PubMed Health⌕ Search

Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 541 records · Page 30Linked to original sources
PubMed1997

The development of antibody delivery systems to target cancer with highly potent maytansinoids.

Improving the tumour selectivity of cytotoxic drugs through conjugation to tumour-reactive monoclonal antibodies may lead to novel, more potent agents for cancer therapy. The maytansinoid drugs are 100- to 1000-fold more cytotoxic in vitro than current clinical anticancer drugs. We recently demonstrated that conjugation of maytansinoid drugs to monoclonal antibodies renders them highly efficacious against cancers of breast and colon in both in vitro and in in vivo tumour models. Antibody-maytansinoids represent a new generation of immunoconjugates that may yet fulfil the promise of effective cancer therapy through antibody targeting of cytotoxic agents.

Journal Article↗
PubMed1997

[Epstein-Barr virus infection and the expression of bcl-2 proto-oncogene in Hodgkin's disease].

OBJECTIVE: To investigate the relationship between Epstein-Barr virus (EBV) and bcl-2 gene. METHODS: Sixty-four paraffin-embeded cases of Hodgkin's disease (HD) were studied. Immunohistochemistry was performed by using monoclonal antibody to latent membrane protein 1 (LMP-1) and bcl-2. In situ hybridization for EBV encoded small mRNA-EBER on 41 cases. Double staining combined in situ hybridization and immunohistochemistry was performed for dual labelling of EBER and bcl-2 in seven cases. RESULTS: The positive rates of LMP-1 and EBER were 39% and 44%. All cases which were EBER positive, also express LMP-1. The positive rate of bcl-2 protein was 23%. Only seven of these cases were also LMP-1 positive. CONCLUSION: All the results suggest that the bcl-2 expression in the R-S cells in this series did not correlate with EBV-positivity.

Adolescent↗
PubMed1997

[Effects of repeated nicotine uptake on brain inositol levels].

In the acute experiments, 30 minutes after nicotine was intraperitoneally injected at the doses of 0.5, 1.0, 1.0, 2.0, 2.0 mg/kg with 5 min interval, the inositol levels were increased in rats cerebral cortex and hippocampus rather than striatum. While the inositol level was decreased in rat cerebral cortex 30 minutes after lithium chloride was given at the dose of 10 mmol/kg. In the chronic experiments, after nicotine at the doses of 2.0-5.0 mg/kg was subcutaneouly injected twice a day for 14 days the inositol level was increased in rat cerebral cortex. In other experiments, nicotine was orally given at the dosese of 2.69, 6.26, 11.53 mg/kg.d for 64 days, the inositol level of rat cerebral cortex was also increased. These indicated that the effects of nicotine on inositol level of rat brain are different from those of lithium chloride, the inositol level of rat cerebral cortex can be increased by repeated administration of nicotine.

Animals↗
PubMed1997

[Actions of salvianolic acid A on CCl4-poisoned liver injury and fibrosis in rats].

AIM: To study the actions of salvianolic acid A (SA-A) on liver injury and liver fibrosis. METHODS: The liver fibrotic rat was made by i.p. injection of CCl4. The model rats were divided into 3 groups treated with SA-A, colchicine (Col), and Salvia miltiorrhiza Bunge (SMB), respectively. Six wk later the rat liver pathology was examined, type I and III collagen in the liver were examined by immunohistochemistical method. Also hydroxyproline (Hyd) and malondialdehyde (MDA) in the liver, alanine aminotransferase (AlaAT), aspartate aminotransferase (AspAT), and albumin (Alb) levels in the serum were measured. RESULTS: SA-A inhibited serum AlaAT and AspAT activities, decreased MDA and Hyd contents, alleviated liver fibrogenesis, protected deposition of type I and III collagen in liver matrix. The actions of SA-A on liver fibrosis were similar to those of Col and SMB, action of SA-A decreasing MDA was better than that of Col. CONCLUSION: SA-A has marked effects against liver injury and fibrosis, associated with its anti-lipid peroxidation actions.

Alanine Transaminase↗
PubMed1997

[Surgical treatment of thoracic aortic aneurysm].

In 80 patients with thoracic aortic aneurysm were treated in our hospital, 62 were males and 18 females. Their age ranged from 20 to 73 years. The aneurysm lesions involved ascending aorta in 45 patients (Marfan's syndrome), aortic isthmus segment in 3, descending aortic aneurysm in 26, and thoraco-abdominal aneurysm in 3. Thoracic aortic aneurysm with dissecting aneurysm were found in 49. Stanford type A was present in 28 cases patients and type B in 21.61 patients underwent surgery including Bentall's operation in 35, Wheat's operation in 3, resection of discending aortic aneurysm with vascular prosthesis grafting in 14, and other types of operation in 9. Operative mortality rate was 6%. In the medically treatment group of patients, spontaneous rupture of the aneurysm occurred in 8. Among them, 5 died in hospital and another 2 at home. In this series of patients, Marfan's syndrome and dissecting aneurysm were the predominant pathological lesion. Since acute rupture of dissecting aneurysm is the main cause of death, surgical treatment should be immediate after the diagnosis is established. In the chronic dissecting aneurysm, early surgical treatment also should be considered.

