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Biomedical subjects

D Li

Publications and source records attributed to D Li.

At least 523 records · Page 29Linked to original sources
PubMed1998

[Immune modulatory and therapeutic effect of lentinan on condyloma acuminatum].

OBJECTIVE: To observe the immune modulatory and therapeutic effect of lentinan on condyloma acuminatum (CA). METHODS: Thirty-six CA patients were randomly divided into two groups, 19 in the test group treated with lentinan plus CO2 laser irradiation and 17 in the control group treated with laser irradiation alone. Their T-lymphocyte subsets of peripheral blood and level of serum interleukin-2 (IL-2) and soluable interleukin-2 receptor (SIL-2R) were determined before and after treatment, and the recurrence rates of the two groups were compared. RESULTS: After treatment, in the test group, the CD4/CD8 ratio, serum IL-2 raised and serum SIL-2R lowered significantly (P < 0.05, 0.05, 0.05 respectively) as compared with before treatment, while those parameters were not changed significantly in the control group. The recurrence rate of the test group was lower than that of the control group, P < 0.05. CONCLUSION: Lentinan could modulate the cellular immunofunction of CA patients and reduce the recurrence rate of CA.

Adjuvants, Immunologic↗
PubMed1998

[Effect of ligustrazine on nitric oxide contents in cerebrospinal fluid and plasma of patients with cerebral infarction].

OBJECTIVE: To probe into the significance of Nitric Oxide (NO) in ischemic cerebral damage and effect of ligustrazine on it. METHODS: The NO contents in cerebrospinal fluid (CSF) and plasma of 20 controls and 62 patients with arteriosclerotic thrombotic cerebral infarction (ligustrazine group and common treatment group) were determined with Griess method before and after treatment. RESULTS: The NO content in CSF before treatment was higher in severe type, it was higher than that in moderate type, and than that in mild type, again higher than that in control group (all P < 0.05) and was positively correlated with the size of infarction (P < 0.01). There was no significant difference between the plasma NO content of patients and that of control group (P > 0.05), but there was a trend that plasma NO content decreased as the patient's condition worsened. After treatment, the curative effect and plasma NO content of ligustrazine group were both markedly higher than those of common treatment group (P < 0.05). There were no significant differences between CSF NO contents of the two groups, respectively, and that of control group (P > 0.05). CONCLUSIONS: Excessive NO produced in brain tissue and insufficient plasma NO participate the course of ischemic brain damage. Ligustrazine could increase the contents of plasma NO selectively.

Adult↗
PubMed1998

[Observation on sleep improvement under noise environment by wearing earplugs].

Sleep experiments were done in 6 subjects under 3 conditions. (1) Quiet, background noise level lower than 45dB (A); (2) Noisy with earplugs, ambient noise level 90dB (A); (3) Noisy, ambient noise level 90dB (A), and subjects wearing earplugs. EEG, REM and EMG during sleep were recorded. Sleep latency, times and duration of waking up, sleep rate of each stage and total sleep rate were analyzed. It shows that sleep under noise condition can be improved by wearing earplugs.

Adult↗
PubMed1998

[Chemical changes of compatibility for shaoyao decoction].

OBJECTIVE: To probe the regular patterns of interactions among chemical components in Chinese medicinal complex prescriptions. METHOD: The active components of Rhubarb, Coptis root and Baikal skullcap root in different patterns of compatibility were determined by TLC-scanner. RESULT: The berberine content in Coptis root can be decreased obviously by Rhubarb, Baikai skullcap root and Licorice root, especially by Rhubarb. Coptis root can also decrease the contents of acid components. CONCLUSION: The acid components can affect each other, thus reducing the contents of effective components.

Berberine↗
PubMed1998

[Bile salt induces apoptosis of hepatocytes: the mechanism of hepatic function injury during obstructive jaundice].

OBJECTIVE: To determine if the bile salt induces hepatocyte apoptosis in vitro. METHOD: Hepatocytes were isolated by in situ collagenase perfusion and plated in 6 well flat bottom with DMEM/F12, 0.5 micro/ml insulin. Two hours later, glycochenodeoxcholate (GCDC) 25, 50, 100, 200, 300 micromol was added and cells evaluated by DNA-PI staining FACS and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) 3, 6, 9, 12, 18, 20, 24 hours later. Agarose gel electrophoresis of DNA extracted from hepatocytes after incubation with GCDC using various experimental conditions. RESULT: The hepatocytes treated with GCDC have a high apoptotic rate as compared with the controls. 100 micromol GCDC treated 24 hours, nearly 61.81% of hepatocytes were apoptotic by FACS evaluation. The TUNEL showed that apoptotic hepatocytes had less cell volume and stained with brown by Biotin-11-dUTP. DNA ladder of bile-salt treated hepatocytes were shown in agarose gel electrophoresis. CONCLUSION: The mechanism of hepatic injury during obstructive jaundice is related to bile salt caused hepatocyte apoptosis.

