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Biomedical subjects

P Li

Publications and source records attributed to P Li.

At least 199 records · Page 11Linked to original sources
PubMed2000

[Induction of protective immune responses in rhesus monkey by immunization with recombinant plasmids of polyvalent epitopes of Plasmodium falciparum using cholera toxin B as adjuvant].

The immunogenicity and protective efficacy of the DNA vaccine which include cholera toxin B subunit (CTB) and polyvalent protective epitopes of Plasmodium falciparum (awte gene) was assessed using rhesus monkeys as animal models. Recombinant plasmids of pCMV-CTB-AWTE were given to five rhesus monkeys three times with two weeks intervals by intramuscle (i.m.) route, immunization dose was 500 micrograms per plasmid per animal. High levels of anti-CTB and anti-malaria epitopes antibodies and P. falciparum epitope specific CTL activity were elicited. The vaccinated groups was challenged with 1.25 x 10(8) of P. cynomolgi parasites. All monkeys of the control group was patent for at least 34 days, the DNA vaccinated groups wasn't infected during the 60 days we detected. The cocktail DNA vaccine which contains multi-stage and multi-epitope antigen gene shows excellent immunogenicity and protective efficacy, the results also suggests that DNA vaccine plays an important role against malaria infection.

Animals↗
PubMed2000

Technology evaluation: HIV ribozyme gene therapy, Gene Shears Pty Ltd.

Ribozymes (catalytic RNAs) can be made to specifically cleave target RNAs that are involved in disease conditions and therefore have potential as therapeutic agents. Gene Shears Pty Ltd is developing hammerhead ribozyme technology for therapy against HIV infection, targeting either the tat gene or the RNA packaging sequence (Psi) of HIV. These ribozymes have been expressed from constructs that were introduced into hematopoietic cells in culture, thereby protecting the cells against viral infection. Two phase I clinical trials are underway to test the safety and feasibility of the approach with the anti-tat ribozyme in human subjects.

Biotechnology↗
PubMed2000

[Distribution patterns of root systems of main planting tree species in Weibei Loess Plateau].

The vertical patterns of root systems of Pinus tabulaeformis, Robinia pseudoacacia, Platycladus orientalis, Pinus sylvestris var. mongolica, Pinus armandi, Prunus armeniacia var. ansu planted in the Weibei Loess Plateau were studied with soil auger. Site conditions had a significant effect on the vertical root distribution of R. pseudoacacia, of which, soil moisture is the key factor. Soil species and soil structure also had great effect on the distribution. P. tabulaeformis had a maximum rooting depth at its young stage(8 years old), but the root density increased with age. There was a great difference in vertical root distribution among the tree species, of them, R. pseudoaccia rooted deepest, which negated the opinion that R. pseudoacacia is a shallow rooted tree species. According to the vertical root distribution of the tree species, the productivity of these species in the south-facing site of yellow loess soil would be in order of R. pseudoacacia > Prunus armeniacia var. ansu > P. tabulaeformis > P. sylvestris var. mongolica > P. armandi > Platycladus orientalis.

China↗
PubMed2000

[Comparison of physiological characteristics of different ecotype plants].

Studies on the responses of photosynthesis, leaf water content and stoma resistance of 4 different ecotype plants to water stresses showed that their mechanism of drought-resistance was different. Mesic plants limited water loss from transpiration by increasing their stoma resistance, while xeric plants decreased water loss by keeping the high concentration of cell protoplasm. The latter had a higher efficiency of keeping water than the former. The leaf water content and stoma resistance was decreased from mesic to xeric plants, while the net photosynthetic rate per unit leaf was increased, indicating the difference of physiological characteristics among different ecotype plants.

Photosynthesis↗
PubMed2000

[Preliminary study on purification function of reed wetland for nutrients from land sources].

The preliminary study on purification function of reed wetland for nutrients from land sources were conducted by irrigation channels and lysimeters. The results show that the purification rates for N, P and CODcr are from 41.7%-64.71% in the channels and 60.0%-75.92% in the lysimeters. The contents of N and P reached the national second level standards of sea water after filtration by lysimeters. By harvest, the good recycle between wetland and land is formed without accumulation.

Ecology↗
PubMed2000

[Effect of plumular axis-cutted cotton on growth and development of cotton bollworm].

