In order to investigate the effects of TGF-beta1 on the expression of MMP-2, -9 and TIMP-1 in human retinal pigment epithelial (RPE) cells, the third-sixth passage cultured RPE cells were treated with TGF-beta1 at different concentrations (0.01, 0.1, 1.0, 10 ng/mL), the expression of MMP-2, -9 and TIMP-1 mRNA was detected by semi-quantitative RT-PCR assays. MMP-2, -9 and TIMP-1 mRNA were expressed in the cultured RPE cells. The values of MMP-2/beta-actin in the cells treated with 0.1, 1.0, 10 ng/mL TGF-beta1 were 1.04 +/- 0.04, 1.07 +/- 0.02 and 1.11 +/- 0.03, respectively, significantly higher than in the control group (0.96 +/- 0.03, P < 0.05-0.01). The expression of MMP-2 mRNA could be up-regulated by TGF-beta1, in a dose-dependent manner. The expression of MMP-9 mRNA in the cultured RPE cells was slightly up-regulated by various TGF-beta1 concentrations treatment. The values of TIMP-1/beta-actin in the cells treated with 0.01 and 0.1 ng/ mL TGF-beta1 were 0.85 +/- 0.01 and 0.97 +/- 0.02 respectively, significantly lower than in the control group (1.07 +/- 0.04, P < 0.01), indicating that the expression of TIMP-1 mRNA was down-regulated by TGF-beta1 at low concentrations. But along with the increase of TGF-beta1 concentrations (1.0 and 10 ng/mL), the expression of TIMP-1 mRNA was slightly up-regulated, not significantly different from that in the control group (P > 0.05). It was concluded that TGF-beta1 might play an important role in the up-regulation of the expression of MMP-2 in RPE cells and result in a directional shift in the balance between MMP and TIMP. This may be facilitated for RPE cells to migrate in the pathogenesis of vitreoretinopathy.

The aim of this study was to explore the effect of small hairpin loop RNA (shRNA) silencing hypoxia-induced factor 1alpha (HIF-1alpha) gene on the expression of vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) in human retinal pigment epithelium (RPE) cells under hypoxic condition. Two target sites of HIF-1alpha mRNA were chosen and two kinds of shRNA were designed and synthesized against the target sites. Then the two kinds of shRNA were transfected into human RPE cells in vitro, respectively. These cells were cultured under hypoxic condition that was simulated by using 150 mumol/L CoCl(2). The mRNA expressions of HIF-1alpha, VEGF and PEDF were tested by semi-quantitative reverse transcription PCR (RT-PCR). The protein levels of HIF-1alpha, VEGF and PEDF were analyzed by Western blotting. After the two kinds of HIF-1alpha-specific shRNA were transfected into RPE cells respectively, the expression of HIF-1alpha mRNA and the levels of HIF-1alpha protein were decreased significantly in RPE cells under hypoxic condition. The expression of VEGF mRNA and the levels of protein significantly were also decreased. However, the levels of PEDF protein was significantly increased, but the expression of PEDF mRNA showed no significant changes. In conclusion, HIF-1alpha-specific shRNA can effectively silence the HIF-1alpha gene, and consequently down-regulate VEGF and up-regulate PEDF expression against hypoxia. These results reveal that HIF-1 is associated with posttranslational mechanism for down-regulating PEDF under hypoxia and provide an explanation for hypoxia-provoked increases in VEGF/PEDF ratios. These results also suggest that HIF-1 is one of the key cytokines to retinal neovascularization.

In order to explore the effect of high glucose concentration and high glucose concentration with hypoxia on the production of hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF), human RPE cells were cultured in 5.56 mmol/L glucose (control group), 5.56 mmol/L glucose with 150 micro mol/L CoCl2 (hypoxic group), 25 mmol/L glucose (high glucose group) and 25 mmol/L glucose with 150 micro mol/L CoCl2 (combination group). RT-PCR was used to detect the expression of HIF-1alpha and VEGF mRNAs. Western blot analysis was used to measure the levels of HIF-1alpha and VEGF proteins. Although the small amount of HIF-1alpha protein was able to be detected in high glucose group but not in control group, there was no significant difference between the expression of HIF-1alpha mRNA of RPE cells in high glucose group and that of RPE cells in control group. As compared with RPE cells in control group, the mRNA expression and the protein synthesis of VEGF in high glucose group were up-regulated. As compared with RPE cells in hypoxic group, the expression of HIF-1alpha mRNA of RPE cells in combination group was not different, but the protein synthesis of HIF-1alpha, the mRNA expression and the protein synthesis of VEGF were more obviously up-regulated. In conclusion, high concentration glucose mainly influence the protein synthesis of HIF-1alpha of RPE cell, and HIF-1alpha protein is able to be accumulated in high concentration glucose. Under hypoxia, the HIF-1alpha protein induced by high concentration glucose is more stable, and the expression of VEGF is obviously increased. It is suggested that high concentration glucose may play a role in retinal neovascularization, especially at ischemia stage of diabetic retinopathy.

