Biomedical subjects

Y Zhao

Publications and source records attributed to Y Zhao.

At least 235 records · Page 13Linked to original sources

PubMed2001

[Survey on the growth of interpupillary distance of Chinese children aged 5 to 17 years].

OBJECTIVE: To investigate the interpupillary distance (IPD) of Chinese children for stipulating the sizes for children spectacle frames. METHOD: The IPD of 10171 children aged 5 to 17 years old was measured with a caliper in four cities. RESULTS: The IPD was positively correlated with the age increase from 5 to 17 years. The IPD in males was larger than that in females. The differences of IPD between males and females in the age groups of 5 to 9 and 10 to 15 years were statistically significant (F = 400.97, P < 0.01). CONCLUSIONS: There are two peak periods of the growth of IPD in Chinese children at 5 to 9 and 10 to 15 years. The IPD in males reaches adult level at age 15 and in females at age 13. The differences of the IPD between male and female and among 4 cities have no practical meaning in stipulating the sizes of children spectacle frames.

Adolescent↗

PubMed2001

[Risk of leukemia among medical X-ray workers in China between 1950 and 1995].

OBJECTIVE: To explore the relationship between low dose radiation and leukemia and assess resultant risk of leukemia. METHODS: The leukemia incidences (1950 - 1995) in 27,011 medical diagnostic X-ray workers and in 25 782 non-radiation workers in hospital employed between 1950 and 1980 in China were compared by O/E system. RESULTS: The relative risk (RR) of leukemia in the medical X-ray workers was 2.17 (95% CI = 1.58 - 2.91, P < 0.01). The highest RR of leukemia was found in those who engaged in X-ray work before 1960 or at age under 20 years. CONCLUSION: There was a relationship between incidence of leukemia and X-ray radiation in X-ray workers and accumulation of radiation dosage and employment at younger age increased the risk of leukemia.

China↗

PubMed2001

[Protective effect of huyin decoction on acute hepatic injury induced by CCl4 in mice].

OBJECTIVE: To observe the protective effect of Huyin decoction on acute hepatic injury induced by CCl4 in mice. METHODS: The model of acute hepatic injury induced by CCl4 was used. The levels of ALT and AST in serum were detected. And histopathology of liver was observed. RESULTS: Huyin decoction could decrease ALT and AST in serum and hepatic histopathological injury of the acute hepatic injury mice. CONCLUSION: Huyin decoction possessed protective effect on acute hepatic injury in mice.

Animals↗

PubMed2001

[Construction of Ag85B DNA vaccine for Mycobacterium tuberculosis and its immunogenicities].

OBJECTIVE: To construct pcDNA3-Ag85B recombinant and evaluate its immunogenicity and types of immune response induced by recombinant pcDNA3-Ag85B. METHODS: Ag85B gene of Mycobacterium tuberculosis was inserted into pcDNA3 to construct DNA vaccine pcDNA3-Ag85B. BALB/c mice were intramuscularly immunized with DNA vaccine, saline and pcDNA3, respectively. The levels of anti-Ag85B antibody were examined with ELISA and the transcripts of IL-2, IL-4, IL-10 and IFN-gamma of spleen lymphocytes stimulated with recombinant Ag85B were tested with RT-PCR at the end of 6th week of inoculation. RESULTS: Compared with control group, the specific antibody levels against Ag85B were much higher and the IL-2 and IFN-gamma transcripts were up regulated in the pcDNA3-Ag85B group. There was no change of IL-4 and IL-10 expressions in three groups. CONCLUSION: The pcDNA3-Ag85B stimulated the specific antibody products and induced the Th1 type cell immunity.

Animals↗

PubMed2001

[The influence of two different casting temperatures on properties of the incorporated keeper].

OBJECTIVE: To probe the clinical possibility of making incorporated keeper cap by high temperature casting. METHODS: The incorporated keepers were equally divided into two groups, and cast by applying medium and high temperatures respectively. The two groups were compared with the following items: the morphological changes and thickness of keeper's oxide film, the combining quality between keeper and alloy, and the magnetic retention force. RESULTS: The two different casting temperatures had the similar influence on the keeper's properties, such as the keeper's metallographical view, magnetic force (medium temperature casting group: 433.6 g; high temperature casting group: 433.8 g), and combining quality with alloy, except for the morphology and thickness of the keeper's oxide film. The oxide films of the high temperature casting group (surface: 7.59 microns combining surface of keeper and alloy: 6.17 microns) were thicker than those of the medium temperature casting group (surface: 4.65 microns; combining surface of keeper and alloy: 3.95 microns). CONCLUSIONS: The incorporated keeper could be made by using high temperature casting method instead of medium temperature one in clinic.

