[Predication of hemodynamic changes of rheumatic heart disease with P wave of electrocardiogram].
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Adolescent↗
Biomedical subjects
M Li
Publications and source records attributed to M Li.
[Experimental study on antagonism of ginkgolides against effect of platelet-activating factor on lung strip of guinea pigs].
OBJECTIVE: To investigate the action of ginkgolides antagonizing the contraction of guinea pigs' lung strip induced by the mixture of platelet-activating factor (PAF) and platelets and its effect of preventing the PAF caused damage of beta-adrenergic receptors. METHODS: The contraction of guinea pigs' isolated lung strip was measured. RESULTS: The mixture of PAF and platelet could produce a serious contraction of lung strip, the IC50 reached 4.69 x 10(-7) mol/L, while the contraction induced by PAF alone was relatively mild, its IC50 only 6.66 x 10(-4) mol/L, the difference between them was significant (P < 0.05). When the platelets were preincubated with ginkgolides for 10 minutes in Tris-Tyrode's buffered saline, the effects of PAF and platelets mixture were significantly inhibited (P < 0.05). Exposure of guinea pigs' lung strip to PAF in vitro resulted in a loss of beta-adrenergic receptors and weakened its respones to isoproterenol, a receptor activating factor, the EC50 would be increased from 1.38 x 10(-6) mol/L to 6.25 x 10(-6) mol/L, P < 0.05. This effect of PAF could also be inhibited by ginkgolides (P < 0.05). CONCLUSION: Ginkgolides is a promising PAF antagonist, and might be used in treating bronchial asthma.
Animals↗
[Inhibition of peripheral blood T cell proliferation by dexamethasone in steroid-resistance asthma].
We investigated the pathogenesis of steroid-resistance (SR). The inhibition of phyto-hemagglutininum-induced T lymphocyte proliferation by dexamethasone (Dex) was investigated by lymphocyte proliferation assay. Plasma cortisol concentration was measured by radioimmune lectrophoresis autoradiography kit. The inhibition effects of Dex (10(-7) mol/L) on the proliferation of lymphocytes from SR asthmatics were significantly less than those from steroid-sensitive (SS) asthmatics (P < 0.05). Plasma cortisol concentrations of SR asthmatics were significantly lower than those of normal subjects (P < 0.01) and SS asthmatics (P < 0.05). There was no correlation between the degree of inhibition by Dex (10(-7) mol/L of SR, SS asthmatics of proliferation of T lymphocytes and plasma cortisol concentration. T lymphocytes from SR asthmatics were insensitive to Dex. Plasma cortisol concentration from SR asthmatics were significantly lower than those of SS asthmatics, that may be due to the large dose of glucocorticoids given in long time.
Adult↗
[Establishment and significance of an extracorporeal bioartificial liver support system].
This experiment was carried out to establish an optimal extracorporeal bioartificial liver support system (EBLSS) and furnish a new therapy for hepatic failure. For this purpose, human hepatocytes were isolated by two-stage perfusion method and cultured by spheroidal aggregates method. Besides, hollow fiber tube was used as bioreactor and the hemodialysis instrument was refited to serve as supplementary circulation unit, which was composed of EBLSS and was tried in normal dogs. A total of 2 x 10(10) human hepatocytes with a viability of 94% was obtained. These hepatocytes became multicellular spheroidal aggregates under non-adherent conditions. After 5 hours circulating on EBLSS, the hepatocytes remained active. At the same time, the monitoring system revealed a normal vital sign in dogs and the laboratory tests found their serum total protein and albumin were increased. These results show that the key technology of bioartificial liver has been dereloped basically and this EBLSS is effective and safe, providing a foundation for the support and treatment of hepatic failure with bioartificial liver.
Animals↗
[The expression of c-fos gene in cultured bovine trabecular cells induced by epidermal growth factor].
