Functional expression of polyethylene terephthalate-degrading enzyme (PETase) in green microalgae.

BACKGROUND: For decades, plastic has been a valuable global product due to its convenience and low price. For example, polyethylene terephthalate (PET) was one of the most popular materials for disposable bottles due to its beneficial properties, namely impact resistance, high clarity, and light weight. Increasing demand of plastic resulted in indiscriminate disposal by consumers, causing severe accumulation of plastic wastes. Because of this, scientists have made great efforts to find a way to biologically treat plastic wastes. As a result, a novel plastic degradation enzyme, PETase, which can hydrolyze PET, was discovered in Ideonella sakaiensis 201-F6 in 2016. RESULTS: A green algae, Chlamydomonas reinhardtii, which produces PETase, was developed for this study. Two representative strains (C. reinhardtii CC-124 and CC-503) were examined, and we found that CC-124 could express PETase well. To verify the catalytic activity of PETase produced by C. reinhardtii, cell lysate of the transformant and PET samples were co-incubated at 30 °C for up to 4 weeks. After incubation, terephthalic acid (TPA), i.e. the fully-degraded form of PET, was detected by high performance liquid chromatography analysis. Additionally, morphological changes, such as holes and dents on the surface of PET film, were observed using scanning electron microscopy. CONCLUSIONS: A PET hydrolyzing enzyme, PETase, was successfully expressed in C. reinhardtii, and its catalytic activity was demonstrated. To the best of our knowledge, this is the first case of PETase expression in green algae.

Real-world effectiveness of bevacizumab based on AURELIA in platinum-resistant recurrent ovarian cancer (REBECA): A Korean Gynecologic Oncology Group study (KGOG 3041).

PURPOSE: To evaluate the effectiveness of bevacizumab with single-agent chemotherapy for platinum-resistant ovarian cancer in a real-world setting. PATIENTS AND METHODS: We enrolled recurrent platinum-resistant ovarian cancer patients from 27 institutions. All had received bevacizumab with single-agent chemotherapy (weekly paclitaxel, pegylated liposomal doxorubicin (PLD), topotecan) between 2015 and 2017 for second- or third-line chemotherapy in routine clinical practice. The primary endpoint was progression-free survival (PFS) and safety. Secondary endpoints included the objective response rate (ORR), PFS2, overall survival, duration of chemotherapy, and reasons for discontinuing chemotherapy. RESULTS: Of 391 patients, 259 (66.2%) received bevacizumab with PLD, 94 (24.0%) with topotecan, and 38 (9.7%) with weekly paclitaxel. The median PFS was 6.1 months with all forms of bevacizumab-containing therapy. Although the cohort with weekly paclitaxel had a better PFS than the PLD cohort (P = 0.028), this finding was not found in patients with a previous platinum-free interval of less than three months. The median duration of therapy was five cycles (range, one to 20 cycles), and 29 patients (7.4%) discontinued treatment because of adverse events from bevacizumab-containing regimens. The PLD cohort had fewer grade ≥ 3 adverse events than the other regimens (PLD, 35.8%; weekly paclitaxel, 52.6%; topotecan, 51.1%; P = 0.012), especially events of hematologic toxicities. CONCLUSION: In Korean ovarian cancer patients, the safety and effectiveness of chemotherapy with bevacizumab in a real-world setting was consistent with the results from a randomized controlled study. The effectiveness and toxicity profiles varied among the chemotherapy regimens, and this finding should be considered in practice. CLINICAL TRIALS REGISTRATION: NCT03367182.

Triglyceride to high density lipoprotein cholesterol ratio and its association with periodontal disease in Korean adults: findings based on the 2012-2014 Korean national health and nutrition examination survey.

OBJECTIVES: The aim of this study is to evaluate whether the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio is associated with periodontal disease in Korean adults. MATERIALS AND METHODS: This cross-sectional study included 12,249 individuals (4,941 men and 7,308 women) who took part in the 2012-2014 Korean National Health and Nutrition Examination Survey. We categorized the TG/HDL-C ratio into three groups. Periodontal disease was defined as a community pocket index score ≥3 with at least one affected site. Multiple logistic analyses were used to analyze the association between TG/HDL-C ratio and periodontal disease. RESULTS: In the study population, prevalence of periodontal disease was 31.6% in men and 21% in women. Compared to the lowest tertile group, OR (95% CI) of the highest tertile group for periodontal disease was 1.474 (1.220-1.780) in men and 1.259 (1.041-1.522) in women after adjusting for age, waist circumference, systolic blood pressure, fasting glucose, current smoking, alcohol drinking, physical activity, household income, oral health behavior, and use of anti-dyslipidemia medication. CONCLUSION: Our study suggests that the TG/HDL-C ratio is associated with periodontal disease in Korean adults. CLINICAL RELEVANCE: TG/HDL-C ratio is a simple and useful marker to reflect insulin resistance. And periodontal disease is also known to be related with insulin resistance. This study indicates that TG/HDL-C ratio was associated with periodontal disease in Korean adults.

