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Biomedical subjects

Ke Yao

Publications and source records attributed to Ke Yao.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Long-term follow-up of visual functions after pediatric cataract extraction and intraocular lens implantation].

OBJECTIVE: To assess the visual acuity and binocular function of children after pediatric cataract extraction and intraocular lens implantation. METHODS: 47 children with 68 eyes (< 13 years old) were included in the study: 12 children with monolateral traumatic cataract, 14 children with monolateral congenital cataract and 21 children with bilateral congenital cataract. Cataract type, cataract extent, age at surgery and presence of strabismus and nystagmus and the best corrected distant visual acuity (BCDVA) before surgery were recorded and as well. In addition, the best corrected near visual acuity (BCNVA) and binocular function were followed up for an average of (41.3 +/- 12.3) months. Statistical analysis was used to define factors that correlated with achieving good visual acuity and binocular function. RESULTS: BCDVA and BCNVA were 0.5 or better in 34 eyes (50.0%) and a good binocular function was achieved in 18 children (38.3%). Age at surgery, extent of cataract, absence of strabismus and nystagmus were significant for good BCDVA. Age at surgery, absence of strabismus and nystagmus, good BCDVA were significant for good binocular function. CONCLUSIONS: Good visual acuity and binocular function can be achieved after pediatric cataract extraction and intraocular lens implantation. Multiple factors correlated with achieving good visual function such as timing of surgery, type and extent of cataract, absence of strabismus and nystagmus etal.

Adolescent↗
PubMed2005

[Advances in surgical management of presbyopia].

Presbyopia is age-related reduction in amplitude of accommodation and can not read comfortably. Current methods such as single-focus glasses, bifocal glasses and progressive additional lens are the most widely used for correction of presbyopia. All surgical solutions for presbyopia do not improve the physiological amplitude of accommodation. This article is an attempt to review the advances in surgical management of presbyopia.

Humans↗
PubMed2004

Special fasciculiform cataract caused by a mutation in the gammaD-crystallin gene.

PURPOSE: To identify ultrastructure changes and genetic defects associated with a special fasciculiform autosomal dominant congenital cataract (ADCC) affecting a large Chinese family. METHODS: Members of the Chinese family affected by this special fasciculiform ADCC were studied. Clinical examinations, light and transmission electron microscopy of the removed lens tissue, linkage analyses using polymorphisms of microsatellite markers, and mutational analyses of candidate genes by direct sequencing were performed. RESULTS: The thirteen affected individuals in the family showed no variability between one another. The lens fiber cells showed focal degeneration, dense globular intracellular deposits, and an enlarged intercellular space. This ADCC was associated with a locus on chromosome 2q33-35 (maximum lod score [Zmax]=3.34; theta=0.05). Mutational analyses of the candidate genes (gamma-crystallin; CRYG), identified a C->A heterozygous transversion at nucleotide position 70 in the gammaD-crystallin gene (CRYGD) exon2, which co-segregated with the presence of ADCCs and was not observed in 100 unrelated controls. CONCLUSIONS: This study identified ultrastructure changes and genetic defects associated with a special fasciculiform ADCC affecting a large Chinese family. It appeared to be caused by a missense mutation in the CRYGD gene, further supporting the notion that alterations to CRYG play an important factor in human cataract formation.

Cataract↗
PubMed2004

Low power microwave radiation inhibits the proliferation of rabbit lens epithelial cells by upregulating P27Kip1 expression.

PURPOSE: The goal of this study was to examine the effects of low power microwave radiation (<10 mW/cm2) on the proliferation of cultured rabbit lens epithelial cells (RLEC). METHODS: Cultured RLEC were exposed to continuous microwave radiation at a frequency of 2,450 MHz and power densities of 0.10, 0.25, 0.50, 1.00, and 2.00 mW/cm2 for 8 h. Cell morphologic changes were observed under a phase-contrast microscope. Cell viability was measured using the MTT assay and cell cycle analysis was measured using flow cytometry. After exposure to 2.00 mW/cm2 microwave radiation for 4, 6, and 8 h, the expression of cell cycle-regulatory proteins, P21WAF1 and P27Kip1, was examined using western blot analysis. Finally, the levels of P21WAF1 and P27Kip1 mRNA were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: After 8 h of radiation treatment, cells treated with 0.50, 1.00, and 2.00 mW/cm2 microwave radiation exhibited decreased cell viability, increased cell condensation and an inhibition of DNA synthesis. RLEC showed significant G0/G1 arrest. No obvious changes could be detected in the 0.10 and 0.25 mW/cm2 microwave treatment groups. Protein expression of P27Kip1 was markedly increased after microwave radiation. However, the mRNA levels were unchanged. On the other hand, there were no detectable differences in P21WAF1 protein expression and mRNA levels between microwave treatment and control groups. CONCLUSIONS: This study suggests that low power microwave radiation higher than 0.50 mW/cm2 can inhibit lens epithelial cell proliferation, and increase the expression of P27Kip1. These effects may account for the decline of lens epithelial proliferation after exposure to microwave radiation.

