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Biomedical subjects

Z Li

Publications and source records attributed to Z Li.

At least 973 records · Page 54Linked to original sources
PubMed1998

[Cardiovascular protective effects and NO-mediated cerebrovasorelaxant effects of extract of ginkgo biloba leaves].

OBJECTIVE: To examine the anti-free radical related cardiovascular protective effects and NO-mediated cerebrovasorelaxant effects of extract of the leaves of Ginkgo biloba(EGb) in isolated preparations. METHODS: Experiments on the anti-free radical related cardiovascular protective effects were performed in rabbit Langendorff heart and isolated aortic rings damaged by diphenyl-picryl hydyazyl(DPPH). Protective effects of EGb were determined by comparing the results of EGb pretreated group with the DPPH-injured controls. Cerebrovasorelaxant effects of EGb were examined in ring preparations of isolated porcine basilar artery in vitro using tissue bath techniques. RESULTS: EGb protected the isolated rabbit heart from the DPPH-injury to the cardiac contractility and the aortic endothelium from DPPH-attenuated ACh-induced relaxation. EGb concentrationde dependently relaxed the basilar artery and this effect was more significant in endothelium intact rings than those endothelium denuded rings. EGb enhanced the TNS-induced relaxation in basilar artery and this effect was abolished by pretreatment of N-nitro-L-arginine or tetrodotoxin. CONCLUSIONS: EGb exerts cardiovascular protection against DPPH-impaired cardiac contraction in rabbit isolated heart and endothelium-dependent relaxation in the aortic ring of rabbit in vitro. EGb relaxes porcine basilar artery and enhances the TNS-induced relaxation via a NO pathway.

Animals↗
PubMed1998

[Mechanism of CD44V6 in human colorectal carcinoma metastasis].

OBJECTIVE: To study the mechanism of CD44V6 in human colorectal carcinoma (HCC) matastasis. METHODS: The effects of CD44V6 on HCC cell adhering to base membrane and vascular endothelium were investigated by human amniotic membrane invasion model and co-culturing HCC cell with vascular endothelium. The influence of CD44V6 variants on cytoskeleton and gap junctional intercellular communication (GJIC) was studied by immunofluorescent confocal 3-dimensional reconstruction and fluorescence recovery after photobleaching technique. RESULTS: CD44V6 antibody can decrease the ability of HCC cells to adhere to amniotic membrane and vascular endothelium. It also can affect the distribution, polymerization and depolymerization of actin of HCC cells, but does not significantly affect GJIC of HCC cells. CONCLUSIONS: CD44V6 may play an important role in promoting HCC cells to adhere to vascular endothelium and base membranes and may affect the distribution, polymerization and depolymerization of actin in HCC cells and facilitate HCC cell metastasis.

Coculture Techniques↗
PubMed1998

[Change of cricoarytenoid joint after recurrent laryngeal nerve damaged].

The arytenoid mobilities and histological changes of cricoarytenoid (CA) joints were observed in 1, 2, 4, 6, 8, 10, 12 months after the injury of recurrent laryngeal nerve (RLN). Eighteen adult dogs were randomly divided into three groups: 1. Unilateral RLN partial damaged (4/18), 2. Unilateral RLN complete damaged (7/18), 3. Bilateral RLN damaged (7/18). The results demonstrated that arytenoid mobilities return to normal and no fibroses of CA joints were found in 6 months after RLN injury in group one. The arytenoid fixations were found in 6 and 4 months after RLN injury in group two and three, respectively. The fibroses of CA joints were more severe in group three than group two after RLN injury.

Animals↗
PubMed1998

Clinical and bacteriologic study of eighty-six patients with systemic lupus erythematosus complicated by infections.

OBJECTIVE: To investigate the clinical and bacteriologic features of patients with systemic lupus erythematosus (SLE) complicated by bacterial and/or fungal infections. METHODS: Statistical analysis was made on basis of the clinical and bacteriologic data of 86 patients with SLE complicated by bacterial and/or fungal infections. RESULTS: One hundred and thirty-three episodes of infections occurred in 86 patients with SLE, in which 51.13% were nosocomial infections and 76.69% occurred in the blood system, respiratory tract, lungs and urinary tract. Gram-negative bacilli, gram-positive cocci, fungal and other bacterial infections accounted for 39.85%, 31.58%, 18.80% and 9.77%, respectively. In the bacterial infections, 18.52% were caused by L-form bacteria and more than 60% of the patients had no apparent toxic manifestations. The odds ratio (OR) of infection increased significantly in patients with damaged functions of the heart, lungs and kidneys, and in those who received high-dosage steroids. CONCLUSIONS: Patients with SLE tend to develop nosocomial infections with gram-negative bacilli which are the most common pathogens. The clinical manifestations of the infection are atypical. Careful inspection and monitoring, timely collecting the specimens for L-form bacterial culture can reduce misdiagnosis and missed diagnosis of the infection.