High-yield production of the VP1 structural protein epitope from serotype O foot-and-mouth disease virus in Escherichia coli.

For effective control of foot-and-mouth disease (FMD), the development of rapid diagnostic systems and vaccines are required against its etiological agent, FMD virus (FMDV). To accomplish this, efficient large-scale expression of the FMDV VP1 protein, with high solubility, needs to be optimized. We attempted to produce high levels of a serotype O FMDV VP1 epitope in Escherichia coli. We identified the subtype-independent serotype O FMDV VP1 epitope sequence and used it to construct a glutathione S-transferase (GST) fusion protein. For efficient production of the FMDV VP1 epitope fused to GST (VP1e-GST), four E. coli strains and three temperatures were examined. The conditions yielding the greatest level of VP1e-GST with highest solubility were achieved with E. coli BL21(DE3) at 25 °C. For high-level production, fed-batch cultures were conducted in 5-l bioreactors. When cells were induced at a high density and complex feeding solutions were supplied, approximately 11 g of VP1e-GST was obtained from a 2.9-l culture. Following purification, the VP1 epitope was used to immunize rabbits, and we confirmed that it induced an immune response.

Association Between the Severity of Periodontitis and Osteoarthritis in Middle-Aged and Older Patients With Type 2 Diabetes Mellitus: A Nationwide Population-Based Study.

OBJECTIVE: Periodontitis and osteoarthritis are major public health concerns that result in decreased quality of life among middle-aged and older adults. We sought to examine whether the severity of periodontitis is related to osteoarthritis according to the presence of type 2 diabetes mellitus. METHODS: This study included 3,527 participants age ≥50 years from the Korean National Health and Nutrition Examination Survey. Periodontitis was assessed using the Community Periodontal Index; severe periodontitis was defined as periodontal tissue forming deep periodontal pockets ≥6-mm depth. Osteoarthritis was defined as Kellgren/Lawrence grade ≥2 on radiographic images of the knee or hip area with joint pain. The odds ratios (ORs) and 95% confidence intervals (95% CIs) for osteoarthritis according to the severity of periodontitis, stratified by type 2 diabetes mellitus, were calculated using multiple logistic regression analyses. RESULTS: Participants with type 2 diabetes mellitus were more likely to have osteoarthritis as the severity of periodontitis increased (nonsevere periodontitis OR 1.23 [95% CI 0.67-2.32]; severe periodontitis OR 3.01 [95% CI 1.51-5.84]) after adjusting for age, sex, body mass index, smoking status, alcohol consumption, regular exercise, education level, household income, hypertension, and frequent tooth-brushing. However, this positive association was not found in individuals without type 2 diabetes mellitus after adjusting for the same covariables. CONCLUSION: Severe periodontitis was positively and significantly associated with osteoarthritis in middle-aged and older individuals with type 2 diabetes mellitus. Our findings suggest that the oral inflammation manifesting in periodontitis may be at least partly involved in the pathogenesis of osteoarthritis, particularly in patients with type 2 diabetes mellitus.

A Phase II Trial to Evaluate the Efficacy of Bortezomib and Liposomal Doxorubicin in Patients With BRCA Wild-type Platinum-resistant Recurrent Ovarian Cancer (KGOG 3044/EBLIN).

