Biomedical subjects

W Li

Publications and source records attributed to W Li.

At least 631 records · Page 35Linked to original sources

PubMed1999

[The effect of defibrase in prevention of experimental atherosclerosis in rabbits].

OBJECTIVE: To study the anti-atherosclerosis effect of difibrase in rabbits. METHODS: Use of computer, light microscope, electron microscope, biochemistry and histochemical methods to identify the total cholesterol (TC) content, mean plaque area in aorta and its cholesterol content, degree of stenosis of coronary arteries of the experimental animals and control animals. RESULTS: Defibrase could decrease the mean plaque area of aorta and the TC content in the experimental animal group was less than that in the control group (P < 0.01). The findings in aortic arches and thoracic aorta were similar to those in the aorta (P < 0.05, P < 0.01). The number of plaques at the small artery openings in the thoracic aorta and abdominal aorta of the experimental group were less than that of the control group (P < 0.01). The cross sections made at the upper third of all hearts showed that the degree of stenosis of coronary artery branches in the heart wall of the experimental group was much less than that of the control group. CONCLUSION: Defibrase can significantly inhibit atherosclerosis.

Animals↗

PubMed1999

[Methodological study on the assay of glycosylphosphatidylinositol-specific phospholipase D activity in serum].

A method for the assay of glycosylphosphatidylinositol-specific phospholipase D(GPI-PLD) activity in human serum was established by using glycosylphosphatidylinositol(GPI) anchored placental alkaline phosphatase(PLAP) as a substrate. Serum GPI-PLD activity was determined both qualitatively and quantitatively by PEG/dextran and triton-X-114 partitioning respectively, and some kinetic properties of its enzymatic reaction were also studied. This method revealed a satisfactory reproductivity(CV = 3.6%) and a high sensitivity(2 microliters serum was sufficient). In addition, it is practical, economical, and feasible to be widely applied. The activities of GPI-PLD measured by this method in 100 normal subjects ranged from 30% to 50% (in terms of the percentage of converting GPI anchored PLAP substrate to the anchor-free product).

Adult↗

PubMed1999

[Effect of calcium and cristata L extracts on bone mineral density and urinary mineral of rats].

In order to study the effect of cristata L for preventing fluoride toxicity, forty male SD rats were randomly divided into five groups. The control group(NC) was fed with staple feed stuff and tap water, the other four groups were fed with staple feed-stuff and high fluorine water. Except the high fluorine group(F), the other groups were fed with cristata L(FC), high calcium(FCa) and cristata L with high calcium(FCCa) respectively. The results showed that the serum calcium, urinary sodium, calcium, hydroxyproline(HOP) and fluorine contents of high fluorine groups were higher than that of control group; and the urinary calcium content of high calcium group was higher than that of control group. The body weight, BMC and BMD of high fluorine groups was lower than that of control group. The weight of groups FC, FCa and FCCa were significantly higher than that of group F. The BMC and BMD of group FCCa were significantly higher than that of group F. This implies that the food high in fluorine can affect the bone mineral density and urinary minerals of rats, the food supplemented with calcium can reduce the effect of high fluorine, and the food supplemented with both calcium and cristata L is better.

Animals↗

PubMed1999

[Effects of cytokines and umbilical cord blood preserved at 4 degrees C on the growth of CFU-GM and HPP-CFC].

We studied the effects of different cytokine combinations and umbilical cord blood preserved at 4 degrees C for 4 days on the growth of CFU-GM and HPP-CFC. The results showed that the growth of umbilical cord blood CFU-GM was markedly different when various combinations of cytokines were used. After 2 weeks culturing with IL-3 alone or plus GM-CSF, the number of umbilical cord blood CFU-GM was increased when compared with GM-CSF group; upon stimulation with GM-CSF plus IL-3 plus IL-6 plus Epo, a significant increase of umbilical cord blood CFU-GM was seen. After umbilical cord blood being preserved 4 days at 4 degrees C, the number of umbilical cord blood CFU-GM and HPP-CFC was decreased.

Blood Preservation↗

PubMed1999

[An experimental study on the biological basis of cortex-to-cortex bone healing after oblique ramus osteotomy].

