The role of optical coherence tomography angiography in distinguishing ischemic versus non-ischemic central retinal vein occlusion.

INTRODUCTION: To observe macular microvascular changes in patients with ischemic and non-ischemic central retinal vein occlusion (CRVO) by optical coherence tomography angiography (OCTA), and explore the value of OCTA in differentiating ischemic and non-ischemic CRVO. METHODS: Cross sectional study. Fifty patients diagnosed as CRVO with macular edema were included. Macular edema in all patients were regressive after three consecutive anti-VEGF treatment. Patients were divided into ischemic and non-ischemic group according to ultra-wide-angle fundus fluorescein angiography (UWFFA). All patients underwent BCVA, IOP, color fundus photography, UWFFA and OCTA. The following parameters were measured: (1) Vessel density (VD): superficial and deep whole VD (SVD, DVD), superficial and deep central fovea VD (SFVD, DFVD), superficial and deep parafoveal VD (SPFVD, DPFVD); (2) Central foveal retinal thickness (CRT); (3) Area of foveal avascular zone (FAZ), perimeter of FAZ (PERIM), avascular index of FAZ (AI) and VD within a width of 300 microns around the FAZ region (FD-300). Comparison between ischemic and non-ischemic group was performed by two independent sample t-tests. Receiver operating characteristic (ROC) curve analysis was used to measure the area under the curve (AUC) of VD for predicting ischemic CRVO. RESULTS: There were no significant differences in IOP, SFVD, DFVD and CRT between ischemic and non-ischemic group, and significant differences in age, BCVA, SVD, SPFVD, DVD, DPFVD, FAZ area, PERIM, AI and FD-300 between ischemic and non-ischemic group. ROC curve analysis showed AUC of DVD and DPFVD in predicting ischemic CRVO was highest (0.962). the threshold was 38.40%, and the sensitivity was 100%, but the specificity of DVD (92.3%) was significantly higher than that of DPFVD (84.6%). Therefore, DVD ≤ 38.40% can be used as the best threshold for determining ischemic CRVO. CONCLUSION: OCTA can quantitatively evaluate the macular microvascular structure of CRVO, which is helpful to distinguish ischemic from non-ischemic CRVO.

Cytokine levels in the aqueous humor of young and senior patients with proliferative diabetic retinopathy.

OBJECTIVE: To evaluate the aqueous humor levels of vascular endothelial growth factor (VEGF), connective tissue growth factor (CTGF), and tumor necrosis factor α (TNF-α) as biomarkers of the severity of proliferative diabetic retinopathy (PDR) in young and senior patients. METHODS: This was a prospective clinical study. From October 2020 to June 2021, 37 patients (37 eyes) who were diagnosed with PDR and received pars plana vitrectomy (PPV) at Tianjin Medical University Eye Hospital were recruited and allocated to either the young (16 patients, 16 eyes) or senior subgroup (21 patients, 21 eyes). Twelve patients with cataracts (12 eyes) who underwent phacoemulsification combined with intraocular lens (IOL) implantation during the same period were recruited in the control group. The fibrovascular proliferation (FVP) grade and PDR severity scores were recorded during PPV. Enzyme-linked immunosorbent assay was used to detect the levels of VEGF, CTGF, and TNF-α in the aqueous humor. RESULTS: (1) Young patients with PDR had a higher FVP grade and PDR severity score (P = 0.037, = 0.009); (2) The levels of the three cytokines in the study group were all significantly higher than in the control group (all P < 0.001); (3) The CTGF level in the young subgroup (2239.55 ± 167.32 pg/mL) was significantly higher than that in the senior subgroup (2114.49 ± 102.04 pg/mL) (P = 0.025). The VEGF level in the young subgroup (311.09 ± 10.74 pg/mL) was significantly lower than that in the senior subgroup (324.85 ± 14.97 pg/mL) (P = 0.004). The TNF-α level was not statistically different between the two subgroups (P = 0.382); (4) The CTGF/VEGF ratio in the young subgroup (7.20 ± 0.54) was significantly higher than in the senior subgroup (6.52 ± 0.39) (P < 0.001); (5) The CTGF/VEGF ratio was positively correlated with the FVP grades (R = 0.377, P = 0.022) and with the PDR severity scores (R = 0.354, P = 0.032) in patients with PDR. CONCLUSION: The aqueous humor CTGF/VEGF ratio was positively correlated with the severity of PDR. A higher CTGF/VEGF ratio in the aqueous humor proved that neovascular fibrosis was more serious in young patients when they received PPV.

