Bioprinting Methods for Fabricating In Vitro Tubular Blood Vessel Models.

Dysfunctional blood vessels are implicated in various diseases, including cardiovascular diseases, neurodegenerative diseases, and cancer. Several studies have attempted to prevent and treat vascular diseases and understand interactions between these diseases and blood vessels across different organs and tissues. Initial studies were conducted using 2-dimensional (2D) in vitro and animal models. However, these models have difficulties in mimicking the 3D microenvironment in human, simulating kinetics related to cell activities, and replicating human pathophysiology; in addition, 3D models involve remarkably high costs. Thus, in vitro bioengineered models (BMs) have recently gained attention. BMs created through biofabrication based on tissue engineering and regenerative medicine are breakthrough models that can overcome limitations of 2D and animal models. They can also simulate the natural microenvironment in a patient- and target-specific manner. In this review, we will introduce 3D bioprinting methods for fabricating bioengineered blood vessel models, which can serve as the basis for treating and preventing various vascular diseases. Additionally, we will describe possible advancements from tubular to vascular models. Last, we will discuss specific applications, limitations, and future perspectives of fabricated BMs.

Evaluation of Various Escherichia coli Strains for Enhanced Lycopene Production.

Lycopene is a carotenoid widely used as a food and feed supplement due to its antioxidant, anti-inflammatory, and anti-cancer functions. Various metabolic engineering strategies have been implemented for high lycopene production in Escherichia coli, and for this purpose it was essential to select and develop an E. coli strain with the highest potency. In this study, we evaluated 16 E. coli strains to determine the best lycopene production host by introducing a lycopene biosynthetic pathway (crtE, crtB, and crtI genes cloned from Deinococcus wulumuqiensis R12 and dxs, dxr, ispA, and idi genes cloned from E. coli). The 16 lycopene strain titers diverged from 0 to 0.141 g/l, with MG1655 demonstrating the highest titer (0.141 g/l), while the SURE and W strains expressed the lowest (0 g/l) in an LB medium. When a 2 × YTg medium replaced the MG1655 culture medium, the titer further escalated to 1.595 g/l. These results substantiate that strain selection is vital in metabolic engineering, and further, that MG1655 is a potent host for producing lycopene and other carotenoids with the same lycopene biosynthetic pathway.

Elastic Dynamic Sling on Subluxation of Hemiplegic Shoulder in Patients with Subacute Stroke: A Multicenter Randomized Controlled Trial.

Background: Shoulder subluxation occurs in 17−64% of hemiplegic patients after stroke and develops mostly during the first three weeks of hemiplegia. A range of shoulder orthoses has been used in rehabilitation to prevent subluxation. However, there is little evidence of their efficacy. AIM: This study aimed to investigate whether there is a difference in the subluxation distance, pain, and functional level of the hemiplegic upper extremity among patients with two different shoulder orthoses. Design: This is a prospective, randomized controlled trial with intention-to-treat analysis. SETTING: Multicenter, rehabilitation medicine department of two university hospitals in South Korea. Population: Forty-one patients with subacute stroke with shoulder subluxation with greater than 0.5 finger width within 4 weeks of stroke were recruited between January 2016 and October 2021. Methods: The experimental group used an elastic dynamic sling while sitting and standing to support the affected arm for eight weeks. The control group used a Bobath sling while sitting and standing. The primary outcome was to assess the distance of the shoulder subluxation on radiography. The secondary outcomes were upper-extremity function, muscle power, activities of daily living, pain and spasticity. Result: The horizontal distance showed significant improvement in the elastic dynamic sling group, but there were no significant differences in the vertical distance between the elastic dynamic and Bobath sling groups. Both groups showed improvements in upper-extremity movements and independence in daily living after 4 and 8 weeks of using shoulder orthoses, and the differences within the groups were significant (p < 0.05). However, there were no significant differences in upper-extremity movements and independence in daily living between the two groups. Conclusions: The subluxation distance showed better results in the elastic dynamic sling, which has both proximal and distal parts, than in the Bobath sling, which holds only the proximal part. Both shoulder orthoses showed improvements in the modified Barthel index, upper-extremity function, and manual muscle testing.

