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Biomedical subjects

L Wang

Publications and source records attributed to L Wang.

At least 1,495 records · Page 83Linked to original sources
PubMed1997

[An experimental study of stretching capacity of lens anterior capsule].

OBJECTIVE: To study the stretching capacity of the lens anterior capsule. METHODS: After continuous circular capsulorhexis (CCC) was performed on 22 bull eyes, the capsular elasticity was measured by gradually opening a modified caliper until the capsular opening was torn. The ratio between the circumference of the opening at rupture and that of the original intact one was used as an index of capsular elasticity. RESULT: The circumference of the intact CCC could be enlarged to an additional 61% before a radial tear occurred. The area of the extended CCC was significantly larger than that of the original CCC and than the cross-section of a lens nucleus tilted 30 degrees. CONCLUSION: The anterior capsule was found to have remarkable stretching capacity, and a suitable size of CCC allows a safe removal of lens substance and intraocular lens implantation without radial tears.

Animals↗
PubMed1997

[Differentiation of lens epithelial cell and effects of serum and ocular tissue on its proliferation in vitro].

OBJECTIVE: To study the pathogenesis of lens posterior capsular opacification (PCO) and the effects of the breakdown of blood-aqueous barrier and remain of lens cortex on PCO in cell culture level. METHODS: The differentiation of cultured bovine lens epithelial cells (BLEC) was observed by Coomassie BB staining, light and electron microscope. The effects of fetal bovine serum, aqueous humor and lens cortex, etc., on the proliferation of BLEC were tested by Giemsa-staining colorimetry. RESULTS: BLEC in vitro could gradually differentiate into lens fiber cells or lens fibers in 1-7 passages. The characteristics of differentiation were that the shape of cells changed from polygon into fusiform and fibriform, the bulk enlarged, and cytoskeleton gradually increased. Fetal bovine serum promoted the proliferation of BLEC depending on its concentration (P < 0.05). High concentration of aqueous humor inhibited the proliferation (P < 0.01). Supernatant and suspension of lens cortex, supernatant of lens nucleus, vitreous humor could promote the proliferation (P < 0.01). CONCLUSION: The differentiation of lens epithelial cells plays important roles in PCO, the breakdown of blood-aqueous barrier, the remain of lens cortex and the prolapse of vitreous may promote PCO by stimulating the proliferation of lens epithelial cells.

Animals↗
PubMed1997

[Effect of B16 cells transfected with IL-2 gene on mouse immunity].

IL-2 was introduced into mice B16 melanoma cell line by using retrovirus infection method. Both B16 and B16-IL-2 cells were treated with Mit C beforehand and were then inoculated intraperitoneally as vaccines in mice respectively. Hanks solution was used instead of the vaccine in the control group. The data showed that the tumor incidence rate was zero in the group receiving B16-IL-2 vaccine followed by B16 inoculation. However, incidence rate was 100% in both the B16 vaccine immunization group and in the control groups. Experiments also indicated that the proliferation of splenic lymphocytes induced by MLTR, the specific cytotoxicity of CTL against B16 cells, the activities of splenic NK, LAK, and the level of IL-2 secretion in mice immunized by B16-IL-2 were much higher than those in the mice immunized only with B16 cells as well as the controls. These data indicated that secretion of IL-2 in mice promoted specific and nonspecific anti-tumor immunity of mice. The theoretic basis was provided for IL-2-secreting tumor vaccine.

Animals↗
PubMed1997

[Image analysis of cell nuclear morphology and DNA content in osteosarcoma of the jaws].

The measurement of nuclear morphology and quantitative analysis of nuclear DNA content were made by Interactive Image Analysis System in 47 osteosarcomas of the jaws. The results showed that with a decreased degree of differentiation, the cell nuclei of osteoblastic and chondroblastic osteosarcomas came to be large and irregular, those of fibroblastic osteosarcomas, however, to be small and round. It was revealed that high-grade osteosarcomas had increased amounts of DNA and that the mean of DNA content, proportion of hyperploid cells and tumor ploidy were found to be of important prognostic value.

Cell Nucleus↗
PubMed1997

[Properties of adherence of erythrocytes to endothelial cells in patients with ischemic stroke].