Improvement of 1,3-propanediol production from crude glycerol by co-cultivation of anaerobic and facultative microbes under non-strictly anaerobic conditions.

BACKGROUND: Natural microbial consortia could efficiently produce 1,3-propanediol (1,3-PDO), a most promising bulk biochemical derived from glycerol that can be used as a monomer in the synthesis of polytrimethylene terephthalate (PTT). While natural microbial communities are made up of a diverse range of microbes with frequently unknown functions, the construction of synthetic microbial consortia allows for the creation of more defined systems with lower complexity. RESULTS: In this study, the synthetic microbial consortia were constructed by combining facultative microbes of Klebsiella pneumoniae DUT2 (KP) and/or Escherichia coli DUT3 (EC) cultures with the strictly anaerobic microbe of Clostridium butyricum DUT1 (CB) cultures under micro-aerobic conditions. The function of EC and KP during the fermentation process was to deplete oxygen and create an anaerobic environment for CB. Furthermore, KP competes with CB for the consumption of crude glycerol and the production of 1,3-PDO. The interaction of commensalism and competition resulted in the construction of synthetic microbial consortia capable of efficiently converting crude glycerol to 1,3-PDO even under micro-aerobic conditions. In a batch fermentation, the synthetic CB:KP co-culture at an initial abundance ratio of 92.5:7.5, yielded a maximum 1,3-PDO concentration of 52.08 g/L, with a yield of 0.49 g/g and a productivity of 1.80 g/(L.h), which increased by 10%, 9%, and 12%, respectively, when compared to the CB mono-culture under strictly anaerobic conditions. The final 1,3-PDO concentration, yield, and productivity by the synthetic CB:KP consortia increased by 16%, 19%, and 84%, respectively, when compared to the KP mono-culture. At an initial abundance ratio of 85:7.5:7.5, the synthetic CB:KP:EC co-culture achieved the highest 1,3-PDO flux of 49.17%, while 7.43%, 5.77%, 3.15% 4.24%, and 2.13% of flux was distributed to butyric acid, acetic acid, lactic acid, ethanol, and succinic acid pathways. In a fed-batch fermentation, the synthetic CB:KP:EC co-culture demonstrated a maximum 1,3-PDO concentration of 77.68 g/L with a yield of 0.51 g/g which is 30% and 13% higher than the production by the CB mono-culture at 0.02 vvm (nitrogen volume/culture volume/min) N2 supply. The initial abundance of CB, which is guaranteed to be at least 85%, enables efficient 1,3-PDO production from crude glycerol via the development of synthetic microbial consortia. CONCLUSION: The synthetic microbial consortia demonstrated excellent performance on 1,3-propanediol production under micro-aerobic conditions through the interaction of commensalism and competition. The experimental results demonstrated the potential benefit of using synthetic microbial consortia to produce 1,3-propanediol from crude glycerol.

Research progress of UWFFA and OCTA in retinal vein occlusion: A review.

Retinal vein occlusion (RVO) is a retinal vascular disease that severely impairs the visual function of patients. Observing the changes of retinal blood vessels before and after treatment is of great significance for the prognostic evaluation of RVO. The rapid development and widespread use of fundus imaging technique, especially ultra-wide-angle fundus fluorescein angiography (UWFFA) and optical coherence tomography angiography (OCTA) have made our observation of the retinal blood vessels of RVO more comprehensive and meticulous. In this paper, we reviewed the latest research progress of UWFFA and OCTA in RVO.

Rapamycin prevents retinal neovascularization by downregulation of cyclin D1 in a mouse model of oxygen-induced retinopathy.

