Search PubMed⌕ Search

Biomedical subjects

Z Liu

Publications and source records attributed to Z Liu.

At least 667 records · Page 37Linked to original sources
PubMed1999

[The T cell activation from peripheral blood of patients with herpetic keratitis following in vitro activation].

OBJECTIVE: To evaluate the T cells activation from peripherial blood(PB) of patients with herpes simplex keratitis following in vitro activation. METHODS: The flow cytometry was used to investigate the expression of HLA-DR, CD25, CD69, CD71 on T cell from PB, the PB in culture, the PB cultured with phytohemagglutinin(PHA) or phorbol 12, 13-dibutyrate(PDB) or PDB and ionophore (IONO), in 7 cases with herpetic stromal keratitis (HSK) and 4 cases with herpetic ulcer keratitis(HUK). 6 normal people were set as control. RESULTS: The percentages of CD3+DR71+ was higher, and the CD3+CD71+ was lower from PB of patients with HSK than those from normal people. After the PB was cultured for 72 hours, the percentages of CD8+CD71+ in lymphocytes from HSK and CD8+DR+, CD8+CD69+, CD8+CD71+ in lymphocytes from HUK were lower than those from nomal people. And the CD8+CD71+ cells from HUK also was lower than those from HSK. When the PB was cultured with PHA for 72 hours, the percentages of CD3+CD71+, CD8+CD69+, CD8+CD71+ from HSK and HUK were lower than those from normal people. The percentages of CD8+CD25+ in lymphocytes from HUK also was lower than those from normal, and the CD8+CD69+ cells in lymphocytes was lower than those from HSK. The percentages of CD3+CD71+ in PB cultured with PDB for 72 hours, CD3+CD69+ in PB cultured with PDB and IONO for 72 hours from HSK were lower than those from normal people. CONCLUSION: The ability of T cells activation decreases in cases with HSK following in vitro activation. The lymphocytes in patients with HUK shows much lower activation than those cases with HUK.

Antigens, CD↗
PubMed1999

[The improvement on related condition of corneal cryopreservation and roles of cryopreserved corneas in emergent keratoplasty].

PURPOSE: To study the cryopreserved corneal endothelium viability on the condition that a series of related factors on long-term corneal cryopreservation were modified. The frozen corneas were used for emergent penetrating keratoplasty on poor condition patients. To evaluate the role of cryopreserved corneas on clinical application, especially on emergent keratoplasty. METHODS: Residual peripheral corneas were stained with Trypan blue and Alizarin red in order to assess endothelium survival rate after central grafts were punched. Specular microscope was used to measure corneal thickness and count endothelium density. The transparent rate of grafts, infective control rate, retinal restorative rate and the recovery degree of visual acurity were emphasized respectively. RESULTS: Endothelium survival rate of grafts was 82.1% averagely. Postoperative endothelium density was 1,642 cells/mm2 and graft thickness was 0.59 mm averagely. The epithelial defects healed after 2-5 days of the operation and edematous grafts were reclear after 2-4 weeks of the operation in all grafts, except for chemical burn and thermal burn. The transparent rate was 87.5%. Infective controll rate was 90.63%. Retinal restorative rate was 55.56%. Some useful visual acurity can be obtained when the infection was under controlled and the retinal was reattached. CONCLUSION: Modified long-term corneal cryopreservation is effective in maintaining endothelium viability and integrity. Furthermore, it could provide donors anytime because of it's unlimited preservative duration. Our study emphasizes especially the role of cryopreserved corneas in emergent keratoplasty.

Adolescent↗
PubMed1999

Corneal topographical changes following strabismus surgery.

PURPOSE: To study corneal topographical changes after strabismus surgery. METHODS: Computer-aided corneal topography was used in 43 strabismus patients (45 eyes) one or two days prior to and six or seven days after strabismus surgery. The spherical and cylindrical equivalents were calculated based on the simulated keratometry. RESULTS: After the surgery, only the changes at 3 mm in the inferior quadrant were statistically significant. The changes at 3 mm in the rest quadrants and the changes at 7 mm were not significant. Significant changes in spherical equivalent were found post-operatively. Neither the horizontal nor the vertical meridional equivalent showed significant changes after surgery. CONCLUSIONS: The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

Adolescent↗
PubMed1999

[Detection of TT virus DNA in peripheral blood mononuclear cells in patients with chronic hepatitis B and hepatocellular carcinoma using PCR and in situ hybridization].

