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Biomedical subjects

F Li

Publications and source records attributed to F Li.

At least 415 records · Page 23Linked to original sources
PubMed1997

[Effects of hypoxia on the release of PDGF-B chain from pulmonary artery endothelial cells and on growth of pulmonary artery smooth muscle cells].

Platelet-derived growth factor (PDGF), content in hypoxic endothelial cells conditioned medium (HECCM) and normoxic endothelial cells conditioned medium (NECM) was determined using protein dot blot assay. The effects of HECCM and NECCM on the growth of pulmonary artery smooth muscle cells (PASMC) were assessed with [3H]-thymidine incorporation technique and flow cytometric analysis. PDGF content in HECCM was higher than that in NECCM. HECCM dramatically enhanced the DNA synthesis in PASMC and significantly promoted the cell cycle progression of PASMC from G0/G1 phase to S phase. In addition, administration of anti-PDGF-B chain monoclonal antibodies blocked markedly the DNA synthesis of PASMC stimulated by HECCM and obviously inhibited the entry of the cells from G0/G1 phase to S phase. These results suggest that increased PDGF release from pulmonary artery endothelial cells under hypoxia could stimulate the proliferation of PASMC which may induce pulmonary vascular reconstruction and involve in the development of hypoxic pulmonary hypertension.

Animals↗
PubMed1997

[The adaptive changes in vascular endothelial cell and resistance to frostbite in cold acclimated rats].

Several functions of vascular endothelial cells (VEC) were investigated in rats acclimated to cold (CA) and with frostbitten feet. The results indicated that in CA rats, the number of endothelial cells in circulatory blood and the contents of 6-keto -PGF1 alpha and TXB2 in plasma were markedly higher, the activity of serum angiotensin I converting enzyme (ACE) was lower, compared with those in rats non-acclimated to cold (NCA), whereas T/P ratio of the two groups was close to each other. After the rats were frostbitten, those parameters in NCA group increased sharply except for a decrease in ACE activity. But in CA group, those parameters decreased temporarily or did not change obviously and the tissue survival area (TSA) significantly increased. The above findings suggest that the adaptive changes in increase of metabolic turnover rate and function of VEC after cold acclimation may be beneficial to the body to enhance the resistance to frostbite and repairing ability.

6-Ketoprostaglandin F1 alpha↗
PubMed1997

[Study on the contents and the activities of antithrombin III in plasma of rats after frostbite].

The changes of the contents and activities of antithrombin III (AT-III) in plasma of rats following frostbite of both hind feet were investigated by means of rocket immunoelectrophoresis and single immunodiffusion. The results showed that the contents and the activities of AT-III were decreased in plasma of rats after frostbite and these changes were closely related to the degrees of cold injury. It is suggested that as a result of depressed anticoagulability, the blood coagulability could be increased after freezing, leading to the dysfunction of circulation and necrosis of local frostbitten tissue ultimately.

Animals↗
PubMed1997

[Effect of frostbite under hypoxia on microcirculatory perfusion in rats].

Changes of microcirculatory perfusion in rats following cold injury of right hind leg under hypoxia were investigated. Male Wistar rats weighing 200 +/- 20 g were randomly divided into three groups: frostbite at normoxia (FN) group; frostbite during acute hypoxia (4 h at 6000 m simulated altitude, FAH) group and frostbite during hypoxia after acclimation (exposure to hypoxia at 6000 m, 4 h daily for 4 weeks, FHAC) group. The results showed that the microcirculatory perfusion of both hind legs decreased markedly in FN after cold injury. It suggests that the frostbite damage can affect microcirculatory perfusion of another leg besides the region of frostbite. The fall of microcirculatory perfusion before freezing in FAH group indicated that there was a compensatory blood redistribution during acute hypoxia. The changes of microcirculatory perfusion in FAH group post-freezing indicated that acute hypoxia can aggravate the frostbite damage. The microcirculatory perfusion of FHAC group pre-freezing was significantly lower than that of FN and FAH group, and after freezing the perfusion of frostbitten leg in FHAC group was significantly lower than that in FN group, suggesting that hypoxia acclimation may cause disturbance of microcirculation and worsen the frostbite damage at high altitude.

Acclimatization↗
PubMed1997

[Biomechanical observation on unstable intertrochanteric fracture fixed by 130 degrees angled-plate].

We examined the stability of unstable intertrochanteric fracture fixed by 130 degrees angled-plate biomechanically, and the stress distribution of the plate. The results showed that after 300 times circle-loading test, the fracture stability was destroied. Stress concentration was observed on the plate, which was aggravated by circle-loading test. These confirmed the inproper biomechanical stature of the plate. Referring to the clinical review, we conclude that using angled-plate to fix unstable intertrochanteric fracture hardly yields satisfactory results, at least, early wight-bearing exercise should not be promoted.