OBJECTIVE: To investigate the effect of epidermal growth factor (EGF) on cultured trabecular cells. METHODS: Molecular hybridization technique was used to investigate the effect of EGF on c-fos expression and its induction of bovine trabecular cells in vitro, and 3H-TdR incorporation method was applied to study the synthesis of DNA. RESULTS: EGF enhanced the incorporation of 3H-TdR into trabecular cells at concentrations ranging from 20-150 ng/ml (P < 0.001). Compared with control, the expression of c-fos appeared at 0.5 hour and 1 hour after stimulation, and did not exist till 2 hr. The level of c-fos expression in cells relied on the concentration of EGF. CONCLUSION: Our results suggest that EGF stimulate trabecular cell proliferation at least in part by the regulation of the c-fos gene and its nuclear protein.
Animals↗
[The effects of adrenergic antagonists on epinephrine determined by the assay of adenosine 3',5'-monophosphate in bovine trabecular cells in vitro].
OBJECTIVE: To compare and assay the effects of various beta-adrenergic antagonists at effective concentrations on epinephrine (EPI). METHOD: Cyclic adenosine 3',5'-monophosphate (cAMP) in trabecular cells was measured by protein binding assay with 3H-cAMP. RESULTS: (1) The effect of EPI increasing cAMP in bovine trabecular cells (BTC) in vitro did not obviously recover at the fifth hour after the removal of 10(-5) mol/L timolol, and partly recovered at the fifth hour after the removal of 10(-6) mol/L timolol. (2) There was only part recovery for the effect of EPI at the fifth hour after the removal of ICI 118, 551 (10(-5) mol/L, and 10(-6) mol/L). (3) There was an obvious recovery for the effect of EPI at the fifteenth minute after the removal of 10(-5) mol/L bisoprolol. CONCLUSION: The effect of timolol and ICI 118, 551 for blocking EPI is strong and sustained; bisoprolol produces a smaller blockade to the effect of EPI, lasting a short time. Our results also presume that BTC contains beta-adrenergic receptors, and beta 2-adrenergic receptors are dominant.
Adrenergic beta-Antagonists↗
[The expression of EGF mRNA and EGF receptors in human trabecular meshwork cells in vitro].
OBJECTIVE: To demonstrate that cultured trabecular meshwork cells can secrete epidermal growth factor (EGF) and there are EGF receptors (EGFRs) on the cells. METHODS: Human trabecular meshwork cells were cultured in vitro and passaged 3-5 times. Immunohistochemical stain was used to detect EGFRs on the trabecular meshwork cell membrane. EGF cDNA probe, alpha-32P isotope labeling and dot blot hybridization autoradiographic method were used to detect EGF mRNA in the cells. RESULTS: Cultured human trabecular meshwork cells were obtained. EGFR immunostain was positive, and the reaction of brown color was at the surface of the cells. Dot blot hybridization autoradiography showed that trabecular cells can express EGF mRNA. CONCLUSIONS: Trabecular meshwork cells can secrete EGF. There are EGFRs on the membrane of trabecular meshwork cells. It is suggested that probably up-regulating the receptors or promoting the cells to secrete growth factors have potential significance in the regeneration of trabecular cells and recovery of the cell functions in open angle glaucoma.
Adolescent↗
[Application of proliferating cell nuclear antigen in the study of human trabecular cell proliferation].
OBJECTIVE: To evaluate the application of proliferating cell nuclear antigen (PCNA) in the study of human trabecular cell proliferation. METHODS: Immunohistochemical technique was used to observe the PCNA expressive level in the fourth passage of human trabecular meshwork, the effects of different concentrations of epinephrine, dexamethasone and epidermal growth factor on the level were also investigated, the results were compared with that of the normal cells cultured at the same time, and analyzed by a graphic device operation system in a computer. RESULTS: A stable proliferating curve was obtained according to the normal cell PCNA level, by which we could choose the best opportunity of drug application. Epinephrine and dexamethasone were found to significantly inhibit cell proliferation, while epidermal growth factor (EGF) could promote the proliferation. CONCLUSION: PCNA is considered to be a useful agent to observe the process of cell proliferation. The above mentioned methods are beneficial to the investigations of biochemical characteristics of trabecular meshwork cells and the pathogenic mechanisms of open-angle glaucoma.