Adherence of erythrocytes to human umbilical vein endothelial cells (HUVEC) in patients with cerebral thrombosis and transient ischemic attack (TIA) were quantitatively studied in the flow chamber system, compared with that in healthy subjects. We found: (a) The adherence of erythrocytes to HUVEC in patients with cerebral thrombosis and TIA increased, compared with that in healthy subjects; (b) The adhesion of erythrocytes to HUVEC in patients with TIA was not significantly different from that of patients with cerebral thrombosis. These suggested that the increased adhesion of erythrocytes to endothelial cells might play an important role in the pathologic process of ischemic stroke.

Aged↗
PubMed1997

[The expression of tumor suppressor gene p53 and Rb gene in nasopharyngeal carcinoma].

In order to observe the relation of tumor supperssor gene p53 and Rb gene to nasopharyngeal carcinoma, we investigated p53 gene mutations in exon 7-8 in 33 cases of nasopharygeal carcinoma (NPC), using single-strand conformation ploymorphism analysis of PCR (PCR-SSCP). The data showed p53 mutations in 7 of 33 specimens at exon 8 (21.2%). No mutation in exon 7 was detected. Analysis of Rb gene in NPC tissues by southern blot revealed the deletion and loss of activity of Rb gene in 11 of 13 cases (86.6%). Our results suggest that Rb gene and p53 gene are closely associated with the tumorigenesis of NPC.

Carcinoma, Squamous Cell↗
PubMed1997

[A three-month follow-up study of excimer laser photorefractive keratectomy for myopia].

In order to evaluate the efficacy of photorefractive keratectomy (PRK) in the treatment of myopia, we summed up and analysed the 3-month follow-up data on 145 cases treated in our hospital. Prior to PRK, refractive dioptal was -1.5 to -11.5; visual acuity was less than 0.1 in 137 cases (94%) and less than 0.5 in 8 cases(6%). One month after operation, the mean refractive dioptal was +0.98 +/- 0.88; visual acuity increased to > or = 1.0 in 95 cases (66%) and to > or = 0.5 in 142 cases(98%). Three months after operation, the mean refractive dioptal was -0.13 +/- 1.09; visual acuity increased to > or = 1.0 in 104 cases(72%) and to > or = 0.5 in 135 cases(93%). There was no severe complication noted in all cases. The results demonstrate that PRK is and effective, safe and predictable treatment for myopia.

Adolescent↗
PubMed1997

[Effect of perilymphatic fistula on distortion product otoacoustic emissions in guinea pigs].

Perilymphatic fistula was induced in 11 healthy guinea pigs to study its effects on distortion product otoacoustic emissions (DPOAEs). DPOAE amplitudes decreased significantly right after formation of the fistula (P < 0.01), and recurred to near pretreatment level in animals whose fistula healed. The amplitude remained below pretreatment level 18 days after fistulization in those animals whose fistula failed to heal. Under light microscope, the organ of Corti was seen normal. The authors feel that DPOAEs may be helpful in detecting perilymphatic fistula.

Acoustic Stimulation↗
PubMed1997

[Influence of intercellular adhesion molecule-1 transcription on nasal epithelial cell by airborne allergenic pollens].

Eleven patients with Artemisia allergic rhinitis were evaluated. Among them 8 were studied during pollen season and 3 out of pollen season. Intercellular adhesion molecule-1(ICAM-1) was detected on nasal epithelial cells by reverse transcription polymerase chain reaction (RT-PCR). The results showed that ICAM-1 was detectable from all samples in the pollen season. However, during off-pollen season 2 of the 3 samples were negative, 1 was positive (who was also positive to house dust). It is suggested that ICAM-1 is detectable on nasal epithelial cells during exposure to specific allergen.

Adolescent↗
PubMed1997

[Integration of visual signals in the brain: mechanisms and functional significance of synchronous oscillation].

How are the functions performed by one part of the nervous system integrated with those of others? One possible way is by synchronous oscillation. We have reviewed recent advances in visual system, where synchronous oscillations have been intensively observed and investigated. This article is concentrated on discussing theoretical reasoning, experimental evidence, possible mechanisms underlying the generation and the functional significance of visual synchronous oscillations. Predictions on several prosperous areas were also outlined.

