Biomedical subjects

L Wei

Publications and source records attributed to L Wei.

At least 109 records · Page 6Linked to original sources

PubMed2000

[Matrix metalloproteinase-1 and coronary atheroslerotic plaque rupture].

OBJECTIVE: To investigate the relationship between matrix metalloproteinase-1 (MMP-1) and coronary atherosclerotic plaque rupture, and the cellular source of MMP-1 within the plaques. METHODS: 42 cases, among which 20 died of acute myocardial infarction, 10 with unstable angina history and 12 with stable angina history but died of other diseases, were selected. All the branch of coronary arteries were examined, parts of the segments were selected for immunohistochemical staining, 5 markers against alpha-smooth muscle actin, CD20, CD45RO, CD68 and MMP-1 were performed. RESULTS: Plaque rupture and thrombosis were found in almost all the cases of acute myocardial infarction and unstable angina. But in the cases of stable angina, the majority of the plaques were stable ones. The expression of MMP-1 in the ruptured plaques were stronger than the unruptured ones (t = -8.07, P < 0.05); Positive relationship was also noted between the expression of CD68 and MMP-1 (r = 0.75, P < 0.05). CONCLUSION: Macrophages are capable of degrading extracellular matrix by secreting MMP-1; Enhanced secretion of MMP-1 within the coronary atherosclerotic plaques has significant relationship with plaque rupture.

Angina, Unstable↗

PubMed2000

[Clinical study on treatment of infantile rotaviral enteritis with Psidium guajava L].

OBJECTIVE: To observe the clinical effect of olium Psidium guajava (PG) in treating infantile rotaviral enteritis. METHODS: Sixty-two patients of rotaviral enteritis were randomly divided into the treated group treated with PG and the control group treated with Gegen Qinlian decoction. The time for ceasing diarrhea, the content of Na+ in blood, the content of Na+ and glucose in stool, and the rate of negative conversion of human rotavirus (HRV) antigen were observed. RESULTS: The rate of recovery in 3 days of the treated group was 87.1%, significantly higher than that of the control group (58.1%, P < 0.05). The time of ceasing diarrhea of the treated group (25.1 +/- 9.5 hr) was significantly shorter than that of the control group (38.7 +/- 15.2 hr, P < 0.01). The content of Na+ and glucose in stool was reduced obviously in the treated group, while the reduction in the control group was insignificant, the treated group was superior to the control group significantly (P < 0.05). The rate of negative conversion of HRV in feces of the treated group was 87.1%, significantly better than that of the control (58.1%, P < 0.05). CONCLUSION: The treatment with PG has good curative effect on infantile rotaviral enteritis.

Adolescent↗

PubMed2000

[A study on characteristics of transdermal absorption of Radix Angelieae Sinensis and its compound formula].

OBJECTIVE: To investigate the characteristics of transdermal absorption of Radix Angelieae Sinensis and its compound formula. METHOD: Using Valia-Chien diffusion cell in vitro, and HPLC to determine the content of ferulic acid(FA). RESULT: The transdermal permeability coefficient (PC)pf FA, which is the main ingredient of Radix Angelieae Sinensis, is greater than that of the monomer (P < 0.01): the PC of FA is decreased when Radix Angelieae Sinensis and Salviae Miltiorrhizae are used together (P < 0.01): borneol helps enhance the permeation of Radix Angelisas Sinensis (P < 0.01); the PC of the compound formula is greater than that of the compatibility (P < 0.01). CONCLUSION: The transdermal absorption of an ingredient of a traditional Chinese drug is affected not by compatibility, but also by other ingredients of the drug. The transdermal absorption of a monomer or a single drug could not fully mirror the absorption of a compound formula.

Angelica sinensis↗

PubMed2000

[Studies on metal porphyrins as two-functional mimic of enzyme].

