A Novel Passive Shoulder Exoskeleton Using Link Chains and Magnetic Spring Joints.

Work-related musculoskeletal disorders represent a major occupational disability issue, and 53.4% of these disorders occur in the back or shoulders. Various types of passive shoulder exoskeletons have been introduced to support the weight of the upper arm and work tools during overhead work, thereby preventing injuries and improving the work environment. The general passive shoulder exoskeleton is constructed with rigid links and joints to implement shoulder rotation, but there exists a challenge to align with the flexible joint movements of the human shoulder. Also, a force-generating part using mechanical springs require additional mechanical components to generate torque similar to the shoulder joint, resulting in increased overall volume and inertia to the upper arm. In this study, we propose a new type of passive shoulder exoskeleton that uses magnetic spring joint and link chain. The redundant degrees of freedom in the link chains enables to follow the shoulder joint movement in the horizontal direction, and the magnetic spring joint generates torque without additional parts in a compact form. Conventional exoskeletons experience a loss in the assisting torque when the center of shoulder rotation changed during arm elevation. Our exoskeleton minimizes the torque loss by customizing the installation height and initial angle of the magnetic spring joint. The performances of the proposed exoskeleton were verified by an electromyographic evaluation of shoulder-related muscles in overhead work and box lifting task.

Pectoral nerve block (Pecs block) with sedation for breast conserving surgery without general anesthesia.

Most regional anesthesia in breast surgeries is performed as postoperative pain management under general anesthesia, and not as the primary anesthesia. Regional anesthesia has very few cardiovascular or pulmonary side-effects, as compared with general anesthesia. Pectoral nerve block is a relatively new technique, with fewer complications than other regional anesthesia. We performed Pecs I and Pec II block simultaneously as primary anesthesia under moderate sedation with dexmedetomidine for breast conserving surgery in a 49-year-old female patient with invasive ductal carcinoma. Block was uneventful and showed no complications. Thus, Pecs block with sedation could be an alternative to general anesthesia for breast surgeries.

Minimally invasive transcanal myringotomy for pediatric early stage congenital cholesteatoma.

OBJECTIVE: Recently, minimally invasive transcanal myringotomy (MITM), which is a useful surgical technique for early stage congenital cholesteatoma (CC) in children, was introduced. The purpose of this study is to evaluate the short-term surgical results of MITM in pediatric early stage CC. MATERIALS AND METHODS: We retrospectively reviewed the charts of 24 patients who underwent MITM between January 2013 and October 2015. RESULTS: The patients' ages ranged from 1 to 16 years (mean, 2.6 years). There were 17 male and 7 female patients. The right side (n = 13) was affected twice as often as the left side (n = 11). The most common site was the anterosuperior quadrant (15 cases). The diameter of the CC on axial computed tomography images ranged from 2.8 to 5.7 mm (mean, 3.9 mm). CCs were graded according to Potsic's system: 18 cases were classified as stage I, 3 case as stage II, and 3 cases as stage III. AllCCs except 1 were closed type. In21 patients, the tympanic membrane closed naturally without recurrence. Three patients showed small persistent dry perforation. Natural closure occurred in these patients, who were treated with paper patches. CONCLUSION: MITM is a simple, effective technique for removing an early stage CC from the middle ear, and it can minimize operative time, length of hospitalization, and postoperative morbidity.

Clinical characteristics of pediatric external auditory canal cholesteatoma.

BACKGROUND & OBJECTIVE: External auditory canal cholesteatoma (EACC) is caused by an invasion of squamous tissue into a localized area of periosteitis in the bony canal wall. The clinical characteristics of pediatric EACC are still unknown because of its rare occurrence. To date, only a single paper has reported that pediatric EACC has a less aggressive growth pattern compared to adult EACC. Further studies are required to understand the clinical behavior of EACC, i.e., its aggressiveness. The purpose of this study was to evaluate the clinical characteristics of pediatric EACC. MATERIALS AND METHODS: The clinical records of all patients diagnosed with EACC in our department from January 1, 2012 to February 29, 2016 were retrospectively reviewed, focusing on the extension of bone erosion, symptoms, and clinical findings. RESULTS: Seven patients had primary pediatric EACC (age range, 5-17 years). All patients showed unilateral EACC. Otalgia and intermittent otorrhea were common symptoms. Bacterial cultures were performed for four patients with otorrhea, which was controlled by diluted vinegar irrigation with a topical antibiotic solution. The most common bone destruction sites were the inferior and posterior walls. All patients required surgical treatment. Four patients (patient nos. 1, 3, 4, and 5) were treated via a postauricular transcanal approach. Three patients (patient nos. 2, 6, and 7) required mastoidectomy. CONCLUSION: Pediatric EACC is not less aggressive than adult EACC. Therefore, early diagnosis and adequate treatment are necessary. Further studies are required to elucidate the clinical features of pediatric spontaneous EACC.