OBJECTIVE: To determine whether the TTV infection occurs in peripheral blood mononuclear cells (PBMCs) of patients with chronic hepatitis B (of medium degree) and in HBsAg positive hepatocellular carcinoma (HCC). METHODS: TTV DNA in PBMCs was detected by nested-polymerase chain reaction(PCR) and in situ hybridization (ISH). RESULTS: 7 of 26 cases of chronic hepatitis B were positive for TTV DNA by nested-PCR with a positive rate of 26.9% that was significantly higher than that of normal control(chi 2 = 14.3, P < 0.001); 4 of 21 HBsAg positive cases were positive for TTV DNA by nested-PCR with a positive rate of 19.0%, also significantly higher than that of normal control(chi 2 = 4.86, P < 0.05). 4 of 7 TTV positive patients with chronic hepatitis B tested by nested-PCR were positive for TTV DNA by ISH in PBMC cytoplasm, with a positive rate of 57.1%. CONCLUSION: (1) A higher incidence of TTV DNA in PBMCs of patients with chronic hepatitis B and in HBsAg positive HCC was identified by nested-PCR and ISH; (2) TTV DNA was in the cytoplasm of PBMCs in patients with chronic hepatitis B.

Adult↗
PubMed1999

[Changes in nasal airway resistance before and after endoscopic sinus surgery].

OBJECTIVE: To study the influence of endoscopic sinus surgery(ESS) on nasal airway resistance (NAR) and to analyze the relationship between NAR and nasal airflow sensation. METHODS: The NAR and nasal airflow sensation were measured with anterior rhinomanometry and visual analogous scale test (VAS) in 42 patients (50 sides) before and after the ESS. RESULTS: NAR decreased significantly after the operation. The change rates in NAR before and after the decongestion were (55.71 +/- 13.90)% and (24.32 +/- 8.73)%, respectively, and there was a significant difference (P < 0.05). The pathological increase in NAR correlated well with subjective sensation of the patients (P < 0.05). CONCLUSION: The improvement of nasal functions by ESS is not due to the alteration of the anatomic structure of the nasal cavity, but to the amelioration of mucosal edema. The rhinomanometry can be used as a useful clinical tool in determining nasal patency.

Adolescent↗
PubMed1999

[Research on expression of telomerase hTR gene in oral precancerous lesion and squamous cell carcinoma]

OBJECTIVE:The aim of present study was to investigate the expression of telomerase hTR gene in oral precancerous lesion and squamous cell carcinoma. METHODS:82 cases were detected by in situ hybridization technique for hTR gene,including 7 cases of normal oral mucosa,7 cases of hyperplasia lesions,30 cases of oral precancerous lesions(dysplasia lesion),38 cases of oral squamous cell carcinomas.RESULTS:Weaker signal of hTR gene expression was observed in normal oral mucosa and hyperplasia lesions,positive cell were present in basal layer,hTR positivity was 28.56%(4 of 14).The expression of hTR gene in the precancerous lesions was gradually strong associated with phenotypic progression and the degree of dysplasia;positive cell extended from basal layer to multi layered epithelium,hTR positivity was 60%(18 of 30).Strong hTR expression was observed in squamous cell carcinoma,the positivity was 81.58%(31 of 38).CONCLUSION:Telomerase is activated frequently during the late stage of oral precancerous lesion and may play a crucial role in oral squamous cell carcinogenesis.

Journal Article↗
PubMed1999

[A study of the mitogen effects of endothelin-1 on human dental pulp cell in vitro]

OBJECTIVE:To investigate the mitogen effects of endothelin-1 (ET-1)with different concentrations on human pulp cells.METHODS:Using in vitro pulp cell cultrue technique and thiazolyl blue tetrazolium bromide (MTT) staining and spectrophotometric assay.RESULTS:Endothelin-1 with different concentration had the mitogenesis on human pulp cells in different degree,which was dependent on ET-1 concentration.CONCLUSION:Endothelin-1 which was mitogen factor on human pulp cells may play a role in the regeneration of pulp tissue.