Enhancement of the solubility of recombinant proteins by fusion with a short-disordered peptide.

In protein biotechnology, large soluble fusion partners are widely utilized for increased yield and solubility of recombinant proteins. However, the production of additional large fusion partners poses an additional burden to the host, leading to a decreased protein yield. In this study, we identified two highly disordered short peptides that were able to increase the solubility of an artificially engineered aggregation-prone protein, GFP-GFIL4, from 0.6% to 61% (D3-DP00592) and 46% (D4-DP01038) selected from DisProt database. For further confirmation, the peptides were applied to two insoluble E. coli proteins (YagA and YdiU). The peptides also enhanced solubility from 52% to 90% (YagA) and from 27% to 93% (YdiU). Their ability to solubilize recombinant proteins was comparable with strong solubilizing tags, maltose-binding protein (40 kDa) and TrxA (12 kDa), but much smaller (< 7 kDa) in size. For practical application, the two peptides were fused with a restriction enzyme, I-SceI, and they increased I-SceI solubility from 24% up to 75%. The highly disordered peptides did not affect the activity of I-SceI while I-SceI fused with MBP or TrxA displayed no restriction activity. Despite the small size, the highly disordered peptides were able to solubilize recombinant proteins as efficiently as conventional fusion tags and did not interfere with the function of recombinant proteins. Consequently, the identified two highly disordered peptides would have practical utility in protein biotechnology and industry.

Does Unilateral Lumbosacral Radiculopathy Affect the Association between Lumbar Spinal Muscle Morphometry and Bone Mineral Density?

Age-related degenerative changes lead to a gradual decrease in bone mineral density (BMD) and muscle mass. We aimed to assess the effects of decreased BMD and lumbar denervation on lumbar spinal muscle morphometry and the relationship between BMD and lumbar spinal muscular morphometry, respectively. Eighty-one patients, aged 50-85 years, diagnosed with unilateral lumbosacral radiculopathy based on electrodiagnostic studies between January 2016 and April 2021 were enrolled. BMD T scores in the lumbar spine and hip were measured using dual-energy X-ray absorptiometry. The cross-sectional area (CSA) of the psoas, multifidus, and erector spinae located in the middle of the lumbar spine, between the L3 and L4 and between the L4 and L5 levels, respectively, was measured using axial MRI. Functional CSA (FCSA) was defined as the CSA of lean muscle mass. Pearson correlation analyses were performed to evaluate the association between BMD T scores and the CSA, FCSA, and the ratio of the FCSA to the CSA (functional ratio) for each side. The CSA of lumbar spinal muscles showed no significant correlation with lumbar BMD. The FCSA and functional ratio of lumbar spinal muscles were significantly correlated with lumbar BMD. There was no correlation between femur BMD and lumbar spinal muscle morphometry.

Biohydrogen production from food waste: Current status, limitations, and future perspectives.

Among the various biological routes for H2 production, dark fermentation is considered the most practically applicable owing to its capability to degrade organic wastes and high H2 production rate. Food waste (FW) has high carbohydrate content and easily hydrolysable in nature, exhibiting higher H2 production potential than that of other organic wastes. In this review article, first, the current status of H2 production from FW by dark fermentation and the strategies applied for enhanced performance are briefly summarized. Then, the technical and economic limitations of dark fermentation of FW are thoroughly discussed. Economic assessment revealed that the economic feasibility of H2 production from FW by dark fermentation is questionable. Current efforts to further increase H2 yield and waste removal efficiency are also introduced. Finally, future perspectives along with possible routes converting dark fermentation effluent to valuable fuels and chemicals are discussed.

Analysis of the outcome of young age tongue squamous cell carcinoma.