Biomechanical Phenomena↗
PubMed1997

[Treatment of patients with dislocation of acromio-clavicular joint using kuntsher nail with steel wire: report of 27 cases].

There has been much controversy about ways of operation of the traumatic dislocation of acromio-clavicular joint. Our studies revealed that internal fixation of acromio-clavicular joint using kuntsher nail with steel wire is superior to traditional internal fixation of crossing kuntsher nail. We treated 27 cases in this way who were followed-up for 22 months to 9 years. Excellent result was achieved in 25 cases (92.6%) and good in 2 (7.4%). No complication was observed. We conclude that the way of internal fixation using kuntsher nail with steel wire to treat the dislocation of acromio-clavicular joint has following advantages: (1) simple operation; (2) minimum injury to articular surface; (3) stable internal fixation; and (4) no side effect.

Acromioclavicular Joint↗
PubMed1997

Clinical and experimental studies on acupuncture treatment of apoplexy at the convalescent stage by consciousness-restoring method.

The consciousness-restoring method and the conventional method of acupuncture were used for treatment of 92 cases of apoplexy at the convalescent stage. They were randomly divided into 2 groups: the consciousness-restoring group (50 cases), and the conventional group (42 cases). The therapeutic results show that the cure rates in the former and latter groups are 43% and 16.67% respectively. The markedly effective and effective rates in the former group are significantly higher than that in the latter group. The experimental results demonstrate that there is remarkable improvement in the majority of criteria of blood rheology, blood lipid, micro-circulation and thrombus formation in vitro, in the former group, and the degree and extent of improvement are markedly better than the latter group.

Acupuncture Therapy↗
PubMed1997

[Preparation of McAb against lung cancer and its application in tumor radioimmunoimaging].

OBJECTIVE: In order to tracing the lung cancer, A monoclonal antibody was produced. METHOD: The McAb, named SM-1, was specifically reacted with lung cancer confirmed by the immunopathological studies, then the McAb was digested into fragments by ficin and bromelain proteases. RESULTS: Both of the enzymatic methods were very effective and the immuno-reactivity of fragments was retained well. In our localization experiments, the T/NT ratio revealed that radioiodinated McAb and fragments could be specifically uptaked by the tumour tissue and the T/NT ratio was higher in fragments group than intact IgG. After injection of 131I-IgG and fragments, the xenografts of human lung cancer bearing in nude mice were visualized distinctly during 36-48 hrs. Eighteen patients with lung cancer received Tc-99m labeled McAb intravenously, 13 cases showed radioactive accumulation in the foci of tumours. CONCLUSION: These preliminary results suggested that SM-1 and its fragments might be a potential agents for radioimmunoimaging diagnosis of lung cancer.

Animals↗
PubMed1997

[The immune response in rats immunized systemically by the surface protein antigen P1 from streptococcus mutans conjugated with procholeragenoid].

This study was carried out to observe the antibody responses in rats after they were immunized with the surface protein P1 of streptococcus mutans when a special adjuvant was used. Antigen P1 was conjugated covalently with procholeragenoid (PCG), and then Sprague Dawley rats were immunized with P1 or the conjugated antigen P1-PCG subcutaneously or intragastrically. Anti-P1 antibody level was assayed at different time points by ELISA. The results showed that the levels of anti-P1 SIgA antibody in saliva rose when P1-PCG was given subcutaneously or intragastrically; the antibody level following the subcutaneous injection was higher and lasted longer, compared with that following the intragastric administretion. The level of anti-P1 IgG antibody in serum only rose when the rats were immunized subcutaneously. These results implied that mucosal immune response or humoral immune response could be induced subcutaneously when PCG was used as an adjuvant.

Animals↗
PubMed1997

[A study on P16 and P53 protein expressions in ovarian serous cystadenocarcinoma].

An immunohistochemical method utilizing avidin-biontin complex (ABC) technique was used in this study to detect P16 and P53 protein expressions in 40 ovarian serous cystadenocarcinomas and 10 serous cystadenomas. The results showed that the total positive rates of P16 and P53 protein were 40% and 60% respectively. The positive staining rate was higher in P53 protein expression than in P16 protein expression in the same cases. The positive staining rates of P16 protein were 16.67%, 33.33% and 52.63% respectively in stages I, II and III. There was no significant difference in histological grading. The postive staining rate of P53 protein expression in poorly differentiated tumor was higher than that in well differentiated group (P < 0.05). These results suggested that P16 and P53 protein expressions of the ovarian serous cystadenocarcinoma might be correlated with human organs, histological type of tumor, cyclin and cyclindependent kinase.

