Correction to: Versatile biotechnological applications of amylosucrase, a novel glucosyltransferase.

[This corrects the article DOI: 10.1007/s10068-019-00686-6.].

Korean Red Ginseng Potentially Improves Maintaining Antibodies after COVID-19 Vaccination: A 24-Week Longitudinal Study.

Despite the effectiveness and safety of COVID-19 vaccines, vaccine-induced responses decline over time; thus, booster vaccines have been approved globally. In addition, interest in natural compounds capable of improving host immunity has increased. This study aimed to examine the effect of Korean Red Ginseng (KRG) on virus-specific antibodies after COVID-19 vaccination. We conducted a 24 week clinical pilot study of 350 healthy subjects who received two doses of the COVID-19 vaccine and a booster vaccination (third dose). These subjects were randomized 1:2 to the KRG and control groups. We evaluated antibody response five times: just before the second dose (baseline), 2 weeks, 4 weeks, 12 weeks after the second dose, and 4 weeks after the third dose. The primary endpoints were changes in COVID-19 spike antibody titers and neutralizing antibody titers. The antibody formation rate of the KRG group was sustained higher than that of the control group for 12 weeks after the second dose. This trend was prominently observed in those above 50 years old. We found that KRG can help to increase and maintain vaccine response, highlighting that KRG could potentially be used as an immunomodulator with COVID-19 vaccines.

Influence of Blending of Nonionic Emulsifiers Having Various Hydrophilic Head Sizes on Lipid Oxidation: Investigation of Antioxidant Polarity Interfacial Characteristics Relationship.

The purpose of this study was to deliver insights into the effect of interfacial composition and antioxidant polarity on the lipid oxidation of emulsions. Emulsions were created using blends of nonionic ethoxylated fatty acid alcohol surfactants with different hydrophilic head sizes, and lipophilic (TBHQ) and amphiphilic (lauryl gallate) antioxidants were incorporated into the emulsions. At the same surfactant concentration, emulsion stabilized with surfactant with a smaller hydrophilic head was more susceptible to lipid oxidation than that stabilized with surfactant with a larger hydrophilic head. When surfactants with a similar hydrophilic head size were used, lipid oxidation in emulsion containing more surfactant was slightly faster than that containing less surfactant. When emulsions were created with a 1:1 molar ratio mixture of surfactants with small and large hydrophilic heads, surfactant concentration (1.00 and 2.932 mM) had little effect on lipid peroxide generation rate. However, the concentration of thiobarbituric acid-reactive substances (TBARSs) in the emulsion prepared at 1.00 mM increased faster than that prepared at 2.93 mM. Alteration of interfacial composition and surfactant concentration did not affect antioxidant ability, regardless of antioxidant polarity, to inhibit lipid peroxide generation. However, the ability of lauryl gallate and TBHQ to prevent TBARS generation was elevated by mixing surfactants with small and large hydrophilic heads and by decreasing surfactant concentration. In most emulsions, lauryl gallate showed a more effective antioxidant ability than TBHQ.

Rapid and non-destructive spectroscopic method for classifying beef freshness using a deep spectral network fused with myoglobin information.

A simple, novel, rapid, and non-destructive spectroscopic method that employs the deep spectral network for beef-freshness classification was developed. The deep-learning-based model classified beef freshness by learning myoglobin information and reflectance spectra over different freshness states. The reflectance spectra (480-920 nm) were measured from 78 beef samples for 17 days, and the datasets were sorted into three freshness classes based on their pH values. Myoglobin information showed statistically significant differences depending on the freshness; consequently, it was utilized as a crucial parameter for classification. The model exhibited improved performance when the reflectance spectra were combined with the myoglobin information. The accuracy of the proposed model improved to 91.9%, whereas that of the single-spectra model was 83.6%. Further, a high value for the area under the receiver operating characteristic curve (0.958) was recorded. This study provides a basis for future studies on the investigation of myoglobin information associated with meat freshness.

Effect of blood flow restriction during low-intensity resistance training on bone markers and physical functions in postmenopausal women.