Dental Casting Technique↗

PubMed2001

Cyclohexylamino-demethoxy-hypocrellin B and photodynamic therapy decreases human cancer in vitro.

2-Cyclohexylamino-2-demethoxy-hypocrellin B (CHAHB) is a new photosensitizer synthesized by the mild reaction between hypocrellin B (HB) and cyclohexylamine, in which the peri-hydroxylated perylenequinone structure of the parent HB is preserved and the photoresponse is enhanced markedly. Electron paramagnetic resonance (EPR) spin trapping measurements and 9,10-diphenylanthracene (DPA) bleaching studies were employed to investigate the photodynamic action of CHAHB in the presence of oxygen. Singlet oxygen ((1)O2) and superoxide anion radical (O2*-) generated by illuminating CHAHB in aerobic solution have been observed. Compared with HB, CHAHB distinctly enhanced the O2(*-)-generating abilities, although (1)O2-generating abilities were lowered. The photodynamic action of CHAHB in the therapy of cancer was investigated in vitro. The results in vitro revealed a much more significant decrease in cancer cell growth than with HB. Laser or dye alone had no effect, indicating that intratumor CHAHB and laser therapy may prove useful in unresectable cancer.

Cell Line↗

PubMed2001

[Protective mechanism of tianmacuzhi granules in brain].

OBJECTIVE: To provide pharmacological evidence for the protective effects of Tianmacuzhi Granules (TMC) in mouse brain in a ischemia--reperfusion model. METHOD: Receptor binding test of NMDA receptor and M receptor in brain, GPx activity determination in brain and liver effected by different dose of TMC were performed. RESULT: TMC could reduce the NMDA receptor activity, increase the M receptor activity and GPx activity of cerebral cortex and hippocampus tissues significantly. CONCLUSION: TMC might antagonize ischemia-reperfusion injury of brain by reducing the glutamate neurotoxicity and increasing the function of cholinergic nerve and effects of anti-peroxidization in brain.

Animals↗

PubMed2001

[Effects of beta-carotene and vitamin C on the expression of c-myc in human leukemic cell].

In order to study the effects of beta-carotene and vitamin C(VC) on the expression of c-myc oncogene in human leukemic cell, myelogenous leukemic cell line HL-60 was cultured in vitro with standard methods. Trypan blue exclusion test and Northern blotting hybridization were used to detect the cell proliferation and the expression of c-myc gene. The results showed that the proliferation of HL-60 cell was inhibited after exposed to VC(5, 10, 100 mumol/L) and the occurrence of proliferation was earlier at lower concentration of VC(5 mumol/L). beta-carotene at 10-100 mumol/L could inhibit the proliferation of HL-60 cell in a dose dependent manner. VC(5 mumol/L) had no influence on the expression of c-myc gene(P > 0.05), but beta-carotene could up-regulate the expression of c-myc(P < 0.05). Our observations suggested that the inhibitory effect of beta-carotene on the proliferation of leukemic cells was caused by inducing apoptosis of HL-60 through up-regulating the expression of c-myc gene; however, the inhibitory effect of vitamin C on cell proliferation was not related to the expression of c-myc gene.

Ascorbic Acid↗

PubMed2001

[The prognostic value of vascular endothelial growth factor in breast cancer].

OBJECTIVE: To define the relevance of VEGF status to the prognosis of breast cancer. METHODS: The tissues of 70 invasive ductal breast carcinomas were evaluated for VEGF protein expression by immunohistochemistry LSAB method, and the prognostic value of VEGF status was assessed in combination with the follow-up data on those breast cancer patients. RESULTS: VEGF status was inversely correlated with relapse-free survival and overall survival. Kaplan-Merier survival curve showed that VEGF-rich tumor group had higher relapse rate and mortality rate. Multivariate regression analysis confirmed that the VEGF status had certain prognostic value, but it could not be considered as an independent prognostic indicator. CONCLUSION: VEGF status is one of the significant prognostic indicators of breast cancer.

Biomarkers, Tumor↗

PubMed2001

[Research on the high strength all ceramic crown by the combination of CAD/CAM and glass infiltrated alumina blocks].

OBJECTIVE: To search for a method that fabricates the high strength all ceramic crown by the combination of CAD/CAM and glass-infiltrated alumina. METHODS: Alumina coping was milled by the Cerec II CAD/CAM and glass was infiltrated into alumina by the capillary effect. Vita alpha ceramic was used to veneer the surface of substructure for all ceramic crown. RESULTS: This technology need not duplicate die and sinter alumina substructure for 10 h, compared with the conventional In-ceram technology. The time of glass infiltration has been decreased from 4 h to 40 minutes by the high capillary effects of prefabricated alumina blocks. CONCLUSION: This is a new method for all ceramic crown by using Cerec II CAD/CAM to mill a simple ceramic block so as to fabricate prosthetics in clinic.