This study was designed to elucidate biological basis of cortex-to-cortex bone healing after oblique ramus osteotomy. 12 rhesus monkeys were subjected to oblique ramus osteotomy bilaterally, and the operated sites were examined by microvascular irrigation section and histology techniques. The results showed that, besides the blood supply from the attachment of lateral pterygoid muscles and capsule of temporomandibular joint to the medial segments, the blood supply from the attachment of medial pterygoid muscles also played an important role. Cortex-to-cortex bone healing was achieved by the formation of a large volume of scab surrounding the operated sites. It is concluded that oblique ramus osteotomy has its good biological basis both in blood supply and cortex-to-cortex bone healing process.

Animals↗

PubMed1999

[Studies on stimulating components of raw Pinellia ternata (Thunb.) (banxia)].

OBJECTIVE: To study the stimulating components of raw Pinellia ternata (Banxia). METHODS: Used the methods of extracting with various organic solvents; x-ray fluorescence spectrometer; scanning electron microanalyzer; oxidation and reduction titrations; and ultraviolet spectrophotometry. RESULTS: Experiments showed that calcium oxalate hydrate (C2CaO4 x H2O) was one of the stimulating components of raw Pinellia ternata, and its shape, and contents related to the stimulation of raw Pinellia ternata. After processing, the shape and contents of calcium oxalate changed, decreased respectively, and the stimulation of Pinellia ternata decreased. CONCLUSION: The needle crystal of calcium oxalate is one of the stimulating components in raw Pinellia ternata.

Animals↗

PubMed1999

[Sonographic measurement of uterine cervix in pregnancy].

The objective of this study was to evaluate the accuracy of the measurement of the cervix by comparing transvaginal sonography (TVS) with transabdominal sonography (TAS) and to assess TVS measurement of the cervix in pregnancy. The cervix was measured in the first, second, third trimesters and at term by TVS in 131 normal singleton pregnancies and by TAS in normal pregnant women. The results showed that TVS was better in providing successful rate and accurate identification of uterine cervical length, compared with TAS. The cervical lengths in the first, second, third trimesters and at term were 30.22 mm, 32.25 mm, 30.04 mm and 25.86 mm respectively. The results suggest that TVS be superior to TAS in cervical measurement and that in normal pregnancy, the cervical length does not change significantly until the time when cervical length shortening begins at term.

Adult↗

PubMed1999

[Changes of placental nitric oxide synthase in patients with pregnancy induced hypertension].

The objective of this study was to determine whether the expression of placental endothelial nitric oxide synthase (eNOS) and/or inducible nitric oxide synthase (iNOS) are changed in pregnancy induced hypertension (PIH). The placentas of 32 patients with PIH and 32 normal pregnancies were studied by immunohistochemistry (Avidin-Biotin-Complex method). The results showed there were eNOS and iNOS antigens in placental tissues from PIH and normal pregnancy. They were all localized in placental villi and syncytiotrophoblast cells. The expression of placenta eNOS decreased significantly in patients with PIH as compared with that of normal pregnancy. The expression of placenta eNOS in mild PIH was higher than that of moderate or severe PIH (P < 0.025, P < 0.005, respectively). There was a negative correlation between blood pressure and the expression of eNOS in placenta (P < 0.0005). There was no significant difference between the expression of iNOS in placenta with PIH and that in normal pregnancy. Also, there was no significant difference of the expression of iNOS in placenta between the mild and moderate PIH, or the mild and severe PIH. Furthermore, there was no correlation between blood pressure and the expression of iNOS in placenta with PIH. It is concluded that the decrease of the expression of eNOS in placenta may be associated with the pathogenesis of PIH.

Adult↗

PubMed1999

[Study on the mechanism of glutamate mediated neurotoxicity by cortical neuron culture technique in vitro].

This study was intended to further explain the mechanism of glutamate (Glu) mediated neurotoxicity. The concentrations of TCa and Ca2+ i were measured in 32 cortical neuron cultures, which were divided into four groups: normal control group (n = 8); 0.5 mmol/L Glu group (Glu group n = 8); 0.5 mmol/L Glu + 100 mmol/L Nimodipine group (antagonist I, n = 8); 0.5 mmol/L Glu + 12 mumol/L MK-801 group (antagonist II, n = 8). The results showed that TCa and Ca2+ i concentrations in Glu group were significantly higher than those in normal control group (P < 0.05); TCa and Ca2+i in both antagonist I and II groups were evidently lower than those in Glu group (P < 0.05); No difference was found between antagonist I and II groups. The results suggest that Glu neurotoxicity is due to the intracellular calcium overload, which may be from the pathway of voltage-dependent calcium channels (VDCCs) and NMDA receptor-operated channels (NROCs).

