Phacoemulsification in the anterior chamber: An alternative surgical technique in post-vitrectomy cataract.

OBJECTIVE: To evaluate the characteristics, safety and effectiveness of a modified technique of phacoemulsification in post-vitrectomy cataracts. METHODS: This retrospective clinical trial comprised 31 patients (31 eyes) with post-vitrectomy cataract, who had undergone phacoemulsification combined with intraocular lens implantation. An alternative surgical technique known as phacoemulsification in the anterior chamber was used for nucleus management in those cases. The following parameters were evaluated: best corrected visual acuity (BCVA), ocular inflammation, intraocular pressure, endothelial cell count and surgical complications. RESULTS: Three months after surgery, the BCVA improved significantly compared with that before surgery (Z=-10.547; p<0.05). There were no significant differences in IOP before and after surgery (Z=-0.474; p>0.05). There was a statistically significant postoperative decrease in endothelial cell densities (Z=-3.916; p<0.05). The mean endothelial cell loss was -8.71%. A little inflammatory response in the anterior chamber in 11 eyes and mild corneal edema in 8 eyes were observed on the first day after surgery, which subsided after a week. The posterior capsular opacification were observed in three eyes, two of which were denser, and the YAG laser was performed for posterior capsular incision. No obvious surgical complications occurred. CONCLUSION: The modified technique of phacoemulsification, with phacoemulsification in the anterior chamber, is safe and effective to deal with post-vitrectomy cataracts.

GABAAα1 and GABAAρ1 subunits are expressed in cultured human RPE cells and GABAA receptor agents modify the intracellular calcium concentration.

PURPOSE: Gamma-aminobutyric acid A (GABAA) receptors (GABAARs), which are ionotropic receptors involving chloride channels, have been identified in various neural (e.g., mouse retinal ganglion cells) and nonneural cells (e.g., mouse lens epithelial cells) regulating the intracellular calcium concentration ([Ca(2+)]i). GABAAR ß-subunit protein has been isolated in the cultured human and rat RPE, and GABAAα1 and GABAAρ1 mRNAs and proteins are present in the chick RPE. The purpose of this study was to investigate the expression of GABAAα1 and GABAAρ1, two important subunits in forming functional GABAARs, in the cultured human RPE, and further to explore whether altering receptor activation modifies [Ca(2+)]i. METHODS: Human RPE cells were separately cultured from five donor eye cups. Real-time PCR, western blots, and immunofluorescence were used to test for GABAAα1 and GABAAρ1 mRNAs and proteins. The effects of the GABAAR agonist muscimol, antagonist picrotoxin, or the specific GABAAρ antagonist 1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA) on [Ca(2+)]i in cultured human RPE were demonstrated using Fluo3-AM. RESULTS: Both GABAAα1 and GABAAρ1 mRNAs and proteins were identified in cultured human RPE cells; antibody staining was mainly localized to the cell membrane and was also present in the cytoplasm but not in the nucleus. Muscimol (100 µM) caused a transient increase of the [Ca(2+)]i in RPE cells regardless of whether Ca(2+) was added to the buffer. Muscimol-induced increases in the [Ca(2+)]i were inhibited by pretreatment with picrotoxin (300 µM) or TPMPA (500 µM). CONCLUSIONS: GABAAα1 and GABAAρ1 are expressed in cultured human RPE cells, and GABAA agents can modify [Ca(2+)]i.

Pre-mixing serum samples with assay buffer is a prerequisite for reproducible anti-Mullerian hormone measurement using the Beckman Coulter Gen II assay.