Aluminum Oxide↗

PubMed2001

[Effects of bite force loss on the expression of IL-6 mRNA in rat periodontium].

OBJECTIVE: The aim of this study is to evaluate the expression of IL-6 mRNA in rat periodontal cells under normal bite force and without bite force, and to explain periodontal remodeling from the molecular level. METHODS: Animal models with normal bite force and without bite force were established by using Wistar rats. In situ hybridization technique was applied to detect changes of IL-6 mRNA expression in rat periodontal tissue. RESULTS: Without bite force, the expression level of IL-6 mRNA increased significantly in periodontal cells. CONCLUSION: This study initially investigates the molecular mechanism of periodontal remodeling, and suggests that the histological morphology may be closely related to the mechanical stimulation.

Animals↗

PubMed2001

[Effects of mechanical stretch on collagen type I and total protein synthesis of human periodontal ligament fibroblasts].

OBJECTIVE: The aim of this study is to investigate the effects of mechanical stretch on type I collagen and total protein synthesis of human periodontal ligament fibroblasts (PDLFs). METHODS: Enzyme link immunosorbent assay (ELISA) and Coomassie brilliant blue stain method were used to examine the anabolism of PDLFs growing on the flexible culture plates subjected to mechanical stretch. The five loading devices of PDLFs were designed and the stain varied from 1% to 8%. RESULTS: Mechanical stretch had no effect on type I collagen synthesis. However, in the range of 1% to 8% of stretch, the protein synthesis was reduced. The mechanical stretching of 2% strain affected the protein synthesis most obviously. CONCLUSION: Mechanical stretch can modify the composition of extracellular matrix of PDLFs.

Cells, Cultured↗

PubMed2001

[Expression of type I collagen mRNA in rat molar periodontal ligament under normal bite force].

OBJECTIVE: The main component of the periodontal ligament(PDL) is collagen fiber, especially type I collagen, and collagen plays an important role in PDL. The aim of this study is to observe the expression of rat PDL mRNA under normal bite force and to investigate the molecular mechanisms of these changes in type I collagen mRNA. METHODS: 40 male Wistar rats were used, and animals were intra-cardiac perfused with a solution of 4% polyformaldehyde under anesthesia. Dissected mandibles were immersed in the same fixation for 6 hours and subsequently decalcified in EDTA. The demineralized specimens were embedded in paraffin and cut into slices with thickness 5 microns. The probe was synthesized and labeled with digoxigenin. Expression of type I collagen mRNA was measured by using in situ hybridization(ISH). RESULTS: Under the normal bite force, the mRNA expression of type I collagen was very strong on the whole, including the alveolar bone side, the root side and the area between them. Positive signals were located mainly in the cytoplasm and some in the nuclei. But the mRNA expression of type I collagen still had spatial characteristics. The signals in some fibroblasts were apparently stronger than those in other fibroblasts in the apical 1/3 fragment of the roots. The signal of type I collagen mRNA was strong near the root sides. The expression signal on the proximal alveolar walls was strong, however, on the distal alveolar wall, there was no expression. CONCLUSION: The expression of type I collagen mRNA is closely related with bite force.

Animals↗

PubMed2001

[Establishment and identification of squamous cell lines carcinoma of tongue transferred with anti-sense cyclin A gene].

OBJECTIVE: The aim of this study is to investigate the relationship between cyclin A and cycle regulation of squamous cells carcinoma of tongue, and to provide basis for cancer gene therapy. METHODS: Eukaryocyte expression vector (pAS-A) containing anti-sense and the full-length human cyclin A complementary DNA (cDNA) (1.77 kb) was constructed and was transferred into squamous carcinoma of the tongue cell line (Tca8113) by Lipofect AMINETM introduction. The positive cell clones were selected with G418. Transcription of Neo gene mRNA and cyclin A mRNA were determined by in situ hybridization. The stable expression of anti-sense cyclin A in the Tca8113 cell line was determined using immunohistochemical methods. RESULTS: After G418 selection, cells transferred anti-sense cyclin A were obtained successfully. The positive cells of in situ hybridization of specific-stained Neoprobe were observed in cells transferred eukaryocyte expression vector. The positive cells of in situ hybridization of cyclin A in cells transferred anti-sense cyclin A were significantly fewer than those in cells transferred cyclin A. The positive rate of cyclin A immunohistochemical stain in cells transferred anti-sense cyclin A was significantly lower than that in cells transferred cyclin A. CONCLUSION: Human anti-sense cyclin A gene is stably expressed in the Tca8113 cell lines.

