Biomedical subjects

Y Zhao

Publications and source records attributed to Y Zhao.

At least 721 records · Page 40Linked to original sources

PubMed1997

[Induction of apoptosis by tea polyphenols in MGC cells].

In order to search for tumor cells apoptosis inducer, the apoptosis effects and mechanism of tea polyphenols were studied. Tea polyphenols is an active compounds purified from tea. The apoptosis effects of tea polyphenols were observed on the human gastric carcinoma cells (MGC) by MTT reduction test, DNA agarose gel electrophoresis and transmission electron microscopy (TEM) technique. Having been treated by tea polyphenols in 125 micrograms.ml-1 for 24 h, DNA extracted from MGC cells showed a typical internuclesosomal DNA degradation, i.e., DNA ladder and apoptotic vehicles were observed under TEM. The effects of tea polyphenols were shown to parallel with its cytotoxic activity in MGC cells. These results suggest that the mechanism of antitumor action of tea polyphenols is related to its apoptosis inducing activity.

Adenocarcinoma↗

PubMed1997

[Relationship between obese gene expressive product and obesity].

In order to study the relationship between obese protein and obesity. A radioimmunoassay for human plasma obese protein (OP) was established using human OP (57-92) and its specific antiserum. We observed the distribution and the characteristics. Of OP in normal human and mouse tissue and changes of plasma OP in obese patients. We also observed the tissue distribution after intravenous injection of 125I-labeled OP fragments (116-167) and (93-105) in rats. The results were as follows. The contents of OP were much higher in brain tissue than those in abdominal adipose tissue; levels of OP in liver and in skeletal muscle tissue were zero; the contents of abdominal adipose tissue were higher in female mice than those in male mice; the contents of plasma OP in normal human beings were 194.3 +/- 17.7 ng/L, while those in mice were 2257.8 +/- 171.9 ng/L. It was also found that the administered OP fragments were widely distributed in various tissue and organs including the brain. Kidney was the richest in the OP fragments; liver and lung ranked second. The half time of the OP fragments in plasma clearance was about 4.5 min. The contents of OP in obese adults and in obese children were much lower than those in normal control group. There was significant negative correlation between OP levels and body mass index, serum concentration of glucose, cholesterol and triglycerides. So the present study indicates the important relationship between the changes of OP contents and the pathogenesis of obesity.

Adipose Tissue↗

PubMed1997

[The expression of proliferating cell nuclear antigen in breast phylloides cystosarcoma and its significance].

OBJECTIVE: To investigate the expression of proliferating cell nuclear antigen (PCNA) in breast phylloides cystosarcoma and its clinicopathological signification. METHODS: Immunohistochemistry (SP method) with monoclonal antibodies PC10 against PCNA was performed in 100 cases of phylloides cystosarcoma and 39 cases of adenofibroma. RESULTS: The positive rate of PCNA in phylloides cystosarcoma was 86%. The average PCNA index (PI) of phylloides cystosarcoma was significantly different among every histologic grading (F = 85.33, P < 0.01). The degree of differentiation was lower, the PI was higher. The PI was closely correlated with histologic grading (r's = 0.77). The PI in grade I phylloides cystosarcoma was higher than that in the group of adenofibroma with abundant mesenchymal cells (t = 3.42, P < 0.01). There was only a low correlation between PI and mitotic figures in phylloides cystosarcoma (r = 0.39). CONCLUSIONS: These findings suggest that the detection of PCNA has considerable practical value in reflecting the proliferation of activity of phylloides cystosarcoma, assisting the pathologists to make histologic grading; distinguishing the malignancy from benign ones (differential diagnosis) and evaluating the prognosis.

Adenofibroma↗

PubMed1997

[The effect of blood-pancreatic juice barrier on antitumor drugs excretion].

Chemotherapy is one of important adjuvant therapies for patients with pancreatic adenocarcinoma, but the mechamism 5-FU and MMC distributed over the pancreas is not known at home and abroad. Based on determining the ratio of the concentration of several kinds of antibioticsin plasma and pancreatic juice, we used fourteen dogs to study the distribution and the relationship of agents in plasma and pancreatic juice after giving 5-FU and MMC intravenously. At the same time, we observed some patients who received Whipple's operation. The results showed that 5-FU and MMC in plasma can penetrate the pancreatic tissue and cross the blood-pancreatic juice barrier (BPJB). Both agents suitable for the adjuvant chemotherapy of pancreatic adenocarcinoma.

Ampulla of Vater↗

PubMed1997

[Histologic study on complication reducing effects of the tumescent technique in liposuction].

