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Biomedical subjects

Z Wu

Publications and source records attributed to Z Wu.

At least 343 records · Page 19Linked to original sources
PubMed1999

[A study on relationship between hypertension and polymorphism of ACE gene in male Yi people in Liangshan Yi autonomous prefecture, Sichuan].

OBJECTIVE: To explore relationship between polymorphism of ACE gene and hypertension. METHODS: A cross-sectional study was conducted and PCR technique was used to analyze gene polymorphism. RESULTS: Genotypes DD, ID and II of ACE gene accounted for 13.0% and 9.7%, 50.9% and 48.4%, and 36.1% and 41.9%, respectively, in the normotensives and hypertensives. Frequencies of I and D alleles for ACE gene were 61.6% and 66.1%, and 38.4% and 33.9%, respectively, in the normotensives and hypertensives. There was no significant difference in distribution of II, ID and DD genotypes and I/D allele frequencies of ACE gene between the hypertensives and normotensives in male Yi people. CONCLUSION: Association between polymorphism of ACE gene and hypertension was uncertain.

Adult↗
PubMed1999

[Preventing and treating effect of total oil of Microula sikkimensis (Hemsl.) on experimental hyperlipemia in rats].

OBJECTIVE: To study the effect of the total oil of Microula sikkimensis on an experimental hyperlipemia model of rat. METHOD: Using feeding method to set up the experimental hyperlipemia model and determining the biochemical criteria. RESULT: The total oil of Microula sikkimensis significantly decreased the contents of cholesterol, triglyceride and MDA in blood serum, and increased the rate between total cholesterol and high density lipoprotein. CONCLUSION: The study provides an important basis for exploiting and utilizing the total oil of Microula sikkimensis.

Animals↗
PubMed1999

[Effects of BMP on periodontal ligament cell's cell cycling and DNA synthesis: a flow cytometry (FCM) analysis].

OBJECTIVE: To investigate the effects of bone morphogenetic protein (BMP) on the cell cycling and DNA synthesis of periodontal ligament cells (PDLCs). METHODS: The 7th passage PDLCs were cultured in a 5% CO2, humid atmosphere at 37 degrees C in DMEM supplement with 10% fetal bovine serum (FBS) for 24 hours, then BMP was added in medium with 1% FBS. After being cultured another 72 hours, cells were trypsinized, washed and fixed with cold alcohol for 1 hour. To measure DNA content, 1.0 x 10(6) cells were washed with PBS, resuspended in 200 microliters PBS mixed with staining liquid (RNA ase, 0.1% triton-100 and propidium iodide) for 30 minutes at 4 degrees C. DNA specific fluorescence was measured on a Coulter Epics Profile-II (Coulter, USA) using 250 mW 488 nm laser light for excitating and collecting fluorescence at 610-630 nm. Phase fraction analysis was performed on DNA content histograms with multicycle software. RESULTS: When compared with the control, the percentage of PDLC in G1 during exponential growth was decreased by a function of BMP, while the percentage of S and (G2 + M) was increased in the experimental group. CONCLUSION: It suggested that the proliferation of PDLC be most probably regulated in the G1 phase of the cell cycle. BMP can be regarded as a positive regulatory growth factor.

Adolescent↗
PubMed1999

[Discussion on the concept problem of the specific retention volume in gas chromatography].

The concept problem in the definition of well-known specific retention volume in GC is proposed in this paper. The specific retention volume Vg is usually defined as the net retention volume per gram of liquid phase corrected to 273.15 K in some literatures, and is widely appeared in journals and textbooks as one of the most important absolute retention value in GC, though it is less practical than the relative retention value in the qualitative analysis. Being inspired in the discussion of pressure correction in GC, the author thinks that the temperature correction term in the Vg definition is neither correct nor necessary. The problem was originated from the misunderstanding of the pressure correction of the adjusted retention volume. It is emphasized here that the net retention volume obtained by correction of the adjusted retention volume by compressibility factor j is the retention parameter in term of the column geometrical volume rather than a gas volume. The net retention volume per gram of liquid phase is an absolute retention parameter sufficient to measure the retention power. The author thinks that it is necessary to discuss and clarify the problem to avoid any possible errors being introduced in some cases, such as in the estimation of some thermodynamic parameters.

Artifacts↗
PubMed1999

[Preparation of collagen-based materials for wound dressing].

This article addressed the methods to develop collagen-based materials for wound dressing. Fresh frozen bovine tendon was treated with 0.05 M acetic acid at pH 3.2 for 48-72 h, then it was homogenized, filtered, and after the process of adding chondroitin sulphate(8%), it was dbubblized; thus 1.5%-2.5% collagen solution was finally prepared. The solution was lyophilized in prefrozen or un-prefrozen mold. The collagen sponge was crosslinked with 0.25% glutaraldehyde for 24 h. Three other wound dressings were developed by similar method, namely collagen membrane with polyurethane membrane onlay, polyurethane-coated collagen membrane and collagen membrane on gauze. It was demonstrated that the property of frozen bovine tendon was stable, and the prepared collagen sponge contained pores of 50-400 microns in diameter. Some factors influencing pore structure and size in the collagen sponge were discussed. The results of this preliminary study suggested that the collagen could be used as wound dressing.

