Value of the NF-κB signalling pathway and the DNA repair gene PARP1 in predicting distant metastasis after breast cancer surgery.

The DNA repair gene PARP1 and NF-κB signalling pathway affect the metastasis of breast cancer by influencing the drug resistance of cancer cells. Therefore, this study focused on the value of the DNA repair gene PARP1 and NF-κB pathway proteins in predicting the postoperative metastasis of breast cancer. A nested case‒control study was performed. Immunohistochemical methods were used to detect the expression of these genes in patients. ROC curves were used to analyse the predictive effect of these factors on distant metastasis. The COX model was used to evaluate the effects of PARP1 and TNF-α on distant metastasis. The results showed that the expression levels of PARP1, IKKß, p50, p65 and TNF-α were significantly increased in the metastasis group (P < 0.001). PARP1 was correlated with IKKß, p50, p65 and TNF-α proteins (P < 0.001). There was a correlation between IKKß, p50, p65 and TNF-α proteins (P < 0.001). ROC curve analysis showed that immunohistochemical scores for PARP1 of > 6, IKKß of > 4, p65 of > 4, p50 of > 2, and TNF-α of > 4 had value in predicting distant metastasis (SePARP1 = 78.35%, SpPARP1 = 79.38%, AUCPARP1 = 0.843; Sep50 = 64.95%, Spp50 = 70.10%, AUCp50 = 0.709; SeTNF-α = 60.82%, SpTNF-α = 69.07%, AUCTNF-α = 0.6884). Cox regression analysis showed that high expression levels of PARP1 and TNF-α were a risk factor for distant metastasis after breast cancer surgery (RRPARP1 = 4.092, 95% CI 2.475-6.766, P < 0.001; RRTNF-α = 1.825, 95% CI 1.189-2.799, P = 0.006). Taken together, PARP1 > 6, p50 > 2, and TNF-α > 4 have a certain value in predicting breast cancer metastasis, and the predictive value is better when they are combined for diagnosis (Secombine = 97.94%, Spcombine = 71.13%).

Continuous, Large-Scale, and High Proportion of Bioinspired Phosphogypsum Composites via Reactive Extrusion.

Biological matter evolution provides an idea for the human design and synthesis of new materials. However, biomimetic materials only stay in laboratory-scale models, and their large-scale industrial applications are yet to be realized. Here, inspired by nacre's architecture, we report a continuous, large-scale method to fabricate phosphogypsum composites by reactive extrusion strategy. After curing for seven days, with more than 50 wt% of beta-hemihydrate phosphogypsum (ß-HPG), the compressive strength and softening coefficient were 24.98 MPa and 0.78, increasing by 110.0% and 20.0%, respectively, compared to the pouring method. The results show that the screw extrusion process can improve the mechanical strength and waterproof properties of ß-HPG hydration specimens without any special chemical admixtures and cements.

Case Report: Multimodal Imaging of Acute Idiopathic Maculopathy in a Chinese Woman.

SIGNIFICANCE: Acute idiopathic maculopathy is a rare disease with the characteristics of sudden, severe, unilateral central vision loss after a flu-like illness. The prognosis is generally good, and poor vision usually results from complications such as choroidal neovascularization or subfoveal pigment degeneration. Multimodal imaging is helpful in the diagnosis and follow-up of this disease. PURPOSE: We report a case of acute idiopathic maculopathy and present multimodal imaging results in the diagnosis of this condition. CASE REPORT: A 37-year-old Chinese woman noted a central scotoma in her right eye a day after a prodrome of flu-like symptoms. Best-corrected visual acuity of the right eye was 20/40. Multimodal imaging was performed, and a diagnosis of acute idiopathic maculopathy was made. The variable clinical appearance of acute idiopathic maculopathy on autofluorescence, near-infrared reflectance, and optical coherence tomography (OCT) was shown. The patient's vision spontaneously recovered to 20/20 two weeks after the onset of the disease, but macular sensitivity, as measured by microperimetry, did not return to normal until 1 month. Retrobulbar injection of triamcinolone was done at 3 weeks to prevent retinal pigment epithelium hyperplasia and choroidal neovascularization. Written informed consent was obtained from the patient. CONCLUSIONS: Our findings suggest that near-infrared reflectance corresponds to the change of the outer retina and retinal pigment epithelium on OCT and complements autofluorescence in the diagnosis and follow-up of acute idiopathic maculopathy. Fundus autofluorescence, near-infrared reflectance, and OCT are recommended as routine examinations in this disease.