Adolescent↗
PubMed1998

[Msp I and Rsa I RFLPs of vWF gene in Chinese Han people].

OBJECTIVE: To study the Msp I and Rsa I restriction fragment length polymorphisms (RFLPs) in the 5' region of human von Willebrand factor gene in Chinese Han people. METHODS: A 226 bp amplified fragment of human vWF gene from 52 unrelated individuals and a 322 bp amplified fragment from 48 individuals were analyzed by Msp I or Rsa I digestion. RESULTS: Complete linkage disequilibrium was observed at both Msp I and Rsa I sites in vWF gene in Chinese Han people. The frequencies at the two sites were 0.20/0.80 for Msp I+/Msp I- and 0.93/0.07 for Rsa I+/Rsa I-. The theoretical heterozygous rates were 36% and 10%, respectively. CONCLUSION: The Msp I and Rsa I RELPs of vWF gene are useful for genetic counseling and prenatal diagnosis of vWD in Chinese Han people.

Alleles↗
PubMed1998

[Detection of gene mutation and genetic analysis of a patient with type 3 von Willebrand disease].

OBJECTIVE: To identify gene mutations in patients with type 3 von Willebrand disease. METHODS: The encoding region of von Willebrand factor (vWF) gene were screened by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). RESULTS AND CONCLUSION: The fragment of vWF gene exon 3 from a patient with type 3 von Willebrand disease displayed an abnormal melting behavior. Direct sequencing demonstrated a homozygous C-->A transition at nucleotide 212 in vWF gene resulting in the substitution of a stop codon for Ser71. The parents of the patient were heterozygous for this mutation as identified by PCR-DGGE and restriction endonuclease digestion analysis.

Adolescent↗
PubMed1998

[Four novel point mutations of factor IX gene detected by denaturing gradient gel electrophoresis].

OBJECTIVE: To identify factor IX gene mutations in patients with hemophilia B. METHODS: The coding regions, splicing junction sites and part of the 5' and 3' flanking regions of factor IX gene were screened by polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). RESULTS: Four amplified fragments showed abnormal electrophoresis patterns, and sequencing of them demonstrated four novel point mutations including a T to G transition at nucleotide 10,380 resulting in intron 3 covering the splicing site, a A to G transition at nucleotide 30,918 resulting in a substitution of Cys for Tyr at codon 266 in exon 8, and a A to C transition at nucleotide 31,007 resulting in a substitution of Pro for Thr at codon 299 in exon 8. CONCLUSION: Detection of mutations by PCR, DGGE and sequencing was useful not only for understanding the structure function relationship of F IX, but also for the carrier detection and prenatal diagnosis.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1998

[Expression of CD44V6 and its effects on cytoskeleton in human colorectal carcinoma cell lines].

OBJECTIVE: To observe the expression of CD44V6 and its effects on cytoskeleton in human colorectal carcinoma(HCC) HT29 and LoVo cell lines. METHODS: Expression of CD44V6 variant in HCC HT29 and LoVo cell lines was investigated by in situ hybridization, immunohistochemistry and quantitative immunofluorescence technique. The effects of CD44V6 variants on cytoskeleton was studied by immunofluorescence and confocal 3 dimension reconstruction technique. RESULTS: CD44V6 was expressed at the mRNA and protein levels in both HT29 and LoVo cell lines, but the expression was higher in LoVo cells than in HT29 cells. When the HT29 cells and LoVo cells were blocked by monoclonal antibodies, it was found that changes developed in the cytoskeleton of these cells. CONCLUSIONS: The expression of CD44V6 is related to the metastatic potentiality of human colorectal carcinoma cells. CD44V6 may affect the distribution, polymerization and depolymerization of actin of HCC cells and promote HCC cell metastasis.