BACKGROUND/AIM: The majority of targeted therapies are focused on BRCA mutations, homologous recombination repair deficiency, and BRCA wild-type platinum-sensitive recurrent ovarian cancer. There is a growing need for platinum-resistant patients without BRCA mutations. Herein, we conducted a phase II multicenter study evaluated the efficacy and safety of bortezomib plus pegylated liposomal doxorubicin (PLD) in patients with BRCA wild-type platinum-resistant recurrent ovarian cancer (NCT03509246). PATIENTS AND METHODS: Ovarian cancer patients with wild-type BRCA who experienced platinum-resistant recurrence after three or less prior treatment cycles from three Institutions were included. All patients received bortezomib, 1.3 mg/m2 subcutaneously (days 1, 4, 8, and 11), and PLD, 40 mg/m2 intravenously (day 4), every 4 weeks. The primary endpoint was best objective response rate (ORR), and secondary endpoints included disease control rate, progression-free survival (PFS), overall survival, and safety. Targeted sequencing was performed to evaluate biomarkers and their potential association with response to treatment. RESULTS: The trial was terminated after 23 patients were recruited because of slow accrual. The median follow-up was 29.5 months. The overall ORR was 8.7% (2/23); partial response was observed in two patients. The median duration of response was 10.5 months, and median PFS was 2.9 months. Treatment-related adverse events (TRAEs) of grade 3/4 were reported in 43.5% of patients. One patient who exhibited TRAEs discontinued treatment. However, grade 4/5 TRAEs were not observed. Mutations in TP53 and CDK12 were detected in 67% (14/21) and 24% (12/21) of patients, respectively. Two patients with partial response harbored mutations in genes related to homologous recombination repair deficiency, including BRCA2, ATM, and CDK12. CONCLUSION: The combination of bortezomib and PLD was well tolerated; however, antitumor activity was not sufficient to warrant further investigation in ovarian cancer.

A novel histone deacetylase 6 inhibitor improves myelination of Schwann cells in a model of Charcot-Marie-Tooth disease type 1A.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth (CMT) disease is the most common hereditary peripheral neuropathy. CMT type 1A (CMT1A) accounts for approximately 50% of CMT patients and is linked to PMP22 gene duplication. Histone deacetylase-6 (HDAC6) has pleiotropic effects, such as regulating lipid homeostasis and cellular stress. Although HDAC6 has been regarded as a promising drug target for neurodegenerative diseases, its inhibition has not yet been tested in CMT1A. Here we have tested the therapeutic potential of CKD-504, a clinical stage HDAC6 inhibitor, in a mouse model of CMT1A EXPERIMENTAL APPROACH: The potency and selectivity of CKD-504 was evaluated, using a HDAC enzyme panel assay and western blots. The therapeutic potential of CKD-504 was evaluated using behavioural testing and electrophysiological assessments in the C22 mouse model of CMT1A. PMP22 protein expression and aggregation were analysed in mesenchymal stem cell-derived Schwann cells from CMT1A patients and sciatic nerves from C22 mice. KEY RESULTS: The HDAC6 inhibitor, CKD-504, modulated molecular chaperon proteins such as HSP90 and HSP70, which are involved in the folding/refolding of proteins such as PMP22. CKD-504 treatment restored myelination in both mesenchymal stem cell-derived Schwann cells from CMT1A patients and sciatic nerves of C22 mice and improved the axonal integrity of the sciatic nerve, leading to behavioural, electrophysiological, and histological improvements in C22 mice. CONCLUSION AND IMPLICATIONS: A novel HDAC6 inhibitor, CKD-504, has potent therapeutic efficacy for CMT1A.

Development of a Shape-Memory Tube to Prevent Vascular Stenosis.

Inserting a graft into vessels with different diameters frequently causes severe damage to the host vessels. Poor flow patency is an unresolved issue in grafts, particularly those with diameters less than 6 mm, because of vessel occlusion caused by disturbed blood flow following fast clotting. Herein, successful patency in the deployment of an ≈2 mm diameter graft into a porcine vessel is reported. A new library of property-tunable shape-memory polymers that prevent vessel damage by expanding the graft diameter circumferentially upon implantation is presented. The polymers undergo seven consecutive cycles of strain energy-preserved shape programming. Moreover, the new graft tube, which features a diffuser shape, minimizes disturbed flow formation and prevents thrombosis because its surface is coated with nitric-oxide-releasing peptides. Improved patency in a porcine vessel for 18 d is demonstrated while occlusive vascular remodeling occurs. These insights will help advance vascular graft design.

Lacrimal silicone intubation for anatomically successful but functionally failed external dacryocystorhinostomy.

PURPOSE: To investigate the efficacy of lacrimal silicone intubation for the management of epiphora in patients who have previously undergone anatomically successful dacryocystorhinostomy (DCR). METHODS: The authors recruited 13 patients (4 male, 9 female) who had persistent epiphora after an anatomically successful primary external DCR and conducted lacrimal silicone intubation through the dacryocystorhinostomy site. RESULTS: Mean patient age was 54.2 years (range 42-80) and mean follow-up was 13.8 months (range 6-30). Epiphora was resolved in all 13 patients following silicone intubation. Spontaneous tube extrusion occurred in three patients, but a new one was easily reintubated. CONCLUSIONS: Lacrimal silicone intubation is a simple safe and effective procedure for patients with epiphora even after anatomically successful DCR.