The purpose of this experiment was to investigate how the tumescent technique reduces complications in liposuction. Histologic examinations revealed that the septa of fat are attached to the deep surface of the dermis and to the fascia superficialis. It is important to retain the septa that contain the perforating vessels and nerves during liposuction. The correct choices for instrument and suction pump can minimize trauma to tissues and reduce complications.

Embolism, Fat↗

PubMed1997

[The value of salivary beta 2 microglobulin concentration for diagnosis of Sjögren's syndrome].

In this paper we measured salivary beta 2 microglobulin (beta 2 m) concentration in 40 patients with Sjögren's syndrome, including 20 patients with systemic lupus erythematosus, 12 patients with recurrent aphthous ulceration and 16 patients with single xerostomia, and in 40 normal controls. The results showed that salivary beta 2 m concentration was more significantly elevated in Sjögren's syndrome patients, compared with that in both normals and other patients. The measurement of beta 2 m concentration in saliva may offer a simple and valuable method for diagnosis of Sjögren's syndrome.

Adult↗

PubMed1997

[A comparative study of autologous facial nerve graft in situ with the vein tubulation: the observation of neurons changes].

For further study of the effects of the repairment of facial nerve with vein tubulation, we used horseradish peroxidase (HRP) retrograde mark method to observe the changes of the labeled cells in facial neucleus after the tubulation of rat facial nerve. And, we compared the changes with nerve graft in situ and the normal group. The results showed: 1. The vein tubulatiton can repair the short defect of facial nerve as well as the nerve graft does. 2. Irregular outgrowth of axon sprouts could be found in both methods. 3. There was few chance for homolateral target organ to be reinnervated by contralateral motoneurons in both methods. 4. Using the vein tubulation method, a more natural relationship between the peripheral target organ and central nucleus may be easily achieved.

Animals↗

PubMed1997

[Effect of nitrogen, phosphorus and potassium on the growth of rhizome of Coptis chinensis Franch and its contents of berberine].

It has been found out that the normal growth of Coptis chinensis is heavily affected and both NRA in leaves and berberine contents in rhizome are very low when seedlings are short of nitrogen, phosphorus and potassium. The plants grow especially worse and most of them soon die off when nitrogen is short. The new leaves are smaller both in number and size when phosphorus and potassium are short. Few roots can grow up and easily get old in the solution short of potassium.

Berberine↗

PubMed1997

[The compressive strength, tensile strength, flexural strength and micro-hardness of Plat-II Castable Ceramics].

In preparation for the clinical use of Plat-II Castable Ceramics (PCC-II), we tested its compressive strength, tensile strength, flexural strength and microhardness. The flexural strength was tested by the three-point bending test. The result showed that the compressive strength was 541.7 MPa; the tensile strength 42.5 MPa; the flexural strength 142.0 MPa; the modulus of elasticity 61.4 GPa; and the micro-hardness 499.6 kg/mm3. The strength anol micro-hardness of PCC-II materials were better than those of human enamel. So PCC-II is applicable to restorations in dentistry.

Ceramics↗

PubMed1997

[Effects of icariin on the differentiation of HL-60 cells].

OBJECTIVE: In order to search for new tumor differentiation inducer, the effects and mechanism of Icariin were studied. METHODS: Icariin is an monomer purified from Epimedium Koreanum Nakai. The differentiation of induction effects of Icariin were observed on the human promyelocytic leukemic cell (HL-60) by NBT reduction test, 125I-cAMP and 125I-cGMP double antibody radioimmune methods, scanning electronic microscopy technique. RESULTS: After treating HL-60 cells with Icariin at concentration 0.1 g/L, reduction of NBT and cAMP/cGMP ratio were increased. There were many rugosities and ball-like processes on the cell surface. CONCLUSION: Icariin had the effects of induction of differentiation on HL-60 cells, the mechanism might be related to elevating the cAMP/cGMP ratio.

Cell Transformation, Neoplastic↗

PubMed1997

[Phenylethanoid glucosides from flos Buddlejae].

Four phenylethanoid glucosides were isolated from the flower of Buddleja officinalis. On the basis of specteral data, they were identified as salidroside(1), verbascoside(2), isoverbascoside(3) and echinacoside(4). Compounds 1, 3 and 4 were obtained from the plant for the first time. Compound 2 showed antibacterial and anticancer activities.

Drugs, Chinese Herbal↗

PubMed1997

[Application of TLC to tannin measurement].