Animals↗
PubMed1998

[Pathological changes of viscera after brain death: an experimental study].

In order to study the viscera changes after brain death while the function of the heart and lung was sustained artificially, 34 cats were used and divided into three groups. The results showed that pathological changes of viscera (heart, lung, liver and kidney) developed, including 1. ischemic cardiomyopathy, endocardiac hemorrhage, focal necrosis, mitochondria and microfilament destruction. 2. pulmonary congestion, edema and parenchymal inflammation. 3. ischemic lesions in the central band of hepatic lobular and ischemic lesions in renal proximal convoluted tubule.

Animals↗
PubMed1998

[The relationship between herpes simplex virus II, human papillomavirus infection and infertility after artificial abortion].

In order to study the relationship between infection of sexually transmitted virus Herpes simplex virus II (HSV2), Human papillomavirus (HPV) and female infertility after artificial abortion, we collected 60 genital samples from infertile women who had accepted artificial abortions and 39 genital samples from normal women. Polymerase chain reaction (PCR) was used to detect HSV2 and HPV. The results were compared by x2. The positive rate of HSV2 in infertile and normal women were 80.0% and 25.6% respectively, there was a significant difference (P < 0.01); but that of HPV were 53.5% and 33.3%, which slowed no significant difference (P > 0.05). Mixed infection rates of HSV2 and HPV were 43.3% and 23.1% in infertile and normal women, a significant difference (P < 0.05) was statistically calculated. The results showed that there was a relationship between infertility after artificial abortion and genital infection of HSV2 and HPV or mited infection of HSV 2 and HPV. Taking total 99 genital samples into calculation, the mired infection rate of HSV 2 was 35.35%, a significant relatedness of HSV2 and HPV infection to infertility was proved by chi 2, chi 2 = 12.5, P < 0.01.

Abortion, Induced↗
PubMed1998

[Detection of hepatitis C virus-C, E, NS3 and NS4 regions' antigens in hepatocellular carcinoma and liver cirrhosis].

Using 4 McAbs to HCV-C, E, NS3 and NS4 regions' antigens and PcAb to HBsAg, 59 cases of hepatocellular carcinoma(HCC) and 35 cases of liver cirrhosis(LC) were tested by immunohistochemistry technique. Positive reactions for hepatitis C virus were mainly present in the cytoplasm of hepatocytes and tumor cells with fine granules. The positive rates of HCV were 17.2% in HCC(29 cases) of Beijing, 26.7% in HCC(30 cases) of Shenyang and 14.3% in LC(35 cases) of Shenyang. C region's McAb had the highest positive rate of detection, which suggested that C region's protein had a high level expression. The positive rates of hepatitis B virus surface antigen were 63.0% in HCC(29 cases) of Beijing, 73.3% in HCC(30 cases) of Shenyang and 54.3% in LC(35 cases) of Shenyang, all of which were higher than their positive rate for HCV detected. In HCC and LC, HBV and HCV inclined to suppress the opposite side.

Aged↗
PubMed1998

[Chinese Chlorella viruses and their molecular biological properties].

An extensive survey for Chlorella viruses revealed that Chlorella viruses are widely distributed over China. Eleven isolates of Chlorella viruses have been isolated, which lysis the Chlorella viruses sp. (strain NC64A). These isolates were named BJ-1, BJ-2, BJ-3, BJ-4, FJ-1, FJ-2, NJ-1, CDT-1, HCJ-1, SCB-1 and SCC-1 respectively. They have several common properties, including polyhedral morphology, and linear dsDNA genomes. However, the restriction patterns of viral DNA, the concentration of m5dC and m6dA in viral DNA, and the composition of viral structure protein are different among these isolates. All of viral major capsid proteins are 54,000 except FJ-1, whose major capsid protein is smaller than 54,000. Western blot analysis showed strong immunological cross reaction among all of viral proteins with PBCV-1's antiserum except FJ-1. It indicates that the homology between these isolates and PBCV-1 is high. Among these isolates, FJ-1 has some special properties.

Base Composition↗
PubMed1998

[Self-organization neural network based ultrasonic heart image segmentation].