The diagnostic value of DNA repair gene in breast cancer metastasis.

Breast cancer is the most common malignant tumor in China and even in the world. DNA repair genes can lead to tumor metastasis by affecting cancer cell resistance. Studies have preliminarily shown that DNA repair genes are related to breast cancer metastasis, but it is not clear whether they can be used as a prediction of the risk of breast cancer metastasis. Therefore, this study mainly discusses the predictive value of DNA repair genes in postoperative metastasis of breast cancer. The nested case-control method was used in patients with breast cancer metastasis after surgery (n = 103) and patients without metastasis after surgery (n = 103). The proteins and mRNA of DNA repair genes were detected by immunohistochemistry and Real-time PCR respectively. In protein expression, PARP1 (OR 1.147, 95% CI 1.067 ~ 1.233, P < 0.05), XRCC4 (OR 1.088, 95% CI 1.015 ~ 1.166, P < 0.05), XRCC1 (OR 1.114, 95% CI 1.021 ~ 1.215, P < 0.05), ERCC1 (OR 1.068, 95% CI 1.000 ~ 1.141, P < 0.10) were risk factors for postoperative metastasis of breast cancer. In addition, we used the ROC curve to study the optimal critical values of MSH2, MLH1, PARP1, XRCC1, XRCC4, 53BP1, ERCC1 and XPA combined with the Youden index, and the effects of MSH2, MLH1, PARP1, XRCC1, XRCC4, 53BP1, ERCC1 and XPA on breast cancer metastasis were verified again. Among them, the risk of metastasis in the PARP1 high expression group was 3.286 times that of the low expression group (OR 3.286, 95% CI 2.013 ~ 5.364, P < 0.05). The risk of metastasis in the XRCC4 high expression group was 1.779 times that of the low expression group (OR 1.779, 95% CI 1.071 ~ 2.954, P < 0.05). The risk of metastasis in patients with ERCC1 high expression group was 2.012 times that of the low expression group (OR 2.012, 95% CI 1.056 ~ 3.836, P < 0.05). So we can conclude that protein expression of PARP1 (cut-off value = 6, Se = 76.70%, Sp = 79.61%), XRCC4 (cut-off value = 6, Se = 78.64%0, Se = 79.61%), ERCC1 (cut-off value = 3, Se = 89.32%, Sp = 50.49%), suggesting that when the PARP1 score is higher than 6 or the XRCC4 score is higher than 6 or the ERCC1 score is higher than 3, the risk of metastasis will increases. Due to PARP1, XRCC4 and ERCC1 belong to a part of DNA repair gene system, and the three proteins are positively correlated by correlation analysis (rPARP1-XRCC4 = 0.343; rPAPR1-ERCC1 = 0.335; rXRCC4-ERCC1 = 0.388). The combined diagnosis of the PARR1, XRCC4 and ERCC1 have greater predictive value for the risk of metastasis of breast cancer (Se = 94.17%, Sp = 75.73%; OR 11.739, 95% CI 2.858 ~ 40.220, P < 0.05). The postoperative metastasis of breast cancer could be effectively predicted when the immunohistochemical scores met PARP1 (IHC score) > 6, XRCC4 (IHC score) > 6 and ERCC1 (IHC score) > 3. In addition, the combined diagnosis of PARP1, XRCC4 and ERCC1 has great predictive value for the risk of breast cancer metastasis.

Down-regulation of GRP78 enhances apoptosis via CHOP pathway in retinal ischemia-reperfusion injury.

Ischemia/reperfusion (I/R) injury is the main cause of retinal apoptosis. But the mechanism remains elusive. During I/R injury, the intracellular calcium levels increase, resulting in the generation of reactive oxygen species, which have been shown to cause endoplasmic reticulum (ER) stress. However, little is known about the correlation between apoptosis and ER stress in retinal I/R injury. In the present study, we demonstrated that ER stress was activated in the retina of rat I/R models. The transcriptional expression of ER stress-associated molecules, glucose-regulated protein-78 (GRP78) and C/EBP-homologous protein (CHOP) were significantly increased in I/R retinas in a time-dependent manner. Partial inhibition of the endogenous expression of GRP78 with antisense oligonucleotide resulted in significant retinal damage and apoptosis in I/R injury rats. Also, the transcriptional expression of CHOP was persistently increased. Our findings indicate that ER stress may play a critical role in I/R injury induced retinal damage, and GRP78 may exert anti-apoptotic actions in I/R retina. Importantly, the persistent high expression of CHOP might serve as a possible mechanism that contributes to the enhanced the I/R-induced apoptosis after GRP78 down-regulation. These results may provide insight into the pathology of retinal I/R injury.