Cell Division↗
[Pharmacokinetics of Caulis Erycibes injection in rabbits].
The pharmacokinetics of single i.m. doses of Caulis Erycibes injection in ten rabbits was studied. The concentration of scopoletin-one of the effective components in Caulis Erycibes injection in serum was analyzed by high performance liquid chromotography with fluorescence monitor. In eight of ten rabbits a second peak was found on the serum concentration-time curve. The absorption of scopoletin was quick with Tmax 1 = 8.08 +/- 3.88 min, Cmax 1 = 145.45 +/- 47.65 ng/ml. The time to the second peak concentration (Tmax 2) was 2.45 +/- 1.79 h, Cmax 2 = 48.66 +/- 41.66 ng/ml. The other parameters were as follows: Ke = 0.56 +/- 0.37 h-1, T1/2 = 1.81 +/- 1.14 h, MRT = 156.61 +/- 98.41, CL/F = 220.54 +/- 109.35 ml/min, Vd/F = 30.49 +/- 19.34 L, AUC = 8.52 +/- 5.15 micrograms.min/ml. The reason for the appearance of double peaks was discussed.
Animals↗
[Chest CT and its assessment of resectability in lung cancer].
OBJECTIVE: To evaluate chest CT and its relation to possible surgical resection in lung cancer patients. METHODS: Ninty-five patients who were diagnosed and confirmed as having lung cancers by surgery and pathology were divided into three groups: (1) Radical resection group; (2) Palliative resection group and (3) Thoractomy group. The diameter of the tumor, the proximity to mediastinum and/or the hilum and the invasion of their lymph nodes were measured. Meanwhile, the changes in the mediastinum and thoracic cavity on the chest CT were noted in these three groups. RESULTS: The diameter of the tumor in each group was 4.10 +/- 1.75, 3.90 +/- 1.20, 5.20 +/- 3.66 (cm, mean +/- s, P > 0.05). The proximity to the mediastinum and/or the hilum and the invasion of their lymph nodes was 2.68 +/- 1.60, 4.02 +/- 1.56, 4.85 +/- 3.28 (cm, mean +/- s, P < 0.01, P < 0.05). The characteristic change in the thoractomy group is deformity in the lymph nodes in the mediastinum and hilum. CONCLUSION: There is no obvious relation between the diameter of the lumg tumor and surgical resection, but the proximity to the mediastinum and/or the hilum and the invasion of their lymph nodes is an important factor. It is possible to perform a radical resection when its contact is less than 2.68 +/- 1.60 cm. Obvious deformity of the mediastinal structures and the hilum is a contraindication for lung cancer surgery.
Adenocarcinoma↗
[Prediction and binding of a mutant p53 peptide to MHC class I molecule].
OBJECTIVE: To predict tumor antigenic peptides from the intact amino acid sequence of tumor antigens, thereby providing a guide to the design and development of tumor peptide-based vaccines. METHODS: Antigenic peptides were predicted by using a computer program PEPMOTIF based on MHC class I allele-specific consensus motifs; and a scoring system was established to assess the likelihood of the peptides to bind to MHC class I molecules. MHC class I-peptide binding assay and MHC class I-peptide stabilization assay were used to determine the binding ability and affinity of the predicted peptides. RESULTS: Three peptides derived from mouse mutant p53 were predicted. mp53P132F(LNKLFFQL) was shown to bind to H-2Kb, but not H-2Db. mp53P246S (MGGMNRSPIL) and mp53P270C (GRDSFEVCV) bound to neither H-2Kb nor H-2Db. A relationship was found between peptide scores and binding of the peptides to the relevant MHC class I molecules. CONCLUSION: The computer program PEPMOTIF combining with a scoring system is a simple and efficient tool for predicting MHC class I binding peptides derived from antigenic proteins.
