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Biomedical subjects

S L He

Publications and source records attributed to S L He.

13 recordsLinked to original sources
PubMed2000

[Levels of plasma TF and TFPI activities in patients with acute leukemia].

OBJECTIVE: To investigate the changes of plasma tissue factor(TF) and tissue factor pathway inhibitor(TFPI) activities in the patients with acute leukemia. METHODS: TF and TFPI activities were measured by using chromogenic assays. RESULTS: Plasma TF activity in the patients with acute leukemia was higher and TFPI activity was lower than those in normal(P < 0.01). In 7 patients who underwent the first chemotherapy, the plasma TF activity was decreased after chemotherapy(P < 0.01), while TFPI activity increased(P < 0.05). CONCLUSION: The unbalance between plasma TF and TFPI activities contributes to the coagulant disorders in acute leukemia.

Adolescent↗
PubMed2000

["Bu-yang huanwu tang" inhibited the pathogentic process of atherosclerosis induced by cholesterol-rich diet in rabbits].

BACKGROUND AND OBJECTIVE: "Bu-yang huanwu tang", a decoction of Chinese herbs widely used in the treatment for cardio- and cerebro-vascular diseases, has been demonstrated to be able to inhibit platelet adhesion and aggregation, to lower blood lipids, to regulate vascular tone from animal experiments. The aim of this study is to determine whether this decoction inhibits the pathogentic process of atherosclerosis induced by cholesterol-rich diet in rabbits. METHODS: Three groups of rabbits received the following different diets for 9 weeks: 1. standard diet; 2. atherogenic diet(standard diet plus 1% cholesterol and 3.3% fat); 3. atherogenic diet plus this decoction(5 g.kg-1.d-1). Plasma lipids, 6-keto-PGF1 alpha, endothelin levels were detected and the histological atherosclerotic changes were evaluated. RESULTS: This decoction inhibited the progression of aortic and abdominal aortic intimal plaques and reduced aortic intimal thickening. CONCLUSION: The anti-atherogenic mechanism might be related to the decrease of plasma cholesterol and triglycerides and the increase of PGI2. The facts suggest that "Bu-yang huanwu tang" has antiatherogenic and antithrombotic effects.

Animals↗
PubMed2000

Mechanical properties of a biodegradable bone regeneration scaffold.

Poly (Propylene Fumarate) (PPF), a novel, bulk erosion, biodegradable polymer, has been shown to have osteoconductive effects in vivo when used as a bone regeneration scaffold (Peter, S. J., Suggs, L. J., Yaszemski, M. J., Engel, P. S., and Mikos, A. J., 1999, J. Biomater. Sci. Polym. Ed., 10, pp. 363-373). The material properties of the polymer allow it to be injected into irregularly shaped voids in vivo and provide mechanical stability as well as function as a bone regeneration scaffold. We fabricated a series of biomaterial composites, comprised of varying quantities of PPF, NaCl and beta-tricalcium phosphate (beta-TCP), into the shape of right circular cylinders and tested the mechanical properties in four-point bending and compression. The mean modulus of elasticity in compression (Ec) was 1204.2 MPa (SD 32.2) and the mean modulus of elasticity in bending (Eb) was 1274.7 MPa (SD 125.7). All of the moduli were on the order of magnitude of trabecular bone. Changing the level of NaCl from 20 to 40 percent, by mass, did not decrease Ec and Eb significantly, but did decrease bending and compressive strength significantly. Increasing the beta-TCP from 0.25 g/g PPF to 0.5 g/g PPF increased all of the measured mechanical properties of PPF/NVP composites. These results indicate that this biodegradable polymer composite is an attractive candidate for use as a replacement scaffold for trabecular bone.

Absorbable Implants↗
PubMed2000

[Revision of the biological significance of the contact system].

Current concept of blood coagulation is divided into two stages: an "initiation" stage which is handled by tissue factor pathway, and an "augmentation" stage handled by intrinsic pathway beginning in factor XI. Recent studies have demonstrated that the contact system is a modulator for vascular biology with vascular tone regulation, anticoagulant, profibrinolytic, antiadhesive and proinflammatory functions. Changes of contact system are associated with sepsis, thrombosis, etc.

Animals↗
PubMed1999

[Expression of tissue factor of astrocytes and its signal transductional pathways].

The aim of this study was to observe the expression of tissue factor (TF) of astrocytes in basic culture medium and under the condition stimulated by thrombin and to explore the relevant signal transduction pathways. The results showed that 4-bromo calcium ionophore (A23187) and phorbol 12-myristate 13-acetate (PMA) enhanced significantly the TF expression of astrocytes, but the expression was decreased markedly by trifluoperazine (TFP) and 1-(5-isoquinolinyl sulfonyl)-3-methyl-piperazine (H7) in the basic medium. Thrombin increased significantly the TF expression of astrocytes, which was obviously inhibited by TFP and H7. The results above indicate that astrocytes can express TF activity in the basic medium, which is promoted by thrombin, probably through some pathways involving Ca2+/CaM and protein kinase C (PKC).

Animals↗
PubMed1997

[Roles of intercellar Ca2+ and protein kinase C played in tissue factor pathway inhibitor and tissue factor expression in human umbilic vein endothelial cells].