BACKGROUND: The incidence of tongue squamous cell carcinoma (TSCC) in young patients has recently increased, and these TSCCs are believed to be etiologically distinct from those in older patients, who have longer exposure to risk factors such as tobacco and alcohol. The prognosis of TSCCs in young patients remains controversial. METHODS: We retrospectively reviewed the records of 117 patients (2001-2011) who were diagnosed with squamous cell carcinoma of the oral tongue. Patients were divided into two age groups, older (ages over 40) and younger (ages 40 and younger). Data were compared between the two groups, and survival rates were analyzed. RESULTS: The results show that there are significant differences in overall, disease-free, and distant metastasis-free survival rates between the two groups. Five-year overall survival rates were 70% in older patients and 42% in young patients (p = 0.033). Five-year disease-free survival rates were 73% in older patients and 40% in young patients (p = 0.011), and 5-year distant metastasis-free survival rates were 97% in older patients and 62% in young patients (p = 0.033).Multivariate analysis revealed that histologic grade was the only independent risk factor for overall survival in both groups of patients (p = 0.002, HR = 2.287). The analysis also demonstrated that age was the critical risk factor for distant metastasis (p = 0.046, HR = 9.687). CONCLUSION: In this study, young (ages 40 and younger) patients with squamous cell carcinoma of the oral tongue had a higher rate of distant metastasis and a worse prognosis. Accordingly, we propose the necessity of an extensive therapeutic regimen that should be used in all young patients with TSCC.

An adaptive detection method for fetal chromosomal aneuploidy using cell-free DNA from 447 Korean women.

BACKGROUND: Noninvasive prenatal testing (NIPT) using massively parallel sequencing of cell-free DNA (cfDNA) is increasingly being used to predict fetal chromosomal abnormalities. However, concerns over erroneous predictions which occur while performing NIPT still exist in pregnant women at high risk for fetal aneuploidy. We performed the largest-scale clinical NIPT study in Korea to date to assess the risk of false negatives and false positives using next-generation sequencing. METHODS: A total of 447 pregnant women at high risk for fetal aneuploidy were enrolled at 12 hospitals in Korea. They underwent definitive diagnoses by full karyotyping by blind analysis and received aneuploidy screening at 11-22 weeks of gestation. Three steps were employed for cfDNA analyses. First, cfDNA was sequenced. Second, the effect of GC bias was corrected using normalization of samples as well as LOESS and linear regressions. Finally, statistical analysis was performed after selecting a set of reference samples optimally adapted to a test sample from the whole reference samples. We evaluated our approach by performing cfDNA testing to assess the risk of trisomies 13, 18, and 21 using the sets of extracted reference samples. RESULTS: The adaptive selection algorithm presented here was used to choose a more optimized reference sample, which was evaluated by the coefficient of variation (CV), demonstrated a lower CV and higher sensitivity than standard approaches. Our adaptive approach also showed that fetal aneuploidies could be detected correctly by clearly splitting the z scores obtained for positive and negative samples. CONCLUSIONS: We show that our adaptive reference selection algorithm for optimizing trisomy detection showed improved reliability and will further support practitioners in reducing both false negative and positive results.

Analysis of morbidity, mortality, and risk factors of tracheostomy-related complications in patients with oral and maxillofacial cancer.

BACKGROUND: This study aimed to analyze and describe the morbidity and mortality associated with tracheostomy in patients with oral cancer and to identify the risk factors associated with tracheostomy complications. METHODS: We performed a retrospective chart review of patients who underwent tracheostomy during a major oral cancer resection between March 2001 and January 2016 at the National Cancer Center, Korea. Overall, we included 51 patients who underwent tracheostomy after oral cancer surgery. We assessed the morbidity and mortality of tracheostomy and determined the risks associated with tracheostomy complications. RESULTS: Twenty-two tracheostomy-related complications occurred in 51 patients. The morbidity and mortality rates were 35.2 % (n = 18) and 0 % (n = 0), respectively. Tracheostomy-related complications were tracheitis (n = 4), obstructed tracheostomy (n = 9), displaced tracheostomy (n = 5), air leakage (n = 1), stomal dehiscence (n = 1), and decannulation failure (n = 2). Most complications (19/22) occurred during the early postoperative period. Considering the risk factors for tracheostomy complications, the type of tube used was associated with the occurrence of tracheitis (p < 0.05). Additionally, body mass index and smoking status were associated with tube displacement (p < 0.05). However, no risk factors were significantly associated with obstructed tracheostomy. CONCLUSIONS: Patients with risk factors for tracheostomy complications should be carefully observed during the early postoperative period by well-trained medical staff.

