Clinical relevance of the glucocorticoid receptor gene polymorphisms in glucocorticoid-induced ocular hypertension and primary open angle glaucoma

AIM: To avoid the side effects of ocular hypertension of glucocorticoid(GC) usage in eye, we must identify susceptible individuals, which exists in about one-third of all population. Further, the majority of all primary open angle glaucoma(POAG) patients show this phenotype.Glucocorticoid receptor(GR) regulates C responsiveness in trabecular meshwork(TM) cells. In this study, single nucleotide polymorphism(SNP) genotyping was used to determine whether there are differences in the Bcl I(rs41423247) and N363S(rs6195) polymorphisms of the GR gene in healthy and POAG patients, and glucocorticoid-induced ocular hypertension(GIOH)populations.METHODS: Three hundred and twenty-seven unrelated Chinese adults, including 111 normal controls, 117 GIOH subjects and 99 POAG patients, were recruited. DNA samples were prepared and the Bcl I and N363 S polymorphisms were screened using real-time polymerase chain reaction(RT-PCR)-restriction fragment length polymorphism(RFLP) analysis. Frequencies of the Bcl I and N363 S polymorphisms were determined and compared using Fisher’s exact test and the Chi-squared test.RESULTS: Only the Bcl I polymorphism was identified in the Chinese Han population. The frequency of the G allele was 21.6 % in normal controls, 18.3% in GIOH patients, and 13.64% in the POAG patients. There was no significant difference in polymorphism or allele frequency in the 3 groups. Furthermore, no N363 S polymorphism was found in the study subjects.CONCLUSION: The Bcl I polymorphisms in GR gene had no association with GIOH and POAG patients, and N363 S polymorphism might not exist in the Chinese Han population. Therefore, the Bcl I polymorphism might not be responsible for the development of GC-induced ocular hypertension or POAG.

Risk factors for flat anterior chamber after glaucoma filtration surgery

AIM： To investigate the incidence rate and risk factors for grade Ⅲ flat anterior chamber（FAC） after glaucoma filtration surgery based on 5-year data.METHODS： Patients who underwent glaucoma filtration surgery in Daping hospital from January 2009 to December 2013 were enrolled in this retrospective study. The incidence of grade Ⅲ FAC following glaucoma filtration surgery was determined. Regression analysis was performed to investigate the influence of glaucoma type, surgical approach, age, and preoperative intraocular pressure（IOP） on the risk of postoperative FAC.RESULTS： A total of 2179 eyes receiving anti-glaucoma surgery were included. Ninety-one eyes suffered from postoperative FAC, with an overall incidence rate of 4.18%. Of 471 eyes with primary open angle glaucoma（POAG）, grade Ⅲ FAC occurred in only 3 eyes（0.64%）. Primary angleclosure glaucoma（PACG） was diagnosed in 1076 eyes, 39（3.62%） of which developed grade Ⅲ FAC, including 12 eyes（12/300, 4%） with acute PACG（aP ACG） and 27 eyes（27/776, 3.48%） with chronic PACG（c PACG）. Six of 259 eyes（2.32%） with secondary glaucoma, 28 of 186 eyes（15.05%） with neovasular glaucoma, 1 of 66 eyes（1.52%） with congenital glaucoma, and 14 of 115 eyes（12.17%） with remnant glaucoma suffered from grade Ⅲ FAC. Of 6 eyes with mixed glaucoma, none developed grade Ⅲ FAC after surgery. When stratified by surgical approach, 24 of 766 eyes（3.13%） undergoing trabeculectomy, 21 of 924 eyes（2.27%） treated by trabeculectomy plus mitomycin C（MMC）, 18 of 109 eyes（16.51%） undergoing Ahmed glaucoma valve implantation, 23 of 201 eyes（11.44%） managed by Ahmed implantation plus MMC, and 5 of 133 eyes（3.76%） treated by Ahmed implantation plus lens extraction or vitrectomy developed grade Ⅲ FAC. Logistic regression analysis revealed that factors including neovasular glaucoma, remnant glaucoma, glaucoma valve implantation, glaucoma valve implantation＋MMC, glaucoma valve implantation＋vitrectomy, age〉60 y, and IOP at admission 〉50 mm Hg were significantly associated with an increased risk for grade Ⅲ FAC.CONCLUSION： The overall incidence of grade Ⅲ FAC after glaucoma filtration surgery is 4.18%. Patients with neovasular glaucoma and remnant glaucoma are at a higher risk of developing FAC. Ahmed glaucoma valve implantation is associated with a higher risk for grade Ⅲ FAC compared with trabeculectomy. No significant correlation was observed between the use of MMC in glaucoma filtration surgery and the risk of postoperative FAC. Higher IOP at admission（〉50 mm Hg） and old age（〉60 y） are risk factors for grade Ⅲ FAC.

Distributed optical fiber acoustic sensor for in situ monitoring of marine natural gas hydrates production for the first time in the Shenhu Area,China

The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in real-time.So it is suitable for monitoring downhole production activities in the process of oil and gas development.The authors applied the DAS system in a gas production well in the South China Sea for in situ monitoring of the whole wellbore for the first time and obtained the distributed acoustic signals along the whole wellbore.These signals can clearly distinguish the vertical section,curve section,and horizontal production section.The collected acoustic signal with the frequency of approximately 50 Hz caused by the electric submersible pump exhibit a signal-to-noise ratio higher than 27 dB.By analyzing the acoustic signals in the production section,it can be located the layers with high gas production rates.Once an accurate physical model is built in the future,the gas production profile will be obtained.In addition,the DAS system can track the trajectory of downhole tools in the wellbore to guide the operation.Through the velocity analysis of the typical signals,the type of fluids in the wellbore can be distinguished.The successful application of the system provides a promising whole wellbore acoustic monitoring tool for the production of marine gas hydrate,with a good application prospect.