Animals↗
Association of Helicobacter pylori infection with precancerous lesions and stomach cancer: a case-control study in Yangzhong County.
Previous study has raised H. pylori infection as a suspected biologic risk factor for gastric cancer. A comparative case-control study involving precancerous lesions and gastric cancer was conducted in Yanzhong county, an area with one of the highest rates of gastric cancer in China to study the relationship between the H. pylori infection and gastric cancer. Subjects in the study were all randomly selected participants of a screening program for gastric cancer sponsored by the Cancer Institute of CAMS in cooperation with Yangzhong county Hospital. Totally, 125 normal controls, 108 superficial gastritis, 111 atrophic gastritis and 110 gastric cancer patients were included in our study according to endoscopy and pathology result. Status of H. pylori infection was evaluated by measuring IgG antibody in plasma with ELISA assay. Our result showed Odds ratios of H. pylori infection were higher among gastritis and cancer groups, 4.5 (95% CI 2.5-7.9) for superficial gastritis, 6.3 (95% CI 3.4-12) for atrophic gastritis, 3.3 (95% CI 1.9-5.9) for gastric cancer. It was found in our study that consumption of pickled vegetables and drinking dirty water increased the relative risk of H. pylori infection for both precancerous lesions and gastric cancer and that H. pylori infection had higher risk of atrophic gastritis and gastric cancer for males and also higher risk of atrophic gastritis for olders. Our results strongly support the casual role played by H. pylori infection in the carcinogenic process of gastric mucosa.
Aged↗
[The effect of indirect trauma on the goat temporomandibular joint: a histopathologic study].
The aim of this experiment was to study the effect of indirect trauma on the goat temporomandibular joint (TMJ). Trauma to the TMJ was achieved through an impact to the right mandibular angles of 20 goats, their left TMJs were used as a controls. The animals were killed after 2 h, 1 month, 3 months and 6 months. Light microscopic observations revealed that the condyles exhibited an eburnated, eroded surface with osteophytes, the disks were thinned or perforated, and the temporal surfaces were thickened and the lining were separated. These changes were histologically similar to those of the advanced osteoarthritis. This study suggests that the indirect trauma on TMJ lead to osteoarthritis.
Animals↗
[Cloning and sequencing of cDNA of E2/NS1 gene of hepatitis C virus].
Hepatitis C virus (HCV) RNA extracted from serum of a patient infected with HCV in Beijing was converted to cDNA by reverse transcription. HCV E2/NS1 gene (approximately 930 bp) was amplified by nested polymerase chain reaction and was inserted into pGEM-T plasmid vector. The 431 bp nucleotide sequence at 5' terminus of this gene was determined by dideoxy-mediated chain termination method. The result of comparison of this sequence and sequences of another 9 HCV isolates suggested that the isolate we obtained was highly homologous to HCV genotype II. There are two hypervariable regions (HVR) at the N terminus of envelope protein encoded by HCV E2/NS1 gene. Several relatively conserved amino acid residues and areas located in and out of HVR were also observed. They are concerned in maintenance of spatial conformation of HCV envelope protein, but their immune function remains to be further studied.
Amino Acid Sequence↗
[The status and significance of mother-to-infant transmission of hepatitis C virus determined by nested polymerase chain reaction].
