To develop a HPLC method for determining stilbene in Radix Polygoni Multiflori and studying its stability. METHOD: HPLC conditions: An Econosphere C18 column, a mixture of methanol-water(30:70) as mobile phase, and UV detection at 310 nm. In addition, the stability of stilbene was studied at high temperature and in acidic solution. RESULT: The linear range of calibration curve was 2.24 x 10(-2)-1.12 x 10(-1) micrograms(n = 6) with a correlation coefficient of 0.99998, the average recovery with RSD being 99.96% +/- 1.54%. CONCLUSION: The method is sensitive, accurate and speedy. Stilbene in aqueous solution is stable, but high temperature(80 degrees C) tends to affect the stability. In acidic solution no stability can be found.

Drug Stability↗
PubMed1999

[Left ventricular function evaluation after mitral valve replacement with preservation the subvalvular apparatus].

The objective of this study was to evaluate the left ventricular function after mitral valve replacement (MVR) with preservation of all chordae. Fourteen patients with a diagnosis of mitral regurgitation were studied. These patients, 4 males and 10 females, age from 24 to 59 years, who underwent mitral valve replacement, in which all chordae tendineae were preserved. The mean follow-up interval was 6 months. Preoperation and postoperation multigated equilibrium radionuclide angiography was performed by Elscint Helix Apex SPECT. Each patient was injected with 740MBq 99mTc-HSA, rest ejection fraction (global EF) of LV (%), regional ejection fraction (EF) of LV (%), PER/S and PFR/S were measured. Regional EF was calculated by the method of dividing the left ventricle into five segments by radial axis. The results showed that the postoperative EF of the whole left ventricle of the chordae-preserved patients was significantly greater than their preoperative EF (40.0% +/- 17.8%, to 51.6% +/- 18.2%, P < 0.02), and also the regional EF at the lateral wall of the chordae-preserved MVR was significantly greater than the preoperative regional EF (an increase from 51.0% +/- 18.1% to 69.7% +/- 21.2%, P < 0.01). MVR with preservation of all chordae, the patient's left ventricular function remarkably improved.

Adult↗
PubMed1999

[Animal experiment of the ketamine effects on traumatic brain injury resulting from impact maxillofacial injury].

OBJECTIVE: To test the effects of ketamine (KET) on traumatic brain injury resulting from impact maxillofacial injury. METHODS: The rat models with middle serious traumatic brain injury were obtained by falling impaction at maxillofacial region of the rats, then the animals were treated with KET in the early stage, and the alteration of the neural function in those rats was observed at the same time. RESULTS: There was obvious difference between the rats in the KET-treating groups and the control group. It took about 2 days fewer than that of the control group for rats in the KET-treating group to recover. CONCLUSION: KET can shorten the recovery time of rats with brain injury resulting from impact maxillofacial injury.

Animals↗
PubMed1999

[A study on the biological properties of fimbriae of Actinomyces viscosus. I. The preparation and determination of fimbriae of A. viscosus].

OBJECTIVE: To build up the methods to prepare and determine the fimbriae of A. viscosus. METHODS: Type 1 and 2 fimbriae were prepared from A. viscosus 5519 and 5951 respectively. Fimbriae were isolated from bacteria cells by mechanical shaking, obtained by collecting the supernatant after centrifugation, and purified by ammonium sulfate precipitations and gel filtration. RESULTS: Electron microscope showed that fimbriae existed in the preparations. The immunological reaction between the fimbriae preparations and specific antibodies against fimbriae attested that they were type 1 or type 2 fimbriae. CONCLUSION: The present study become a foundation for further study on the biological properties of fimbriae of A. viscosus.

Actinomyces viscosus↗
PubMed1999

[Diagnosis and treatment of internal jugular phlebectasia (three cases report].

OBJECTIVE: To discuss the diagnosis and treatment of patients with rare abnormal veins: the internal jugular phlebectasia. METHODS: Three patients with swollen during straining or crying were diagnosed as internal jugular vein dilatation by ultra-sonography, DSA and MRI. Then an operation of envelopment of the right internal jugular vein with the sternocleidomastoid muscle was performed in two cases. In the third case, the bilateral internal jugular ectasia, the right internal jugular vein were resected and the left internal jugular vein was enveloped with the resected vein. RESULTS: These three patients were treated satisfactorily by operation, and no recurrence in the following two years. CONCLUSION: To those who want their internal jugular phlebectasia to be treated, the operation of envelopment of internal jugular vein with sternocleidomastoid muscle is a good method.

Adolescent↗
PubMed1999

[A study on biological properties of fimbriae of Actinomyces viscosus. II. Chemical characteristics of fimbriae of A. viscosus].