Animals↗
PubMed2004

Expression and proteolytic activity of calpain in lens epithelial cells of oxidative cataract.

OBJECTIVE: To study the role of calpain in the mechanism of oxidative cataract through detecting the level of intracellular free Ca(2+), the expression and proteolytic activity of calpain in the lens epithelial cells (LECs) of H(2)O(2)-induced cataract. METHODS: Rat lenses were cultured in vitro and cataract was induced by H(2)O(2). The level of intracellular free Ca(2+) was measured by fluorescence determination with fura-2/AM. The expression of m-calpain protein in LECs was detected with immunohistochemical method. The proteolytic activity in LECs was measured using a fluorogenic synthetic substrate. RESULTS: There were significant differences of the level of intracellular free Ca(2+) (P=0.001, 0.000, 0.000), the expression of m-calpain (P=0.001, 0.000, 0.000) and the proteolytic activity of calpain (P=0.001, 0.000, 0.000) between H(2)O(2)-induced and control group at 6, 12 and 24 h, respectively. CONCLUSIONS: H(2)O(2) can increase intracellular free Ca(2+), then enhance the expression and proteolytic activity of calpain which may play a role in the mechanism of oxidative cataract of rat.

Animals↗
PubMed2004

Assessment of macular function by multifocal electroretinogram in diabetic macular edema before and after vitrectomy.

The purpose of this study was to assess the effects of vitrectomy on retinal function in macular and paramacular areas in patients with diabetic macular edema (DME). Ten eyes of 9 patients with successful vitrectomy for DME were evaluated by multifocal electroretinogram (mfERG), optical coherence tomography (OCT), and visual acuity preoperatively and 1, 2, 3, 4, 5 and 6 months postoperatively. Compared with pretreatment values, the response of the positive wave (P1) in macular and paramacular areas tended to decrease in latency from the second postoperative month, and increase in amplitude at the third postoperative month. There was no significant change in response of the negative wave (N1). The tendency in the change of macular function is coincident with that of macular morphology. Therefore, The multifocal ERG may provide objective criteria for the functional evaluation of DME before and after vitrectomy.

Aged↗
PubMed2004

Role of anions in nitric oxide-induced short-circuit current increase in isolated porcine ciliary processes.

PURPOSE: To investigate how nitric oxide (NO) modulates short-circuit current (Isc) in isolated porcine ciliary processes. METHODS: Isc changes (Ussing-type chamber) induced either by the NO donors SNP or SIN-1, or by the cGMP analogue 8-pCPT-cGMP were assessed. The effect of inhibitors of guanylate cyclase (10 microM ODQ, 100 microM LY83583), protein kinase G (30 microM Rp-8-pCPT-cGMP, 3 microM KT 5823), protein kinase A (1 microM KT 5720), or protein kinase C (1 microM Go6983) on SNP- or 8-pCPT-cGMP-induced Isc changes were investigated. The effect of inhibitors of anion channel (100 microM niflumic acid, 1 mM DIDS, and 1 mM 9-AC), K+-channel (10 mM TEA, 10 mM BaCl2), Na+-channel blockers (1 mM amiloride), Na+-K+-2Cl- cotransporter inhibitor (0.5 mM bumetanide), or carbonic anhydrase inhibitor (1 mM acetazolamide) was studied. In Cl(-)- or HCO3(-)-free Krebs-Ringer solution, the effect of SNP- or 8-pCPT-cGMP-induced Isc changes was accessed. RESULTS: SNP, SIN-1, or 8-pCPT-cGMP increased Isc with a change in the potential difference that became more negative toward the nonpigmented epithelium (aqueous) side. The Isc increase induced by SNP or SIN-1, but not by 8-pCPT-cGMP, was prevented by ODQ and LY83583. SNP- and 8-pCPT-cGMP-induced Isc increases were prevented by Rp-8-pCPT-cGMP or KT5823 (but not by KT5720 or Go6983), or by niflumic acid, DIDS, 9-AC, or acetazolamide (but not by TEA, BaCl2, amiloride, or bumetanide). The effect of SNP and 8-pCPT-cGMP was abolished in Cl(-)- and reduced in HCO3(-)-free solutions. CONCLUSIONS: NO activates a guanylate cyclase-cGMP-protein kinase G pathway that appears to stimulate stroma-to-aqueous anionic transport, possibly Cl-, in porcine ciliary epithelium.