BACKGROUND: Rapamycin (RAPA) is a potent angiogenic inhibitor and the aim of this study is to identify the inhibitory effect of RAPA on retinal neovascularization (RNV) in experimental oxygen-induced retinopathy (OIR). METHODS: Forty-two 7-day-old C57BL/6 J mice were randomly divided into normoxia control group (14 mice), OIR group (14 mice), and rapamycin (RAPA) group. OIR model was induced in OIR and RAPA group. Vehicle and RAPA (2 mg/kg/d) was injected intraperitoneally daily from postnatal day 12 (P12) in OIR and RAPA groups, respectively. RNV was evaluated using fluorescence angiography and histopathology on P17. Non-perfused areas of retina were analyzed by Image-Pro plus 6.0 software. Retinal expression of cyclin D1 was detected both at mRNA and protein levels. RESULTS: RAPA treatment significantly decreased RNV, non-perfused areas and number of endothelial cell nuclei breaking through the internal limiting membrane (ILM) in OIR mice. Moreover, RAPA decreased activation of cyclin D1 in retina caused by OIR. CONCLUSION: RAPA can inhibit RNV by downregulating the expression of cyclin D1, which indicates its therapeutic potential in treating RNV-related diseases.

Mesoporous bimetallic Fe/Co as highly active heterogeneous Fenton catalyst for the degradation of tetracycline hydrochlorides.

Mesoporous bimetallic Fe/Co was prepared as a Fenton-like catalyst to degrade the tetracycline hydrochlorides (TC). The nanocasting strategy with KIT-6 as a hard template was carried out to synthesize the mesoporous bimetallic catalyst. The mesoporous bimetallic Fe/Co catalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, and Brunauer-Emmett-Teller (BET) method. The results showed that the catalyst has significant nanofeatures; the surface area, pore size, and particle size were 113.8 m2g-1, 4 nm, and 10 nm, respectively. In addition, the effects of the operating parameters, such as the iron-to-cobalt ratio, pH, H2O2, and initial TC concentrations on its catalytic performance were investigated. The best operating parameters were as follows: iron-to-cobalt ratio = 2:1 to 1:1, pH = 5-9, H2O2: 30 mmol, initial TC less than 30 mg/L. Furthermore, the mesoporous bimetallic Fe/Co showed a good performance for degrading TC, achieving a removal rate of 86% of TC after 3 h under the reaction conditions of H2O2 = 30 mmol, mesoporous bimetallic Fe/Co = 0.6 g/L, TC = 30 mg/L, pH = 7.0, and temperature = 25.5 °C. The mesoporous bimetallic Fe/Co catalyst shows good stability and reusability. This work demonstrated that mesoporous bimetallic Fe/Co has excellent catalytic efficiency, smaller amounts of leached ions, and wider pH range, which enhance its potential applications.

Adenoviral Vector-Mediated Delivery of p21WAF1/CIP1 Prevents Retinal Neovascularization in an Oxygen-Induced Retinopathy Model.

OBJECTIVE: To evaluate the inhibitory effect(s) of adenovirus (Ad) vector-mediated delivery of p21WAF1/CIP1 (Ad-p21) on retinal neovascularization (RNV) in an animal model of oxygen-induced retinopathy (OIR). METHODS: RNV was determined by examination of retinal fiat mounts and sections postnatal (P) day-17 (P17). Non-perfused retinal areas were analyzed using Image-Pro plus 6.0 software. Reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis were used to measure mRNA and protein expression of p21 and cyclin-dependent kinase (CDK) 2. RESULTS: Compared with phosphate buffer saline (PBS) and Ad-NC group mice, non-perfused retinal areas, neovascularization, and number of endothelial cell nuclei breaking through the internal limiting membrane (ILM) in Ad-p21 group mice were significantly reduced. There were fewer non-perfused retinal areas in Ad-p21 mice than in either PBS or Ad-NC group mice, the differences being significant (F = 101.634; p < 0.05). Levels of p21 mRNA and protein in the Ad-p21 group had increased significantly compared with the other three groups (F = 839.664, 509.817; p < 0.05). Levels of CDK2 mRNA and protein in the Ad-p21 group decreased significantly (F = 301.858, 592.882; p < 0.05). CONCLUSIONS: Ad-p21 inhibits RNV in OIR. A potential underlying mechanism for this may be that overexpression of p21 arrests the cell cycle at the G1- to S-phase transition via inhibition of CDK2 activity.

[Study on Intelligent Automatic Tracking Radiation Protection Curtain].

