Objective To determine whether kringle 4-5 could inhibit choroidal neovascularization (CNV) in mice induced by argon laser photocoagulation. Methods Fundus laser photocoagulation was performed on C57BL/6J mice to induce CNV. In treatment group, 20 ?g (low dosage group) and 50 ?g (high dosage group) kringle 4-5 were injected retrobulbarly after photocoagulation. In control group, equilibrium liquid was injected retrobulbarly. Choroidal neovascularization was evaluated on the 7th and 14th day after photocoagulation by fundus fluorescein angiography. The mice were killed on the 14th day after photocoagulation, the lesions were evaluated histologically and immunohistochemically, and the expression of CD105 was detected. The Expression of VEGF and bFGF was detected by immunohistochemistry on the 4th day after photocoagulation. Results The incidence of CNV was 64.3% in control group, 51.2%(P

Background The vitreoretinal traction plays a critical role in the formation of macular hole and cystoid macular edema.Enzymatic vitreolysis has potential in relieving vitreoretinal traction as a simple and less invasive method in comparison with pars plane vitrectomy.ObjectiveThis study is to investigate the effects of plasmin mutant with kringle domains deficiency(Plm△K)on vitreoretinal interface in new Zealand white rabbits.Methods Plm△K was prepared through activating plasminogen mutant with Kringle domains deficiency (Plg△K) by tissue plasminogen activator (tPA).100μL of Plm△K at the dose of 0.5,1.0 and 1.5μmol/min was injected respectively into the vitreous of 48 New Zealand white rabbits and 16 eyes for each dose.B-scan and optical coherence tomography (OCT) were performed to detect the structure variety at the vitreoretinal interface in 1 day and 7 days after injection.The gross anatomy analysis with triamcinolone acetonide fine particle suspension,as well as histopathological examinations by scanning electron microscopy,was performed in the different time points mentioned above.Results Two peptide chains were determined with the relative molecular weight about 26000 and 5000 by the gel imaging analysis of reduced SDS-PAGE.Separation of the posterior vitreous cortex from retina was found after intravitreous injection under the B-scan and OCT.The ultrastructure change of vitreoretinal interface as well as the examination of fine particle suspension by triamcinolone acetonide demonstrated the same outcome.The degree of remnants of vitreous cortex showed the negative correlation with the dosage of Plm△K (r=-0.9516,P=0.048).No significant correlation was found between the degree of remnants of vitreous cortex and the action time(r=-0.720,P=0.470).There was no obvious morphological difference in outer layer of retina between control eyes and Plm△K-treated eyes.No drug-related adverse event was found after intravitreous injection of Plm△K.Conclusion Intravitreous injection of Plm△K alone can induce complete separation of vitreous from retina.This procedure is safe and effective.

Objective: To summarize the effectiveness of delayed skin-stretching device in treatment of skin and soft tissue defects. Methods: Between December 2014 and December 2016, 10 cases of skin and soft tissue defects were treated with delayed skin-stretching device. There were 6 males and 4 females with an average age of 53 years (range, 42-64 years). The skin and soft tissue defects were caused by acute trauma in 6 cases. The incision could not be closed directly after making incisions because of osseous fascia syndrome in 3 cases. The skin soft tissue defect caused after huge carbuncle incision and drainage in 1 case. The defect located at thigh in 4 cases, lower leg in 3 cases, upper arm in 2 cases, back in 1 case. The defect area ranged from 10 cm×4 cm to 22 cm×12 cm. Pinch test was performed on the wound margin, which confirmed that the wound could not be closed directly. Results: Tension blisters were found in 3 cases during traction, and no complications such as impaired blood circulation or skin necrosis occurred in all cases. Skin defects closed directly after continuously stretching for 7-18 days. No skin graft or free flap repair was performed in all patients. The wound healed well after operation. All the 10 patients were followed up 5-8 months (mean, 6.5 months). There was no necrosis around the wound margin and the scar was linear. The sensation and function were not affected. Conclusion: Delayed skin-stretching device is an effective method to treat skin and soft tissue defects, which has the advantages of simple operation, lower risk of operation, less complications, and reliable effectiveness.

Objective:To explore the application effect of sustainable skin-stretching device in scalp and soft tissue defect.Methods:From June 2017 to January 2020, 5 patients (3 males and 2 females, aged 31-57 (38.0±2.1) years) with large area of scalp and soft tissue defect and skull exposure were admitted to Department of Reparative and Reconstructive Surgery of the Second Hospital of Dalian Medical University. The wound area ranged from 16.0 cm×8.0 cm to 18.0 cm×12.0 cm. The sustainable skin-stretching device was installed after debridement operation for scalp wound. The wound was stretched from the 3rd day after installation of the device, at a basic speed of 1 mm/d and finished for 3 times on average. During stretching, close attention was paid to the changes in blood flow of the wound margin and the subjective feeling of the patients. When the result was negative in the squeezing and pinching test for wound margin after stretching, the further stretching was stopped, the final stretching state was maintained for 3 days, and the wounds were sutured directly. The wound healing during stretching of sustainable skin-stretching device and the occurrence of complications were observed. The rest wound areas after stretching for 5, 10, 15, and 20 days were measured. The wound healing and hair growth were observed during follow-up.Results:All the wounds of 5 patients was sutured directly after stretching for 19-23 d. There was no tension blister on the margin of wounds during stretching, and the margin of wounds healed well after being sutured without skin necrosis. After stretching treatment for 5-20 d, the wound areas were gradually decreased. During follow-up of 2-11 (4.5±1.5) months, the elasticity, color, feeling, and regenerated hair growth of the stretched scalp tissue were close to those of the surrounding normal skin tissue. The linear scar formed on the margin of wounds, but no scar formed on the wounds.Conclusions:The application of sustainable skin-stretching device can reduce the difficulty in repairing scalp and soft tissue defect, with the regenerated hair growing well after treatment, which is worthy of clinical promotion.

Glutamate decarboxylase, a unique pyridoxal 5'-phosphate-dependent enzyme, catalyzes α-decarboxylation of L-glutamate to γ-aminobutyrate. However, glutamate decarboxylase from different sources has the common problem of poor thermostability that affects its application in industry. In this study, proline was introduced at 13 different positions in glutamate decarboxylase by using the design strategy of homologous sequence alignment between Thermococcus kodakarensis and Lactobacillus brevis CGMCC No.1306. A mutant enzyme G364P with higher thermostability was obtained. Compared to the wild type, thermostability of the mutant G364P was significantly improved, the half-life time (t1/2) at 55 °C and the semi-inactivation temperature (T₅₀ ¹⁵) of the mutant G364P increased 19.4 min and 5.3 °C, respectively, while kcat/Km of the mutant enzyme remained nearly unchanged. Further analysis of their thermostability by molecular dynamics simulations were performed. The root mean square deviation of G364P and root mean square fluctuation in the loop region including G364 were lower than the wild type at 313 K for 10 ns, and G364P increased one hydrophobic interaction in the loop region. It proves that mutation of flexible 364-Gly to rigid proline endows glutamate decarboxylase with enhanced thermostability.
Glutamate Decarboxylase ; Glutamic Acid ; Lactobacillus brevis ; Molecular Dynamics Simulation ; Proline