Gold nanorod-photosensitizer complex obtained by layer-by-layer method for photodynamic/photothermal therapy in vitro.

Gold nanorod (GNR)-photosensitizer (PS) complex was prepared using anionic PS (sodium salt of purpurin-18) and cationic poly(allylamine hydrochloride) by layer-by-layer method, and was characterized by transmission electron microscopy, UV-vis spectroscopy, and zeta potential. The GNR-PS complex is a promising agent for synergistic (photothermal and photodynamic) therapy (PTT/PDT), in which PTT generates heat as well as operates the PS release which maximize the following PDT activity. The combined dual therapy, PTT followed by PDT, exhibits a significantly higher photocytotoxicity result based on synergistic effect of hyperthermia from PTT as well as singlet oxygen photogeneration from PDT.

Magnetic resonance findings of acute severe lower back pain.

OBJECTIVE: To determine abnormal MRI findings in adults hospitalized with acute severe axial LBP. METHOD: Sixty patients with back pain were divided into 3 groups consisting of 1) 23 adults with acute axial severe LBP who could not sit up or stand up for several days, but had not experienced previous back-related diseases or trauma (group A), 2) 19 adults who had been involved in a minor traffic accident, and had mild symptoms but not limited mobility (group B), and 3) 18 adults with LBP with radicular pain (group C)., Various MRI findings were assessed among the above 3 groups and compared as follows: disc herniation (protrusion, extrusion), lumbar disc degeneration (LDD), annular tear, high intensity zone (HIZ), and endplate changes. RESULTS: THE MRI FINDINGS OF A GROUP WERE AS FOLLOWS: disc herniation (87%), LDD (100%), annular tear (100%), HIZ (61%), and end plate changes (4.4%). The findings of disc herniation, annular tear, HIZ, and LDD were more prevalent in A group than in B group (p<0.01). HIZ findings were more prevalent in A group than in group B or group C (p<0.05). CONCLUSION: Patients with acute severe axial LBP were more likely to have disc herniation, LDD, annular tear, HIZ. Among LBP groups, there was a significant association of HIZ on MRI with acute severe axial LBP.

Notch signal activates hypoxia pathway through HES1-dependent SRC/signal transducers and activators of transcription 3 pathway.

We report a Notch signal-induced pathway that leads to transcriptional activation of HIF1-alpha gene. HeLa/rtTAA/TRE-N1-IC cell line capable of doxycycline-induced expression of human Notch1-IC was established. The induction of Notch signaling activates HIF1-alpha and its target gene expression in HeLa/rtTAA/TRE-N1-IC cells. Notch signaling enhanced signal transducers and activators of transcription 3 (STAT3) phosphorylation required for HIF1-alpha expression. SRC kinase was found to be responsible for the enhanced STAT3 phosphorylation in response to Notch signaling. Activation of SRC/STAT3 pathway by Notch signaling was dependent on the expression of Notch effector HES1 transcription factor. The induction of HES1 enhanced STAT3 phosphorylation at Tyr 705 as well as SRC phosphorylation at Tyr 416 in inducible HeLa/rtTAA/TRE-HES1 cells, which express HES1 in response to doxycycline treatment. However, the treatment of Trichostatin A that interferes with HES1 transcriptional regulation did not affect STAT3 phosphorylation, and the expression of dominant negative HES1 failed to interfere with HES1-dependent SRC/STAT3 pathway. These observations have led us to the conclusion that HES1-dependent activation of SRC/STAT3 pathway is independent of HES1 transcription regulation. This study first reports HES1-dependent SRC/STAT3 pathway that provides a functional link between Notch signaling and hypoxia pathway.

Intracellular delivery enhancement of poly(amino acid) drug carriers by oligoarginine conjugation.