In order to overcome the shortcomings of traditional X-ray inspection taking passive protection mode, this paper combines the automatic control technology, puts forward a kind of active protection X-ray equipment. The device of automatic detection of patients receiving X-ray irradiation part, intelligent adjustment in patients and shooting device between automatic tracking radiation protection device height. The device has the advantages of automatic adjustment, anti-radiation device, reduce the height of non-irradiated area X-ray radiation and improve the work efficiency. Testing by the professional organization, the device can decrease more than 90% of X-ray dose for patients with non-irradiated area.

Overexpression p21WAF1/CIP1 in suppressing retinal pigment epithelial cells and progression of proliferative vitreoretinopathy via inhibition CDK2 and cyclin E.

BACKGROUND: P21 is one kind of cyclin-dependent kinase inhibitor that can prevent cells from going through the G1/S phase checkpoint and inhibit cell proliferation. Proliferative vitreoretinopathy (PVR) is a proliferative response in the eye. The aim of this study was to determine whether p21Waf1/Cip1 (p21) suppresses the proliferation and migration of retinal pigment epithelial (RPE) cells in vitro and controls PVR development in vivo. METHODS: Cell cycle analyses and transwell assays were conducted to assess cell proliferation characteristics and the migration ability of RPE cells after transfection with p21. Western blot and reverse-transcription polymerase chain reaction technologies were used to detect the expression of p21, CDK2 and cyclinE in RPE cells and rabbit retinal tissues. The impact of increasing p21 expression on PVR development was conducted by implantation of an adenovirus vector containing rabbit p21 (rAd-p21) in a PVR rabbit model. The prevalence of PVR and retinal detachment was determined by indirect ophthalmoscopy on days 3, 7, 14, and 21 after the injection of rAd-p21 into the vitreous. B scans and hematoxylin-eosin staining were employed to check rabbit retinas on day 21. RESULTS: Cell cycle analyses and transwell assays showed that p21 inhibited the proliferation and migration of RPE cells. Increased expression of p21 was detected in cultured RPE cells and rabbit retinas after transfection with the p21 gene, whereas levels of CDK2 and cyclinE were decreased. The increase in p21 expression effectively suppressed the development of PVR in a rabbit model. CONCLUSIONS: The increase in p21 expression in RPE cells not only inhibits the proliferation and migration of RPE cells in vitro, but also suppresses the development of PVR in vivo, which indicates its therapeutic potential in treating PVR.

Vitreous and plasma VEGF levels as predictive factors in the progression of proliferative diabetic retinopathy after vitrectomy.

PURPOSE: To investigate the vitreous and plasma levels of vascular endothelial growth factor (VEGF) in patients with proliferative diabetic retinopathy (PDR) and to determine whether they predict a disease prognosis after primary vitrectomy. METHODS: Fifty patients (50 eyes) with PDR who underwent pars plana vitrectomy (PPV) and 56 healthy controls (56 eyes) were enrolled in this retrospective study. Clinical data were collected and analyzed. Vitreous and plasma VEGF concentrations were measured using enzyme-linked immunosorbent assays. VEGF levels and clinical data were compared and analyzed to see if they provide a prognosis of PDR progression after primary vitrectomy at more than 6 months follow-up. Correlation of VEGF concentrations between vitreous fluid and plasma was analyzed. RESULTS: The average BCVA was significantly improved after surgery (P<0.001). Vitreous and plasma VEGF levels were significantly elevated in PDR patients than those in healthy controls (P vitreous<0.001; P plasma<0.001). Both vitreous and plasma VEGF levels were significantly higher in PDR progression group than in stable group (P vitreous < 0.001; P plasma = 0.004). Multivariate logistic regression analyses showed that the increased vitreous VEGF level was associated with the progression of PDR after primary PPV (OR = 1.539; P = 0.036). Vitreous VEGF level was positively associated with plasma VEGF level in PDR patients (P<0.001). CONCLUSION: The increased VEGF level in vitreous fluid may be identified as a significant predictive factor for the outcome of vitrectomy in patients with PDR.

Inhibitory effect of adenoviral vector-mediated delivery of p21WAF1/CIP1 on retinal vascular endothelial cell proliferation and tube formation in cultured Rhesus monkey cells (RF/6A).