Segmentation is one of the most difficult problems in multidimensional reconstruction of ultrasonic heart image. In the present paper, a segmentation method of ultrasonic heart image using the self-organization neural network has been studied. This is an unsupervised segmentation method, which can segment images through clustering automatically. The results show that the present method has significant benefits over the traditional K-means algorithm.

Algorithms↗
PubMed1998

[Synthesis of new pyrazoline fluorescent compounds and their IR spectra and fluorescence property].

The Fluorescent compounds of pyrazoline have been used in many field. According to Schellhammer theory, we designed and synthesized five new benzothiazoyl pyrazoline compounds. Their infrared spectra and fluorescent spectra of five compounds were detected. The results showed that five compounds have fluorescence, fluorescence emission wavelength is about 450nm. Effect of different substituents on the fluorescent intensity was investigated.

Fluorescent Dyes↗
PubMed1998

Effect of nickel chloride on mouse T-lymphocyte subsets.

The study was carried out to observe the effect of nickel chloride (NiCl2) on T-lymphocyte subsets, CD4, CD8 and CD4/CD8 ratios in vivo. BALB/C mice were injected i.p. with NiCl2 every other day for 2 w. The NiCl2 doses were 1, 3, 6, 9 or 12 mg/kg. Lymphocytes were obtained from mouse spleen and cultured in the presence of monoclonal antibody FITC conjugated, anti-CD4 or anti-CD8. Samples were determined with a flow cytometer. A suppressive effect on CD4-positive cells was found in the 6 mg/kg group, but this subset was restored to the control level in the 9 and 12 mg/kg groups, suggesting that there was an "immune tolerance" effect. No significant changes were found in CD8-positive cells and CD4/CD8 ratios. The results suggested the NiCl2 had a deleterious effect on mouse T-lymphocytes in short-term in vivo exposure, but the effects may depend on the dose and cell subset.

Animals↗
PubMed1998

p16INK4A adenovirus-mediated gene therapy for human head and neck squamous cell cancer.

Inactivation of the tumor suppressor gene p16INK4A is the most common genetic alteration in human head and neck squamous cell cancer (HNSCC), making it an ideal target for gene replacement. We constructed a replication-defective, recombinant adenovirus capable of directing a high level of p16INK4A protein expression (Ad5-p16) to investigate its benefit in treating HNSCC. Initial in vitro experiments in four human HNSCC cell lines demonstrated that Ad5-p16 treatment significantly inhibits cell growth with up to 96% efficiency. Flow cytometric analysis showed that Ad5-p16 induced a maximum G1-S cell cycle arrest of 90%. Subsequent studies in a nude mouse model demonstrated that Ad5-p16 treatment significantly reduced (cell line 011) or stabilized (cell line 012) established tumors when compared with control treatments (P < 0.008). These results demonstrate for the first time a significant antitumor effect of Ad5-p16 against human HNSCC in vivo and support the potential application of Ad5-p16 to treat locally advanced, unresectable, or metastatic head and neck cancer, as well as microscopic residual disease after surgical resection.

Adenoviridae↗
PubMed1998

Effects of iron deficiency on iron distribution and gamma-aminobutyric acid (GABA) metabolism in young rat brain tissues.

Effects of iron deficiency on the distribution of iron and glutamate decarboxylase (GAD), gamma-aminobutyric acid transaminase (GABA-T) activities and GABA concentrations in different brain regions in young rats were investigated. Iron deficiency was induced by feeding an iron-depleted diet (0.32mg/100g) in weanling rats for 3 weeks or 6 weeks. The values of hemoglobin (Hb), hematocrit (Ht) and red blood cells (RBC) decreased with the progress of anemia. The concentrations of serum iron in the rats fed iron-depleted diets were lower than those of corresponding controls. On the other hand, the concentrations of total iron-binding capacity (TIBC) and unsaturated iron-binding capacity (UIBC) in serum were higher than those of corresponding controls. These results showed that hypochromic and typical iron-deficiency anemia had occurred in these rats. At the same time, iron deficiency also resulted in significantly low iron concentrations in the brain, especially in the hypothalamus, midbrain and thalamus, and striatum and hippocampus. Although the changes in GABA concentrations in corresponding brain regions were not observed, the activities of the GABA-synthesizing enzyme GAD and GABA-degrading enzyme GABA-T of the rats fed iron-depleted diets for 6 weeks decreased significantly. This study provides evidence that iron deficiency in the brain could change the utilization and metabolism of GABA.