The method of plumular axis cutting was used to induce the resistance of cotton plants to cotton bollworms(Heliothis armigera). The bollworm was cultured in the laboratory, and the effect of induced cotton on the duration of larval development and weights of larvae and pupae was studied. In the treatments of infection and control, the lengths of larval period were delayed by 3 days and 0.5 days, the weights of larvae were decreased by 19.60% and 11.45%, and the pupae weights were decreased by 10.81% and 6.54%, respectively. After the 8 days old larvae were reared with induced cotton leaves for 3 days, the infected and uninfected cutted plants resulted in a decrease of the relative growth rates of larvae by 22.9% and 17.2% respectively, and in a decrease of the relative feeding rates by 26.1% and 21.4% respectively. It is suggested that plumular axis cutting could induce the resistance of cotton plants to bollworm, and influence the growth and development speed of bollworms through retarding their feeding and digestion. Combining with the treatment of Pseudomona gladioli D-2251 strain could obviously increase the insect-resistance of cotton plants.

Animals↗
PubMed2000

Preclinical trials of human erythrocyte superoxide dismutase injection.

OBJECTIVE: To assess the quality of human erythrocyte superoxide dismutase (SOD) injection reaching the official standard for its clinical uses. METHODS: Human erythrocyte SOD injection prepared by McCord-Fridovich's method without column chromatography but with some modifications was used in preclinical trials, to observe the general pharmacology and pharmacodynamics of the product. RESULTS: The quality of human erythrocyte SOD injection conformed to the official standard of a biological product, which was found to be non-toxic and did not have any effects on the central and autonomic nervous systems as well as cardiovascular and respiratory systems. The efficacy of anti-inflammation and promotion of immuno-regulation especially on carrageenan and adjuvant-induced polyarthritis were shown in animals. CONCLUSION: Human erythrocyte SOD injection is appropriate for prophylactic and therapeutic uses in clinical trials.

Animals↗
PubMed2000

[A clinical evaluation of two new materials for restoration of dental wedge-shaped defects].

OBJECTIVE: To evaluate clinically two new materials (Dyract Cem and 3M-Vitremer) for restoration of dental wedge-shaped defects with modified USPHS evaluation criterion. METHODS: 317 teeth with wedge-shaped defects were restored by Dyract Cem and 192 teeth by 3M-Vitremer clinically. The 1 year and 2 year follow-up results were evaluated with modified USPHS evaluation criterion. RESULTS: 1 year successful rate was 91.17% in Dyract Cem group and 81.77% in 3M-Vitremer group, and 2 years successful rates were 88.64% and 80.21% separately. The differences of successful rates between the two groups are significant statistically, but there are no significant differences in main indexes except stain rate when analysed item by item with USPHS evaluation criterion. Successful rates were related with the abrasive degree of the restored teeth. CONCLUSIONS: Both Dyract Cem and 3M-Vitremer have high successful rates and a lot of advantages for restoration of dental wedge-shaped defects. The modified USPHS evaluation criterion is a valuable method for clinical evaluation.

Adult↗
PubMed2000

[Cataract extraction with rotated-chipping phacoemulsification in the capsule].

OBJECTIVE: To observe the clinical effects of rotated-chipping phacoemulsification in the capsule. METHODS: The operation of continuous circular capsulectomy, nuclear hydrodissection, cataract extraction with rotated-chipping phacoemulsification in capsule and intraocular lens implantation was performed on 215 eyes. RESULTS: Rotated-chipping technique was successfully completed in 215 eyes. In the operation 2 to 4 circles were rotated with the ultrasonic energy 19.3% for 12 seconds on average. The rate of corneal endothelium loss was 7.5%. CONCLUSION: The technique of rotated-chipping phacoemulsification in capsule is safe and rapid which can be used for cataracts with nuclei of various degrees in sclerosis.

Aged↗
PubMed2000

[Community -based comprehensive prevention and control of hypertension in China (CCPACH Study)-prevalence and epidemiological characteristics in urban and rural area].

OBJECTIVE: To understand the epidemiological features and prevalence of essential hypertension in the rural communities. METHODS: A community-based survey on essential hypertension was carried out in urban and rural areas involving 280,000 population. RESULTS: The prevalence rate of hypertension in age 35 years and over was 31.7% and 32.9% in urban and rural respectively; the average age of the patients' in urbans was significantly higher than in rural areas. Among non-hypertensive cases, more than 50% of the population having risk factors of hypertension in both urban and rural areas. Rates of treatment and control awareness of hypertension were 56.3%, 26.8% and 4.4% respectively in urban; comparing to 40.3%, 17.5% and 2.6% respectively, in the rural areas. More than half of the diagnosed patients before survey did not take antihypertensive medicine for treatment in both areas. The proportions the classification of hypertension were similar in both areas with majority of them, mild and isolated systolic hypertension. CONCLUSIONS: It was demonstrated that there is an urgent need to carry out comprehensive prevention and control for hypertension in urban and rural area.