There has been little report on the use of in measuring tannin in traditional Chinese medicinal preparations by TLC. Gallic acid, the decomposd product of tannin, was in bright yellow and green color, showing a strong specificity. The measurement of gallic acid can provide reliable indexes for quality assay of TCM preparations.

Chromatography, Thin Layer↗

PubMed1997

[Separation and identification of the compounds from Achyranthes bidentata Bl].

Eight compounds were separated from the roots of Achyrathes bidentata by repeated chromatography. On the basis of physicochemical properties and spectral analysis their structures were elucidated as alpha-spinasterol (1), beta-sitosterol (2), chrysophanol (3), dibutyl phthalate (4), palmitic acid (5), alpha-spinasterol-3-O-beta-D-glucoside (6), daucosterol (7) and ecdysterone (8). Compounds 1-7 were isolated from the plant for the first time.

Anthraquinones↗

PubMed1997

[Effect of butachlor on CH4 emission and anaerobes in paddy soil].

Effects of butachlor on CH4 emission and the count of anaerobes in paddy soil or in the media were studied. The results obtained showed that CH4 emission and growth of methanogens would be greatly affected at field rates of butachlor within 2 weeks, but this adverse effects would disappear as time went on. CH4 emission and methanogenic activities would be retarded by butachlor in media for longer time. The amount of butachlor available to act upon anaerobes depended on application rate and method of application.

English Abstract↗

PubMed1997

[Effect of environment on the teleutospore viability of Ustilago coicis].

The teleutospores of Ustilago coicis can retain their germinating power under indoor dry conditions for about five years. They can survive the winter in the fields in Beijing. Increase of soil humidity could reduce the number of teleutospores in soil. Rotation is an efficient method to control the head smut of Jobs-tears and the rotation cycle is two years minimum.

Ecology↗

PubMed1997

Neoplastic transformation and cytogenetic aberrations of rat tracheal epithelial cells induced by alpha-particle irradiation.

Primary rat tracheal epithelium (RTE) cells can be transformed in vitro by alpha-particles irradiation. One out of 3 isolated morphologically transformed colonies gave rise to an immortal cell line and ultimately became neoplastic by successive passaging. Cytogenetic analysis was performed on the cell line in order to understand how the specific chromosome alterations participate in the process of neoplastic transformation of RTE cells. The 5th, 18th, 39th passage cells and the colony cells isolated from soft agar (SA) culturing of the 40th passage cells were analyzed. The results showed that the 20th passage cells were nontumorigenic, but the 40th passage cells were tumorigenic. The increase of the length of the long arm of chromosome 15 (15q+) was frequent at the 5th passage (67.8%), especially in SA cells in which it occurred in a clonal fashion (100%). Therefore, 15q+ might be the critical gene lesion after alpha-particles irradiation. Monosomy of chromosome 8 that occurred frequently at passage 5 (54%) and 40 (53%) might be correlated with earlier transformation of RTE cells. In addition, three marker chromosomes (M1, M2 and M3) showed a passage-dependent increase. In particular M1 and M2 that were highly frequent at passage 39 (90%) suggested that they might play an important role in the process of cell transformation.

Alpha Particles↗

PubMed1997

[Research on bond strengths of Vita II and plat II ceramic bonding to teeth].

This study compared the tensile bond strengths of Vita II machinable ceramic and Plat II castable ceramic bonding to teeth with three resin cements. The three adhesive cements were Vita cerec, Panavia 21 and TF adhesives. The results showed: 1. The Vita cerec was a good adhesive for Vita II ceramic bonding to enamel and dentine, the bond strengths were 8.91 MPa and 8.48 MPa; 2. The Panavia 21 was suitable for Plat II ceramic bonding to enamel and dentine, the bond strengths were 10.92 MPa and 7.13 MPa respectively. And it was also a good adhesive for Vita II ceramic bonding to enamel, the bond strength was 7.48 MPa; 3. TF had poor adhesive effects for both ceramic materials.

Dental Bonding↗

PubMed1997

[Marginal fit of CAD/CAM ceramic inlays].

The purpose of this in vitro study was to investigate the marginal and internal fit of Cerec-2 inlays before and after adhesion. The test showed: 1. Before luting, the axial marginal space was 67 +/- 18 microns, cervical marginal space was 84 +/- 22 microns and the mean occlusal marginal space was 58 microns. 2. After luting, the thickness of the luting composite was 118 +/- 37 microns at axial margin, and 123 +/- 17 microns at cervical margin, the mean occlusal margin space was 80 microns. This study demonstrated the marginal adaptation of Cerec-2 inlays satisfied the clinical demand, especially at occlusal margin.

Computer-Aided Design↗