4-Aminobutyrate Transaminase↗
PubMed1998

[Polymorphism of HLA-DQA1,-DQB1 genes in Uygur and Kazak ethnic groups and comprehensive analysis of 25 related populations].

HLA-DQA1 and -DQB1 genes were investigated in two Chinese minor natinalities, Uygur and Kazak using PCR-RFLP genotyping method. Of the 8 DQA1 alleles, DQA1 *0301 was the most common in Uygurs and Kazaks. DQA1 *0401 and *0601 were the rarest alleles in Uygurs and *0601 in Kazaks. Of the 16 DQB1 alleles tested, DQB1 *0201 and *0301 were the most frequent alleles in Uygurs and Kazaks. DQB1 *0502, *05032 and *0504 in Uygurs, *05032, *0504 and *0605 in Kazaks were absent. Neither DQA1 nor DQB1 difference was found between the two populations. From the phylogenetic tree based on the gene frequencies of HLA-DQA1 and -DQB1 in Uygur, Kazak and other 25 related ethnic groups, we suggest that Uygurs and Kazaks have a closer relationship, and they are closer to Mongoloid, not Caucasoid.

Adult↗
PubMed1997

An Electrical Suspension Method for Measuring the Electric Charge on Small Silicone Oil Droplets Dispersed in Aqueous Solutions

The electric charge on small liquid droplets dispersed in another immiscible liquid is of fundamental interest in various colloidal and interfacial phenomena and industrial processes. In this paper, the authors present a new experimental method to measure the charge on small silicone oil droplets in aqueous solutions. Basically, an oil droplet was kept stationary inside a test cell between two electrode plates by application of an electric field of an appropriate polarity and strength. Thus, the electric charge on the oil droplet was determined from the force balance among the electrical force, the gravitational force, and the buoyancy force exerted on it. By using the electrical suspension method, the effects of two different silicone oils, pH values, valences, and concentrations of three different electrolytes on the measured electric charge were investigated. One of the two silicone oils is heavier (rho1 = 1050 kg m-3) and the other is lighter (rho2 = 963 kg m-3) than the aqueous solutions. There was an appreciable difference between the measured electric charges for the two silicone oils. The point of zero charge (pzc) for the heavier oil droplets was found to be pH approximately 5.0, which is essentially the same as the value for the mineral oil droplets in the oil-in-water (O/W) emulsions reported by other researchers. It was also observed that the electric charge depends strongly on not only the concentrations but also the ionic valences of electrolytes added to the solutions. More specifically, divalent and trivalent cations, such as Ca2+ and Al3+, were more readily adsorbed on the oil-water interface. Therefore, their effects were more pronounced than that of monovalent cations, Na+, on reducing the negative charge or even reversing the charge polarity as their ionic concentrations increase, in accordance with the valence difference. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Oncogenic raf-1 induces the expression of non-histone chromosomal architectural protein HMGI-C via a p44/p42 mitogen-activated protein kinase-dependent pathway in salivary epithelial cells.

The enzyme activity of mitogen-activated protein kinase (MAP kinase) increases in response to agents acting on a variety of cell surface receptors, including receptors linked to heterotrimeric G proteins. In this report, we demonstrated that Raf-1 protein kinase activity in the mouse parotid glands was induced by chronic isoproterenol administration in whole animals. To investigate the molecular nature underlying cellular responses to Raf-1 activation, we have stably transfected rat salivary epithelial Pa-4 cells with human Raf-1-estrogen receptor fusion gene (DeltaRaf-1:ER) and used mRNA differential display in search of messages induced by DeltaRaf-1:ER activation. Through this approach, the gene encoding non-histone chromosomal protein HMGI-C was identified as one of the target genes activated by oncogenic Raf-1 kinase. Activation of Raf-1 kinase resulted in a delayed and sustained increase of HMGI-C expression in the Pa-4 cells. The induction of HMGI-C mRNA level is sensitive to both the protein synthesis inhibitor cycloheximide and transcription inhibitor actinomycin D. The role of the extracellular signal-related kinase (ERK) signaling pathway in the HMGI-C induction was highlighted by the result that the MAP kinase kinase (MEK) inhibitor, PD 98059, blocked DeltaRaf-1:ER- and 12-O-tetradecanoylphorbol-13-acetate-stimulated HMGI-C induction. Altogether, these findings support the notion that the Raf/MEK/ERK signaling module, at least in part, regulates transcriptional activation of the chromosomal architectural protein HMGI-C.

Amino Acid Sequence↗