Animals↗
PubMed1999

[Autodetection of cell adhesion by light transmission].

To set up a new effective method for measuring the adhesion between red blood cells and vascular endothelial cells, we studied the relationship between adhesive red blood cells and light transmission by using Microscope-Photometric-Monolayer-Technique Elias-c Analyzer in our department. The results showed that the method of light transmission measurement on the adhesion between red blood cells and vascular endothelial cells is simple, effective and reliable.

Cell Adhesion↗
PubMed1999

[Effects on the amount of total hemolytic complement levels(CH50) and immunoglobulin in serum induced by the implantation of biomaterials into rats].

Three kinds of biomaterials, PES, YP and SR, were implanted into the subcutaneous tissue of rats and stayed there for 7, 14, 30, 60 and 90 days. Then using the immunity assaying system (Beckman, ICS) and the standard method of measuring the value of total hemolytic complement levels (CH50), we determined the values of immunoglobulin and CH50 in serum of rats. The results showed the amounts of IgG and IgA of rats with the implanted YP and SR materials were significantly higher than those of the control groups, and their value of CH50 was significantly lower than that of the control group. There was no significant difference between the PES group and the control group.

Animals↗
PubMed1999

[Effects of immobilization on the mechanical properties of rabbit patellar tendon].

The aim of this study was to evaluate the effect of immobilization on the mechanical properties of rabbit patellar tendon(PT). IN this study, the rabbit knee was immobilized in extension for 6 weeks, then the mechanical properteis of PT were investigated. The results showed that the stress-strain relationship of PT could be expressed with exponential functions, and there were significant differeces between the normal group and the immobilized group in their theoretical curves of stress-strain relationship and two material constants of PT. Also, significant differences were found in tensile strength and tangent modulus between the two groups, but the maximum load of PT in the immobilized group did not decrease significantly. On the basis of the findings listed above, it is believed that PT would remodel and change its mechanical properties in response to the changes of mechanical stress exerted on it when the knee is immobilized.

Animals↗
PubMed1999

[Quantitative backscatter imaging].

Some methods for producing quantitative backscatter images are presented. As a basis, the data reduction method calculates absolute coefficient. The reference phantom method is easier to implement for clinical application. An application method is also presented which separates the contributions of scatter size and scattering strength to backscatter signal and displays Size image and Strength image separately. This method is generally accepted by the medical community. At last, the recent development of ultrasonic backscatter imaging is reviewed.

Algorithms↗
PubMed1999

Pilot study of schistosomiasis control in Poyang lake region.

AIM: To perform a longitudinal survey of the control of schistosomiasis in Fanhu Village hyperendemic for schistosomiasis, Poyang Lake region of Jiangxi Province from 1992 to 1996. METHODS: Annual mass chemotherapy and health education were implemented in all investigated individuals, in 1996, artesunate was used in high risk population in transmission season as a prophylactic measure. RESULTS: The prevalence of S. japonicum infection reduced from 26.0% in 1992 to 10.7% in 1994, the intensity of infection (geometric mean of EPG of feces) in residents decreased from 1.92 in 1992 to 0.55 in 1994, and the morbidity indicators such as hepatomegaly and splenomegaly in the cases also have been improved significantly after chemotherapy. In 1995, both the infection rate and intensity of infection of schistosomiasis were recurred from 10.7% and 0.55 in 1994 to 18.4% and 1.04 respectively due to the floods. In 1996, the infection rate reduced to 5.0% and the intensity of infection also decreased to 0.25 due to the additional measure. CONCLUSION: A mass chemotherapy in conjunction with health education and oral artesunate for preventing reinfection in transmission season is effective for the control of schistosomiasis in lake regions.

Adolescent↗
PubMed1999

[Experimental study on carotid artery resection with vascular replacement by an autogenous vein graft].

OBJECTIVE: In order to observe the survival rate and the histologic changes of the reestablished common carotid artery system. METHOD: A planned resection of the carotid artery was done and the common carotid artery system was reestablished by interposing an autogenous external jugular vein graft in 15 white rabbits. RESULT: 12 survived, the other 3 rabbits died from graft thrombosis, the survival rate was 80%. Histologic examination demonstrated the smooth internal tunic in the anastomotic part of the carotid-jugular and no graft thrombosis. Angiography demonstrated the free circulation of the blood and no aneurysm in the anastomotic vein. CONCLUSION: It is concluded that it is possible that in selected patients, a planned resection of the carotid artery with replacement by interposing an autogenous external jugular vein graft will be done.

Anastomosis, Surgical↗
PubMed1999

The killing effect of photodynamic therapy using benzoporphyrin derivative on retinoblastoma cell line in vitro.