Adult↗
PubMed1997

[Chemical constituents of fructus Amomi].

Seven compounds have been isolated from Fructus Amomi. They were identified as bornyl acetate, camphor, borneol, beta-sitosterol, vanillic acid, stearic acid and palmitic acid. The vanillic acid was found in this medicine for the first time. Fifty-seven components were identified from the volatile oil of Fructus Amomi on the basis of GC-MS analysis. Eight components in the volatile oil over 1% in content are bornyl acetate, camphor, borneol, limonene, camphene, myrecene, carene-3 and alpha-terpeneol.

Drugs, Chinese Herbal↗
PubMed1997

[Inhibitory effect of 7 agents on bovine testis aldose reductase].

The inhibitory effects of seven agents on aldose reductase were studied by enzymatic kinetics using the purified enzyme from bovine testis, sorbinil, tolrestat, silybin and berberini were found to exhibit a marked enzyme-inhibitory effect with Ki values of 1.08 mumol/L, 0.12 mumol/L, 3.5 micrograms/ml, and 2.7 micrograms/ml respectively. The established assay system described in this paper may be useful in screening aldose reductase inhibitors.

Aldehyde Reductase↗
PubMed1997

[Direct protection of injured primary cultured hepatocytes of rats treated with carbon tetrachloride by salvianic acid B].

The incorporation of [3H]thymidine obviously tends to decrease in the primary cultured hepatocytes of rats when the cells are treated with carbon tetrachloride. Meanwhile the activity of ALT markedly increases in the medium. But these pathologic alterations are inhibited by Salvianic acid B(SA-B) and the effect of 10(-6) mol/L SA-B is the best.

Alanine Transaminase↗
PubMed1997

Stereopsis disorders in patients with congenital nystagmus.

PURPOSE: To investigate the stereopsis functions in the cases of congenital nystagmus (CN) and determine the relations between nystagmus, visual acuity (VA) and stereoacuity (SA). METHODS: The random-dot stereograms was used to examine the patients' SA, crossed and uncrossed disparity. The oscillation types of the eyeballs were determined under the naked eyes cooperating with the electronystagmorgraphy (ENG) examination. VA was measured at 5 m and 30 cm with distance and near International Standard Charts. The patient was permitted to see the target with his compensatory head posture. RESULTS: Of the 57 patients tested, only 8 cases have normal stereopsis including normal SA, crossed and uncrossed disparity, which are all the jerk nystagmus. Forty-one have abnormal SA including 19 stereoblind, 18 abnormal stereopsis and 4 abnormal SA only. Serious damages of stereopsis exist in most of the pendular and more than half of the jerk nystagmus. The relations between stereopsis and VA are that (1) the better the VA is, the less the stereopsis is damaged, and the SA improved as VA is improved, i.e. SA is directly proportional to VA, but is nonlinear. It can be expressed as an S-shaped function; (2) the stereopsis damages may appear in normal VA in distance (6 cases) or normal VA at 30 cm, which we can not explain; (3) stereopsis is more marked with near VA than with VA in distance; (4) normal SA (SA < or = 60") is not achieved by any subject at monocular or binocular vision less than 0.4, stereoblind appears as soon as VA is under 0.1. CONCLUSION: VA and/or SA can be damaged by the abnormality of CN. Both VA and SA can be apparently affected by the oscillation types although VA is demonstrated to affect SA.

Adolescent↗
PubMed1997

[Preliminary study of biomechanic property on human forethigh skin].

HLC0-I biomechanical living-tissues testing mechanic was adopted for testing the biomechanical property of normal adult forethigh skin. The figures acquired were calculated using one dimension strain energy function and the constitutive equation of mono-way stress and strain was established. The results showed that the relationship between stress and strain could be expressed by the exponential function. The rise of stress was not evident when the strain was lower than 1.2, but the stress rose much sharply when the strain was higher than 1.2. The curves were nonlinear. This suggests that when we sew up a wound or perform skin transplantation, the strain should be lower than 1.2.

Adult↗
PubMed1997

[An experimental study on regeneration device for urine and waste water in space station].

The principle, structure and function of the regeneration system for urine and waste water treatment were introduced. The experimental results demonstrated that, the treatment capacity was 1.2-1.9 kg/h, and the regeneration efficiency exceeded 92%. The quality of the treated water were: TOC < 20 g/m3, (NH3 + NH4+) < 10 g/m3, electric conductivity < 100 micro s/cm, pH= 6-8.

Ecological Systems, Closed↗
PubMed1997

Changes in bone noncollagenous proteins and bone mineral loss in lumbar vertebrae of tail-suspended rats.