Adult↗
PubMed2000

[Evaluation on the effects of community-based comprehensive prevention and control of hypertension in the rural areas in China].

OBJECTIVE: To explore the strategies and measures of community-based comprehensive prevention and control of hypertension in the rural areas. METHODS: Community-based comprehensive prevention and control of hypertension was put in practice in 120,000 people in Fangshan District of Beijing during the period of "The Ninth Five-Year Plan (1996 - 2000)". RESULTS: After intervention, blood pressure of the whole subjects were under control and kept the level of baseline data; the rate of increase of prevalence in the intervention areas was below the rate of that from 1979 to 1991 in China (the former was 14.7%, while the latter was 53.7%); the incidence rate of the subjects was 1.4%, close to the average rate of age 15 and above in China; the rates of awareness, treatment and control were above the levels of baseline data; SBP and DBP of the patients decreased by 2.9% and 5.6%, respectively; while the rate of having high risk factors reduced by 13.4% on average. CONCLUSION: The community-based comprehensive strategies and measures played an important and effective role in prevention and control of hypertension in rural areas.

Adult↗
PubMed2000

[Evaluation on the effect of Benazepril for hypertension through postmarketing surveillance].

OBJECTIVE: To evaluate the efficacy and safety of Benazepril used among the essential hypertensives. METHODS: 1 831 essential hypertensive patients aged 35 to 75 were randomly selected from a community and followed for 18 months. The level of blood pressure, status of taking Benazepril and side effects were sequencially collected. RESULTS: 1/3 of the patients had taken antihypertensive drug before the study and the rate of compliance was over 96%. The effective rate of Benazepril was 73.6% at three months and increased to 84.7% at 18 months. Comparing with the baseline data, SBP and DBP declined 10.8 mmHg and 6.7 mmHg respectively. The rate of side effect was 22.7%. Cough was most commonly seen among side effects. The peak of first recording on side effect occurred at three months including 60% of them mild. CONCLUSION: Results showed that Benazepril had good efficacy and safety for the essential hypertension patients in a long-term observation.

Adult↗
PubMed2000

[Acute myeloid leukemia M2and t (8; 19) (q22; q13)].

OBJECTIVE: Report for the first time of two cases of acute myeloid leukemia (AML) M(2) with t (8; 19) (q22; q13). METHODS: Chromosome specimens were prepared by short-term culture of bone marrow cells and karyotype analyses were carried out using R-and G-banding techniques. Immunophenotyping of the blast cells was analyzed by flow cytometry with a panel of monoclonal antibodies. AML1/ETO fusion gene was tested by "nested" reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Karyotype analyses showed 46, XX, t (8; 19) (q22; q13) [28]/46, XX [2] in case 1 and t (8; 19) (q22; q13), del (9) (q12q22) [23]/46, XY [2] in case 2. In case 2, the blast cells expressed CD(13) (38.8%), CD(33) (31.8%), CD(34) (80.9%), and CD(19) (63.9%) and RT-PCR assay revealed no AML1/ETO fusion gene transcript. CONCLUSION: t (8; 19) (q22; q13) is a variant form of t (8; 21) (q22; q22). Its molecular entity remains to be elucidate.

Adolescent↗
PubMed2000

[Preliminary studies on chemotaxonomy of Caprifoliaceae L].

OBJECTIVE: To study the taxonomy of Caprifoliaceae. METHOD: Using chemotaxonomical methods to discuss the distribution characteristics of chemical constituents in Caprifoliaceae family. RESULTS: Iridoids and flavonoids were confirmed as the characteristic constituents of Caprifoliaceae family. CONCLUSION: Though there are great deviations among the genera of Caprifoliaceae family, it is not recommended to separate genus Sambucus and genus Viburnum from Caprifoliaceae family.

Caprifoliaceae↗
PubMed2000

[In vitro studies about the effects of implant materials on calmodulin, introcellular calcium of rat osteoblasts].