The antibodies to hepatitis C virus (HCV) and HCV RNA in sera from 11 mothers and their children born after 9-13 months were detected by several tests. It was shown that the positive rate of anti-HCV in infants was significantly lower by ELISA based on synthetic peptides (23.52%) than by second generation ELISA with recombinant antigens (2nd ELISA) (41.18%) (P<0.05). At birth, six babies were positive for anti-HCV in cord blood and venous blood by 2nd ELISA. Among them, serum anti-HCV disappeared in 5 cases after 1 to 5 months but was persistently detected in one cases. The anti-HCV positive sera from these six babies were tested by recombinant immunoblot assay (RIBA) and shown to be positive in 4 cases and indeterminate in 2 cases. By reverse-transcription polymerase chain reaction (RT-PCR), HCV RNA was found in 5 babies, three of them became negative 1-5 months after birth, two babies were positive with HCV RNA for 9 months and 13 months respectively. These findings suggested that the evaluation of the status of mother-to-infant transmission was limited by the low level of serum anti-HCV in infants, "passive transfer" of anti-HCV from mothers and different method of tests used. HCV RNA detection by RT-PCR is a more reliable marker to demonstrate the mother-to-infant transmission of HCV.
Enzyme-Linked Immunosorbent Assay↗
[Detection of human papillomavirus DNA sequence in esophageal carcinoma using polymerase chain reaction].
Human Papillomavirus (HPV) DNA sequence in 68 paraffin-embedded specimens of esophageal carcinoma collected from high-risk Shantou City was detected and typed by polymerase chain reaction (PCR) technique. The results showed a 66.18% (45/68) positive rate of HPV DNA. Among these esophageal carcinoma specimens, 44 out of the 45 positive specimens were squamous cell carcinoma and one was adenosquamous carcinoma. The HPV DNA types detected were mostly HPV-6, -11, and -16. HPV-6 DNA was found in 19 (27.94%) of the 68 specimens, HPV-11 DNA in 25 (36.76%) and HPV-16 in 19 (27.94%) specimens. Among these three types, the difference gave no statistical significance (P > 0.05). But HPV-18 DNA was detected in only 6 (8.82%) specimens and the HPV in other 6 specimens was unidentified. It should be noted that as many as 24 (53.33%) of the 45 positive cases had multi-infection (coinfection of 2 or 3 types). Our results suggested that a higher detectable rate of HPV DNA was found in Shantou City as a high-risk region and that HPVs might be closely associated with the pathogenesis of the esophageal carcinoma.
Adult↗
[Gas chromatographic analysis of fatty acids in phosphatidylglycerol from needles of two crosses of Chinese Fir].
This paper reports a method for determination of fatty acids in phosphatidylglycerol from needles of two crosses of Chinese Fir with different cold-resistance. Some simplifications and improvements for analytical method of DEAE CL-6B column chromatography and of silica thin layer chromatography were also discussed. After being extracted with chloroform and methanol, phosphatidylglycerol was isolated from the general lipid extract by using DEAE CL-6B IEC and Silica TLC. Quantitative analysis was conducted by gas chromatography on a DB-FFAP (30m x 0.32mm i.d.) column. The results showed that there was a difference in the ratio of fatty acid (18:1+18:2+18:3)/[16:0+16:1(3t)] between the two crosses of Chinese Fir with different cold-resistance, 1.12 for that with higher cold-resistance and 1.25 for that with lower cold-resistance. A special fatty acid 16:1(3t) was found in both of the two crosses.
Chromatography, Gas↗
[A survey on mother's nutritional knowledge-attitude on the feeding of young child in Guangdong province].
A survey on mother's nutrition knowledge-attitude on the feeding of young child was conducted in Guangdong province in 1995 among 414 mothers of 0 to 18 months old children. The results showed that the nutritional knowledge-attitude level of the mothers was low in both city and township. Only 51% of them had qualified level. The level of general nutritional concepts and the nutritional knowledge-attitude during weaning period were significantly lower than that of breastfeeding and follow-weaning. It suggests that the promotion of nutritional education in the feeding of young children is urgent in Guangdong province especially in township and rural area. It is necessary to focus on the improvement of nutritional knoweledge in weaning period and general nutrition concepts.
Breast Feeding↗