In this study, four metal porphyrins (tetraphenylporphyrinesulfonatoiron, tetraphenylporphyrinesulfon-atocopper, tetraphenylporphyrinesulfonatomanganese, and tetraphenyl porrphyrinesulfonatocobalt) were used as dual function mimicry of superoxide dismutase (SOD) and catalase (CAT). The first function, scavenging O2.-, has been proved by using riboflavine-methionine photoreduction method in the concentration range of 10(-5)-10(-6) mol/L. The second function, scavenging H2O2, has been demonstrated by means of spectrophotometry, and the percentage of decomposing H2O2 increases with the concentration of the imitating compounds. Metal porphyrins, SOD and CAT were measured by the liver homogenate technique of mice and the results showed that they had obvious action of decreasing the lipid peroxidation. Tetraphenylporphyrinesulfonatomanganese was measured by isolated ischemia reperfusion heart of rats. The results indicated that the Mn-TPPS4 could reduce the damages of active oxygen and had evidently protective effects on isolated ischemia-reperfusion mocardium of rats.

Animals↗

PubMed2000

[Combined therapy for 121 cases of advanced cancer of the maxillary sinus].

OBJECTIVE: To investigate the possibility of combined therapy (chemotherapy + surgery) for advanced cancer of maxillary sinus. METHOD: Pre-operative radiation + surgery for 61 cases and preoperative chemotherapy + operation for 60 cases were performed. Radiotherapy referred to the use of linear accelerator and/or 60 Co with the dosage of 40-60 Gy. Chemotherapy referred to the administration of CDDP. VCR, and pingyangmycin. RESULT: The survival rate observed in the 61 cases treated with radiation operation was 36.1%; while the other 60 cases treated by chemotherapy + operation had a survival rate of 31.1%. CONCLUSION: The better way to treat advanced cancer of the maxillary sinus is pre-operative chemotherapy + surgery. In addition, repeated application of chemotherapy can raise the effect of surgical treatment.

Adolescent↗

PubMed1999

[Variation of primary structure in nonstructural region 5 b of hepatitis C virus].

OBJECTIVE: To analyze the sequence variation in the nonstructural region 5 b(NS5 b) of hepatitis C virus (HCV) of China. METHODS: Complementary DNA fragments from sera of 49 Chinese patients were amplified by reverse transcription nested polymerase chain reaction (RT-nested-PCR) and the products were cloned and sequenced. RESULTS: 33 clones belonged to genotype 1 b and 16 clones were genotype 2 a. Several conserved nucleotide sites were found to be different from those of Japanese isolates though they belonged to an identical genotype. Comparison of average homology among the 33 clones of genotype 1 b and the 16 clones of genotype 2 a indicated that the average homology among genotype 2 a was lower than that among genotype 1 b. A deletion of three nucleotides and a frame-shift, resulting from the introduction of an in-frame stop codon, were firstly observed in the NS5 b region. CONCLUSION: The nucleotide sequences of different HCV isolates of a same subtype may possibly possess the characteristics for different geographical distribution and so a definite epidemic HCV strain may emerge from a definite area.

Base Sequence↗

PubMed1999

Are predicted structures good enough to preserve functional sites?

BACKGROUND: A principal goal of structure prediction is the elucidation of function. We have studied the ability of computed models to preserve the microenvironments of functional sites. In particular, 653 model structures of a calcium-binding protein (generated using an ab initio folding protocol) were analyzed, and the degree to which calcium-binding sites were recognizable was assessed. RESULTS: While some model structures preserve the calcium-binding microenvironments, many others, including some with low root mean square deviations (rmsds) from the crystal structure of the native protein, do not. There is a very weak correlation between the overall rmsd of a structure and the preservation of calcium-binding sites. Only when the quality of the model structure is high (rmsd less than 2 A for atoms in the 7 A local neighborhood around calcium) does the modeling of the binding sites become reliable. CONCLUSIONS: Protein structure prediction methods need to be assessed in terms of their preservation of functional sites. High-resolution structures are necessary for identifying binding sites such as calcium-binding sites.