OBJECTIVE: To investigate the chemical characteristics of two purified fimbriae. METHODS: The specific antibodies against type I and type II fimbriae of A. viscosus were prepared and the purity of the two purified fimbriae had been identified by the specific antibodies. Then, chemical analysis and amino acid analysis of the two purified fimbriae were done. RESULTS: The two purified fimbriae were mainly composed of proteins and small amount of carbohydrate. The two types of fimbriae contained large amounts of aspartic acid, glutamic acid, alanine, lysine and glycine, and high percentage of nonpolar amino acid was analysed while basic amino acids were present in a very small amounts. CONCLUSION: These results may help to understand the relationship between the chemical characteristics of two types of fimbriae and their biological activity.

Actinomyces viscosus↗
PubMed1999

[Study on the combination of isotachophoresis and high performance liquid chromatography for the separation of complex samples].

A method on the combination of isotachophoresis (ITP) and high performance liquid chromatography (HPLC) for the separation and analysis of the complex samples containing proteins and metals is proposed. The instrumental system consisted of a self-made Model OCEP-1 isotachophoresis analyser, main parts of Waters high performance liquid chromatograph and a self-made Model IHI-1 interface. The interface is simple and convenient to use. The injection volume of the interface was determined accurately with a neutralization titration method. In ITP experiment the leading electrolyte was 2.5 mmol/L HCl containing 30 mmol/L of 18-crown-6; the terminating electrolyte was 5 mmol/L Tris+Cl-(pH 6.0); ITP current, 40 microA; detection of metal ions, potential gradient detector. In HPLC experiment the column was a mu-Bondapak C18, reversed-phase column, 4 mm x 200 mm, 10 microns, 12.5 nm; the mobile phase A, V(isopropanol with 5% volume fraction):V(butanol) = 2:1 containing 2.2 mmol/L HCl (pH 2.63); the mobile phase B, V(isopropanol with 50% volume fraction):V(butanol) = 2:1; low pressure gradient elution, mobile phase B changed from 0 to 70% in 17.5 minutes; flow rate, 1.0 mL/min; detection wavelength 225 nm; temperature, 25 degrees C. The experimental results showed that proteins were interfered in the determination of the metals with ITP method. It also showed that HPLC with the use of C18 column can separate the proteins but not the metal ions. By using this new combination system, a complex sample of the proteins and metal ions was injected to the HPLC, the proteins Lys, BSA and OVA were well separated in HPLC, while NH4+, K+, Na+, and Ca2+ were less retained and eluted first. Then the latter was introduced into the system of the ITP with the aid of the interface for separation. Satisfactory results were obtained.

Calcium↗
PubMed1999

[Study on correlation between in vivo and in vitro tests of biomaterials--correlation between leukocyte chemotaxis test and muscular implant test in rabbits].

The purpose of this study was to investigate the correlation between the results of in vivo and in vitro tests of biomaterials. With muscular implant test and leukocyte chemotaxis test, the levels of tissue toxicity of seven biomaterials were evaluated. The samples with high-level toxicity showed weak leukocyte chemotaxis, which would influence the anti-inflammatory reaction to foreign bodies. By the method of Spearman rank correlation, the coefficient was between 0.89286-0.98198 indicating that the correlation of the two tests is excellent.

Animals↗
PubMed1999

[Instrumental analysis and systematic investigation on heavy oils from coal. I. Analysis of hydrocarbon class composition].

A study on the analysis of hydrocarbon class composition was carried out by thin layer chromatography with flame ionization detection(TLC/FID). The optimum analytical conditions, experimental reproduction, standard deviation, quantitative correction factors of hydrocarbon class and so on were investigated. The instrument used were Mark III, LATROSCAN TH-10 analyzer, thin layer rod was a CHROMAROD silica rod(150 mm x 0.9 mm i.d). A satisfactory TLC/FID analytical method was established after a series of experiments and investigation. Typical heavy oils from coal were investigated based on this method. The optimum conditions were that the flame ionization detector was operated at a hydrogen flow rate of 100 mL/min corresponding to 90 kPa and air flow rate of 1.9 L/min. The determinations in groups of saturated hydrocarbons, aromatics, resins and asphaltenes were performed by using n-heptane, toluene and V(chloroform):V(methanol) = 95:5 as developing solvents. The developing distances were controlled at 10 cm, 5.5 cm and 2.5 cm respectively. In the present paper qualitative and quantitative analysis have been studied. And the method established was sufficiently applied to determine heavy oils from coal of coking plants of Shanxi.

English Abstract↗
PubMed1999

[Separation and analysis of amino acids in secretion of psylla chinesis yang et li].

We used ion-exchange resin column chromatography to separate amino acids in secretion of Psylla Chinese Yang et Li and used capillary gas chromatography to analysis n-butyl-N-trifluoracetyl derivatives of the amino acids. Qualitative analysis was done by comparing with the standard amino acids and quantitative analysis by internal standard method. We determined thirteen amino acids in the secretion.

English Abstract↗