STUDY QUESTION: Does pre-mixing stored serum samples with assay buffer improve the reproducibility of the Beckman Gen II assay for anti-Müllerian hormone (AMH)? SUMMARY ANSWER: Pre-mixing serum samples with assay buffer is a prerequisite for reproducible measurement of AMH in serum using the Beckman Coulter Gen II assay. WHAT IS KNOWN ALREADY: Discrepancies in the results obtained from AMH assays have raised doubts concerning the clinical utility of measuring AMH. Sample storage conditions may be responsible for the lack of reproducibility of results obtained from the Gen II kit. STUDY DESIGN, SIZE, DURATION: This was a prospective study in which serum samples were stored at three different temperatures and assayed for AMH at times 0, 4, 8, 12, 24, 48 h and 1 or 2 weeks after collection. Volunteers (n = 28) were healthy non-pregnant and early pregnant women aged 22-41 years. Anonymized long-term stored samples (n = 42, stored at -20° for 2 weeks) from fertility clinic attendees were also included. For determining the reference range, 179 samples from healthy pregnant women presenting for first trimester screening were used. PARTICIPANTS/MATERIALS, SETTING, METHODS: Thirty separate assays were performed by two operators using four different Gen II kit lots with both kit and in-house quality controls (QCs) included in each assay. In addition to the standard protocol, a modified protocol (pre-mixing samples with assay buffer) was used for selected sample groups. MAIN RESULTS AND THE ROLE OF CHANCE: In non-pregnant women, AMH concentrations remained unchanged in serum stored for up to 8 h at room temperature, -20 and -80°C. At room temperature, levels started to rise by 24 h, increasing by up to 29% of the time 0 h value by 48 h and 26% after 1 week. Significant changes versus baseline (time 0 h) in measured AMH concentration were also observed after storage at -20 and -80°C (only at the 12 h time point). In the pregnant group, there was a 50% increase above baseline in samples stored for 48 h at room temperature. When samples were pre-mixed with assay buffer, AMH concentrations showed a consistent increase versus the standard assay in both non-pregnant (29%) and pregnant (280%) groups, regardless of storage conditions and duration, but concentrations remained constant during long-term storage (2 weeks). Stored fertility clinic patient samples also exhibited stability of AMH values after a consistent 2-fold increase following pre-mixing. Kit QCs were consistent over 30 weeks using either standard or modified protocols while the in-house pooled serum QC rose over time unless using the modified protocol. Overall, there was a 2-fold increase in medians in the pre-mixed reference range, with the biggest increase observed in the oldest age bracket (41-45 years, 3.4-fold). LIMITATIONS, REASONS FOR CAUTION: The cause of the observed instability of AMH in stored serum samples requires further investigation, which is outside the scope of this publication. A larger and wider population study is necessary for a more reliable and clinically relevant reference range. WIDER IMPLICATIONS OF THE FINDINGS: Our study has confirmed previous findings of lack of consistency in AMH concentrations when measured with the Gen II assay. Pre-mixing serum samples with assay buffer gave higher but also the most consistent results regardless of storage conditions; therefore, we propose that all serum samples for AMH assay should be pre-mixed with assay buffer. Furthermore, clinical laboratories that offer AMH measurement as part of the assessment of endocrinopathies, such as polycystic ovary syndrome or premature ovarian failure, or for management of ovulation induction as part of assisted reproduction, must re-establish their own normal ranges using the modified method. STUDY FUNDING/COMPETING INTEREST(S): No funding was obtained for this study. There are no conflicts of interest to declare.

Inhibition of form-deprivation myopia by a GABAAOr receptor antagonist, (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA), in guinea pigs.

PURPOSE: To investigate the effects of the relatively selective GABAAOr receptor antagonist (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA) on form-deprivation myopia (FDM) in guinea pigs. METHODS: A diffuser was applied monocularly to 30 guinea pigs from day 10 to 21. The animals were randomized to one of five treatment groups. The deprived eye received daily sub-conjunctival injections of 100 µl TPMPA at a concentration of (i) 0.03 %, ( ii) 0.3 %, or (iii) 1 %, a fourth group (iv) received saline injections, and another (v) no injections. The fellow eye was left untreated. An additional group received no treatment to either eye. Prior to and at the end of the treatment period, refraction and ocular biometry were performed. RESULTS: Visual deprivation produced relative myopia in all groups (treated versus untreated eyes, P < 0.05). The amount of myopia was significantly affected by the drug treatment (one-way ANOVA, P < 0.0001); myopia was less in deprived eyes receiving either 0.3 % or 1 % TPMPA (saline = -4.38 ± 0.57D, 0.3 % TPMPA = -3.00 ± 0.48D, P < 0.01; 1 % TPMPA = -0.88 ± 0.51D, P < 0.001). The degree of axial elongation was correspondingly less (saline = 0.13 ± 0.02 mm, 0.3 % TPMPA = 0.09 ± 0.01 mm, P < 0.01, 1 % TPMPA = 0.02 ± 0.01 mm, P < 0.001) as was the VC elongation (saline = 0.08 ± 0.01 mm, 0.3 % TPMPA = 0.05 ± 0.01 mm, P < 0.01, 1 % TPMPA = 0.01 ± 0.01 mm; P < 0.001). ACD and LT were not affected (one-way ANOVA, P > 0.05). One percent TPMPA was more effective at inhibiting myopia than 0.3 % (P < 0.01), and 0.03 % did not appreciably inhibit the myopia (0.03 % TPMPA versus saline, P > 0.05). CONCLUSIONS: Sub-conjunctival injections of TPMPA inhibit FDM in guinea pig models in a dose-dependent manner.