Actins↗
PubMed1998

Sma I, Hha I, Msp I and Rsa I restriction fragment length polymorphisms in the von Willebrand factor gene of Chinese population.

OBJECTIVE: To study Sma I, Hha I, Msp I and Rsa I restriction fragment length polymorphisms in vWF gene of Chinese population. METHODS: The vWF gene from 52 unrelated individuals of Han Nationality, 44 of Yi tribe, 42 of Dai tribe was analyzed by polymerase chain reaction and digestion of the endonucleases of Sma I, Hha I, Msp I and Rsa I. RESULTS: The allele frequencies were 0.38:0.62 for Sma I+:Sma I- and 0.38:0.62 for Hha I+:Hha I-; 0.20:0.80 for Msp I+:Msp I-; 0.93:0.07 for Rsa I+:Rsa I- in Chinese Han population. The theoretical heterozygous rates were 0.46, 0.46, 0.36 and 0.13 of these polymorphisms, respectively. The allele frequencies were 0.43:0.57 for Sma I+:Sma I- and 0.43:0.57 for Hha I+:Hha I-, 0.26:0.74 for Msp I+:Msp- in Yi tribe and 0.36:0.64 for Sma I+:Sma I- and Hha I+:Hha I-, 0.17:0.83 for Msp I+:Msp I- in Dai tribe. The theoretical rates were 0.49 for Sma I and Hha I and 0.38 for Msp I in Yi tribe; and 0.45 for Sma I and Hha I, 0.28 for Msp I in Dai tribe, respectively. CONCLUSIONS: The allele frequencies and theoretical rates of these polymorphisms in vWF gene are different between Chinese populations and Caucasians. They should be useful for the carrier detection and prenatal diagnosis in vWD families of Chinese.

Alleles↗
PubMed1998

[Study on contractile properties of the posterior cricoarytenoid muscle after delayed reinnervation].

To study date on the contractile properties of posterior cricoarytenoid muscle after delayed reinnervation of different reinnervated methods. Twenty four dogs were reinnervated at 0,4,5,6,10 and 12 month interval following recurrent laryngeal nerve via the phrenic nerve anastomosed to the recurrent laryngeal nerve after cutting the adductor branch and ansa cervicalis-sternothyroid muscle pedicle implanted into the posterior cricoarytenoid muscle. After 6 months, a series of contractions were recorded from each side in twenty living dogs. The results showed that contractile force of reinnervated muscle decreased gradually with the time of denervation, but contractile force of muscle was no significantly difference between reinnervated side of nerve anastomosed group in 4 months after denervated and normal side, and it was significantly difference between nerve anastomosed group and nerve-muscle pedicle implanted group at some time of delayed reinnervation. The contractile time of reinnervated side of two operated groups was similar to that of normal side. The conclusion demonstrated that the contractile properties can indicate exactly reinnervated degree of muscle, and the earlier reinnervation was performed, the better curative effect was.

Anastomosis, Surgical↗
PubMed1998

[Studies on the role of colchicine in bleomycin-induced pulmonary fibrosis in rats].

OBJECTIVE: It has well been known that cytokines and extracellular matrix protein (ECM) have played an important role in pulmonary fibrosis in animal model as well as in patients. The purpose of this study was to evaluate the suppressive effect of colchicine (Colc.) in bleomycin (BLM)-treated rats. METHOD: Consecutive changes of interleukin-6(IL-6) and interleukin-8 (IL-8) released by alveolar macrophage (AM) were measured with murine B-cell hybridoma 7TD1 cells and micro membrane filter test. ECM and lipid peroxidation were observed with radioimmunoassay and biochemical assay respectively. RESULT: (1) Colc. significantly suppressed release of IL-6 by AM from day 7 to 28 (P < 0.05). But the level of IL-6 remained higher than that of the control. On the day 1 to 3, IL-8 released by AM markedly decreased (P < 0.01) and the peak of IL-8 secretion had not appeared. (2) Colc. had no protective effects on AM lipid peroxidation injury. (3) Colc. markedly decreased the level of fibronectin (FN) by AM on day 7, 14 (P < 0.01), as well as the level of laminin (LN) in bronchoalveolar lavage fluid (BALF) on day 7 to 28. However, the level of LN remained higher than that of control. (4) Colc. lessened the collagen deposition, and the lung hydroxyproline (HYP) content decreased on day 7, 14 and 28 (P < 0.05) compared with that of the control. (5) Colc. decreased exudation of inflammatory cells in the early response, as well as the degree of fibrosis in the late stage. CONCLUSION: Lipid peroxidation of AM might be one of the mechanisms of tissue injury and of AM activation, which increases the release of cytokines (IL-6, IL-8) and deposition of extracellular matrix proteins (FN, LN). Colc. exertes somewhat inhibitory effects on the process of pulmonary fibrosis in animal model. Factors other than AM and its cytokines might also be involved in the pathogenesis of pulmonary fibrosis in experimental rats.