The purpose of the present study was to elucidate the roles that protein kinase C (PKC) and calcium played in the tissue factor (TF) synthesis and tissue factor pathway inhibitory (TFPI) release in human umbilic vein endothelial cells (HUVEC). A23187 was used to represent calcium ionophore and phorbol 12-myristate 13-acetate (PMA) as that of PKC activator. TF activity in the lysed HUVEC was measured using one stage clotting assay. TFPI activity in the conditioned medium of HUVEC was assessed by the two-step chromogenic method. The results showed that the TF activities in A23187, PMA and A23187 + PMA groups were remarkably higher (P < 0.01) than that in control. Among the three treated groups, the TF activities in both A23187 group and A23187 + PMA group were lower than that in the PMA group (P < 0.05), but the difference between the former two groups was statically insignificant (P > 0.05). In contrast to the control group, the TFPI activity in the A23187 group was not statistically different (P > 0.05). However, the TFPI activities in the PMA group and the A23187 + PMA group were markedly higher than those in the control group and the A23187 group (P < 0.01). These findings indicate that PKC and calcium ion promote TF synthesis in HUVEC but the effect of the former is stronger than that of the latter, and that the release of TFPI from HUVEC is facilitated by PKC and not significantly affected by calcium ion.

Calcium↗
PubMed1993

[Changes in oxygen free radical and prostacyclin in thromboangiitis obliterans and its relationship with syndrome differentiation].

Malondialdehyde (MDA) and 6-keto-PGF1 alpha levels in plasma and erythrocyte superoxide dismutase activities (Ery-SODA) were observed in 56 cases of thromboangiitis obliterans (TAO). The results showed that: (1) Ery-SODA and 6-keto-PGF1 alpha levels lowered and MDA raised significantly in TAO (P < 0.01), compared with that in control. (2) 6-keto-PGF1 alpha levels were markedly related with Ery-SODA and MDA in TAO (P < 0.01). (3) Ery-SODA and 6-keto-PGF1 alpha levels were lower and MDA higher in III phase of TAO than that in II phase. (4) Ery-SODA and 6-keto-PGF1 alpha levels markedly declined and MDA contents elevated significantly in Dampness-Heat (DH) and Heat-Toxin (HT) group, compared with that in Yin-Cold (YC) group and Blood-Stasis (BS) group, respectively (P < 0.05, P < 0.01); all above substances between YC and BS group or between DH and HT group had no significant differences (P > 0.05). (5) Ery-SODA and 6-keto-PGF1 alpha levels were lower and MDA higher in Heat Syndrome than that in Cold Syndrome (P < 0.01). It suggested that oxygen free radical and lipid peroxide response that might participate in vascular endothelial cell injury in TAO markedly increased and the detection of these substances might provide complementary evidences for syndrome differentiation of TAO.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Micronuclei in mouse skin cells following in vivo exposure to benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene, chrysene, pyrene and urethane.

Detection of micronuclei (MN) in skin cells from HRA/Skh hairless mice treated with chemical or physical agents may prove informative in qualitative and quantitative studies of skin carcinogenesis. MN induction and cell survival were estimated in cytokinesis-blocked keratinocytes, cultured for 4 days in vitro, after a single topical dose of various organic compounds. Treatment with 2.56 micrograms (10 nmol) 7,12-dimethylbenz[a] anthracene (DMBA) resulted in maximal MN induction in cells removed from skin 12-24 hr after topical administration (79-88 MN/1,000 cells compared with 10-16 MN/1,000 cells in acetone-treated controls). Even in cells removed only 1 hr after DMBA treatment, a significant increase in MN was evident. However, to allow sufficient time for metabolic activation, a sampling time for of 24 hr was adopted for all test substances. Dose-dependent increases in MN were observed with DMBA, benzo[a]pyrene, chrysene, and urethane. Increased numbers of micronucleated cells were detected at the lowest doses administered in the present study (0.128, 0.5, 50, and 50 micrograms, respectively). Although reduced cell recovery occurred following exposure of mice to acetone, pyrene, and other chemicals, there was no evidence that cytotoxicity contributed to MN scored in keratinocytes. Moreover, the probable noncarcinogen, pyrene, failed to induce MN at doses from 2.5 micrograms to 2.5 mg/mouse. These results show that it is possible to assess chemical exposure in skin by measuring cell survival and skin genotoxicity by measuring MN induction in cultured keratinocytes. The available data suggest that MN induction may be a useful indicator of the carcinogenic potential of chemicals applied to the skin.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

[Effect of buyang huanwu decoction on the antithrombotic functions of the vessel wall].

The effects of Buyang Huanwu Decoction (BYHWD) on the antithrombotic functions of vessel wall were studied with human umbilical vein perfusion. It was observed that the both of Von Willebrand factor release stimulated by thrombin from the vessel walls and conversion of fibrinogen to fibrin catalyzed by thrombin were inhibited by BYHWD. There were no obvious effects of BYHWD on the thrombin adsorption to the vessel walls and the thrombin induced release of PGI2 as well as fibrinolysis inhibiting activity from the vessel walls.

Blood Vessels↗