BACKGROUND: The aim of this study was to investigate the effects of 12-week low intensity resistance training (RT) with blood flow restriction on bone mineral density (BMD), bone turnover markers (BTM), physical functions, and blood lactate concentration in postmenopausal women with osteoporosis or osteopenia. METHODS: 26 study participants (56 ± 1.8yrs, T-score: -2.5 ± 0.7) were randomly assigned into Moderate to High-Intensity RT (MHIRT, n = 7), BFR combined with Low-Intensity RT (LIBFR, n = 7), Low-Intensity RT (LIRT, n = 6), or Control group (CON, n = 6). Exercise group performed leg press, leg extension, biceps curl, and triceps extension 3 times a week for 12 weeks. Training intensity were set at 60% of 1-repetition maximum (1-RM) for MHIRT, and at 30% of 1-RM for LIBFR and LIRT, and reset every 4 weeks for increasing intensity. RESULTS: Lower, and upper limb 1-RM only increased in MHIRT (65%, p < 0.001), and LIBFR (40%, p < 0.05), while LIRT only showed increment on lower limb 1-RM (28%, p < 0.05). All exercise groups demonstrated significant increment on blood lactate concentration after training session (p < 0.001). However, LIBFR showed 2.7 folds higher increment than LIRT (p < 0.001). Although no changes were observed in MHIRT, LIBFR, and LIRT, CON showed significant decrease in BMD (p < 0.05). While, LIRT showed no responses on BTM, LIBFR significantly increased bone formation markers (P1NP) about 7.05 ng/ml (p < 0.05). Lastly, balance improvement was only found in MHIRT, and LIBFR (p < 0.05). CONCLUSION: 12-week LIBFR can be implied as a safe, and effective method to improve muscle strength, P1NP, and balance similar to MHIRT in postmenopausal women with osteoporosis or osteopenia.

Versatile biotechnological applications of amylosucrase, a novel glucosyltransferase.

Amylosucrase (AS; EC 2.4.1.4) is an enzyme that has great potential in the biotechnology and food industries, due to its multifunctional enzyme activities. It can synthesize α-1,4-glucans, like amylose, from sucrose as a sole substrate, but importantly, it can also utilize various other molecules as acceptors. In addition, AS produces sucrose isomers such as turanose and trehalulose. It also efficiently synthesizes modified starch with increased ratios of slow digestive starch and resistant starch, and glucosylated functional compounds with increased water solubility and stability. Furthermore, AS produces turnaose more efficiently than other carbohydrate-active enzymes. Amylose synthesized by AS forms microparticles and these can be utilized as biocompatible materials with various bio-applications, including drug delivery, chromatography, and bioanalytical sciences. This review not only compares the gene and enzyme characteristics of microbial AS, studied to date, but also focuses on the applications of AS in the biotechnology and food industries.

Sex- and fiber-type-related contractile properties in human single muscle fiber.

This study aimed to examine the distribution and contractile properties of single muscle fiber sex/myosin heavy chain (MHC) type-related differences and to evaluate the correlation of cross-sectional area (CSA) and specific force (SF) in a single muscle fiber. Six young men and six young women were participated in this study. Muscle sample was obtained from vastus lateralis muscle. To examine potential gender differences within each fiber contractile properties (CSA, maximal isometric force, SF, maximal shortening velocity) and relationship between CSA and SF of single fiber using Pearson correlation. After mechanical measurements, single muscle fiber determined MHC isoforms using silver stain. MHC isoform composition did not differ by sex (chi-square=6.978, P=0.073). There were sex-related differences in CSA and maximal isometric force (P<0.05), but no fiber type-related differences (P>0.05). Related to SF and maximal shortening velocity, there were no sex-related differences only fiber type-related differences (P<0.05). However, there were differences in SF between single fiber types in men but not in women. A negative correlation was found between CSA and SF in both men and women (P<0.05). It is suggested that there might be different mechanical properties of cross-bridges according to sex.

Role of l-carnitine and oleate in myogenic differentiation: implications for myofiber regeneration.

