Bone regeneration potential of sub-microfibrous membranes with osteogenic induction of rBMSC for tissue engineering

Purpose: To examine the biocompatibility and osteoinductive potential of  sub-microfibrous membranes with cells in vitro and in vivo.Methods: Polylactic acid (PLA) and poly-ε-caprolactone (PCL) were blended at various volume ratios (PLA:PCL = 100:0, 70:30, 50:50, 30:70 and 0:100) and each membrane form was prepared by electrospinning. Cell viability,  biocompatibility, and bone regeneration were measured.Results: The membranes from the PLA/PCL blends prepared by an electrospinning process showed a range of diameter distribution ranging from 1,580 to 550 nm. The cells of 100 % PCL membrane (smallest diameter) exhibited significantly higher adhesion and proliferation than those of the other membranes. Among the  membranes from PLA/PCL blends, PCL membrane showed weak inflammatory changes in the early stages of implantation without acute or chronic inflammation. PCL membranes with osteogenically-induced cells successfully stimulated new bone formation in a rate calvarial defect model.Conclusion: The results indicate that biodegradable PCL sub-microfibrous membrane produced by electrospinning process seems to have excellent biocompatibility, and may be used as a scaffold for bone tissue engineering.Keywords: Biocompatibility, Hard tissue, Biomaterial availability, Bone remodeling, Polylactic acid, Poly-ε-caprolactone, Osteoinductive potential, Sub-microfibrous membrane

Cordycepin inhibits human ovarian cancer by inducing autophagy and apoptosis through Dickkopf-related protein 1/β-catenin signaling

Cordycepin, the major active component from Cordyceps militaris, has been reported to significantly inhibit some types of cancer; however, its effects on ovarian cancer are still not well understood. In this study, we treated human ovarian cancer cells with different doses of cordycepin and found that it dose-dependently reduced ovarian cancer cell viability, based on Cell counting kit-8 reagent. Immunoblotting showed that cordycepin increased Dickkopf-related protein 1 (Dkk1) levels and inhibited β-catenin signaling. Atg7 knockdown in ovarian cancer cells significantly inhibited cordycepin-induced apoptosis, whereas β-catenin overexpression abolished the effects of cordycepin on cell death and proliferation. Furthermore, we found that Dkk1 overexpression by transfection downregulated the expression of c-Myc and cyclin D1. siRNA-mediated Dkk1 silencing downregulated the expression of Atg8, beclin, and LC3 and promoted β-catenin translocation from the cytoplasm into the nucleus. These results suggest that cordycepin inhibits ovarian cancer cell growth, possibly through coordinated autophagy and Dkk1/β-catenin signaling. Taken together, our findings provide new insights into the treatment of ovarian cancer using cordycepin

Fabrication of AlGaN/GaN Fin-Type HEMT Using a Novel T-Gate Process for Improved Radio-Frequency Performance

To increase the radio-frequency (RF) performance of AlGaN/GaN-based fin-type high electron mobility transistors (HEMTs), a novel T-gate process was developed and applied to fabricate a device with high RF performance. In a single lithography process, the applied T-gate process shows a technique for forming a T-gate using the reactivity difference of several photoresists. The fabricated device has a steep fin width (W-fin) of 130 nm, a fin height (H-fin) of 250 nm, and a gate length (L-G) of 190 nm. The device exhibits a low leakage current (I-off) of 6.6 x 10(-10) A/mm and a high I-on/I-off current ratio of 4.7 x 10(8). Moreover, the fabricated device achieved a high cut-off frequency (f(T)) of 9.7 GHz and a very high maximum oscillation frequency (f(max)) of 27.8 GHz. The f(max) value of the proposed device is 138% higher than that of GaN-based fin-type HEMTs without T-gate.1

Expression of Keratin 10 in Rat Organ Surface Primo-vascular Tissues

AbstractThe primo-vascular system is described as the anatomical structure corresponding to acupuncture meridians and has been identified in several tissues in the body, but its detailed anatomy and physiology are not well understood. Recently, the presence of keratin 10 (Krt10) in primo-vascular tissue was reported, but this finding has not yet been confirmed. In this study, we compared Krt10 expression in primo-vascular tissues located on the surface of rat abdominal organs with Krt10 expression on blood and lymphatic vessels. Krt10 protein (approximately 56.5 kDa) was evaluated by western blot analysis and immunohistochemistry. Krt10 (IR) in the primo-node was visualized as patchy spots around each cell or as a follicle-like structure containing a group of cells. Krt10 IR was also identified in vascular and lymphatic tissues, but its distribution was diffuse over the extracellular matrix of the vessels. Thus Krt10 protein was expressed in all three tissues tested, but the expression pattern of Krt10 in primo-vascular tissue differed from those of blood and lymphatic vascular tissues, suggesting that structural and the regulatory roles of Krt10 in primo-vascular system are different from those in blood and lymphatic vessels

A Trainable Hearing Aid Algorithm Reflecting Individual Preferences for Degree of Noise-Suppression, Input Sound Level, and Listening Situation