OBJECTIVE: To investigate the inhibitory effect(s) of adenovirus (Ad) vector-mediated delivery of p21(WAF1/CIP1) (Ad-p21) on proliferation and tube formation in Rhesus monkey choroid-retina vascular endothelial cells (RF/6A). METHODS: In vitro-cultured RF/6A cells were divided into three groups: phosphate-buffered saline (PBS), Ad-p21-transfected, and negative control. Plasmid vectors were transfected via Ad-p21. The mRNA and protein expressions of p21 and cyclin-dependent kinase (CDK)2 in RF/6A cells were measured by reverse transcription-PCR (RT-PCR) and western blot analyses. Cell-cycle distributions were analyzed by flow cytometry. Matrigel was used as a matrix for endothelial cell tube formation. RESULTS: Expressions of p21 mRNA and protein were greater, and expressions of CDK2 mRNA and protein lower, in the Ad-p21-transfected group than in either the PBS or negative control groups. Cell-cycle distribution analysis indicated that the proportion of G0/G1 cells was significantly higher in the Ad-p21 transfected group than in either the PBS or negative control groups (p = 0.000). There were significantly fewer endothelial cell tubes in the Ad-p21-transfected group than in either the PBS or negative control groups (p = 0.004). CONCLUSIONS: Ad-p21 inhibits RF/6A cell proliferation and tube formation. The underlying mechanism to account for this may be that overexpression of p21 arrests the cell-cycle transition from the G1- to the S-phase via inhibition of CDK2 activity.

ABO blood type, diabetes and risk of gastrointestinal cancer in northern China.

AIM: To explore the potential risk factors related to gastrointestinal cancer in northern China. METHODS: A total of 3314 cases of gastrointestinal cancer (esophageal, gastric, pancreatic and biliary) and 2223 controls (including healthy individuals, glioma and thyroid cancer) were analyzed by case-control study. Multivariable logistic regression analysis was applied to evaluate the association between different cancers and hepatitis B surface antigen, sex, age, blood type, diabetes, or family history of cancer. RESULTS: Type 2 diabetes was significantly associated with gastric, biliary and pancreatic cancer with an OR of 2.0-3.0. Blood type B was significantly associated with esophageal cancer [odd ratio (OR) = 1.53, 95% confidence interval (CI) = 1.10-2.14] and biliary cancer (OR = 1.49, 95% CI = 1.09-2.05). The prevalence of type 2 diabetes was significantly higher in gastric, biliary and pancreatic cancers compared with other groups, with ORs ranging between 2.0 and 3.0. Family history of cancer was strongly associated with gastrointestinal compared with other cancers. CONCLUSION: Blood type B individuals are susceptible to esophageal and biliary cancer. Type 2 diabetes is significantly associated with gastric, biliary and especially pancreatic cancer.

[Treatment of postoperative endophthalmitis following cataract surgery without intraocular lens removal].

OBJECTIVE: To explore the effects of vitrectomy combined with silicone oil injection on the treatment of postoperative endophthalmitis following cataract surgery without intraocular lens removal, and to analyze the relative factors. METHODS: This was a retrospective case series study. Clinical data of 7 eyes of 7 patients with postoperative endophthalmitis following cataract surgery underwent the treatment of vitrectomy combined with silicone oil injection without intraocular lens removal from 2003 to 2008 were collected. The outcomes of vision, slit lamp examination, direct and indirect ophthalmoscopy, IOP, and B-scan were observed, and the surgical effects were analyzed. RESULTS: Five patients were male, and 2 patients were female. The age ranged from 67.0 to 84.0 years with a mean of 70.0 + or - 4.5. The onset of endophthalmitis ranged from 1 to 3 days with a mean of 2 days. Silicone oil was removed in 5 eyes 3 to 6 months postoperatively. Preoperative visual acuity ranged from non light perception to hand moving. The mean preoperative intraocular pressure (IOP) was (35.0 + or - 0.5) mmHg with a range from 35.0 to 56.0 mmHg. Follow-up periods ranged from 6 to 43 months with a mean of (10 + or - 6) months. Postoperative visual acuity ranged from non light perception to 0.8. Postoperative vision increased in 6 eyes (86%), and was stable in 1 eye (14%). The mean postoperative IOP was (18.0 + or - 1.5) mmHg with a range from 10.0 to 20.0 mmHg, this was significantly lower than that preoperatively (t = 1.94, P < 0.05). Postoperative complications mainly included fibrous exudates in the anterior chamber at early stage after the surgery (7 eyes) and temporary intraocular pressure elevation (1 eye). There was no retinal detachment and atrophia bulbi. CONCLUSION: Vitrectomy combined with silicone oil injection may be a safe and effective method in treating postoperative endophthalmitis following cataract surgery without intraocular lens removal.