Evaluation of anti-Mullerian hormone in the first trimester as a predictor for hypertensive disorders of pregnancy and other adverse pregnancy outcomes.

BACKGROUND: Prediction of pre-eclampsia and adverse pregnancy outcomes with biomarkers has been proposed. AMH is an ovary-specific growth factor, used to predict ovarian reserve, which changes with age similar to the change in age-related fertility. AIMS: The aim of the study was to determine whether AMH tested in the first trimester of pregnancy was associated with pregnancy hypertension or adverse pregnancy outcomes. MATERIALS AND METHODS: Retrospective cohort study of women who delivered singleton fetuses ≥20 weeks' gestation at Royal Hospital for Women, Sydney, Australia (n = 331). AMH was tested in 2011 via Beckman-Coulter Gen II ELISA method on frozen serum collected at the time of first trimester aneuploidy screening (10-13 + 6 weeks' gestation). Outcome data were obtained from the hospital database (ObstetriX). Main outcome measures were pregnancy hypertension (pre-eclampsia and gestational hypertension) and composite adverse pregnancy outcome. RESULTS: The median AMH level was 9.7 pmol/L (interquartile range (IQR) 3.9-17.3). There was a trend towards women with pregnancy hypertension having lower AMH levels than women without pregnancy hypertension (median 5.1 pmol/L, IQR 1.5-13.2 vs 9.4 IQR 3.9-17.3; P = 0.06). After adjusting for BMI ≥25, parity ≥1 and age ≥35, women with an AMH less than the 10th centile had a 3.3-fold increased risk of pregnancy hypertension (OR 3.3, 95% CI 1.2-8.7, P = 0.01). There were no other associations between low AMH concentration and adverse maternal or neonatal outcomes. CONCLUSIONS: Women with a very low AMH (1.5 pmol/L) in early pregnancy may have an increased risk of pregnancy hypertension. No other adverse pregnancy outcomes were identified.

Boosting Lithium Storage of a Metal-Organic Framework via Zinc Doping.

Lithium-ion batteries (LIBs) as a predominant power source are widely used in large-scale energy storage fields. For the next-generation energy storage LIBs, it is primary to seek the high capacity and long lifespan electrode materials. Nickel and purified terephthalic acid-based MOF (Ni-PTA) with a series amounts of zinc dopant (0, 20, 50%) are successfully synthesized in this work and evaluated as anode materials for lithium-ion batteries. Among them, the 20% atom fraction Zn-doped Ni-PTA (Zn0.2-Ni-PTA) exhibits a high specific capacity of 921.4 mA h g-1 and 739.6 mA h g-1 at different current densities of 100 and 500 mA g-1 after 100 cycles. The optimized electrochemical performance of Zn0.2-Ni-PTA can be attributed to its low charge transfer resistance and high lithium-ion diffusion rate resulting from expanded interplanar spacing after moderate Zn doping. Moreover, a full cell is fabricated based on the LiFePO4 cathode and as-prepared MOF. The Zn0.2-Ni-PTA shows a reversible specific capacity of 97.9 mA h g-1 with 86.1% capacity retention (0.5 C) after 100 cycles, demonstrating the superior electrochemical performance of Zn0.2-Ni-PTA anode as a promising candidate for practical lithium-ion batteries.

The key role of concentrated Zn(OTF)2 electrolyte in the performance of aqueous Zn-S batteries.

In this communication, the electrolyte chemistry in aqueous Zn-S batteries was illustrated systematically. Compared to Zn(AC)2 and ZnSO4, Zn(OTF)2 electrolyte can achieve better electrochemical performance due to the impact of larger CF3SO3- anions on the solvation shell structure of Zn2+. Moreover, a reversible capacity of 788 mA h g-1 in concentrated Zn(OTF)2 electrolyte (3 M) is obtained and shows higher retention due to higher Zn-nucleation overpotential and slower corrosion reactions.

Dilute Hybrid Electrolyte for Low-Temperature Aqueous Sodium-Ion Batteries.

A hybrid electrolyte based on low-concentration sodium nitrate with glycerol as an additive was proposed for aqueous sodium-ion batteries (ASIBs) towards low-temperature performance. Based on this dilute hybrid electrolyte and configured by bimetallic Prussian blue analogue (Ni2 ZnHCF) cathode and 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) anode, the full cell demonstrated surprising cycle performance with a specific capacity of 60 mAh g-1 (>800 cycles) and achieved prominent performance at low temperature. Glycerol effectively expanded the electrochemical stability window of the hybrid electrolyte to 2.7 V from formation of strong hydrogen bonds with water molecules and realized the operation of the cell at low temperature, delivering a stable reversible capacity of 40 mAh g-1 at -10 °C. The hybrid electrolyte of glycerol-water provides a new alternative in development of low-cost, long-lifespan, and low-temperature ASIBs and other aqueous battery systems.