Effect of resveratrol on Bcl-2 and VEGF expression in oxygen-induced retinopathy of prematurity.

PURPOSE: To explore the effect of resveratrol on B-cell leukemia/lymphoma-2 (Bcl-2) and vascular endothelial growth factor (VEGF) expression in rats with oxygen-induced retinopathy of prematurity (ROP). METHODS: Seven-day-old Sprague-Dawley rats (N = 60) were randomly assigned to five groups. Group A received normal partial oxygen pressure and groups B, C, D, and E received 75% ± 2% oxygen for 5 days to induce ROP. The rats in groups C, D, and E were intragastrically treated with resveratrol (10, 30, and 60 mg/kg/d, respectively) once daily for 5 days. Rats were killed at 17 days of age and the retina was collected. RESULTS: Western blot analysis revealed increased Bcl-2 protein expression in group B versus group A. Levels of Bcl-2 decreased with the increase of resveratrol concentration in groups C, D, and E. The optical density of Bcl-2 protein expression in group B was four times higher than that in group A (P < .01). When compared with group B, expression of Bcl-2 and VEGF in groups C, D, and E decreased in a dose-dependent manner. Significant differences in expression of Bcl-2 and VEGF were also noted among the three treatment groups with resveratrol (P < .01). After treatment with resveratrol at 10, 30, and 60 mg/kg/d, the inhibition rate of Bcl-2 expression was 11.1%, 38.1%, and 69.8% and that of VEGF expression was 3.4%, 23.0%, and 43.7%, respectively. CONCLUSION: Resveratrol can significantly inhibit expression of Bcl-2 and VEGF in the retina of neonatal rats with oxygen-induced ROP. It may provide a protective effect on retinal neovascular diseases, including ROP.

[Effect of genistin on proliferative vitreoretinopathy].

OBJECTIVE: To examine the effect of genistin on traumatic proliferative vitreoretinopathy (PVR) in rabbits. METHODS: Traumatic PVR was induced in pigmented rabbits by intravitreal injection of platelet rich plasma. The eyes then received an intravitreal injection of dimethyl sulfoxide (0.1 mL), 2 or 40 µg genistin (0.1 mL), and 1 mg fluorouracil(0.1 mL), respectively to form 4 groups. The eyes were examined ophthalmoscopically on distinct days after the surgery and the stage of PVR was evaluated. The model eyes and normal eyes in the 40 µg genistin group carried ERG test on the 28th day. All model eyes in the 4 groups were observed by light microscope on the 28th day. RESULTS: In the control eyes, the retina was detached after 10 d, the PVR had progressed to higher stages with time. In the eyes injected 40 µg genistin or fluorouracil, the PVR also developed; however, the severity of PVR was lower than that in the control eyes. PVR was significantly inhibited in the 40 µg genistin group compared with the control eyes after 14 d (P<0.05). Histological examination of the genistin-treated eyes disclosed no morphological changes, and ERG analysis revealed no significant functional changes. CONCLUSION: Intravitreal injection of genistin is safe and effective in reducing traumatic PVR in clinical treatment.

Multilocus outbreak of foodborne botulism linked to contaminated sausage in Hebei province, China.

In 2007, an outbreak of foodborne botulism occurred in Hebei province, China. An epidemiological investigation and laboratory detection studies showed that sausage contaminated by type A Clostridium botulinum caused this outbreak of food poisoning. Its clinical and epidemiological features were different from previous reports of food poisoning.

[Treatment of patients with rhegmatogenous retina detachment combined with non-secondary glaucoma].