A vitreous hemorrhage animal model in rabbits using force percussion injury.

PURPOSE: To make a standard vitreous hemorrhage (VH) animal model in rabbits for clinical and experimental research using force percussion injury (FPI). METHODS: Ten New Zealand white adult rabbits age 3 to 4 months with a body weight between 2 and 2.5 kg without any ocular disorders were given bilateral blunt trauma to the eyes with FPI. Two adult rabbits without any ocular disorders were in the control group without any trauma. All traumatic eyes were examined with slit lamp, indirect ophthalmoscope, B-scan, and pathology. Slit lamp photographs and ocular fundus photographs were also taken. All these examinations were performed 1, 3, 7, 14, 30, and 60 days after the ocular trauma. We checked for the presence or absence of VH in all traumatic eyes. Retinal detachment was assessed by B-scan. RESULTS: All 20 eyes in the experimental group had post-traumatic VH after ocular injury (success ratio 100%). Seventeen of 20 eyes (85%) were good models (GM) and developed severe VH. VH began to decrease one week after the ocular trauma and then was gradually absorbed and disappeared within two months after the ocular trauma. Three eyes (15%) had a little blood in the anterior chamber. Six eyes (30%) had some exudates in the anterior chamber. Only one eye (5%) had a slight traumatic cataract within one week (5-7 days) and kept stable. Lens displacement was also found in three eyes (15%). No retinal detachment or choroidal hemorrhage were found in any traumatic eyes. Both groups were followed up for two months. Rabbits in the control group were normal and were without VH. CONCLUSION: A reproducible experimental model of VH in rabbit eye has been successfully made. Massive VH was demonstrated on clinical observations and echography and was confirmed by histopathological examinations. VH was totally absorbed two months after the ocular trauma in our model. Our model is a simple, reliable, reproducible, and stable tool for the research on the mechanism and treatment of VH.

[The expression of vascular endothelial growth factor of vitreous in patients with proliferative diabetic retinopathy].

OBJECTIVE: To explore the expression of vascular endothelial growth factor of vitreous in patients with proliferative diabetic retinopathy, and to analyze the relative factors. METHODS: It was a case-control study. Data of 50 eyes of 50 PDR patients who underwent vitrectomy were retrospectively analyzed. The vitreous fluid samples were obtained during surgery. The VEGF level in vitreous fluid was determined by enzyme linked immunosorbent assay, and the expression of vascular endothelial growth factor of vitreous in patients with proliferative diabetic retinopathy was analyzed. The mean follow-up was 9 months with a range from 6 to 26 months. The VEGF levels in vitreous fluid were compared between PDR patients and normal control, and silicone oil tamponade group and without silicone oil tamponade group by t-test. The changes of VEGF levels in vitreous fluid in eyes with regression, stabilization, and progression were analyzed by analysis of variance. The effects of VEGF levels in vitreous fluid on PDR were analyzed by analysis of variance. RESULTS: The mean VEGF level of vitreous was (592.4801 +/- 587.4267) ng/L in PDR patients, and it was (131.3022 +/- 26.9192) ng/L in normal control. VEGF level was significantly higher in PDR patients than that in normal control (t = 3.2315, P < 0.05). There were 10 eyes (20%) with progression of PDR, 10 eyes (20%) with stabilization, and 30 eyes (60%) with regression. Vitreous level of VEGF was significantly higher in eyes with progression of PDR than that in eyes with stabilization or regression of PDR (q = -3.3187, -4.0843; P < 0.05). Vitreous level of VEGF was significantly higher in eyes without retinal photocoagulation than that in eyes underwent panretinal photocoagulation or local photocoagulation (q = -4.2187, -3.9672; P < 0.05). CONCLUSION: There is a correlation between the expression of VEGF of vitreous and the severity of PDR. The expression of VEGF of vitreous presents a relatively lower level in patients with stabilization and regression of PDR.