Comparison of two high-throughput semiconductor chip sequencing platforms in noninvasive prenatal testing for Down syndrome in early pregnancy.

BACKGROUND: Noninvasive prenatal testing (NIPT) to detect fetal aneuploidy using next-generation sequencing on ion semiconductor platforms has become common. There are several sequencers that can generate sufficient DNA reads for NIPT. However, the approval criteria vary among platforms and countries. This can delay the introduction of such devices and systems to clinics. A comparison of the sensitivity and specificity of two different platforms using the same sequencing chemistry could be useful in NIPT for fetal chromosomal aneuploidies. This would improve healthcare authorities' confidence in decision-making on sequencing-based tests. METHODS: One hundred and one pregnant women who were predicted at high risk of fetal defects using conventional prenatal screening tests, and who underwent definitive diagnosis by full karyotyping, were enrolled from three hospitals in Korea. Most of the pregnant women (69.79 %) received NIPT during weeks 11-13 of gestation and 30.21 % during weeks 14-18. We used Ion Torrent PGM and Proton semi-conductor-based sequencers with 0.3× sequencing coverage depth. The average total reads of 101 samples were approximately 4.5 and 7.6 M for PGM and Proton, respectively. A Burrows-Wheeler Aligner (BWA) algorithm was used for the alignment, and a z-score was used to decide fetal trisomy 21. Interactive dot diagrams from the sequencing data showed minimal z-score values of 2.07 and 2.10 to discriminate negative versus positive cases of fetal trisomy 21 for the two different sequencing systems. RESULTS: Our z-score-based discrimination method resulted in 100 % positive and negative prediction values for both ion semiconductor PGM and Proton sequencers, regardless of their sequencing chip and chemistry differences. Both platforms performed well at an early stage (11-13 weeks of gestation) compared with previous studies. CONCLUSIONS: These results suggested that, using two different sequencers, NIPT to detect fetal trisomy 21 in early pregnancy is accurate and platform-independent. The data suggested that the amount of sequencing and the application of common, simple, and robust statistical analyses are more important than sequencing chemistry and platform types. This result has practical implications in countries where PGM is approved for NIPT but the Proton system is not.

Reconstruction with fibular osteocutaneous free flap in patients with mandibular osteoradionecrosis.

BACKGROUND: Osteoradionecrosis is a delayed complication from radiation therapy which causes chronic pain, infection and constant deformity after necrosis. Most of the osteoradionecrosis occurs spontaneously or after the primary oncologic surgery, dental extraction or by trauma of prosthesis. The treatment of osteoradionecrosis relies on both conservative measures and surgical measures. The fibular osteocutaneous free flap has become more popular choice for reconstruction of maxillofacial defects as a treatment of osteoradionecrosis. METHODS: We presented our experiences from 7 patients with osteoradionecrosis who have had reconstruction surgery with fibular osteocutaneous free flap at National Cancer Center during the recent 5 years. We performed segmental mandibular resection with fibular osteocutaneous free flap for all 7 patients of advanced osteoradionecrosis who were not controlled by conservative treatment such as wound irrigation, debridement, and antibiotics. RESULTS: A wide range of techniques were available for the reconstruction of composite defects resulted from the treatment of advanced mandibular osteoradionecrosis. Significant improvement was noted in relieving pain and treating trismus after the surgery however difficulty in swallowing and xerostomia showed less improvement. CONCLUSIONS: We concluded that fibular osteocutaneous free flap can be performed safely in patients with osteoradionecrosis and yields positive outcomes with significantly increased success rate. The fibular osteocutaneous free flap was our preferred choice for the mandibular reconstruction due to its versatility and predictability.