OBJECTIVE: To discuss the cause of disease, treatment and therapeutic effect in patients with rhegmatogenous retina detachment (RRD) combined with non-secondary glaucoma. METHODS: Clinical data of 28 patients with RRD combined with primary or congenital glaucoma were retrospectively analyzed. RESULTS: Twenty-five out of the 28 patients succeeded with one operation (89.3%). The intraocular pressure of post-operation:on the 1st day was 10 approximately 46 (28.1+/-6.5) mmHg, on the 7th day was (18.9+/-7.2) mmHg, and on the last re-examination day was (17.6+/-6.2) mmHg. Anti-glaucoma operation was performed in 10 patients after the retinal operation. Chroidal hemorrhage was found in 2 patients and 2 chroidal exudations were found after the retinal operation. CONCLUSION: The proportion of primary open angle glaucoma is higher than that of primary angle closure glaucoma, and trauma or surgery before the retinal operation is an important cause in glaucoma patients with RRD. There is no obvious difference in the ratio of surgical success between non-secondary glaucoma with RRD and those RRD patients without glaucoma. Vitreotomy+ silicon oil injection or drainage of subretinal fluid+air injection+cryocoagulation+explants is recommended. Chroid is easily involved. It is important to control the intraocular pressure during and after the surgery. The final visual acuity is rather poor, which may be related to the glaucoma and intraocular pressure.

[The effects of caspase-3 in apoptosis of cultured retinal microvascular pericytes induced by advanced glycation end products].

OBJECTIVE: One of the earliest changes observed in the development of diabetic retinopathy (DR) is the selective loss of pericytes and acellular capillaries. We tested the hypothesis that advanced glycation end products (AGE) might be involved in the disappearance of retinal pericytes by apoptosis and further investigated the activity and effect of caspase-3 at the same time. METHODS: Cultured bovine retinal microvascular pericytes (BRPs) were exposed to various concentrations of advanced glycation end products-bovine serum albumin (AGE, 0.47, 1.88, 7.50 micromol/L) for 4 days. We assayed the degree of pericytes apoptosis by fluorescence activated cell sorting, and further measured the caspase-3 activity and the effect of selective caspase-3 inhibitor Z-DEVD-fmk on apoptosis and the of ratio Bcl-2/Bax expression. RESULTS: The results showed that AGE could induce significantly the apoptosis of BRPs in a dose-dependent manner compared with controls (r = 0.867, P < 0.01), associated with an increase in intracellular caspase-3 activity. Selective caspase-3 inhibitor Z-DEVD-fmk inhibited pericyte apoptosis induced by AGE. CONCLUSION: These data suggest that the pericyte loss in DR involves an apoptotic process, and that activation of caspase-3 are associated with apoptotic process, which can provide new therapeutic perspectives in diabetic retinopathy.

[The expression of HIF-1 in the early diabetic NOD mice].

PURPOSE: To study the retinal expression of HIF-1 alpha in the diabetic NOD mice. METHODS: NOD mice were divided into normal control group and diabetes group randomly, sacrificed at 2, 4, 6, 8 or 12 weeks. Eyes were enucleated and retinas were isolated and used for western blot, or eyes were sectioned for immunohistochemical staining for HIF-1 alphal. RESULTS: Compared to the normal control group, blood sugar of diabetes mice increased significantly but the weights decreased significantly (P < 0.01). Western blot of retinal lysates showed low levels of HIF-1 alpha at the 6th weeks that were markedly increased at the 12th weeks in the diabetes group. Immunohistochemistry showed increased staining for HIF-1 in the inner retina, but not in the outer retina. CONCLUSION: The retinal HIF-1 alpha levels increasing showed that retinal ischemia happening in the early diabetes. HIF-1 alpha may participate in the secondary damage of retinal ischemia induced by early diabetes.

Advanced glycation end-products induce apoptosis involving the signaling pathways of oxidative stress in bovine retinal pericytes.

One of the histopathologic hallmarks of early diabetic retinopathy is the selective loss of pericytes. Evidences suggest that the pericyte loss in vivo is mediated by apoptosis. However, the underlying cause of pericyte apoptosis is not fully understood. This study investigated the effect of advanced glycation end products (AGEs) on apoptotic cell death in bovine retinal pericytes (BRPs). After incubation of BRPs with 0.47, 1.88, 7.5, 30 microM of AGE-bovine serum albumin (BSA) for 4 days, we assayed the pericytes apoptosis by FACS (fluorescence activated cell sorting), and further measured the signaling pathway involved. The results showed that AGE-BSA could induce significantly the apoptosis of BRPs in a dose-dependent manner compared with controls, associated with an increase in intracellular malondialdehyde level and caspase-3 activity; a decrease in intracellular catalase, SOD activities and Bcl-2/Bax ratio. SOD and selective caspase-3 inhibitor Z-DEVD-fmk can inhibit pericyte apoptosis induced by AGE-BSA. These data suggest that the pericyte loss in diabetic retinopathy involves an apoptotic process, and that elevated AGE observed in diabetes may cause apoptosis in BRPs through an oxidative stress mechanism. The decreased Bcl-2/Bax ratio and activation of caspase-3 are associated with apoptotic process.