Animals↗

PubMed1999

Synthesis and biological activities of spiroheterocyclic growth hormone secretagogues.

The synthesis and biological activities of a series of spiroheterocyclic growth hormone secretagogues are reported. Modification of the spiroindane part-structure of the prototypal secretagogue L-162,752 revealed that the spiroindane could be replaced with spirobenzodihydrothiophen derivatives to enhance not only in vitro potency but also oral activity. In this study non-aromatic D-2-amino-4-cyclohexylbutanoic analogs (8a-8d) were also identified to be active secretagogues.

Animals↗

PubMed1999

IFN-beta suppresses experimental autoimmune neuritis in Lewis rats by inhibiting the migration of inflammatory cells into peripheral nervous tissue.

The putative prophylactic and therapeutic effect of interferon-beta (IFN-beta) on autoimmune inflammation of the peripheral nervous system was evaluated in experimental autoimmune neuritis (EAN), a well-known animal model of the human Guillain-Barré syndrome (GBS). We report that treatment of rats with 300,000 U of recombinant rat IFN-beta (rrIFN-beta) given every other day starting at the day of immunization prevented clinical signs of EAN. When treatment was started at the onset of disease development, the cytokine clearly ameliorated EAN. Both B- and T-cell responses towards peripheral myelin were suppressed by the IFN-beta, and immunohistochemical analyses revealed a strong decrease in the numbers of infiltrating CD4(+) T cells, macrophages, and other inflammatory cells as well as a significant reduction in MHC class II antigen expression and monocyte chemotactic protein-1 (MCP-1) production, which induces chemotaxis and chemokinesis of leukocytes from blood. It is concluded that the observed suppression of EAN by rrIFN-beta is associated with a decrease in the migration of inflammatory cells into peripheral nervous tissue.

Adjuvants, Immunologic↗

PubMed1999

Antigen-specific immunosuppression: nasal tolerance to P0 protein peptides for the prevention and treatment of experimental autoimmune neuritis in Lewis rats.

Experimental autoimmune neuritis (EAN) is an autoimmune inflammatory demyelinating disease of the peripheral nervous system (PNS), and represents an animal model of the human Guillain-Barré syndrome (GBS). In this study, we report that nasal administration of the neuritogenic peptide 180-199 and of the cryptic peptide 56-71 of the rat neuritogenic P0 protein of peripheral nerve myelin prevents EAN and attenuates ongoing EAN. Both peptides effectively decreased the severity and shortened clinical EAN. Both a prophylactic and a therapeutic approach proved to be beneficial. These effects were associated with T and B cells hyporesponsiveness to the peptide antigens, reflected by downregulated Th1 cell responses (interferon-gamma secretion) and macrophage function, whereas Th2 cell responses (IL-4 secretion) and transforming growth factor-beta mRNA expression were upregulated.

Administration, Intranasal↗

PubMed1999

IL-1 beta and IFN-gamma induce the regenerative epidermal phenotype of psoriasis in the transwell skin organ culture system. IFN-gamma up-regulates the expression of keratin 17 and keratinocyte transglutaminase via endogenous IL-1 production.

Skin biopsies from healthy human skin and non-lesional skin from patients with psoriasis were cultured for 24 h and stimulated with interleukin-1 beta (IL-1 beta) and interferon-gamma (IFN-gamma) in a skin organ culture model and the induction of the psoriasiform regenerative epidermal phenotype was analysed using immunostaining. In the presence of IL-1 beta, the psoriasiform regenerative epidermal phenotype was clearly induced. This involved strong up-regulation of the expression of keratin 16, keratin 17, and keratinocyte transglutaminase (TGk) in the suprabasal layers, strong up-regulation and a shift of the expression of keratin 5 and integrin beta 1 from the basal to suprabasal keratinocytes, and induction of the expression of ICAM-1 and HLA-DR on basal keratinocytes. The effects of IL-1 beta in the organ cultures of normal skin could be completely neutralized by anti-IL-1 polyclonal antibodies. The effects of IFN-gamma in healthy and non-lesional psoriatic skin were qualitatively similar to those of IL-1 beta. The IFN-gamma-induced epidermal expression of keratin 17 and TGk could be completely blocked by culturing the biopsies in the presence of IL-1ra or anti-IL-1 antibodies, while the induction of HLA-DR and ICAM-1 was not inhibited. The induction of the psoriasiform regenerative epidermal phenotype by IFN-gamma is partially mediated via endogenous epidermal IL-1.