Immediate implant placement for schizophrenic patient with outpatient general anesthesia.

The difficult oral healthcare in intellectually disabled patients with poor behavioral control has led to debate over the cost-effectiveness and validity of implant treatment in these patients. The patient in the present report had schizophrenia that had led to poor oral care and severe dental caries in the full mouth. Tooth extraction and a removable prosthesis were planned, but the guardian wanted an implant procedure. Since the guardian showed strong will and cooperation with regard to the patient's oral healthcare, extraction followed by immediate implant placement was performed across two rounds of general anesthesia. Since the outcome appears successful, we present this case report. Immediate implant placement after tooth extraction requires fewer surgeries and rounds of general anesthesia, reduces horizontal bone resorption, and can achieve better esthetic results. Therefore, as long as a certain degree of oral care is possible, this can be a positive option for restoration of a partially edentulous mouth, even in intellectually disabled patients.

The relationship between cisplatin resistance and histone deacetylase isoform overexpression in epithelial ovarian cancer cell lines.

OBJECTIVE: To investigate the relationship between cisplatin resistance and histone deacetylase (HDAC) isoform overexpression in ovarian cancer cell lines. METHODS: Expression of four HDAC isoforms (HDAC 1, 2, 3, and 4) in two ovarian cancer cell lines, SKOV3 and OVCAR3, exposed to various concentrations of cisplatin was examined by western blot analyses. Cells were transfected with plasmid DNA of each HDAC. The overexpression of protein and mRNA of each HDAC was confirmed by western blot and reverse transcriptase-polymerase chain reaction analyses, respectively. The cell viability of the SKOV3 and OVCAR3 cells transfected with HDAC plasmid DNA was measured using the cell counting kit-8 assay after treatment with cisplatin. RESULTS: The 50% inhibitory concentration of the SKOV3 and OVCAR3 cells can be determined 15-24 hours after treatment with 15 µg/mL cisplatin. The expression level of acetylated histone 3 protein in SKOV3 cells increased after exposure to cisplatin. Compared with control cells at 24 hours after cisplatin exposure, the viability of SKOV3 cells overexpressing HDAC 1 and 3 increased by 15% and 13% (p<0.05), respectively. On the other hand, OVCAR3 cells that overexpressed HDAC 2 and 4 exhibited increased cell viability by 23% and 20% (p<0.05), respectively, compared with control cells 24 hours after exposure to cisplatin. CONCLUSION: In SKOV3 and OVCAR3 epithelial ovarian cancer cell lines, the correlation between HDAC overexpression and cisplatin resistance was confirmed. However, the specific HDAC isoform associated with resistance to cisplatin varied depending on the ovarian cancer cell line. These results may suggest that each HDAC isoform conveys cisplatin resistance via different mechanisms.

Progesterone modulates the expression of interleukin-6 in cultured term human uterine cervical fibroblasts.

PROBLEM: The preventative value of progesterone in preterm labor has been recently recognized, especially when it is administered via vaginal suppository. This study was undertaken to evaluate the effect of progesterone on interleukin-6 (IL-6) production in human uterine cervical fibroblasts (UCFs) treated with lipopolysaccharides (LPS). METHOD OF STUDY: Human uterine cervical tissue was obtained at term, prior to the onset of labor, during the scheduled cesarean section or cesarean hysterectomy. Primary UCF cultures were established and confirmed by immunohistochemistry. IL-6 mRNA and protein expressions were examined by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. RESULTS: Lipopolysaccharides stimulation induced a clear time- and dose-dependent increase in IL-6 mRNA and protein levels in UCFs (P < 0.05). Progesterone treatment significantly attenuated LPS-induced increases in IL-6 mRNA and protein expressions in UCFs (P < 0.05). Estrogen exposure had no effect on LPS-induced IL-6 up-regulation and did not modulate the effects of progesterone. CONCLUSION: Our preliminary results suggest that vaginal progesterone might prevent spontaneous preterm labor through a mechanism involving anti-inflammatory effects on UCFs, particularly suppression of IL-6 production.