[Splicing site mutation of D19S418 in PRPF-31 gene and its phenotypic characters with autosomal dominant retinitis pigmentosa].

OBJECTIVE: To evaluate the disease-causing gene and phenotypic characters of a large family with autosomal dominant retinitis pigmentosa (adRP). METHODS: Disease status and associated ocular abnormalities of eight patients and six unaffected members who represent different generations of this family were assessed by measurement of visual psychophysics, full-field and multifocal electrophysiology (ERG and mfERG) and funds fluorescent angiography (FFA). The DNA samples of nineteen patients and fifteen unaffected individuals in this family were examined by Genome scanning, linkage analysis and mutation detection to identify coding sequence changes. RESULTS: A case with variable, early onset night blindness before 10 years and visual field loss in their teens was found. Macular dystrophy, progressing to a retinitis pigmentosa phenotype was demonstrated in most adult cases. Both a-wave and b-wave amplitudes of photopic and scotopic full-field ERG were marked reduced and nearly non-detectable, demonstrating severe damage of photoreceptor systems. There were two obligate gene carriers in the family which remained asymptomatic in the clinical. But one of them was found with a minimal RP characteristic and the other was normal by examination of fundus and ERG. An unreported splicing site mutation (IVS5-1G > A) was identified in intron 5- acceptor site of PRPF-31 gene on chromosome 19. ERG and molecular genetic findings were consistent with the reclassification of this disease as an autosomal dominant RP. CONCLUSION: It is a novel splicing site mutation that IVS5-1G > A of D19S418 site in PRFP31, the relative phenotypes by which main displayed type I/diffuse has variable expressivity and complex phenotype.

[Risk factors of retinal redetachment after expected silicone oil removal].

PURPOSE: To analyze the clinical risk factors of the occurrence of retinal redetachment after expected silicone oil removal. METHODS: Clinical data were studied retrospectively. A total of 105 eyes of 104 consecutive patients were enrolled according to the criteria as follows: the expected intraocular silicone oil removal was performed after pars plana vitrectomy for complicated rhegmatogenous retinal detachment (RRD); the retina was flat during silicone oil tampanade; the patients were dealt with by the same surgeon. RESULTS: With a mean postoperative follow-up of 310 days, 11 of 105 eyes (10.4%) developed retinal redetachment after silicone oil removal. The redetachment rate was higher in the aphakic eyes (21.1%) than in the phakic/pseudophakic eyes (4.5%) (OR 5.69, P < 0.05). However, the factors, including giant tear, PVR grade C3 and D, previous failed retinal detachment surgery, high myopia, had no significance with retinal redetachment (Ps > 0.05). Among the 77 eyes undergoing prophylactic 360 degree laser retinopexy before silicone oil removal, 4 eyes had retinal redetachment (5.2%). The redetachment ratio was lower than those without prophylactic laser retinopexy (OR 0.16, P < 0.05). CONCLUSION: Aphakia is a risk factor of retinal detachment after removal of silicone oil. Prophylactic 360 degree laser retinopexy can reduce the incidence of retinal redetachment.

Matrix metalloproteinases expression in choroidal neovascular membranes.

PURPOSE: To investigate the expression of matrix metalloproteinases (MMPs) in choroidal neovascular membranes with age-related macular degeneration (AMD). METHODS: Seventeen choroidal neovascular membranes surgically removed from AMD patients with pars plana vitrectomy and subretinal membranes peeling were investigated. The expression of MMP-2 and MMP-9 was determined with immunohistochemical technique. RESULTS: Immunohistochemistry staining in choroidal neovascular membranes for MMP-2 and MMP-9 was observed in 17 specimens. There was no detective of MMP-2 and MMP-9 in normal retinas. CONCLUSIONS: MMP-2 and MMP-9 were found in choroidal neovascular membranes, may degrade the Bruch membrane and be associated with the perforation of new vessels into Bruch membrane, involving a basic pathogenic process of AMD.

A novel PRPF31 splice-site mutation in a Chinese family with autosomal dominant retinitis pigmentosa.