OBJECTIVE: To evaluate the killing effect of photodynamic therapy (PDT) using new photosensitizer benzoporphyrin derivative complexed with human low density lipoprotein on retinoblastoma (RB) cell line in vitro. METHODS: The experiment of photodynamic killing effect on RB cell line in vitro was performed by using benzoporphyrin derivative (BPD or Verteporfin) and monochromatic light at the wavelength around 690 nm. Seven BPD concentrations (2,500 ng/ml, 1,250 ng/ml, 625 ng/ml, 312.5 ng/ml, 156.25 ng/ml, 78.125 ng/ml, 39.0625 ng/ml) and three energy densities (1.2 J/cm2, 2.4 J/cm2 and 3.6 J/cm2) were applied. The damage of the tumor cells was evaluated by MTT assay 24 hours after PDT. The changes of the ultrastructure of RB cells were observed under eleceronic microscope 4 hours after PDT. RESULTS: There was a significant dose-response relationship between tumor cell damage and BPD concentration in the medium under light irradiation at the energy density of 1.2 J/cm2. At each BPD concentration, the inhibition rate increased with the rise of energy density. RB tumor cell necrosis was found widely under electronic microscope. CONCLUSIONS: This study suggested that RB cells are very sensitive to the PDT induced by BPD in vitro. RB tumor cell were directly killed by photodynamic effect induced by BPD.

Cytotoxicity, Immunologic↗
PubMed1999

[Clinical study on keratoplasty with corneal cryopreservation].

PURPOSE: To evaluate the clinical application value of the corneal cryopreservation in keratonosus. METHODS: 32 patients with keratonosus treated by corneal transplantation were clinically observed. RESULTS: In 32 keratonosus cases, 59.37% (19 cases) of the grafts remained transparant; in 24 corneal ulcer preforation cases, 45.83% (11 cases) of the grafts were transparent, all eyeballs(100%) were remained. CONCLUSION: Corneal cryopreservation can be a practical, effective method in the treatment of keratonosus in district hospitals.

Adolescent↗
PubMed1999

[Soluble IL-2 receptor levels in patients with Graves' ophthalmopathy].

OBJECTIVE: Soluble interleukin-2 receptor (sIL-2R) levels in sera with Graves' ophthmopathy was investigated for its relationship to the clinical manifestations and therapeutic effects. METHODS: sIL-2R levels were measured in sera of 41 patients with Graves' ophthalmopathy which had not yet received specific treatment for their ophthalmopathy and euthyroid during the entire study period and 49 normal subjects. RESULTS: In untreated patients, the mean levels of sIL-2R were significantly higher than those in the normal subjects (P < 0.001). There was no difference in the levels of sIL-2R between patients with hyperthyriod Graves' ophthalmopathy and those with enthyroid Graves' ophthalmopathy. The levels of sIL-2R in patients with response for corticosteoids treatment were significantly higher than that in patients with non-response for corticosteoids treatment (P < 0.001), but there were no differences between the each class present in the NOSPECS classification of ophthalmopathy. 12 patients with response for corticosreoids had lower sIL-2R levels After 3-month treatment than pertreatment. CONCLUSION: These results suggested that elevated sIL-2R levels in patients with Graves' ophthalmopathy may be derived from ophthalmopathy itself, e.g. intra-orbital activated lymphocytes, and serve as a useful parameter to evaluate clinical activity score and predict value of corticosteoids treatment outcome.

Adult↗
PubMed1999

[The restoration of the "double peak" in OCT images based on inverse Wiener].

It has been found that the high reflectivity film of the reference mirror in OCT may cause a socalled "double peak effect" in the result images. To eliminate this a restoration algorithm is proposed here. The method is based on the mathematical modals of the point-spread function of OCT with consideration of double peak effect. The power spectrum of the noise and signal are estimated by the average smooth periodogram method. An inverse wiener filter algorithm, which avoids the illness condition in common inverse filter, gives the final restored images. The algorithm is also capable of the image degrading recovery due to the aberration and the band-limited spectrum.

Algorithms↗
PubMed1999

[Otoacoustic emissions for newborn hearing screening].

OBJECTIVE: To evaluate the validity of transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) in newborn hearing screening and to establish the feasible pass/fail criteria of screening. METHODS: One hundred and eight newborns (216 ears) were screened by TEOAE and DPOAE with Celesta 503 Cochlear Emission Analyzer. The outcome of OAE screening was compared with that of auditory brainstem response(ABR) test. RESULTS: When the criterion of passing TEOAE screening was based on the correlation coefficient of waveforms equal to or greater than 0.60 (r > or = 0.60), the co-positivity and co-negativity to the ABR results were 100% and 93.8% respectively. When the pass criterion of DPOAE was set as that the response levels were greater than the 5th percentile (P5) of the normal newborns in more than five out of eight frequencies, the co-positivity and co-negativity were 100% and 94.3% respectively. The outcome of TEOAE and DPOAE screening between r > or = 0.60 and P5 showed the best correlation, r = 0.6583 (n = 216, P = 0.0001). CONCLUSION: r > or = 0.60 and P5 were the feasible pass criteria of TEOAE and DPOAE for newborn hearing screening respectively. OAE proved to be an objective tool for rapid and effective test in universal newborn hearing screening.

Acoustic Stimulation↗