Journal Article↗
PubMed1999

[The visible spectra study of the conformation equilibrium of iron-metal-free porphyrin dimers].

A series of iron(III)-metal-porphyrin dimers linked with flexible alkoxyl chain at para position of two phenyl rings have been synthesized and characterized. An equilibrium of two conformations of porphyrin dimers (open and closed) has been studied by visible spectra. The intensity of absorption band 680 nm relates to equilibrium of two conformations. With the increase of the length of the alkoxyl chain,the closed conformation forms more easily. With the addition of axial ligand, the ferric ion of the dimers tends to bind with imidazole, and the intensity of the band 680 nm gradually decreases and disappears.

Dimerization↗
PubMed1999

[Studies on the infrared and fluorescence spectra of europium lanthanum-benzoate complexes].

A series of mixed rare earth complexes of benzoic acid with europium and lanthanum were synthesized by the reaction of trivalent rare earth chlorides with ammonium benzoate in aqueous solution. Their composition is expressed with the general formula (Eu(1-chi)La(chi)) L3, where L = C6H5COO(-1), chi = 0.0-1.0. Their infrared and fluorescence spectra were investigated. The characteristic asymmetric (v(as)) and symmetric (v(s)) stretching vibrations of carboxyl group for rare earth complexes shift to lower frequency in comparison with sodium benzoate, and both the absorption bands show splitting. In addition, the difference between v(as) and v(s), deltav (120-125) cm(-1), is lees than that of sodium benzoate (deltav =137 cm(-1)). These situations show that the coordinating pattern of the carboxyl groups in the complexes is the form of chelation-bridging, therefore, it may be suggested that the rare earth (Eu, La) benzoates are a heteronuclear polymers. The dependence of the relative fluorescence intensity of the mixed rare earth complexes upon the content for La3+ ions was discussed. The results show that the emission intensity for Eu3+ ions can be greatly enhanced if a part of Eu3+ ions in europium benzoate were substituted by La3+ inos. When chi = 0.4, 0.5 or 0.7, the fluorescence intensity of the rare earth complexes can rise above 40%.

English Abstract↗
PubMed1999

[FTIR and fluorescence emission spectra of sulfonated PS and its ionomers].

The FTIR spectra of sulfonated polystyrene and Zn and La ionomers change with sulfonation degree and the kind of metal ion. With increasing the sulfonation degree, the stretching vibrational strength of -SO3H and -SO3 increases. Because of the interaction of polar group, the FTIR spectra around 1200 cm(-1) or so split. On the other hand, the degree of sulfonation influences somewhat on the intensity and position of fluorescence spectra of sulfonation polystyrene and its ionomers.

English Abstract↗
PubMed1999

[Determination of P in superhigh-P cast iron by EDXRF].

In this paper preparation of standard samples of superhigh-P cast iron has been studied and P in the samples has been determined by EDXRF and powder compacting. In the process the procedure of powder compacting and the software of a multifunctional Lucas-Tooth intenstity correction have been developed. The method is rapid and simple. Analytical results were satisfactory.

English Abstract↗
PubMed1999

[Spectrophotometric determination of trace amount of cadmium in marine products].

The colour reaction of Cd(II) on xylend orange in the presence of hexamethylenetetramine-KNO3-HNO3 has been studied. Cd(II) forms the complex at pH = 6.2-6.4 (lambda(max) = 578.4 nm) with an apparent molar absorptivity of 1.6 x 10(4) L x mol(-1) x cm(-1). Beer's law is obeyed for Cd(II) in the range of 0.5-6 microg x mL(-1). The detection limit is 0.007 microg x mL(-1) with the recovery of 90%-105%. The method is simple and highly sensitive, and has been applied to the analysis of sample with satisfactory results.

Animals↗
PubMed1999

[Software package for self-constructed CCD-ICP-OES. 1. Software system and design idealogy].

A software package and its design idealogy for the self-constructed CCD-ICP-OES are described. The MS Windows 95TR was used as the operating platform. The Software package written in MS Visual C + + TR V 4.2 included the control of grating and CCD, the dynamic monitoring, the treatment of spectral signal, the fixing of wavelength position, the automatic fixing of spectral line, the quantitative analysis, the stripping method, the Kalman filter and the artificial neural network.

English Abstract↗