In order to improve the production of agro-antibiotic 2-16,the producing strain(Streptomyces ahygroscopicus var.huangshanensis) was treated by protoplast regeneration,ultraviolet radiation,NTG mutagenesis and low energy C~(+) ion implantation.At last,a high-yield strain No.515 was obtained.The production of ~()No.515 was increased by 223.10%.By using Plackett-Burman design and Response Surface Analysis provided by SAS software,the cultivation condition of No.515 was optimized.The amount of agro-antibiotic 2-16 was increased by 38.53% when the strain No.515 was cultivated in the optimum medium instead of the initial one.

Objective To investigate the distribution,drug resistance characteristics and genotypes of extended-spectrum-lactamases (ESBLs)-producing strain in pathogenic gram-negative rod in infection of newborn in Guangzhou.Methods The standard was performed by the production for ESBLs by phenotypic screening and confirmatory test provided by the National Committee for Clinical Laboratory Standards in 2001.The method of polymerase chain reaction(PCR) amplification was perbonmed and DNA sequences were analyzed by ESBLs gene sequencing.Results Total of 71 un-repicated and consecutive Gram-negative bacilli were isolated from 13 hospitals in Guangzhou,and the prevalence of ESBLs-producing clinical Gram-negative isolates was 59.2%(42/71).The PCR results showed that most pathogenic bacilli which infected newborn could be separated two or more genes of ESBLs.The type of TEM,SHV,CTX-M1,CTX-M9,OXA was 35.6%, 26.7% ,10.9%,24.8%,2.0%,respectively.The result of drug resistance monitoring showed that pathogenic gram-negative bacillui which infected newborn were Escherichia coli and Klebsiella pneumonia mostly.Most parts of them were drug fast and even multidrug resistant to the commonly used antibiotics.The sensitive drugs were lmipenem(the rate of sensitivty 100%),cefoperazone/sulbactam(87.3%),piperacillin/tazbatam(85.3%),ceftazidime(82%),aztreonam(82%),cefepime(81.8%).Conclusions In Guangzhou,the incidence rate of ESBLs-producing strain are very high inpathogenic bacilli which infected in newborn and is multidrug resistance.The genetypes of produced ESBLs are TEM,SHV,CTX-M1,CTX-M9,OXA.

Objective To study the effect of antiapoptosis factors PED/PEA-15 and XIAP on prostate cancer cells(PC-3)apoptosis.Methods The expressions of XIAP and PED/PEA-15 in prostate cancer cells(PC-3)were respectively assayed using the RT-PCR technique.XIAP and PED/ PEA-15 specific siRNA vectors were designed and constructed and then were transiently cotransfected into PC-3 cells under induction of liposome.The effects of siRNA vectors on PED/PEA-15 and XIAP transcription were assayed by RT-PCR technique,and the effect of XIAP and PED/PEA-15 on cancer cell apoptosis were determined by flow cytometry and microscope observation.Results PED/PEA- 15 and XIAP were both highly expressed in PC-3 cells.Enzyme digestion analysis and DNA sequencing confirmed that the PED/PEA-15 and XIAP-specific siRNA expression vectors were constructed successfully.The designed siRNA sequences of PED/PEA-15 and XIAP could specifically inhibit their transcription.The PC-3 cells which were cotransfected with PED/PEA-15 and XIAP- specific siRNA vectors were more sensitive to doxorubicin.The apoptosis rate of cotransfected cells was significantly increased.Conclusions PED/PEA-15 and XIAP might be involved in the development of prostate cancer.

An experimental model of rhegmatogenous retinal detachment (RRD) in rabbits was established to simulate the pathophysiologic condition of human RRD. 24 rabbits were randomly divided into 3 groups and underwent vitrectomy with a vitrector and/or retinotomy with a Charles flute needle, with 12 in group I (vitrectomy and retinotomy), 7 in group I (retinotomy) and 5 in group III (vitrectomy). All animals underwent follow-up examinations with direct and indirect ophthalmoscopy and fundus photography 12 h and day 1, 3, 5, 7, 10, 14, 21, and 28 after the procedure(s). Retinal changes were recorded. As a result, 10 RRDs were successfully established in group I. Direct and indirect ophthalmoscopy and fundus photography demonstrated typical features of RRD. No RRD developed in group II and III. It was concluded that the experimental rhegmatogenous retinal detachment produced in a rabbit model after vitrectomy with retinotomy in this study was a convenient and reliable one. This RRD model mimicked the typical pathophysiological changes in humans.
*Disease Models, Animal ; Random Allocation ; Retina/surgery ; *Retinal Detachment ; Vitrectomy