Animals↗
PubMed2004

[Combined surgery for cataract and glaucoma: phacoemulsification, foldable intraocular lens implantation and viscocanalostomy].

OBJECTIVE: To assess the outcome of phacoemulsification-intraocular lens (IOL) implantation combined with viscocanalostomy (P-C group), compared with that of phacoemulsification-IOL implantation combined with trabeculectomy (P-T group). METHODS: Combined phacoemulsification with corneal incision, foldable intraocular lens implantation and viscocanalostomy was performed in 21 eyes of 19 cataract patients with primary open-angle glaucoma. All patients were followed up for 3 - 6 months. RESULT: Intraocular pressure (IOP) was significantly lower in both P-C group and P-T group (P=0.000). There was no statistically significant difference between two groups. Visual outcome was similar in both groups. Complications of P-C group included Descemet's membrane puncture in 2 eyes, Schlemm's tube puncture in 2 eyes and IOP spikes in 3 eyes (at 24 hours postoperatively). The P-C group experienced significantly less inflammation than the P-T group. CONCLUSION: Phacoemulsification-IOL implantation combined with viscocanalostomy is a safe and effective surgery, with lower complicatin rate and easier ambulatory care.

Aged↗
PubMed2004

[Localization and screening of autosomal dominant coralliform cataract associated gene].

OBJECTIVE: To identify the genetic defect for the autosomal dominant coralliform cataract affecting a four-generation Chinese family. METHODS: Genomic DNA from the family members was typed for whole genomic linkage analysis. Two-point LOD scores were calculated using the LINKAGE program package (version 5.1). Mutation analysis of candidate genes was performed by direct sequencing. RESULTS: Thirteen of the 38 individuals had congenital cataracts. The maximum two point LOD score, 3.5 at theta=0.1 was obtained for the marker D2S325. Mutation analysis of the gamma-crystallin gene cluster identified a C --> A mutation in exon 2 of gamma-D crystallin gene (CRYGD) associated with cataracts in this family. This mutation resulted in a substitution of threonine for proline at amino acid 23 (P23T) of the protein. CONCLUSION: The results suggest that the coralliform cataract phenotype is due to a mutated gamma-D gene, and the sequence change is identical with that recently reported to be related with lamellar cataract, a distinct clinical entity, thus providing evidence that the same genetic defect may be associated with different opacity location. The pathogenesis needs further investigation.

Base Sequence↗
PubMed2004

[Surface modification of poly methyl methacrylate intraocular lens by alpha-allyl glucoside].

A method for improving the biocompatibility of the intraocular lens (IOL) and reducing the cell attachment was adopted in this study. The alpha-Allyl glucoside was used for the surface modification of the poly methyl methacrylate (PMMA) IOL by way of plasma-induced in situ polymerization. The surfaces of the control and treatment IOLs were characterized by contact angle estimation and ESCA techniques. The resolution, diopter and anti-fatigue of loops were determined by physical and optical methods. Cell attachment on the surfaces was examined by light microscopy. The results indicated that all of the treatment groups had excellent physical and optical properties. The modification with the use of alpha-Allyl glucoside could improve the hydrophilicity of the anterior surface of the PMMA IOLs and reduce the cell attachment.

Allyl Compounds↗
PubMed2004

Autosomal dominant coralliform cataract related to a missense mutation of the gammaD-crystallin gene.

BACKGROUND: Congenital cataract is a sight-threatening disease that affects about 1 - 6 cases per 10000 live births and causes 10% - 30% of all blindness in children. About 25% of all cases are due to genetic defects. We identified autosomal dominant congenital coralliform cataracts-related genetic defect in a four-generation Chinese family. METHODS: Complete ophthalmological examinations were performed prior to lens extraction. Lens samples were then studied by electron microscopy. Genomic DNA from family members were examined using whole-genomic linkage analysis, with two-point logarithm of odds (LOD) scores calculated using the Linkage program package (version 5.1). Mutation analysis of candidate genes was performed by direct sequencing. Finally, a three-dimensional protein model was predicted using Swiss-Model (version 2.0). RESULTS: Eleven of the 23 examined individuals had congenital cataracts. Ultrastructure studies revealed crystal deposits in the lens, and granules extensively dispersed in transformed lens fiber cells. The maximum two-point LOD score, 3.5 at theta = 0.1, was obtained for the marker D2S325. Mutation analysis of the gamma-crystallin (CRYG) gene cluster identified a mutation (P23T) in exon 2 of gammaD-crystallin (CRYGD). Protein structure modeling demonstrated that the P23T mutation caused a subtle change on the surface of the gammaD protein. CONCLUSIONS: The results suggest that the coralliform cataract phenotype is due to a mutated CRYGD gene, and that this sequence change is identical to one reported by Santhiya to be related to another distinct clinical condition, lamellar cataract. This study provides evidence that this same genetic defect may be associated with a different phenotype. This is the first report identifying the genetic defect associated with an autosomal dominant congenital coralliform cataract.