Animals↗

PubMed1999

[Effect of bushenjiannao 1 decoction on learning and memory functions and anti-fatigue ability in mice].

OBJECTIVE: To observe the anti-dementia effect of Bushenjiannao 1 decoction on mice. METHOD: The learning and memory tests were realized with a water maze on the learning and memory impact of mice induced by scopolamine and cycloheximide. The effect of Bushenjiannao 1 decoction on the independent activity and anti-fatigue ability of mice were also investigated. RESULT: Bushenjiannao 1 decoction used at a medium dose of 15 g crude drug/kg and a higher dose of 45 g crude drug/kg could significantly improve the learning and memory abilities of mice injected with scopolamine. Higher doses could improve these abilities of mice injected with cycloheximide, and also improve the anti-fatigue ability of mice. No significant differences were observed in the independent activity of mice between the groups. CONCLUSION: Bushenjiannao 1 decoction helps improve the learning and memory abilities and enhance the anti-fatigue ability, but has no effect on excitability of the central nervous system.

Animals↗

PubMed1999

[Studies on individual characters of juvenile delinquents in Fujian province].

Ashenk's Character Questionnaire was adopted to study the relationship between juvenile delinquency and individual characters. 621 delinquents at the age of 13-19 and 1371 school students (as control group) were questioned, and results were statistically analyzed. For male delinquents of 16-19, scores of extroversion, psychosomatic and nervosity were significantly higher than for control group (P < 0.01). For male delinquents of 13-15, scores of psychosomatic and nervosity were significantly higher than for control group (P < 0.01). For female delinquents of 16-19, score of nervosity was lower than for control group (P < 0.05). Different types of delinquency had no statistical relations with characters. The study reveals that characters of psychosomatic and nervosity might be related with male delinquent crimes, and that stabilization with female delinquent crimes.

Adolescent↗

PubMed1999

[Clinical therapeutic effects observation of iodophors on irrigation and disinfection of root canal].

OBJECTIVE: To evaluate clinical effects of iodophors on root canal therapy. METHODS: 147 teeth with root canal therapy collected from clinical patients were divided into two groups: experimental and control group. In experimental group, 0.05% and 0.5% iodophors were taken as irrigate agent and disinfectant, respectively, while in control group, 3% H2O2 + 0.9% NS and Fc were used. RESULTS: Clinical therapeutic effects evaluation indicated that there was no statistically significant difference of alteration of clinical syndromes after the administration and the therapeutic effect between experimental group and control group during the period of root canal therapy. CONCLUSION: Iodophors could be taken as a kind of candidate drugs on irrigation and disinfection of root canal therapy.

Adolescent↗

PubMed1999

[A study on the biological properties of fimbriae of Actinomyces viscosus. I. The preparation and determination of fimbriae of A. viscosus].

OBJECTIVE: To build up the methods to prepare and determine the fimbriae of A. viscosus. METHODS: Type 1 and 2 fimbriae were prepared from A. viscosus 5519 and 5951 respectively. Fimbriae were isolated from bacteria cells by mechanical shaking, obtained by collecting the supernatant after centrifugation, and purified by ammonium sulfate precipitations and gel filtration. RESULTS: Electron microscope showed that fimbriae existed in the preparations. The immunological reaction between the fimbriae preparations and specific antibodies against fimbriae attested that they were type 1 or type 2 fimbriae. CONCLUSION: The present study become a foundation for further study on the biological properties of fimbriae of A. viscosus.

Actinomyces viscosus↗

PubMed1999

[A study on biological properties of fimbriae of Actinomyces viscosus. II. Chemical characteristics of fimbriae of A. viscosus].

OBJECTIVE: To investigate the chemical characteristics of two purified fimbriae. METHODS: The specific antibodies against type I and type II fimbriae of A. viscosus were prepared and the purity of the two purified fimbriae had been identified by the specific antibodies. Then, chemical analysis and amino acid analysis of the two purified fimbriae were done. RESULTS: The two purified fimbriae were mainly composed of proteins and small amount of carbohydrate. The two types of fimbriae contained large amounts of aspartic acid, glutamic acid, alanine, lysine and glycine, and high percentage of nonpolar amino acid was analysed while basic amino acids were present in a very small amounts. CONCLUSION: These results may help to understand the relationship between the chemical characteristics of two types of fimbriae and their biological activity.

Actinomyces viscosus↗

PubMed1999

[A study on biological properties of fimbriae of A. viscosus. III. Adherence activity of fimbriae of A. viscosus].