The purpose of the study is to clarify whether the noncollagenous proteins play a role in bone mineral loss and whether the quality of osteocalcin (OC) is deteriorated in simulated weightlessness. Noncollagenous proteins, such as OC and albumin, have been shown to be effective in promoting bone mineralization. In this study, the contents of OC, albumin, and mineral in the third lumbar vertebra (L3) were determined in rats suspended by tail for 21 days. The concentration of serum-immunoreactive osteocalcin (irOC) were also measured before and after adsorption to hydroxylapatite. The results showed that the contents of mineral, osteocalcin, and albumin in L3 were significantly decreased in suspended rats. The concentration of serum irOC and serum irOC with a high affinity to hydroxylapatite (irOCbound) were significantly decreased, but the low affinity (irOCfree) remained unaffected. The data suggest that the mineral loss in L3 of suspended rats is related to the decreased contents of osteocalcin, and albumin in bone mass. The incomplete gamma-carboxylation of osteocalcin in suspended rats is also one of the important causes of bone loss.

Albumins↗
PubMed1997

[Effects of octacosanol in food physiological parameters in tail-suspended rats].

The purposes of the experiment were to observe the physiological effects of octacosanol in food on tail-suspended rats and to investigate the possibility of using octacosanol in health food for astronauts. 24 male Wistar rats were randomly divided into free action control, tail-suspension and tail suspension plus octacosanol (TSO) groups. Octacosanol was emulsified into water by supersound and given to TSO rats with a dosage of 25 mg/kg wt d. The results showed that octacosanol elevated the weight of thymus, improved biomechanical properties of the femur and improved membrane fluidity of red blood cell. It suggests that octacosanol can counteract some effects of simulated weightlessness on rats. Therefore, octacosanol may be added to natural foods to benefit the health of cosmonauts.

Aerospace Medicine↗
PubMed1997

[Diagnosis of hepatitis E virus infection in sporadic acute hepatitis].

The solid-phase enzyme immunoassay (EIA) was used for detecting anti-HEV immunoglobulin G (IgG) and M (IgM) by using a recombinant chimeric antigen (ORF3-2) from the open reading frame (ORF) 2 and 3 of hepatitis E virus gene. These sera were collected from the patients with sporadic acute viral hepatitis. The positive rate for anti-HEV IgG was 15.22% (7) among 46 patients with acute hepatitis, 5 of the 7 IgG positive sera were also positive (71.4%) for anti-HEV IgM. 91.8% (93) and 76.4% (78) were positive separately for anti-HEV IgG and IgM among 102 patients of suspected HEV infection (these patients were negative for anti-HAV, anti-HBV and anti-HCV), about 2/3 patients of HEV infection detected were simultaneously HEV-IgG and IgM positive. In control group of 98 normal persons, 4 (4.08%) were positive for anti-HEV IgG, but none were IgM positive. Paired sera of the patients in the acute phase and convalescent phase were detected, the titers of anti-HEV IgG with 4-16 fold decrease were seen in 6 cases and with 2-fold rise in 1 case.

Acute Disease↗
PubMed1997

[Indirect UV detection of short chain carboxylic acids in oil field water by high performance capillary zone electrophoresis].

Short chain carboxylic acids are the major aqueous organic species in oil field water. It is considered that they play an important role in the geochemical evolution of second porosity in oil reservoir. In this paper, short chain carboxylic acid anions were analyzed by HP(3D)CE high performance capillary electrophoresis system (Hewlett-Packard, Germany) with a buffer system of dinitrobenzoic acid-hexadecyltrimethyl ammonium bromide (CTAB). The influence of buffer pH and the concentrations of electrolyte, surfactant and methanol on the seperation of short chain carboxylic acids have been studied. The results showed that the best separation of short chain carboxylic acids could be done with the buffer of 10mmol/L dinitrobenzoic acid, 0.5mmol/L CTAB and 5% methanol at pH=9. Separations were performed in a 50cm x 50microm i.d. fused silica capillary (effective length 48.5cm) at 25 degrees C. A negative potential of 30kV was used for each experiment. Sample was introduced into the capillary by pressure at 50kPa for 10s. Indirect UV detection was operated at 254nm and reference wavelength at 380nm for all experiments. Negative peak was changed into positive one by exchanging between detection wavelength and reference wavelength. Capillary was rinsed for 10min with 0.1mol/L sodium hydroxide and buffer solution before each run. Oil field water was injected directly after filtered through 0.45microm membrane. The result was satisfactory.

Buffers↗
PubMed1997

[Multi-elemental analysis by preconcentration on EDTA-cellulose microcolumn coupled to ICP-AES].

EDTA-cellulose was prepared by chloroacetic acid covalently bound to filter flakes. Fe, Cu, Zn, V, Mn, Co, Ni, Al, Cd and Pb were preconcentrated on microcolumn filled with EDTA-cellulose and analyzed with ICP-AES after being eluated with dilute HNO3. At given pH value, alkali and alkaline earth metal ions can be quantitatively separated as matrix elements, and did not interfere eluate determine. High concentration factor was obtained. The usefulness of the method is shown by analyses of Standard Reference Materials.

English Abstract↗