The Effectiveness of Conbercept Combined with Panretinal Photocoagulation vs. Panretinal Photocoagulation in the Treatment of Diabetic Retinopathy: A Meta-Analysis.

OBJECTIVE: This meta-analysis aimed to compare the effect and safety of conbercept with panretinal photocoagulation (PRP) vs. PRP in the treatment of diabetic retinopathy (DR). METHODS: Relevant studies were identified through systemic searches of PubMed, EMBASE, China National Knowledge Infrastructure, and Wanfang database up to December 2020. The results of conbercept and PRP in patients with DR were analyzed, including overall effectiveness, best corrected visual acuity, central macular thickness, and complications. RESULTS: 12 articles involving 1244 patients with DR were identified for this meta-analysis. The results of the meta-analysis showed that conbercept combined with PRP significantly increased the level of overall effectiveness and significantly reduced the central thickness of macula and the incidence of complications compared with the control group. CONCLUSIONS: Conbercept with PRP tended to be more effective than PRP alone in terms of functional outcomes for treating DR.

Morphological and cytological changes of meibomian glands in patients with type 2 diabetes mellitus.

AIM: To observe the changes of microcellular structure of meibomian glands (MGs) in type 2 diabetes mellitus (DM), and to explore its correlation with the duration of diabetes. METHODS: The study assessed 132 eyes of 132 patients with type 2 diabetes mellitus (DM group) and 100 eyes of 100 non-diabetic participants (NDM group). All patients underwent the examination of the Keratograph 5M system to obtain the meibography which were used to evaluate the structure dropout of the MGs. And then laser scanning confocal microscopy (LSCM) was performed for observing the acinar cells and ducts of the MGs to obtain the following parameters: the MG acinar unit density (MGAUD), MG acinar longest diameter (MGALD) and MG acinar shortest diameter (MGASD). The examination results of the right eye were selected for analysis. RESULTS: Compared with that in NDM group, the meiboscore was significantly higher (Z=-4.057, P<0.001), and there were more MGs dropout in DM group. With the prolongation of the course of diabetes, the absence of MGs aggravated and the MGs dropout score increased (r=0.596; P<0.001). LSCM showed that there were various cytological alterations in acinar cells of MGs with the progress of diabetes duration, such as expansion, atrophy or fibrosis of MG acinar units, decreased density of MG acinar units, deposition of lipid substances, infiltration of inflammatory cells, proliferation of fibrous tissues, etc. And the opening of the glandular duct changed from smooth at the beginning to narrow, blocked, fibrotic and so on. Compared with that in NDM group, the MGAUD in DM group was significantly lower (Z=-9.713; P<0.001), the MGALD and MGASD were significantly larger (Z=-9.751, -6.416; P<0.001). With the duration of diabetes, the MGAUD reduced, the MGASD increased (r=0.860, 0.364, P<0.001); but the MGALD had no correlation with diabetic duration (r=0.133, P=0.151). CONCLUSION: With the progress of diabetes, the meibomian glandular acinar cells of diabetic patients show various manifestations. Those changes may result in the dysfuction of the MGs, tear film instability and dry eye symptoms in patients with type 2 DM.

[Determination of the synthetic route based on impurity profiling of methamphetamine].

OBJECTIVE: Impurity profiling of seized methamphetamine may play an important role in the determination of the synthetic method employed and the criminal investigations of drug traffic routes. METHODS: A sample of methamphetamine was dissolved in buffer solution. Impurities were extracted with ethyl acetate containing four internal standards (n-decane, n-pentadecane, n-eicosane and n-octacosane) and analyzed by GC-MS. RESULTS: These data are suggestive of ephedrine/pseudoephedrine as the main precursor of the methamphetamine samples seized during 2006-2007. Six samples of selected eight samples were synthesized via the more specific ephedrine/hydriodic acid/red phosphorus method. CONCLUSION: Ephedrine/pseudoephedrine is common material used to synthesize methamphetamine.

Maternal Diabetes, Large-for-Gestational-Age Births, and First Trimester Pregnancy-Associated Plasma Protein-A.