PURPOSE: Myogenic progenitors play a critical role in injury-induced myofiber regeneration. The purpose of this study was to characterize the effects of oleate and L-carnitine on the overall behavior of proliferating myogenic progenitors (myoblasts) and its link to the mitochondrial biogenic process. METHODS: C2C12 myoblasts were cultured either with no treatment, oleate, L-carnitine, or their mixture. Proliferating myoblasts were investigated under a phase-contrast microscope. Myonuclei and myosin heavy chain were stained with DAPI and MF20 antibody, respectively, in differentiated myotubes and visualized under florescence microscopy. Mitochondrial biogenic markers and porin were assessed by qRT-PCR or immunoblotting. RESULTS: Increased proliferation rate was observed in myoblasts conditioned with oleate or a mixture of oleate and L-carnitine in contrast to that in non-treated (NT) and L-carnitine-treated myoblasts. Myoblast viability was not statistically different among all tested groups. Fusion index and myotube width were greater in oleate- or L-carnitine-conditioned myotubes than those in NT myotubes, with the greatest effect seen in myotubes conditioned with the mixture. The gene expressions of Pgc1-α, Nrf1, and Tfam were the greatest in myotubes conditioned with the mixture, whereas the level of Ncor1 expression was lower compared to those of the other groups. Protein level of porin was the greatest in myotubes conditioned with the mixture, followed by that of individually treated myotubes with oleate and L-carnitine. CONCLUSION: These results provide a critical piece of cellular evidence that combined treatment of oleate and L-carnitine could serve as a potential therapeutic strategy to facilitate biological activation of myogenic progenitors.

Mild Hyperthermia-Induced Myogenic Differentiation in Skeletal Muscle Cells: Implications for Local Hyperthermic Therapy for Skeletal Muscle Injury.

The percutaneous application of controlled temperature on damaged muscle is regarded as a prevalent remedy. However, specific mechanisms are not completely understood. Therefore, cellular behaviors of myoblasts were investigated under a physiological hyperthermic temperature. The myoblasts were cultured under no treatment (NT, 37°C, 24 h/day), intermittent heat treatment (IHT, 39°C, 2 h/day), and continuous heat treatment (CHT, 39°C, 24 h/day) during proliferation, migration, or myogenic differentiation. Although the effects of mild heat on migration were not observed, the proliferation was promoted by both IHT and CHT. The myogenic differentiation was also enhanced in a treatment time-dependent manner, as evidenced by an increase in myotube size and fusion index. The gene expressions of mitochondrial biogenesis (Pgc-1α, Nrf1, and Tfam), a subset of mitochondrial dynamics (Mfn1 and Drp1), and a myogenic regulatory factor (myogenin) were increased in a heat treatment time-dependent manner. Interestingly, the mild heat-induced myogenic differentiation and myogenin expression were retarded significantly in PGC-1α-targeted siRNA-transfected cells, suggesting that mild hyperthermia promotes myogenic differentiation via the modulation of PGC-1α. This study provides cellular evidence supporting that local hyperthermic treatment at 39°C is regarded as an effective therapeutic strategy to promote satellite cell activities in regenerating myofibers.

Synergistic Effects of Proprioceptive Neuromuscular Facilitation and Manual Lymphatic Drainage in Patients with Mastectomy-Related Lymphedema.