Objectives In an effort to improve hearing aid users’ satisfaction, recent studies on trainable hearing aids have attempted to implement one or two environmental factors into training. However, it would be more beneficial to train the device based on the owner’s personal preferences in a more expanded environmental acoustic conditions. Our study aimed at developing a trainable hearing aid algorithm that can reflect the user’s individual preferences in a more extensive environmental acoustic conditions (ambient sound level, listening situation, and degree of noise suppression) and evaluated the perceptual benefit of the proposed algorithm. Methods Ten normal hearing subjects participated in this study. Each subjects trained the algorithm to their personal preference and the trained data was used to record test sounds in three different settings to be utilized to evaluate the perceptual benefit of the proposed algorithm by performing the Comparison Mean Opinion Score test. Results Statistical analysis revealed that of the 10 subjects, four showed significant differences in amplification constant settings between the noise-only and speech-in-noise situation (P<0.05) and one subject also showed significant difference between the speech-only and speech-in-noise situation (P<0.05). Additionally, every subject preferred different β settings for beamforming in all different input sound levels. Conclusion The positive findings from this study suggested that the proposed algorithm has potential to improve hearing aid users’ personal satisfaction under various ambient situations

Effects of the Simultaneous Application of Nonlinear Frequency Compression and Dichotic Hearing on the Speech Recognition of Severely Hearing-Impaired Subjects: Simulation Test

ObjectivesThe clinical effects of the simultaneous application of nonlinear frequency compression and dichotic hearing on people with hearing impairments have not been evaluated previously. In this study, the clinical effects of the simultaneous application of these two techniques on the recognition of consonant-vowel-consonant (CVC) words with fricatives were evaluated using normal-hearing subjects and a hearing loss simulator operated in the severe hearing loss setting.MethodsA total of 21 normal-hearing volunteers whose native language was English were recruited for this study, and two different hearing loss simulators, which were configured for severe hearing loss in the high-frequency range, were utilized. The subjects heard 82 English CVC words, and the word recognition score and response time were measured.ResultsThe experimental results demonstrated that the simultaneous application of these two techniques showed almost even performance compared to the sole application of nonlinear frequency compression in a severe hearing loss setting.ConclusionThough it is generally accepted that dichotic hearing can decrease the spectral masking thresholds of an hearing-impaired person, simultaneous application of the nonlinear frequency compression and dichotic hearing techniques did not significantly improve the recognition of words with fricatives compared to the sole application of nonlinear frequency compression in a severe hearing loss setting

First Fatal Oseltamivir-Resistant 2009 Pandemic Influenza A (H1N1) Case in an Adult in Korea

It has been suggested that oseltamivir-resistant influenza viruses harboring the H274/275Y mutation are less virulent than are those that are oseltamivir-sensitive, and fatality attributed to infection with an oseltamivir-resistant virus is very rare. Here we report the first fatal adult case of oseltamivir-resistant 2009 pandemic influenza A (H1N1) in Korea. A 60-year-old Korean male who had hypertension, diabetes mellitus, chronic kidney disease, and dilated cardiomyopathy visited Chonnam National University Hospital because of a 7-day history of chest pain and dyspnea. The patient was at another clinic and had been medicated with oseltamivir (75 mg twice daily) beginning 7 days before admission. Empirical antibiotics were started on the first day of hospitalization. Reverse-transcriptase polymerase chain reaction for 2009 pandemic influenza A (H1N1) was reported to be positive, and a double dose of oseltamivir (150 mg twice per day) was started on day four of hospitalization. However, the pneumonia worsened and the patient died, despite 3 days of high-dose antiviral therapy and 6 days of antibacterial therapy. An H275Y mutation was detected in the neuraminidase gene sequence. This case shows that oseltamivir resistance after short-term drug exposure is possible and can be fatal, emphasizing that early use of zanamivir should be considered in suspicious cases

Safety and feasibility of countering neurological impairment by intravenous administration of autologous cord blood in cerebral palsy

<p>Abstract</p> <p>Backgrounds</p> <p>We conducted a pilot study of the infusion of intravenous autologous cord blood (CB) in children with cerebral palsy (CP) to assess the safety and feasibility of the procedure as well as its potential efficacy in countering neurological impairment.</p> <p>Methods</p> <p>Patients diagnosed with CP were enrolled in this study if their parents had elected to bank their CB at birth. Cryopreserved CB units were thawed and infused intravenously over 10~20 minutes. We assessed potential efficacy over 6 months by brain magnetic resonance imaging (MRI)-diffusion tensor imaging (DTI), brain perfusion single-photon emission computed tomography (SPECT), and various evaluation tools for motor and cognitive functions.</p> <p>Results</p> <p>Twenty patients received autologous CB infusion and were evaluated. The types of CP were as follows: 11 quadriplegics, 6 hemiplegics, and 3 diplegics. Infusion was generally well-tolerated, although 5 patients experienced temporary nausea, hemoglobinuria, or urticaria during intravenous infusion. Diverse neurological domains improved in 5 patients (25%) as assessed with developmental evaluation tools as well as by fractional anisotropy values in brain MRI-DTI. The neurologic improvement occurred significantly in patients with diplegia or hemiplegia rather than quadriplegia.</p> <p>Conclusions</p> <p>Autologous CB infusion is safe and feasible, and has yielded potential benefits in children with CP.</p