Poly(2-hydroxytethyl aspartamide) (PHEA) was effectively translocated in both fixed and unfixed HeLa cells, when oligoarginine (Arg(8)) known as one of the cell-penetrating peptides was conjugated via a thioether linkage. The internalization of PHEA-Arg(8) into cells was a temperature-dependent process, and the studies at endocytosis inhibition conditions suggested that an endocytosis was a key mechanism. The fluorescence spectra of PHEA-Arg(8) in liposome solutions showed that PHEA-Arg(8) was collectively adsorbed in the negative liposome membrane due to the high cationic property of a conjugated Arg(8), representing that a surface adsorption was a first step in the internalization of PHEA-Arg(8). The membrane leakage activity of PHEA-Arg(8) was much lower than that of Arg(8) own, meaning that PHEA-Arg(8) does not effectively disrupt the cell membrane integrity. The uptake of polymer conjugates increased with the incubation time and reached saturation after several hours. The increase in the number of peptide conjugated to one polymer chain could increase the collective adsorption of polymer conjugates and enhance the cellular uptake. Thus, it is believed that PHEA-Arg(8) could be internalized by an adsorptive-endocytosis. A model conjugate of PHEA-Arg(8) with methotrexate (PHEA-MTX-Arg(8)) inhibited the cell proliferation about several orders of magnitude more active than PHEA-MTX.

14-3-3epsilon inhibits MK5-mediated cell migration by disrupting F-actin polymerization.

The signal pathway by which 14-3-3epsilon inhibits cell migration induced by MAPK-activated protein kinase 5 (MK5) was investigated in cultured HeLa cells. Both in vivo and in vitro analyses have revealed that 14-3-3epsilon interacts with MK5. 14-3-3epsilon bound to MK5 inhibits the phosphorylation of HSP27, a known substrate of MK5. Disturbance of actin cytoskeleton organization by 14-3-3epsilon was shown in transfected cells transiently expressing 14-3-3epsilon as well as established cells stably expressing 14-3-3epsilon. Moreover, overexpression of 14-3-3epsilon resulted in the inhibition of cell migration induced by MK5 overexpression or TNFalpha treatment. Our results suggest that 14-3-3epsilon bound to MK5 inhibits cell migration by inhibiting the phosphorylation of HSP27 whose phosphorylation regulates F-actin polymerization, actin cytoskeleton organization and subsequent actinfilament dynamics.

Inhibition of NF-kappaB acetylation and its transcriptional activity by Daxx.

We propose a biochemical mechanism by which Daxx modulates NF-kappaB transcriptional activity. Both chromatin immunoprecipitation (ChIP) assay and electrophoretic mobility shift assay (EMSA) have confirmed Daxx-mediated repression of transcriptional competence of NF-kappaB in HeLa cells. Overexpression of Daxx repressed the expression of NF-kappaB-regulated genes such as I kappa B alpha and IL8. Co-immunoprecipitation assay revealed the existence of intermolecular association between endogenous Daxx and p65 subunit of NF-kappaB stimulated by TNFalpha. Here, we suggest that Daxx-mediated repression of NF-kappaB transactivation correlates with the inhibition of p65 acetylation by Daxx. Based on the finding that the Daxx binding N-terminal side of p65 includes the major sites of acetylation mediated by p300/CBP, we further propose that the physical interaction between Daxx and p65 provides a functional framework for the inhibition of p65 acetylation by p300/CBP and subsequent repression of NF-kappaB transcriptional activity.

Dose-dependent UV stabilization of p53 in cultured human cells undergoing apoptosis is mediated by poly(ADP-ribosyl)ation.

The effect of poly(ADP-ribosyl)ation on the stability of p53 in SK-HEP1 cells treated with UV light was examined. Intracellular levels of p53 increased in cells treated with a low dose of UV light (20 J/m2), whereas they increased but then declined after a higher dose of UV (100 J/m2). Intracellular levels of p53 in the UV treated SK-HEP1 cells were dependent on the UV dose. Use of proteasome inhibitors revealed that p53 is degraded by proteasomal proteolysis after high doses of UV light. We present evidence that, at low doses, poly(ADP-ribose)polymerase (PARP) poly(ADP-ribosyl)ates p53 and protects it from proteasomal degradation before caspase-3 is activated, whereas at high doses the cells undergo UV induced apoptosis and PARP is cleaved by caspase-3 before it can protect p53 from degradation. Destabilization of p53 by cleavage of PARP may be important in cell fate decision favoring apoptosis.

Self-aggregates of oligoarginine-conjugated poly(amino acid) derivatives as a carrier for intracellular drug delivery.

N(omega)-2,2,4,6,7-Pentamethyldihydrobenzofuran-5-sulfonyl (N(omega)-Pbf)-protected oligoarginine was directly conjugated to poly(amino acid) derivatives modified with a long alkyl chain. The final concentration of conjugated peptides was easily controlled by the feed ratio of oligoarginine to polymer backbone and a final soluble polymeric system was obtained by the deprotection of N(omega)-Pbf groups. The polymeric conjugates formed stable self-aggregates of size range of 8-40 nm in aqueous solution and effectively internalized into HeLa cells by adsorptive endocytosis.