High molecular weight hyaluronic acid increases the differentiation potential of the murine chondrocytic ATDC5 cell line

Osteoarthritis (OA) is a group of common, chronic, and painful inflammatory joint diseases. One important finding in OA patients is a remarkable decrease in the molecular weight of hyaluronic acid (HA) in the synovial fluid of affected joints. Therapeutic HA is available to patients in most parts of the world as a viscosupplementation product for the treatment of OA. Previous clinical reports show that high molecular weight HA (HMWHA) more effectively relieves pain than low molecular weight HA (LMWHA). However, the mechanism behind this finding remains unclear. In this study, we investigated whether a LMWHA (Low‐0.9 MDa) and two types of HMWHA (High‐1.9 MDa and 6 MDa) differentially affected chondroregulatory action. We tested this using ATDC5 cell, a murine chondrocytic cell line widely used in culture systems to study chondrogenic differentiation. We found that HMWHA, especially hylan G‐F 20 (High‐6 MDa), significantly induced aggrecan and proteoglycan accumulation, nodule formation, and mRNA expression of chondrogenic differentiation markers in a time‐ and dose‐dependent manner. In addition, we showed that HMWHA prevented TNF‐α induced inhibition of chondrogenic differentiation, with no effect on cell proliferation or viability. These results reveal that HMWHA significantly promotes chondrogenic differentiation of ATDC5 cells in vitro, and suggest that HMWHA plays a significant chondroregulatory role in vivo. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1619–1627, 2014.     

Usefulness of QuickDASH in patients with cervical laminoplasty

Purpose

Clumsiness and numbness of the upper extremity is one of the most common complaints of patients with cervical myelopathy. However, most previous evaluations after cervical laminoplasty have only been based on physicians’ points of view. We used Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) self-report questionnaire, which was designed to measure physical function and symptoms in people with upper-limb disorders to evaluate functional outcomes after laminoplasty.

Methods

Ninety-four patients who underwent laminoplasty for cervical myelopathy and replied to the questionnaire were included in this study. The average age was 62 years, and mean follow-up period was 61 months. The Japanese Orthopedic Association (JOA) score, Neck Disability Index (NDI), Short-Form Health Questionnaire of 36 questions (physical component score, PCS), upper-extremity pain (Numerical Rating Scale), and QuickDASH (0–100, 0 being least severe) were used to evaluate surgical outcomes. Satisfaction with treatment was also investigated, and internal consistency and criterion-related validity were evaluated. The QuickDASH cutoff value for patient satisfaction was determined by receiver operating characteristic curve (ROC) analysis.

Results

The mean total JOA scores were 10 before and 13 after surgery, and average postoperative QuickDASH score was 30. Cronbach α of the QuickDASH was 0.94. QuickDASH was significantly correlated with JOA score for upper-extremity motor and sensation, NDI, PCS, and pain. Cutoff value of the QuickDASH was 34.0 by ROC analysis. Significantly better QuickDASH scores were found for patients who were satisfied with treatment than for those who were not, whereas JOA score for upper-extremity motor function did not show a significant difference.

Discussion

QuickDASH had significant correlations with disease-specific JOA scores and other generic outcome measures. Moreover, QuickDASH significantly reflected patients’ satisfaction with treatment, whereas the JOA score for upper-extremity motor function did not.

Conclusion

QuickDASH was useful in evaluating upper-extremity functional outcomes after cervical laminoplasty.     

Simultaneous improvement in electrical conductivity and Seebeck coefficient of PEDOT:PSS by N2 pressure-induced nitric acid treatment

As a thermoelectric (TE) material suited to applications for recycling waste-heat into electricity through the Seebeck effect, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) is of great interest. Our research demonstrates a comprehensive study of different post-treatment methods with nitric acid (HNO₃) to enhance the thermoelectric properties of PEDOT:PSS. The optimum conditions are obtained when PEDOT:PSS is treated with HNO₃ for 10 min at room temperature followed by passing nitrogen gas (N₂) with a pressure of 0.2 MPa. Upon this treatment, PEDOT:PSS changes from semiconductor-like behaviour to metal-like behaviour, with a simultaneous enhancement in the electrical conductivity and Seebeck coefficient at elevated temperature, resulting in an increase in the thermoelectric power factor from 0.0818 to 94.3 μW m⁻¹ K⁻² at 150 °C. The improvement in the TE properties is ascribed to the combined effects of phase segregation and conformational change of the PEDOT due to the weakened coulombic attraction between PEDOT and PSS chains by nitric acid as well as the pressure of the N₂ gas as a mechanical means.