Purpose: Manual lymphatic drainage (MLD) and proprioceptive neuromuscular facilitation (PNF) are potential therapeutic strategies to reduce mastectomy-induced edema. The purpose of this study was to investigate whether the combination of these therapies would induce synergistic effects to treat lymphedema-related complications and to analyze a possible physiological mechanism involved in the observed effects. Methods: A total of 55 patients diagnosed with mastectomy-induced lymphedema were recruited and randomized into three experimental groups: PNF group (n = 17), MLD group (n = 20), and PNF + MLD group (n = 18). They were subjected to designated rehabilitation program three times a week for 16 weeks. ROM (flexion of the shoulder joint), edema size, arterial blood flow velocity, and degree of pain and depression were measured every 4 weeks over experimental period. Results: Lymphedema volume, VAS pain scale, and Beck depression scale were decreased in PNF and MLD groups for 16 weeks in a time-dependent manner. In combination, a greater reduction of these variables was observed over 16 weeks compared to each PNF and MLD. While axillary arterial blood circulation rate in the affected extremity was increased in both PNF and PNF + MLD groups over 16 weeks, this value was not increased in MLD group throughout the experimental period. A greater reduction of scales of VAS pain and Beck Depression Inventory (BDI) was observed in PNF + MLD group after the 16 week-treatment, as compared to each PNF and MLD group. Pearson's coefficients test demonstrated that there are significant correlation of depression against pain (r = 0.616, p < 0.01), ROM (r = -0.478, p < 0.01), and lymphedema size (r = 0.492, p < 0.01). Conclusion: The combination of MLD and PNF induces potent synergistic effects on edema volume, shoulder range of motion (ROM), pain, and depression in patients with lymphedema. In addition, an increased rate of axillary arterial blood flow in PNF-treated patients provide a potential physiological mechanism by which local arterial pulsation in the affected extremity plays a positive role in the treatment of lymphedema. Therefore, it is suggested to incorporate an element of PNF into traditional MLD method to facilitate treatment process for patients with lymphedema.

Oleate Prevents Palmitate-Induced Atrophy via Modulation of Mitochondrial ROS Production in Skeletal Myotubes.

Accumulation of saturated fatty acids contributes to lipotoxicity-related insulin resistance and atrophy in skeletal muscle. Conversely, unsaturated fatty acids like docosahexaenoic acid were proven to preserve muscle mass. However, it is not known if the most common unsaturated oleate will protect skeletal myotubes against palmitate-mediated atrophy, and its specific mechanism remains to be elucidated. Therefore, we investigated the effects of oleate on atrophy-related factors in palmitate-conditioned myotubes. Exposure of myotubes to palmitate, but not to oleate, led to an induction of fragmented nuclei, myotube loss, atrophy, and mitochondrial superoxide in a dose-dependent manner. Treatment of oleate to myotubes attenuated production of palmitate-induced mitochondrial superoxide in a dose-dependent manner. The treatment of oleate or MitoTEMPO to palmitate-conditioned myotubes led to inhibition of palmitate-induced mRNA expression of proinflammatory (TNF-α and IL6), mitochondrial fission (Drp1 and Fis1), and atrophy markers (myostatin and atrogin1). In accordance with the gene expression data, our immunocytochemistry experiment demonstrated that oleate and MitoTEMPO prevented or attenuated palmitate-mediated myotube shrinkage. These results provide a mechanism indicating that oleate prevents palmitate-mediated atrophy via at least partial modulation of mitochondrial superoxide production.

Age-related functional changes and susceptibility to eccentric contraction-induced damage in skeletal muscle cell.

Depending upon external loading conditions, skeletal muscles can either shorten, lengthen, or remain at a fixed length as they produce force. Fixed-end or isometric contractions stabilize joints and allow muscles to act as active struts during locomotion. Active muscles dissipate energy when they are lengthened by an external force that exceeds their current force producing capacity. These unaccustomed eccentric activities often lead to muscle weakness, soreness, and inflammation. During aging, the ability to produce force under these conditions is reduced and appears to be due to not only reductions in muscle mass but also to alterations in the basic mechanisms of contraction. These alterations include impairments in the excitation-contraction process, and the action of the cross-bridges. Also, it is well known that age-related skeletal muscle atrophy is characterized by a preferential atrophy of fast fibers, and increased susceptibility to fast muscle fiber when aged muscles are exposed to eccentric contraction followed by the impaired recovery process has been reported. Taken together, the selective loss of fast muscle fiber in aged muscle could be affected by eccentric-induced muscle damage, which has significant implication to identify the etiology of the age-related functional changes. Therefore, in this review the alteration of age-related muscle function and its impact to/of eccentric induced muscle damage and recovery will be addressed in detail.