PURPOSE: The autosomal dominant form of retinitis pigmentosa (ADRP) can be caused by mutations in 13 genes and a further locus for which the gene remains to be identified. This study was intended to identify mutations in a large Chinese pedigree with ADRP. METHODS: A genome scan was conducted in the family. The whole coding sequences and the intron-exon boundaries of candidate genes were amplified and sequenced. The reverse transcriptase polymerase chain reaction (RT-PCR) was performed to amplify the mutated mRNA. RESULTS: The strongest evidence of linkage was detected with three adjacent microsatellite markers genotyped between D19S902 and D19S210 on chromosome 19q13.33-13.43. Within the region, a single nucleotide change (G>A) at position -1 of Intron 5 of PRPF31 was found. The consensus AG doublet of the Intron 5 splice acceptor was changed to AA. The mutation co-segregated with the disease phenotype, suggesting that it was the disease-causing mutation in this family. This splicing site mutation is predicted to cause an erroneous splicing of Exon 6. By RT-PCR, we found the mutated nucleotide of Intron 5 (A) and the first nucleotide of Exon 6 (G) was regarded as a new splice acceptor, resulting in 1 bp deletion of the first codon of Exon 6 (GAG-to-AG) at the mRNA level. This change led to a frameshift and truncated protein of 196 amino acids with 56 novel amino acids prior to a premature stop. CONCLUSIONS: A novel splicing mutation (IVS5-1G>A) in the pre-mRNA splicing-factor gene PRPF31 causes retinitis pigmentosa in a large Chinese family. The mutation results in a truncated protein of PRPF31.

[Corneal combined amniotic membrane transplantation for early severe alkali chemical injury of the eye].

OBJECTIVE: To investigate the effect of lamella corneal transplantation combined amniotic membrane transplantation for the early severe alkali burns of eyes. METHODS: Twenty-three eyes with an over second-degree acute corneal alkali injury in 2 weeks were treated by lamella corneal transplantation combined amniotic membrane transplantation. After the operation the patients were treated with an intense and prolonged regimen of topical steroids and topical and systemic vitamin C. All patients were followed up for 6-12 months. RESULTS: Seven eyes were cornea transparent, 10 semi-transparent, and 6 opaque in the 23 eyes, respectively. The visual acuity of 3 eyes was better than 0.3, that of 5 eyes was between 0.25 to 0.1, and that of the other 15 eyes was below 0.1. No eye was enucleated due to the corneoscleral melting. CONCLUSION: Lamella corneal transplantation combined amniotic membrane transplantation may clear away the necrotic tissues and cells of corneal or conjunctiva, prevent and reduce the complication, and improve the prognosis of the patients.

[The effect of phacoemulsification combined silicone oil remove and intraocular lens implantation on the eyes with silicone oil temponade].

PURPOSE: To study the effect of phacoemulsification combined silicone oil remove and intraocular lens implantation on the eyes with silicone oil temponade. METHODS: Forty cases (41 eyes) performed phacoemulsification combined silicon oil remove and intraocular lens implantation were retrospectively studied and followed back for 2-18 months, analysis the recover of eyesight and complication of postoperation and during the operation. RESULTS: Except three cases had retina detachment after silicone oil remove, all others patients improved the eyesight in some degree. The main complication during the operation was the posterior capsule tear. The complication of postoperation was retinal detachment. CONCLUSION: It is an effective and safe way that the phacoemulsification combined silicone oil remove for eyes with silicone oil temponade.

[Expression of matrix metalloproteinase in human pterygia].

PURPOSE: To determine the cellular distribution and activation of MMP-2 and MMP-9 in human pterygium. METHODS: The expression and activation of MMP-2 and MMP-9 were determined by immunohistochemistry and quantitative gelatinase zymography from 27 pterygia (26 cases, 18 eyes in stationary pterygia and 9 eyes in progressive pterygia) and 6 normal conjunctival specimens. RESULTS: MMP-2 was expressed in all pterygium examined, specifically localized to the epithelium. MMP-9 was the most abundant in pterygium vascular endothelium and inflammatory cell. MMP-2 levels were no difference between the stationary pterygia [(235+/-18.17) scanning units] and the progressive pterygia [(221+/-22.53) scanning units]. MMP-9 levels in the progressive pterygia [(159+/-19.28) scanning units] were significantly higher than that in the stationary pterygia [(46+/-32.21) scanning units] (P < 0.05). CONCLUSION: This investigation located the expression of MMP-2 and MMP-9 in pterygium of the human eyes. These enzymes may be responsible for the progression of pterygia.