Cataract↗
PubMed2004

[Dynamic changes of tissue inhibitors of metalloproteinases in the rabbit iris and aqueous humor after lens mechanical injury].

OBJECTIVE: To investigate dynamic changes of expression of tissue inhibitors of metalloproteinases (TIMPs) in the rabbit iris and aqueous humor after the lens mechanical injury. METHODS: Rabbit lens was mechanically injured by a needle through the limbus. Eyes were enucleated on the 1st, 3rd, 7th and 15th day after injury, the aqueous humor was collected and the iris was isolated. The activity of two main TIMPs (TIMP-1 and TIMP-2) in the aqueous humor and the iris was assessed by reverse zymography assay while the activity of matrix metalloproteinase-2 (MMP-2) was analyzed by zymography assay. RESULTS: In the healthy and uninjured rabbit eye, neither TIMP-1 nor TIMP-2 was detected in the aqueous humor or in the iris. In the iris of the injured eye, the activity of TIMP-1 and TIMP-2 was increased significantly 1 day after the injury (P < 0.05), the activity of MMP-2 was inhibited. In the aqueous humor of the injured eye, the activity of TIMP-1 and -2 increased significantly (P < 0.05) 1 day after the injury and the activity of MMP-2 was not detectable. The activity of TIMP-1 and -2 decreased afterwards and no significant difference was detected between the injured eyes and the control eyes 7 days after the injury (P value was 0.097 and 0.777, respectively), while the activity of MMP-2 was increased gradually. CONCLUSION: TIMPs are involved in the acute inflammation process after the lens injury, which may play an important role in the inhibition of inflammation and in the wound healing.

Animals↗
PubMed2004

[Clinical observation of combined surgery for cataract and glaucoma: phacoemulsification and viscocanalostomy].

OBJECTIVE: To evaluate the therapeutic effects and safety of phacoemulsification-intraocular lens (IOL) implantation combined with viscocanalostomy (V-P) and compared the outcomes of phacoemulsification-IOL implantation combined with trabeculectomy (T-P). METHODS: Combined phacoemulsification with corneal incision, foldable intraocular lens implantation and viscocanalostomy was performed in 30 eyes of 28 cataract patients with primary open-angle glaucoma. RESULTS: Follow-up was performed up to 6 months after surgery. The mean intraocular pressure (IOP) of V-P group was (14.65 +/- 2.70) mm Hg (1 mm Hg = 0.133 kPa) with a mean pressure reduction of 10.33 mm Hg compared with IOP before the operation (P = 0.000). There were no statistical differences of the IOP within two groups during postoperative 1 week, 1 and 6 month (P = 0.661, 0.381, 0.526). Postoperatively, the best corrected visual acuities of V-P group were > or = 0.5 in 18 eyes (follow-up 29 eyes, 62.1%), 20 eyes (28 eyes, 71.4%), 24 eyes (30 eyes, 80.0%) at 1 week, 1 month and 6 months, but no statistical difference with T-P group, (P = 0.621, 0.702, 0.893). Complications of V-P group included: Descemet's membrane puncture 2 eyes (6.7%), Schlemm's tube puncture 2 eyes (6.7%) and IOP spikes 4 eyes (13.3% at 24 hours postoperatively). The V-P group showed a significantly less inflammation, hyphema and choroidal detachment than that in the T-P group. CONCLUSIONS: Phacoemulsification-IOL implantation combined with viscocanalostomy is a safe and efficacious surgery with lower complications.

Adult↗
PubMed2004

[Study on ultrastructure changes and the genetic locus for a special phenotype cataract].