Peak torque and average power at flexion/extension of the shoulder and knee when using a mouth guard in adults with mild midline discrepancy.

[Purpose] This study was conducted to investigate the changes in torque and power during flexion and extension of the shoulder and the knee joints caused by midline correction using mouth guards made from different materials in adults with mild midline discrepancy. [Subjects] The subjects of this study were males (n=12) in their 20s who showed a 3-5 mm difference between the midlines of the upper and lower teeth but had normal masticatory function. [Methods] The torque and average power of the lower limb and upper limb were measured during flexion and extension according to various types of mouth guard. [Results] There were significant differences in relative torque and average power between three conditions (no mouth guard, soft-type mouth guard, and hard-type mouth guard) at shoulder flexion and extension. There were no significant differences in relative torque and average power between the three conditions at knee flexion and extension. [Conclusions] These results suggest that use of a mouth guard is a method by which people with a mild midline discrepancy can improve the stability of the entire body.

The Effect of a PNF Technique Program after Mastectomy on Lymphedema Patients' Depression and Anxiety.

[Purpose] This study was conducted to examine the effects of exercises applied with PNF techniques performed for 30 minutes per session, three times per week, after receipt of radiation therapy following mastectomy on depression and anxiety in patients diagnosed with lymphedema and to prepare basic data for creation of self-directed exercise programs for lymphedema patients that will enable them to perform exercises within the range of no pain. [Methods] The subjects of this study were 45 patients selected from among those diagnosed with breast cancer who showed lymphedema after anti-cancer therapy following mastectomy. [Results] The Beck depression score changed significantly during the five assessment periods however, there was no significant difference between the treatment groups. Post hoc analyses revealed that there was significant improvement in the Beck depression score from 4 weeks in all three groups. The interaction between group and time was also statistically significant. [Conclusion] In conclusion, PNF techniques helped to improve the depression and anxiety rates. Four weeks after the start of therapy, PNF techniques Depression and anxiety to create a greater degree of decline was on display.

The Effects of PNF Techniques on Lymphoma in the Upper Limbs.

[Purpose] The purpose of this study were to identify whether painless dynamic PNF techniques can reduce lymphedema, and to provide basic reference data for use in the treatment of lymphedema patients. [Subjects] This experiment was conducted from March 2012 to July 2012 at Busan University Hospital D. The subjects were upper extremity lymphedema patients who were receiving rehabilitation treatment. Those with dual lymphedema site pain or who did not want to participate in the experiment were excluded. [Methods] A total of 40 women participated in this study, and they received PNF techniques before the application of lymph compression bandages. Group 1 of 20 subjects were adminstered PNF techniques three times a week for 30 minutes each time. Group 2 of 20 subjects only edema reducing massage for 30 minutes. [Results] The interaction between treatment method and treatment time was significant, which indicates that the change in edema at different measurement times was different according to treatment methods. In this study, Group 1 had a steeper rate of decline in edema than Group 2. [Conclusion] In conclusion, both massage and PNF techniques helped to lower edema rates. Four weeks after the beginning of treatment, a larger degree of decline in edema was exhibited in the PNF group than in the massage group.

Microcarriers designed for cell culture and tissue engineering of bone.

Microspherical particulates have been an attractive form of biomaterials that find usefulness in cell delivery and tissue engineering. A variety of compositions, including bioactive ceramics, degradable polymers, and their composites, have been developed into a microsphere form and have demonstrated the potential to fill defective bone and to populate tissue cells on curved matrices. To enhance the capacity of cell delivery, the conventional solid form of spheres is engineered to have either a porous structure to hold cells or a thin shell to in-situ encapsulate cells within the structure. Microcarriers can also be a potential reservoir system of bioactive molecules that have therapeutic effects in regulating cell behaviors. Due to their specific form, advanced technologies to culture cell-loaded microcarriers are required, such as simple agitation or shaking, spinner flask, and rotating chamber system. Here, we review systematically, from material design to culture technology, the microspherical carriers used for the delivery of cells and tissue engineering, particularly of bone.