Carcinoma, Squamous Cell↗

PubMed2001

[Effects of unilateral cleft lip and palate prosthesis on the development of maxillary and facial soft tissue].

OBJECTIVE: The effect of unilateral cleft lip and palate prosthesis on the development of maxillary and facial soft tissue was investigated. METHODS: The standard cephalometric measurement was used in patients with complete unilateral cleft lip and palate operated in different periods. We obtained data by measurement. RESULTS: Hard tissue: ANS-X, PNS-X and N-ANS in the group of patients were statistically different from those of the normal control group, but in ANS-PNS and N-PO, there is no statistical difference in these two groups. Angles of hard tissue: There is statistical difference in < N. W. ANS and < SNA between the control and the group of patients. There is only statistical difference in < SNB between the D group and the control group. There is no difference among other groups. Ratios of hard tissue: The ratios of ANS-X/S-X and PNS-X/S-x in the control group were higher than those of the group of patients, and the ratios of S-Go/N-Po, Ar-Go/N-Po and N-Po/AN in the group of patients were higher than those of the control group. The ratio of NMC/SUBN: It is the highest ratio in the control group, and there is no difference between ratios in the control group and the C group, but there is statistical difference between the control and other patient groups (P < 0.05). CONCLUSION: Comparing with normal persons, the defect of maxillary length development is apparent in the patients with complete unilateral cleft lip and palate due to congenital development deformity. The figure of soft tissue in patients with unilateral cleft lip and palate is anastomotic with the figure of their hard tissue. The excavation of bony middle 1/3 in face results in paramorphia of soft tissue adhering on the bony tissue. We can conclude that in order to obtain better articulation function, the palatoplasty should be carried out early.

Adolescent↗

PubMed2001

[One stage otoplasty treatment for congenital malformations of the auricle and middle ear].

OBJECTIVE: To investigate the application of one stage otoplasty for congenital atresia of the external acoustic canal and malformations of the middle ear and the auricle. METHOD: Patients with the ear malformations were given surgical reconstruction of one stage otoplasty. The auricle was reconstructed with the rib which was encapsulated with the superthin temporal flap. According to the malformations of the middle ear in patients, I style tympanoplasty and III style tympanoplasty were carried out respectively. All patients were performed myringoplasty with temporal fascia and reconstructed the external acoustic canal with full thickness skin-grafting. RESULT: A long term follow-up (4-6 years) demonstrated that 11 ears were survival of which 8 ears figuration were ideal. The hearing improvement was observed in all patients. CONCLUSION: One stage otoplasty is effective for treatment of the congenital malformations of the external and middle ear.

Adult↗

PubMed2001

[Clinical observation of TNF-alpha content in nasopharyngeal secretion of patients with nasopharyngeal carcinoma].

OBJECTIVE: To detect the changes of tumor necrosis factor-alpha (TNF-alpha) in nasopharyngeal secretion of patients with nasopharyngeal carcinoma(NPC). METHOD: The content of TNF-alpha in nasopharyngeal secretion was determined by radioimmunoassay (RIA) in 20 controls, 52 patients with NPC. RESULT: The average concentrations of TNF-alpha were (12.95 +/- 4.62) pmol/L in control group, (33.68 +/- 15.13) pmol/L in NPC group and (64.00 +/- 11.57) pmol/L in NPC with necrosis group. The content of TNF-alpha in nasopharyngeal secretion in control group was lower significantly than that of patients with NPC (P < 0.01). CONCLUSION: The level of TNF-alpha in nasopharyngeal secretion of NPC patients was higher than that of normal subjects. To detect the content of TNF-alpha in nasopharyngeal secretion is a useful test for the study and diagnosis of NPC.

Adult↗

PubMed2001

[Observations of the curative effect with various liquid for post operative irrigation of ESS of treating chronic sinusitis and nasal polyps].

OBJECTIVE: To explore the influence of liquid for post-operative irrigation on the effect of ESS. METHOD: 192 cases with chronic sinusitis and/or nasal polyps of groupIIstageII who had undergone the ESS from September, 1998 to June, 1999 and completed a 3-month follow-up were divided randomly into 3 groups to accept 3 different kinds of irrigation liquid. The evaluation of curative effect was according to the index of HaiKou ESS-97. RESULT: The curative effect of Herba Houttuyniae group was better than the other two. CONCLUSION: The post-operative care is important and the irrigation liquid can affect the effect of ESS.

Adolescent↗