Biological responses of ligament fibroblasts and gene expression profiling on micropatterned silicone substrates subjected to mechanical stimuli.

In this study, ligament fibroblasts were cultivated on micropatterned silicone substrates and subjected to cyclic stretching to simulate the in vivo biomechanical environment during ligament healing. Without stretching, ligament fibroblasts were aligned parallel to the microgrooves on the silicone substrate surface. However, we previously reported that uniaxial cyclic stretching induces alignment perpendicular to the stretching axis. With stretching on a microgrooved surface, cell proliferation and collagen production were greatly enhanced. The exact functions of the micropatterned surface and mechanical stimuli are unknown. Therefore, in gene expression microarray experiments, genes whose expression is inhibited by subculture from passage 0 (P0) to passage 8 (P8) and enhanced by micropatterning and stretching were sought out. The following six genes were selected: MGP, GADD45A, UNC5B, TGFB1, COL4A1, and COL4A2. The selected genes play fundamental roles in cell proliferation, differentiation, apoptosis, and structural maintenance. On the basis of the obtained gene expression profiles, we identified candidate genes that might be involved in responses to a micropatterned surface and mechanical stretching.

Polytetrafluoroethylene as a spacer graft for the correction of lower eyelid retraction.

PURPOSE: To evaluate the efficacy of porous expanded polytetrafluoroethylene (e-PTFE, Goretex) containing large pores made with a 21-gauge needle as a graft for the correction of lower lid retraction. METHODS: e-PTFE grafts were implanted between the tarsus and lower lid retractor via a transconjunctival approach with/without amniotic membrane transplantation, or via a transcutaneous approach. Rabbits were examined and assessed for comeal and conjunctival complications and for e-PTFE graft status. Rabbits were sacrificed for a histological study at 8 weeks postoperatively. RESULTS: e-PTFE grafts were uniformly extruded 3 weeks postoperatively in eyelids operated on via the transconjunctival approach. However, rabbits operated on via the transcutaneous approach demonstrated e-PTFE graft retention; in addition, dense fibrovascular ingrowths into the large pores of e-PTFE were observed histologically. CONCLUSIONS: e-PTFE is a good substitute for other graft materials as a spacer in lower lid retraction operations, especially as an interpositional graft using a transcutaneous approach.

Rapid isolation of antibody from a synthetic human antibody library by repeated fluorescence-activated cell sorting (FACS).

Antibodies and their derivatives are the most important agents in therapeutics and diagnostics. Even after the significant progress in the technology for antibody screening from huge libraries, it takes a long time to isolate an antibody, which prevents a prompt action against the spread of a disease. Here, we report a new strategy for isolating desired antibodies from a combinatorial library in one day by repeated fluorescence-activated cell sorting (FACS). First, we constructed a library of synthetic human antibody in which single-chain variable fragment (scFv) was expressed in the periplasm of Escherichia coli. After labeling the cells with fluorescent antigen probes, the highly fluorescent cells were sorted by using a high-speed cell sorter, and these cells were reused without regeneration in the next round of sorting. After repeating this sorting, the positive clones were completely enriched in several hours. Thus, we screened the library against three viral antigens, including the H1N1 influenza virus, Hepatitis B virus, and Foot-and-mouth disease virus. Finally, the potential antibody candidates, which show K(D) values between 10 and 100 nM against the target antigens, could be successfully isolated even though the library was relatively small (∼ 10(6)). These results show that repeated FACS screening without regeneration of the sorted cells can be a powerful method when a rapid response to a spreading disease is required.

Epithelial thickness of the palatal mucosa: a histomorphometric study in Koreans.

Subepithelial connective tissue grafting (SCTG) is a frequently used method in the field of periodontal plastic surgery. There are relatively few reports defining epithelial thickness criteria for palatal mucosal SCTG. The aim of this study was to histologically measure the epithelial thickness of the palatal mucosa in a sample of Korean patients, with the goal of minimizing epithelium-associated complications after root coverage procedures. A total of 30 Korean patients (12 males and 18 females) were enrolled in this study. To measure epithelial thicknesses, palatal mucosa adjacent to premolars and molars was obtained during procurement of SCTG. The effects of donor site, age and gender on the thickness of the epithelium were assessed and compared by histomorphometric analysis. The mean epithelial thickness of the palatal mucosa in our 30 patients was 430.63 µm, ranging from 113 to 823 µm. Epithelial thickness was not associated with donor site or age, but there were significant differences between genders, with males having much thicker palates than females.