Animals↗
PubMed1998

[Level of NCF and TNF-alpha in the BALF of ILD patients and their clinical significance].

OBJECTIVE: To investigate the relationship between the level of the neutrophil chemotactic factor(NCF), tumor necrosis factor-alpha(TNF-alpha) in patients with interstitial lung disease(ILD) and the activity of ILD. METHOD: The NCF activities in the BALF and in the serum from 11 patients with sarcoidosis, 7 with idiopathic pulmonary fibrosis (IPF) and 8 normal subjects were determined using the membrane filter and radio-immunoassay. The level of TNF-alpha was also detected. RESULT: In the 7 IPF patients, the level of NCF and TNF-alpha (203 +/- 44 cells/10 HP, 11.7 +/- 2.9 ng/L) in the BALF was higher than that in 8 control patients (83 +/- 45 cells/10 HP, 6.5 +/- 1.4 ng/L, P < 0.01). The level of NCF and TNF-alpha in the BALF from 11 patients with sarcoidosis (186 +/- 50 cells/10 HP, 12 +/- 3 ng/L) was highet than those in 8 control patients (P < 0.01). The level of NCF and TNF-alpha in the BALF from patients with IPF was positive correlated with the percentage of neutrophil (NCF: r = 0.89, P < 0.01; TNF-alpha: r = 0.86, P < 0.05). The level of NCF and TNF-alpha in the BALF of patients with sarcoidosis was positive correlated with the percentage of lymphocyte (NCF: r = 0.78, P < 0.01; TNF-alpha: r = 0.73, P < 0.01. CONCLUSION: The level of NCF and TNF-alpha in the BALF from patients with IPF and sarcoidosis can act as the marker of the activity of alveolitis of IPF and sarcoidosis.

Adult↗
PubMed1998

[Detection and identification of the DNA between Mycobacterium tuberculosis and Mycobacterium nontuberculosis by triplex polymerase chain reaction technique].

OBJECTIVE: To improve the specificity and sensitivity of polymerase chain reaction (PCR) technique for detecting and identification of DNA of M. tuberculosis and M. nontuberculosis. METHOD: Three pairs of oligonucleotide primer were used in triplex-PCR. A 383 bp DNA fragment encoding part of the 65,000 mycobacterial surface antigen, a 123 bp fragment corresponding to a specific M. tuberculosis complex sequence which was the insertion sequence 6110 (IS 6110) and a 268 bp fragment for human beta-globin were amplified by triplex-PCR respectively. RESULT: The sensitivity of the triplex-PCR-electrophoresis for the DNA of mycobacterium was 0.6 pg. The specific bands of 383 bp and 123 bp among the amplified DNA from M. hominis, M. bovis, BCG and M. simiae were present in the agarose gel. By contrast, only a band of 383 bp was found among the M. nontuberculosis which contained M. avium, M. chelonae, M. scrofulaceum, M. xenopi, M. kansasii, M. intracellulare and M. smegmatis. Compared with the standard strains, there was an additional 268 bp band in simulated clinical samples infected by Mycobacterium. The above 3 specific bands were found neither in other 15 bacterial species tested nor in Mycoplasma pneumoniae. 182 clinical samples were examined by culture, smear and triplex-PCR. 72 nontuberculous clinical samples were all negative. In 110 tuberculosis clinical samples, the positive rates were 2.7%, 13.6% and 32.7%, respectively. CONCLUSION: The triplex-PCR possesses a high specificity and sensitivity. This method could detect and identify the DNA of M. tuberculosis and M. nontuberculosis except M. simiae. It is a valuable tool for early diagnosis and differentiation for infection of M. tuberculosis and M. nontuberculosis.