OBJECTIVE: To report the ultrastructure changes and map the genetic locus for a special phenotype autosomal dominant congenital cataract (ADCC) in a large Chinese family. METHODS: A large four-generation Chinese family affected by this special phenotype ADCC was analyzed. Clinical examinations, light and transmission electron microscopy analysis of the removed lens tissue were performed. Blood samples were taken for DNA extraction and two-point linkage analyses between the polymorphisms of microsatellite markers near the gamma-crystallin gene (CRYG) and the disease-associated locus was also determined. RESULTS: The lens fiber cells displayed abnormal inter- and intracellular alterations, including irregular refractivity, focal degeneration and irregular and enlarged intracellular spaces. Linkage analysis showed that there was linkage between the ADCC disease-associated locus and D2S2208, D2S2382 and D2S164. CONCLUSIONS: There were characteristic alterations to the lens fiber cells of this special phenotype ADCC and the CRYGD gene might be the disease-associated.

Cataract↗
PubMed2004

[Effects of transfected SOCS3 gene on proliferation of human lung adenocarcinoma cell line A549].

BACKGROUND & OBJECTIVE: Previous studies showed that signal transducers and activators of transcription 3(STAT3) could be constantly activated in many kinds of tumor cells; constantly activated STAT3 could make cell malignant transformation, and enhance the malignant proliferation of tumor cells. The suppressors of cytokine signaling (SOCS) proteins, a recently identified family, could suppress the tyrosine-phosphorylated process of STAT protein to negatively regulate STAT-mediated cytokine signaling, which is closely related to cell survival, proliferation, and apoptosis. Among the SOCS protein family, SOCS3 is the most potent inhibitors of cytokine-induced signaling. This experiment was to investigate the effect of SOCS3 on proliferation of human lung adenocarcinoma cell line A549. METHODS: A549 cells were co-transfected with pEFSOCS3 and pSV2neo by liposome, expression of SOCS3 mRNA and protein was determined by reverse transcriptase-polymerase chain reaction (RT-PCR), and immunocytochemistry. Tyrosine-phosphorylated STAT3 level was measured by Western blot analysis. MTT assay and (3)-TdR incorporation were used to measure the cell proliferation in pEFSOCS3-transfected group, and control group (non-transfected, and pEF-transfected A549). RESULTS: Compared with control group, tyrosine-phosphorylated STAT3 level suppressed greatly in pEFSOCS3-transfected A549 cells (P< 0.01). The inhibitory rate of cell growth in pEFSOCS3-transfected group was 40.58%, and in control group was 32.23%. (3)-TdR incorporation (48 056+/-1 331) in pEFSOCS3-transfected group was significantly lower than that of control group (81,481+/-2,584, and 75,590+/-2,678, P< 0.01). CONCLUSION: SOCS3 protein might inhibit proliferation of A549 cells by lowering the tyrosine-phosphorylated level of STAT3 protein.

Adenocarcinoma↗
PubMed2004

[Low-intensity microwave blockes cell cycle and regulate cell cycle related gene expression in rabbit lens epithelial cells].

OBJECTIVE: To study the cell cycle arrest induced by different doses of microwave in cultured rabbit lens epithelial cells (RLECs) and its effects on the related gene expression of P21(WAF1), P27(Kip1) and c-myc. METHODS: Cultured rabbit lens epithelial cells were exposed to microwave radiation with frequency of 2450 MHz and power density of 0.10 mW/cm(2) (A group), 0.25 mW/cm(2) (B group), 0.50 mW/cm(2) (C group), 1.00 mW/cm(2) (D group) and 2.00 mW/cm(2) (E group) for 8 hours. The morphological change of RLECs was observed under microscope, effects of microwave radiation on RLECs cell cycle were measured by flow cytometry. Expression of P21(WAF1), P27(Kip1) and c-myc were evaluated by western blot after 2.00 mW/cm(2) microwave radiation for 4 hours, 6 hours and 8 hours respectively. All the results were compared with F group, which was as controls without microwave radiation. RESULTS: 8 hours after radiation, RLECs of C, D and E groups showed RLECs cell swelling, congregation and detachment, the percentage of cells in G(0)/G(1) phase obviously was increased (P < 0.01). No obvious change could be detected in 0.10 mW/cm(2) and 0.25 mW/cm(2) microwave groups. The gene expression of P27(Kip1) was increased and c-myc was decreased after 2.00 mW/cm(2) radiation, it did not affect the gene expression of P21(WAF1). CONCLUSION: Microwave exceeding 0.50 mW/cm(2) can block RLECs cell cycle at G(0)/G(1) phase, which may be related to regulation of P27(Kip1) and c-myc expression, but not P21(WAF1).

Animals↗