Sugarcane bagasse oxidation using a combination of hypochlorite and peroxide.

Reactive oxygen species (ROS) such as singlet oxygen ((1)O(2)), superoxide (O(2)(-)), hydroxyl radicals (OH(*)), or hypochlorite ion (OCl(-)), can remove both hemicellulose and lignin from lignocellulose. Ox-B (US Patent 6,866,870), an ROS producing solution containing sodium hypochlorite and hydrogen peroxide, was investigated for its ability to oxidize sugarcane bagasse. Treatment with equivalent amounts of hypochlorite produced similar results. Ox-B differentiated from hypochlorite when low concentration treatments were used and they were followed by a caustic wash. Cellulases hydrolyzed 80-100% of the cellulose present after Ox-B/caustic treatment compared to 40% or less for NaOCl/caustic treatment. Ox-B treatment was temperature independent and complete within 3h. It was pH dependent, with best results obtained when the pH was controlled at 8. Although highly effective, in order for Ox-B to be industrially feasible for alcohol production, the chemical cost must decrease to justify its use.

Manufacturing of multi-layered nanofibrous structures composed of polyurethane and poly(ethylene oxide) as potential blood vessel scaffolds.

One of the current limitations in using electrospun nanofibrous materials for tissue engineering is that cells have difficulty penetrating into the materials. For this, multi-layered electrospun structures composed of polyurethane (PU) and poly(ethylene oxide) (PEO) were fabricated and tested in vitro. A 20% (w/v) PU solution was electrospun for 30 min, while a 20% (w/v) PEO solution was electrospun for 5, 15 or 30 min, alternatively. Then, the PEO was extracted by immersing the structure in distilled water to make multi-layered structure. The characteristics of fabricated structures were examined by SEM, FT-IR spectroscopy, mechanical tests and cell penetration test. The bioactivities of smooth muscle cells (SMCs) on these scaffolds were assessed by quantifying DNA, collagen and glycosaminoglycan (GAG) levels. Although hybrid PEO-extracted scaffolds had a little of residual PEO, they were more penetrable than PU alone scaffolds. Also, they showed higher bioactivity than PU-alone scaffolds. The results of this study provided potential of this structure in the application not only to the development of artificial blood vessels but also to other types for tissue engineering.

Electrospun PLGA nanofiber scaffolds for articular cartilage reconstruction: mechanical stability, degradation and cellular responses under mechanical stimulation in vitro.

We investigated the potential of a nanofiber-based poly(DL-lactide-co-glycolide) (PLGA) scaffold to be used for cartilage reconstruction. The mechanical properties of the nanofiber scaffold, degradation of the scaffold and cellular responses to the scaffold under mechanical stimulation were studied. Three different types of scaffold (lactic acid/glycolic acid content ratio = 75 : 25, 50 : 50, or a blend of 75 : 25 and 50 : 50) were tested. The tensile modulus, ultimate tensile stress and corresponding strain of the scaffolds were similar to those of skin and were slightly lower than those of human cartilage. This suggested that the nanofiber scaffold was sufficiently mechanically stable to withstand implantation and to support regenerated cartilage. The 50 : 50 PLGA scaffold was degraded faster than 75 : 25 PLGA, probably due to the higher hydrophilic glycolic acid content in the former. The nanofiber scaffold was degraded faster than a block-type scaffold that had a similar molecular weight. Therefore, degradation of the scaffold depended on the lactic acid/glycolic acid content ratio and might be controlled by mixing ratio of blend PLGA. Cellular responses were evaluated by examining toxicity, cell proliferation and extracellular matrix (ECM) formation using freshly isolated chondrocytes from porcine articular cartilage. The scaffolds were non-toxic, and cell proliferation and ECM formation in nanofiber scaffolds were superior to those in membrane-type scaffolds. Intermittent hydrostatic pressure applied to cell-seeded nanofiber scaffolds increased chondrocyte proliferation and ECM formation. In conclusion, our nanofiber-based PLGA scaffold has the potential to be used for cartilage reconstruction.