OBJECTIVE: 1. To evaluate the effects of the four implant materials, hydroxyl poly calcium sodium phosphate (HPA), hydroxyapatite (HA), bioglass ceramics (BGC) and titanium (Ti) on the calmodulin (CaM) content of osteoblasts, the concentration of intracellular free calcium and the ATPases activity of cell membrane of rat osteoblasts cultured in vitro; 2. To reveal the biological compatibility of the four implant materials and the index to estimate the biological compatibility condition. METHODS: The powders of HPA, HA, BGC and Ti were sterilized and made into extracted solutions with 199 culture medium. The isolated osteoblasts, which were taken from three-day-old sparague Dawley rats' calvaria, were incubated in 199 culture medium also. Then the osteoblasts were mixed and incubated into the four kinds of extracted solutions of the implant materials. After three days of co-incubation, the cells were taken out, and the cellular calmodulin content were measured with radiobiological analysis. The concentration of intracellular free calcium were under fluorescent analysis, and the ATPases activities of cell membrane were estimated with colorimetric analysis. RESULTS: 1. Calmodulin content of the osteoblasts co-incubated with all the implant materials decreased, and moreover, only that of the Ti group decreased more obviously than that of the Ti and HPA group (P < 0.05). 2. The concentration of intracellular free calcium of all the co-incubated osteoblasts were as normal as that of the control group. 3. Ca(2+)-ATPases activities of osteoblasts co-incubated with HPA, HA, BGC increased (P < 0.05), and Na+/K(+)-ATPases activities of the cells co-incubated with HPA, HA were strenghtened (P < 0.05). CONCLUSION: The indexes of cellular calmodulin content, concentration of intracellular free calcium and ATPases activity of cell membrane can reflect the biological compatibility of implant materials, and they may be used as indexes of estimating biological compatibility condition.

Animals↗
PubMed2000

[In vitro studies about the effects of implanted materials on osteocalcin and alkaline phosphatase of rat osteoblasts].

OBJECTIVE: To evaluate the effects of the four implant materials, hydroxyl poly calcium sodium phosphate (HPA), hydroxyapatite (HA), bioglass ceramics (BGC) and titanium (Ti) on osteocalcin secreting amount and alkaline phosphatase activity of rat osteoblasts cultured in vitro, and expose the biological compatibility conditions of the implant materials as well as the index to estimate cytocompatibility. METHODS: The powders of HPA, HA, BGC and Ti were sterilized and made into extracted solutions with 199 culture medium, and the isolated osteoblasts which were taken from three-day-old Sprague-Dawley rats' calvaria, were incubated in 199 culture medium too. Then the osteoblasts were mixed and incubated into the four kinds of extracted solutions of the implant materials. After eight days of co-incubation, the cells were taken out to measure alkaline phosphatase activity with velocity analysis, and the extracellular liquid was used to estimate osteocalcin secreting amount with radioisotope analysis. RESULTS: 1. Osteocalcin secreting amount of the osteoblasts co-incubated with HPA, HA, BGC were as normal as the control, while that of other cells co-incubated with titanium was reduced (P < 0.05). 2. Alkaline phosphatase activities of all the co-incubated osteoblasts were as normal as the control. CONCLUSION: The osteocalcin secreting amount and alkaline phosphatase activity can reflect the biological compatibility of implant materials, and they may be used as indexes to evaluate biological compatibility condition of implant materials.

Alkaline Phosphatase↗
PubMed2000

[Isolation, purification and bioactivities of exopoly saccharides from fermented broth of Ganoderma lucidum].

The exopolysaccharides of Ganoderma lucidum(GLEP) extracted from the fermentation broth after removing protein by Sevage and protease digestion procedures, were applied to a column of DEAE-cellulose(OH- form), and eluted stepwise with distilled water, sodium hydrogen carbonate (0.1 mol/L, 0.3 mol/L, 0.5 mol/L successively) and 0.1 mol/L sodium hydroxide. Five fractions were obtained, and the main fraction was known as GLEP-I, furthermore subjected to chromatography on a column of SepharoseC1-6B, eluted at a flow rate of 30 mL/(cm2.h), the relative viscosity of sample solution of 1.5. Two fractions, GLEP-IFr1 and GLEP-IFr2 with a ratio of 3.8:1, were obtained. Molecular weight of GLEP-IFr1 and GLEP-IFr2 was estimated to be 38,000 and 22,000 Dalton respectively by Membrane Osmometer. The animal test showed that GLEP-IFr1 could inhibited the growth of Sarcoma 180 tumor in mice. The average inhibition ratio was 57.4% (i.p. 10 mg/kg for 10 days). The result of immunological activity showed that GLEP-IFr1 could significantly improve macrophage cytophagy.

Animals↗