Adult↗

PubMed1999

A meta-analysis of epidemiological studies in depression of older people in the People's Republic of China.

BACKGROUND: There has been little information about depression in Chinese elderly people. In order to investigate whether or not there is an excess of depression among the Chinese elderly, we have performed a meta-analysis of the published epidemiological studies. METHODS: Papers published in the literature from The People's Republic of China included in the Chinese medical databases were obtained. Some additional papers collected from other sources were also included. The fixed/random effects model and Poisson model were employed for data analysis. RESULTS: There were 10 cross-sectional studies (23 samples divided according to men/women and urban/rural subjects) giving sufficient prevalence data on depression (13 565 subjects) or depressive mood (8476 subjects). The pooled prevalence of depression was 3.86% (95%CI 3.37-4.42%), while that of depressive mood was 14.81% (14.20-15.64%). The risk of depression in the rural communities (5.07%, 3.61-7.13%) was higher than in the urban (2.61%, 2.22-3.08%). The same trends were observed for depressive mood. The patterns of risk factors were similar to those in western countries. CONCLUSIONS: Chinese tradition and culture may be explanatory factors for the low prevalence, provided the methodological issues have not seriously biased the results.

Aged↗

PubMed1999

Interaction between calcium-activated chloride channels and the cystic fibrosis transmembrane conductance regulator.

We investigated interactions between cystic fibrosis conductance regulator (CFTR) and endogenous Ca2+-activated Cl- channels (CaCC) in bovine pulmonary artery endothelium (CPAE). CPAE cells, which do not express CFTR, were transiently transfected with wild-type (WT) CFTR and the deletion mutant deltaF508 CFTR. Currents through CaCC were significantly reduced after expression of WT CFTR. This inhibition was increased by stimulation (isobutylmethylxanthine, forskolin) of CFTR in cells expressing WT CFTR. There were no such effects when deltaF508 mutant CFTR, which is retained in the endoplasmic reticulum, was expressed. It is concluded that CFTR and CaCC are functionally coupled probably through a direct channel-channel interaction.

1-Methyl-3-isobutylxanthine↗

PubMed1999

Reducing degradation of azo dye by zero-valent iron in aqueous solution

The reducing degradation kinetics of five azo dyes, Acid orange II, Acid orange IV, Acid orange GG, Acid red 3B and Orange I, by zero-valent iron powder in aqueous solution were studied. It showed that the degradation is a two-step reaction, with the first step being reversible. Solution acidity and iron surface area are the factors greatly influencing the degradation rates, and with increasing of acidity and iron surface area, the degradation rates increase.

Journal Article↗

PubMed1999

Block by fluoxetine of volume-regulated anion channels.