Background A main cause of visual impairment in proliferative diabetic retinopathy (PDR) is vitreous hemorrhage and retinal detachment due to contraction of fibrovascular membrane.To explore the pathogenic mechanism of fibrovascular membrane is a new target for the prevention and management of PDR.Objective This study was to determine the change in expression of vascular endothelial growth factor (VEGF),connective tissue growth factor(CTGF) and pigment epithelium derived factor(PEDF) in the proliferative membranes of patients with PDR after intravitreal injection of avastin,an anti-VEGF agent.Methods This study was approved by the Medical Ethic Committee of Tianjin Medical College,and written informed consent was obtained from each patient before enrollment.A prospective randomized-controlled study was designed.Twenty-six eyes of 24 patients with PDR scheduled for surgery were enrolled from January to June,2008 in Tianjin Medical College Eye Hospital.The patients were randomized into the simple vitrectomy group and avastin injection combined with vitrectomy group,with matched gender,age and disease duration.1.25 mg (0.05 ml) of avastin was intravitreally injected prior to surgery,and vitrectomy was performed 10 days after injection in the avastin injection combined with vitrectomy group,and only vitrectomy was given in the simple vitrectomy group.Preretinal membrane was collected during the surgery.Expression of VEGF,CTGF and PEDF in the preretinal membranes was assayed by immunochemistry.Results VEGF,CTGF and PEDF were expressed in the cytoplasm.The rate of VEGF expression in the preretinal membranes was 30.77％ in the avastin injection combined with vitrectomy group,showing a significant reduction in comparison with the simple vitrectomy group(100.00％)(U =4.000,P＜0.01).The rate of expression CTGF was remarkable elevated in the avastin injection combined with vitrectomy group compared with the simple vitrectomy group (92.31％ vs.62.54％)(U=7.500,P=0.048).However,no significant difference was found in the expression rate of PEDF between the two groups(100.00％ vs.92.31％) (U =65.500,P =0.299).Conclusions The results suggest that intravitreal injection of anti-VEGF drugs resulted in the decrease of VEGF expression and increased CTGF expression in proliferative membranes from patients with PDR.

Background Retinal angiomatous proliferation (RAP) is a subtype of neovascular age-related macular degeneration (AMD).There are currently very few studies on RAP.Objective This study was to explore the pathogenic mechanism of RAP in apolipoprotein E-deficient (ApoE-/-) mice with dyslipidemia.Methods Twenty-four 2-month-old SPF ApoE-/-mice were randomly divided into the high fat diet group and the normal diet group,and twelve 2-month-old C57BL/6 mice received the normal diet as controls.A diet with a higher content of fat was given for 4 consecutive months in the high fat diet group,and normal diet was given in the same way in the mice of the normal diet group.The mice were sacrificed at 6 months of age.The expression of vascular endothelial growth factor (VEGF) in the retinal pigment epithelial (RPE) cells,the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) in the outer plexiform layer (OPL),microvascular density (MVD) and microvascular area (MVA) in the OPL were examined by immunohistochemistry and semi-quantitatively by histopathology with the Mias 2000 Imaging Analyzer System.The expression of VEGF protein in the retina was examined by Western blot.Results The MVD in the retinal OPL were (20.67±3.20) and (19.50± 1.87),respectively,in the ApoE-/-mice of the high fat diet group and the normal diet group,which were significantly higher than that (12.50±1.87) of the C57BL/6 normal diet group (all at P＜0.01).MVA in the retinal OPL were (626.49± 120.99) μm2 and (514.06±88.83) μm2 in the ApoE-/-mice of the high fat diet group and the normal diet group,respectively,showing a significant increase in comparison with the (336.52±84.96) μm2 of the C57BL/6 normal diet group (P＜0.01).The staining area of VEGF in RPE cells was (21 048±1849) μm2 in the ApoE-/-mice of the high fat diet group,showing a significant increase in comparison with the (17 116±2023) μm2 of the C57BL/6 normal diet group.However,no significant difference was found in the staining area of VEGF between the ApoE-/-mice with normal diet group and the C57BL/6 normal diet group ([17 854±2967] μm2 vs.[17 116±2023] μm2) (P＞0.05).Significant elevation was also seen in the staining area of VEGFR-2 in the retinal OPL of the ApoE-/-mice of the high fat diet group (12 193±3806)μm2 and the ApoE-/-mice of the normal diet group (11 969± 3616)xm2 compared with C57BL/6 mice of the normal diet group (5387±2225)μm2(all at P＜0.01).The relative expression values (VEGF/β-actin) of VEGF in the retinas were (1.51 ±0.32) and (1.17±0.39) in the ApoE-/-mice of the high fat diet group and the normal diet group,respectively,showing a significant increase in comparison with (0.28±0.14) of the C57BL/6 normal diet group (P＜0.01).Conclusions The expression of VEGF and VEGFR-2 in the retinas increases in the ApoE-/-mouse,which leads to the enlargement of MVD and MVA in the retinal OPL and subsequent RAP occurrence.

Adult ; Female ; Humans ; Hyperlipoproteinemia Type III ; pathology ; Male ; Middle Aged ; Nephrosis, Lipoid ; pathology