Animals↗
PubMed1997

[Comparison of two extraction methods for maxingshigan decoction].

The semi-bionic extraction and the extraction with water, two methods for the Maxingshigan Decoction, were compared. The results show that the semi-bionic extraction is superior to the extraction with water in the yield of ephedrine, hydrocyanic acid, glycyrrhetinic acid, calcium ion and extract.

Calcium↗
PubMed1997

[Determination of oleanolic acid contents in differently-processed Achyranthes bidentata Bl. by HPLC].

The contents of oleanolic acid in differently-processed products of Achyranthes bidentata were determined by HPLC. The result showed the contents to be in the following sequence: salt-broiled product > alcohol steamed product > alcohol-broiled product > unprocessed product. The average recovery rate was 100.2% and RSD 1.54%. The determination method has thus proved up to the standard for quantitative analysis.

Chromatography, High Pressure Liquid↗
PubMed1997

Vitrectomy for complicated Eales disease.

PURPOSE: We determined the efficacy of pars plana vitrectomy in a series of patients with complicated Eales disease. METHODS: Clinical records were reviewed on 47 consecutive patients (49 eyes) who underwent vitrectomy for persistent vitreous hemorrhage (PVH) and/or traction retinal detachment (TRD) with neovascular membranes (NVM). All cases were divided into 4 subgroups of eyes with PVH (without obvious NVM, n = 9), NVD (NVM from the optic disc, n = 10), NVP (peripheral NVM, n = 11), or ENV (extensive NVM and logn-standing TRD, n = 17). RESULTS: The study included 8 women and 39 men with a mean age of 27.3 years (range, 16 to 50 years). The visual acuity was light perception in 15 eyes, hand motions in 18 eyes, counting fingers in 6 eyes and 0.02 to 0.1 in 10 eyes before vitrectomy. Visual acuity improved postoperatively in all eyes with PVH, NVD of NVP with a mean visual acuity of 0.32 (range, 0.05 to 1.0, n = 28) except 3 eyes unchanged. There was no significant difference (P > 0.05) in the patient age, preoperative visual acuity, or visual improvement after vitrectomy among these 3 subgroups. In the eyes with ENV, however, postoperative visual improvement was obtained but limited in 9 eyes (range, 0.02 to 0.15). Visual acuity was unchanged in 9 eyes. There was a significant difference (P < 0.01) in postoperative visual acuity between the eyes with ENV and the eyes with PVH, NVD or NVP. CONCLUSIONS: Vitrectomy with removal of persistent vitreous hemorrhage and focal neovascular membranes and endolaser photocoagulation may lead to improved visual acuity in the majority of eyes with Eales disease. However, extensive fibrovascular membranes and long-standing retinal detachment result in poor visual outcome. Earlier surgery can be considered to prevent visual loss in the patients.

Adolescent↗
PubMed1997

[Cloning and restriction analysis of saw1--a key gene for differentiation of Streptomyces ansochromogenes].

saw1--a essential gene for sporulation of Streptomyces ansochromogenes was cloned, 7 kb of DNA fragment in Streptomyces plasmid pIJ702 could recover the sporulation of saw1-deficient strain W51 which could not form spore with white phenotype of aerial hyphae. The recombinant plasmid was deleted by some restriction enzymes, the result showed that 2.5 kb DNA fragment in pIJ702 still has function to recover sporulation of W51. The sequencing and expression of saw1 gene is carrying out at present.

Cloning, Molecular↗
PubMed1997

[Protective effect of puerarin on acute cerebral ischemia in rats].

Acute incomplete brain ischemia in rats was induced by bilateral carotid artery occlusion(BCAO). BCAO results in severe suppression of EEG and increase of brain water content. Left middle cerebral artery occlusion(MCAO) in rats by electrical coagulation results in increase of brain water content of ipsilateral hemisphere and contralateral hemiparesis. The typical ischemic neuropathological damage emerges in both BCAO and MCAO models. Intraperitoneal injection of puerarin significantly helps improve all these brain ischemic disturbances.

Animals↗