1. We have used the whole-cell patch clamp technique to study the effect of fluoxetine, a commonly used antidepressant drug, on the volume-regulated anion channel (VRAC) in calf pulmonary artery endothelial (CPAE) cells. We also examined its effects on other Cl- channels, i.e. the Ca2(+)-activated Cl- current (I(Cl,Ca) and the cystic fibrosis transmembrane conductance regulator (CFTR) to assess the specificity of this compound for VRAC. 2. At pH 7.4 fluoxetine induced a fast and reversible block of the volume-sensitive chloride current (I(Cl,swell)), with a Ki value of 6.0+/-0.5 microM (n = 6-9). The blocking efficiency increased with increasing extracellular pH (Ki= 0.32+/-0.01 microM at pH 8.8, n = 3-9), indicating that the blockade is mediated by the uncharged form of fluoxetine. 3. Fluoxetine inhibited Ca2(+)-activated Cl(-) currents, I(Cl,Ca), activated by loading CPAE cells via the patch pipette with 1000 nM free Ca2+ (Ki= 10.7+/-1.6 microm at pH 7.4, n=3-5). The CFTR channel, transiently transfected in CPAE cells, was also inhibited with a Ki value of 26.9+/-9.4 microM at pH 7.4 (n = 3). 4. This study describes for the first time the effects of fluoxetine on anion channels. Our data reveal a potent block of VRAC at fluoxetine concentrations close to plasma concentrations. The results suggest a hydrophobic interaction with high affinity between uncharged fluoxetine and volume-activated chloride channels. Ca(2+)-activated Cl- currents and CFTR are also blocked by fluoxetine, revealing a novel characteristic of the drug as a chloride channel modulator.

Animals↗

PubMed1999

UNC-11, a Caenorhabditis elegans AP180 homologue, regulates the size and protein composition of synaptic vesicles.

The unc-11 gene of Caenorhabditis elegans encodes multiple isoforms of a protein homologous to the mammalian brain-specific clathrin-adaptor protein AP180. The UNC-11 protein is expressed at high levels in the nervous system and at lower levels in other tissues. In neurons, UNC-11 is enriched at presynaptic terminals but is also present in cell bodies. unc-11 mutants are defective in two aspects of synaptic vesicle biogenesis. First, the SNARE protein synaptobrevin is mislocalized, no longer being exclusively localized to synaptic vesicles. The reduction of synaptobrevin at synaptic vesicles is the probable cause of the reduced neurotransmitter release observed in these mutants. Second, unc-11 mutants accumulate large vesicles at synapses. We propose that the UNC-11 protein mediates two functions during synaptic vesicle biogenesis: it recruits synaptobrevin to synaptic vesicle membranes and it regulates the size of the budded vesicle during clathrin coat assembly.

Adaptor Proteins, Vesicular Transport↗

PubMed1999

Nonlinear electrostatic waves in a magnetized plasma.

The modulational interaction of finite-amplitude high-frequency electrostatic waves propagating at an arbitrary angle to an external magnetic field with slow plasma motion is considered. A set of nonlinear evolution equations describing the interaction is obtained. New types of solitary waves propagating at near sonic speeds are found.

Journal Article↗

PubMed1999

Neuropsychological symptoms in Chinese male and female painters: an epidemiological study in dockyard workers.

OBJECTIVES: To study the prevalences of neuropsychological symptoms in male and female dockyard painters in China and to compare them with those in British dockyard painters. METHODS: All 116 painters were identified, active and retired, who had been employed in two Chinese dockyards for at least 1 year together with a matched random sample of 263 dockyard non-painters. Neuropsychological and personality questionnaires that we had used previously in a study of United Kingdom dockyard painters were used, translated into Chinese. Neuropsychological symptoms in painters and controls were compared, adjusting for age, educational level, smoking, alcohol intake, and personality. RESULTS: The response rate was 94% for painters and 97% for controls. Highly significant excesses of symptoms were found in painters, suggestive of neuropsychological dysfunction. Both male and female painters showed higher relative risks than were found in similar tradespeople in the United Kingdom. The relative risk increased with increasing score of both neurological and psychological symptoms. Relative risk of having a high symptom score, compared with controls and adjusted for confounders, was 6.61 (95% confidence interval (95% CI) 2.36 to 18.50) for 2-15 years exposure, 14.88 (5.74 to 38.56) for 16-22 years and 9.42 (3.97 to 22.36) for > or = 22 years. CONCLUSION: These results indicate that neuropsychological symptoms are associated with heavy exposure to painting work in China, and that the phenomenon is likely to be found worldwide wherever there is such exposure to solvent based paints. The high response rate in this study answers a possible criticism of the earlier United Kingdom study.

Adolescent↗