OBJECTIVE: To investigate the adherence activity of two types of fimbriae of A. viscosus on tooth surface or with S. sanguis 34. METHODS: The inhibited adherence tests, coaggregation tests and the inhibited coaggregation tests were done. RESULTS: 1. The purified type I and type II fimbriae inhibited the adherence of A. viscosus to salivary-treated hydroxyapatite (SHA) and the two specific IgG to type I and type II fimbriae blocked the adsorption of strain T14V, strain 5519 and strain 5951 to SHA; 2. Only type II fimbria indirectly mediated the visible agglutination of S. sanguis 34 and only IgG to type II fimbriae inhibited coaggregation of strain T14V and strain 5915 with S. sanguis 34. CONCLUSION: Type I and type II fimbriae have adherence ability, and only type II fimbria has the agglutination activity. Additionally, the methods which were used to prepare fimbriae don't damage the biological activity of fimbriae.

Actinomyces viscosus↗

PubMed1999

[Study of cytotoxicity of bioprosthetic heart valve material and its store solution].

This study compared the cytotoxicities of bioprosthetic heart valve materials crosslinked by glutaraldehyde, stored in 4% formaldehyde or Hank's solution. Human embryonic pulmonary fibroblasts or L-929 cell culture in vitro were used. Cell proliferative inhibition index(CP II) was calculated for bioprosthetic heart valve materials using different store methods in different rinse periods(before, 10 days, 20 days, 30 days). The results demonstrate: (1) bioprosthetic heart valve materials stored in 4% formaldehyde or in Hank's solution both have significant cytotoxicity, and the longer the rinse time continues, the lower the cytotoxicity declines; (2) HEL cell is more sensitive than L-929 cell in detecting the cytotoxicity of toxic biomaterials but for weak toxic biomaterials the two cell lines are not significanth different; (3) formatldehyde solution increases the cytotoxicity of biomaterials stored in it, but the enhanced cytotoxicity can be easily relieved by rinse. The authors conclude that bioprosthetic heart valve materials have long term significant cytotoxicity and the biomaterial cytotoxicity test using human fibroblasts is more sensitive and precise than other tests.

Animals↗

PubMed1999

[Analysis of products of thymine irradiated by heavy ion beam with capillary gas chromatography].

In this study some chromatographic methods with capillary column, such as GC, GC-MS, GC-FTIR, were used to analyze the products of thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution. Because of the complexity and small amounts of the products after irradiation by heavy ion beams, it is very difficult to separate them, while with the methods of capillary gas chromatography this problem can be overcome. From the results of GC-MS analysis we can determine the molecular weight of the product, and from the results of GC-FTIR analysis we can get structure information of the product. By this way the products such as 5,6-dihydrothymine, 5-hydroxyl-5-methylhydantoin, 5-hydroxyl-6-hydrothymine, 5-hydro-6-hydroxylthymine, 5-hydroxymethyluracil, trans-thymine glycol, cis-thymine glycol and dimers were determined. Though these products are the same as those from thymine irradiated by gamma ray in N2O saturated aqueous solution, the mechanism of heavy ion beam interact ion with thymine aqueous solution is different from that of gamma ray. The main products from thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution are formed by hydroxyl additions between 5-6 band of thymine, while those by gamma ray are dimers of thymine.

Electrophoresis, Capillary↗

PubMed1999

[Conjugational actinomycetes of plasmid RSF101 from Escherichia coli to the rare actinomyceces of Nocardia asteriodes and Streptoverticillum caespitosus].

RSF1010 is a naturally occurring Escherichia coli broad host-range plasmid about 8.7 kb in size. It can be mobilized at high frequency between different gram-negative bacterial species when transfer functions are available in trans. Following the pioneering work of conjugational transfer of RSF1010 from E. coli to Streptomyces lividans and Mycobacterium smegmatis, the transfer of this plasmid by conjugation from E. coli S17.1 tp two gram-positive rare actinomycetes, Nocardia asteroides 3927 and Streptoverticillum caespitosus ATCC27422 was first time reported in this study. Southern blot analysis of the total DNA extracted from the actinomycetes' exconjugants proved that RSF1010 had been transferred from E. coli into the two new hosts and maintained staby in the exconjugants. Meanwhile, partial deletions of RSF1010 replicon loosing its antibiotics resistance makers were readily detected in E. coli. The implenmentation of this observation was discussed.

Actinomyces↗