Cyclin-Dependent Kinase Inhibitor p16↗
PubMed1997

[Detection of p53 gene mutations in hepatocellular carcinoma].

This study screened 32 cases of hepatocellular carcinoma (HCC) from Chengdu detecting HBV DNA. HBsAg and p53 mutations by using Southern blot hybridization, immunohistochemistry and polymerase chain reaction/restriction enzyme digest methods, respectively. The results revealed all the cases had been infected by HBV; the frequency of HBV DNA integration into HCC cell was 72%, and the positive staining for HBsAg 96.3%(26/27). Of the 32 cases, 8 showed nuclear staining of p53 protein (25%), no mutation of p53 gene at all in 27 nontumorours liver tissues was identified. The resluts suggest the inactivation of p53 function may play a significant role in the genesis of HBV-associated HCC; however, the largely negative p53 mutation results in the current study conversely indicate that hepatocarcinogenesis may even involve other comprehensive mechanisms. Further studies are worth doing to evaluate the possible contribution of HBV to the p53 mutation in HCC.

Adult↗
PubMed1997

[An analysis of acute leukemia cells TfR expression in children].

There are a lot of transferrin receptors on the acute leukemia cells. We used the method of "Receptor Radioligand Assay" to determine the numbers of TfR binding sites on leukemia cells from 20 child patients with acute lymphocyte leukemia (ALL) and 9 with acute myeloid leukemia (AML). The results showed the numbers of TfR binding sites of AML cells were higher than those of ALL cells, and the numbers of complete remission group were lower than those of dead or relapse group. This indicated there might be a relationship between the TfR expression and the prognosis.

Adolescent↗
PubMed1997

[Identification of realgar and arsenopyrite and their sublimates].

In this paper, two traditional Chinese medicinal minerals realgar and arsenopyrite, as well as their sublimates are identified in their nature, physical and optical properties, chemical compositions and trace elements. The result has shown that there are marked differences among realgar, arsenopyrite and their sublimates, and it should be particularly noted that the difference between the two sublimates will certainly affect the quality of the two minerals that are used as poisonous drug in China.

Arsenic Trioxide↗
PubMed1997

[Effects of icarrin on secretive function of cultured granulosa and adrenal cortical cells of rats].

Icarrin was added to cultured cells and the hormones in culture fluid were determined after 3 hours of incubation. The results showed that icarrin (30-1000 micrograms/L) could promote the estradiol production of granulosa cells. The most effective concentration was 100 micrograms/L. Icarrin also exerted a stimulatory effect on corticosterone production at the highest dosage (1000 micrograms/L).

Adrenal Cortex↗
PubMed1997

[Cloning and expression in Escherichia coli of an alkaline and thermostable exolipase from Pseudomonas pseudoalcaligenes].

A gene coding for an alkaline and thermostable exolipase of Pseudomonas pseudoalcaligenes was cloned into Escherichia coli LE392 by inserting Sau3 AI-generated DNA fragments into the BamHI site of pIJ285. Four colonies with esterase and lipase activities on the tributyrin agar plate were isolated by screening the constructed pseudomonas pseudoalcaligenes genomic library. Only one out of the four positive colonies showed lipase activity on the agar plate contatining olive oil and Rhodamine-B. Subclones of the 45 kb insert carrying lipase gene was obtained in E. coli HB101 using pUC118 as a vector, two of which (HB101 (pHZ1402) and HB101 (pHZ1403)), retained lipase activity, but the level seems to be different. They carried 3.0 kb and 2.9 kb inserts with a 2 kb overlapping sequence. The lipase activity of HB101 (pHZ1403) is about 4 times higher than that of HB101 (pHZ1402), as 5 times as that of original strain P. pseudoalcaligenes.

English Abstract↗
PubMed1997

[Conjugation and identification of the surface protein antigen P1 from streptococcus mutans MT6R with the cholera toxin B subunit and procholeragenoid].

To make an effective antigen to prevent dental caries, the surface protein antigen P1(Ag I/II) was purified and identified by the rabbit anti-Ag I/II serum and was covalently conjugated to CTB and PCG by SPDP respectively. GM1-ELISA showed that both the conjugated P1-CTB and P1-PCG possess the ability to bind GM1 specifically without losing the antigenicity of P1. This results showed that the conjugated antigens could be used in the immune prevention against dental caries.

Antigens, Bacterial↗