Adolescent↗
PubMed1998

[Separation and determination of carotenoids in Fructus lycii by isocratic non-aqueous reversed-phase liquid chromatography].

High performance liquid chromatography using a non-aqueous reversed phase with isocratic elution of C18 columns is a powerful tool for investigating the carotenoid composition of Fructus Lycii. This paper compared the effect of different eluents on the separation of carotenoids. An optimum solvent system consisting of acetonitrile and methylene chloride is suitable for simultaneous separation of compounds from polar xanthophylls to nonpolar carotenoid esters. Ten carotenoids were separated from Fructus Lycii by using Shim-pack CLC-ODS column(150 mm x 6 mm i.d.) and mobile phase of acetonitrile/methylene chloride(60:42, V/V) with a flow rate of 1 mL/min. The eluates were monitored with UV/VIS detector at 456 nm. The method which permit direct analysis of carotenoid extracts without saponification in 30 min provides a true information of carotenoids composition in Fructus Lycii as they exist. Fructus Lycii contains 2952 micrograms/g of total carotenoids, but 98.6% of carotenoids are existed as esterified forms, zeaxanthin dipalmitate are accounted for 77.5% of the total carotenoide.

Carotenoids↗
PubMed1998

[An experimental study on curative effect of Chinese medicine qing yi tang in acute necrotizing pancreatitis].

OBJECTIVE: To observe the curative effect of the traditional Chinese medicine (TCM) Qing Yi Tang (QYT) in acute necrotizing pancreatitis (ANP). METHODS: Twenty three dogs were randomly divided into 3 groups. In control group (n = 7), animals underwent laparotomy only. In ANP group (n = 8), acute necrotizing pancreatitis was induced by injection of 0.5 ml/kg 5% sodium taurocholate with 300 u/kg trypsin into the pancreatic duct. While in TCM group (n = 8) were fed everyday with QYT after onset of ANP. All animals were sacrified 7 days later and organs were gathered and cultured. Mucosal and luminal floras of the intestine were analysed. Pancreas and ileal mucosa were examined histologically and ultra-microscopically, the levels of lipopolysaccharide (LPS) and amylase in blood were determined. RESULTS: In TCM groups, histologic and ultra-structural damages in pancreas and ileal mucosa were much milder as compared with those of ANP group. In ANP group, there was a significant increase of E. coli and bacterocoids, and a significant decrease of bifidobacteria, lactobacilli and enterococci in the intestinal mucosa, while in TCM groups, these changes were alleviated significantly (P < 0.05 or P < 0.01). As compared with ANP group, the bacterial translocation (BT) rate was reduced from 100% to 50%, and the counts of translocated bacteria were decreased 10-40 times, the levels of LPS and amylase reduced 2 to 3 times. CONCLUSION: TCM recipe QYT showed their protective effects on gut barrier function by alleviating the damage of intestinal mucosa and microecologic disturbance following acute pancreatitis. As a result, the chances of BT and enterogenic infection declined. These preparation might be promising in the prophylaxis and treatment of infection complicating ANP.

Animals↗
PubMed1998

[Study on nitric oxide in isolated cochlear neuron of chicken with chemically modified carbon fiber microelectrode].

OBJECTIVE: Nitric oxide(NO) is involved in neural signaling that is important to the physiologic and pathophysiologic activities of cochlea and vestibule. This study is to compare physiologic function of mammalian cochlea with that of chicken cochlea. METHODS: Using chemically modified carbon fiber microelectrode to measure qualitatively NO which was released from isolated cochlear neuron cluster of chicken in response to certain agonists, such as ATP, L-Arg and ACh. The presence of NO release is indicated by elevation of amplitude and lasting time of microelectric current. RESULTS: The results demonstrated that No releases stimulated by ACh and L-Arg were similar in amplitude but the lasting time stimulated by ACh was shorter than that of L-Aeg. Response to ATP, however, differred apparently in a manner which the amplitude was larger than that of ACh and L-Arg, whereas the lasting time approximated to that of L-Arg but longer than that of ACh. Before application of agonists, preapplication of L-NNA, a NOS antagonist no current changes could be monitored. CONCLUSION: These data suggested that chicken cochlear ganglion can synthesize and release NO. The effective mechanism of the agonists and possible role of NO in the cochlea is discussed.

Acetylcholine↗