CONTEXT: Maternal pregnancy-associated plasma protein-A (PAPP-A) is measured at nuchal translucency scanning to assess the risk of fetal chromosomal disorders. OBJECTIVE: The aim of this study was to examine whether PAPP-A might also be a predictor of gestational diabetes (GDM), type 2 diabetes (T2D), or large-for-gestational-age (LGA) births. DESIGN: PAPP-A levels were measured in serum from 1664 women at their 10-14-week nuchal translucency scan at a tertiary referral hospital. Maternal diabetes was categorized as T2D, "early GDM" (GDM diagnosed < 22 wk), and "late GDM" (GDM diagnosed ≥ 22 wk). The relationship between PAPP-A multiples of the median (MoM), maternal diabetes, and LGA was examined with multivariate regression models. RESULTS: PAPP-A MoM was significantly lower in women with T2D and women who developed GDM than in nondiabetic women. PAPP-A MoM was 41.3% lower in T2D, 22.6% lower in early GDM, and 8.6% lower in late GDM. Women in the lowest quartile of PAPP-A MoM were 2.7 times more likely to have early GDM (odds ratio [OR], 2.74; 95% confidence interval [CI], 1.2-6.1) compared with the highest quartile. Birth weight had a positive linear association with PAPP-A MoM. Women in the highest PAPP-A MoM quartile were twice as likely to have an LGA baby (OR, 2.2; 95% CI, 1.39-3.46; P = .0007). CONCLUSIONS: Routinely tested first-trimester PAPP-A is a novel biomarker for maternal diabetes and LGA. PAPP-A decreased with increasing severity of maternal diabetes. Although this cannot infer causality, low PAPP-A may help identify women at risk of GDM, and high PAPP-A may help identify pregnancies at risk of LGA.

GABAB receptor antagonist CGP46381 inhibits form-deprivation myopia development in guinea pigs.

The aim was to investigate the effects of the GABAB receptor antagonist, CGP46381, on form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs had monocular visual deprivation induced using a diffuser for 11 days (day 14 to 25). The deprived eyes were treated with daily subconjunctival injections (100 µl) of either 2% CGP46381, 0.2% CGP46381, or saline or received no injection. The fellow eyes were left untreated. Another six animals received no treatment. At the start and end of the treatment period, ocular refractions were measured using retinoscopy and vitreous chamber depth (VCD) and axial length (AL) using A-scan ultrasound. All of the deprived eyes developed relative myopia (treated versus untreated eyes, P < 0.05). The amount of myopia was significantly affected by the drug treatment (one-way ANOVA, P < 0.0001). The highest dose tested, 2% CGP46381, significantly inhibited myopia development compared to saline (2% CGP46381: -1.08 ± 0.40 D, saline: -4.33 ± 0.67 D, P < 0.01). The majority of these effects were due to less AL (2% CGP46381: 0.03 ± 0.01 mm, saline: 0.13 ± 0.02 mm, P < 0.01) and VCD (2% CGP46381: 0.02 ± 0.01 mm, saline: 0.08 ± 0.01 mm, P < 0.01) elongation. The lower dose tested, 0.2% CGP46381, did not significantly inhibit FDM (P > 0.05). Subconjunctival injections of CGP46381 inhibit FDM development in guinea pigs in a dose-dependent manner.

Comparison of riboflavin/ultraviolet-A cross-linking in porcine, rabbit, and human sclera.

PURPOSE: To compare the biomechanical properties of porcine, rabbit, and human sclera before and after riboflavin/ultraviolet-A (UVA) collagen cross-linking (CXL). METHODS: Eight rabbits, 8 porcine eyeballs, and 8 human eyeballs were included. One rabbit eye and half of each bisected human and porcine eyeball were treated with riboflavin/UVA CXL. Untreated fellow rabbit eyes and eyeball halves served as controls. A 10 mm × 20 mm scleral band was harvested from each specimen. From this band, two 3.5 mm × 15.0 mm strips were prepared for biomechanical testing. The biomechanical parameters were ultimate stress, stress and Young's modulus. RESULTS: Values of stress, and Young's modulus showed that human sclera was 4 times stiffer than porcine sclera and 3 times stiffer than rabbit sclera. In rabbit sclera, both the stress and Young's modulus were significantly increased by CXL (P < 0.05). In porcine sclera, only the ultimate stress was significantly increased by CXL (P < 0.05). The biomechanical properties of human sclera were not statistically affected by CXL (P > 0.05). CONCLUSIONS: Human sclera has higher biomechanical stiffness than porcine and rabbit sclera. With the same irradiation dose, riboflavin/UVA CXL increases the biomechanical stiffness of rabbit sclera but not porcine or human sclera.