As a thermoelectric (TE) material suited to applications for recycling waste-heat into electricity through the Seebeck effect, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) is of great interest.     

An initial trial of quantitative evaluation of autoimmune pancreatitis using shear wave elastography and shear wave dispersion in transabdominal ultrasound

Background/ObjectivesWe aimed to examine therapeutic efficacy and prognosis prediction of autoimmune pancreatitis (AIP) using shear wave elastography (SWE) and shear wave dispersion (SWD) in transabdominal ultrasound (US).MethodsThe subjects were 23 patients with diffuse type 1 AIP who underwent SWE and SWD, and 34 controls with a normal pancreas. Elasticity and dispersion were defined as the pancreatic elastic modulus (PEM) and dispersion slope, respectively. PEM and dispersion slope were compared between AIP and control cases, and the short-term therapeutic effect and long-term prognosis were examined.ResultsPEM (30.9 vs. 6.6 kPa, P < 0.001) and dispersion slope (15.3 vs. 13.0 (m/sec)/kHz, P = 0.011) were significantly higher in AIP cases than in controls. Among the 17 AIP patients followed-up in two weeks after treatment, these parameters were 12.7 kPa and 10.5 (m/sec)/kHz with median decrease rate of 37.2% and 32.8%, respectively, which were significantly higher than the change in the size of pancreatic parenchyma (14.4%, P = 0.026). Fourteen of these subjects were followed up for >12 months, during which 2 had relapse; diabetes improved in 5 and worsened in 2; in 60% of cases, the pancreatic parenchyma was atrophied. The % change in PEM after two weeks was tended to be higher in non-atrophy cases.ConclusionSWE and SWD measurement in US may be useful for quantitative assessment of AIP and evaluation of short-term treatment efficacy.     

Activation of ventrolateral preoptic neurons by the somnogen prostaglandin D2

Prostaglandin D₂ (PGD₂) is an extensively studied sleep-promoting substance, but the neuroanatomical basis of PGD₂-induced sleep is only partially understood. To determine potential regions involved in this response, we used Fos immunohistochemistry to identify neurons activated by infusion of PGD₂ into the subarachnoid space below the rostral basal forebrain. PGD₂ increased nonrapid eye movement sleep and induced striking expression of Fos in the ventrolateral preoptic area (VLPO), a cluster of neurons that may promote sleep by inhibiting the tuberomammillary nucleus, the source of the ascending histaminergic arousal system. Fos expression in the VLPO was positively correlated with the preceding amount of sleep and negatively correlated with Fos expression in the tuberomammillary nucleus. PGD₂ also increased Fos immunoreactivity in the basal leptomeninges and several regions implicated in autonomic regulation. These observations suggest that PGD₂ may induce sleep via leptomeningeal PGD₂ receptors with subsequent activation of the VLPO.     

Reconstruction of the external auditory canal using full-thickness rolled-up skin graft after lateral temporal bone resection for T1 and T2 external auditory canal cancer

ObjectiveTo present our results of the external auditory canal (EAC) reconstruction procedure using rolled-up full-thickness skin graft with tympanoplasty after lateral temporal bone resection (LTBR) for early-stage EAC carcinoma.Patients and MethodsA retrospective review of 15 patients who had undergone LTBR with reconstruction of the EAC for T1 and T2 EAC cancer between 2016 and 2020.ResultsPostoperative mean air-bone gap was 30.7 decibel hearing level. Although a few patients experienced chronic granulation, persistent otorrhea, and/or laterization of the tympanic membrane, most patients showed no serious complications related to the EAC reconstruction.ConclusionEAC reconstruction using a full-thickness skin graft in combination with tympanoplasty is useful for minimizing the hearing loss, maintaining the cosmetic appearance, and facilitating the observation into the ear cavity.     

Left non-recurrent inferior laryngeal nerve in a patient with right-sided aortic arch and aberrant left subclavian artery

Non-recurrent inferior laryngeal nerve (NRILN) is rare but one of the important anatomical variations in thyroid and parathyroid surgery. Almost all cases were observed on the right side with aberrant right subclavian artery and left NRILN have been reported in only five cases so far. Here, we reported a 38 year-old Japanese male with left NRILN accompanying adenomatous goiter. He was referred to our hospital for the surgical treatment of left thyroid goiter. Preoperative computed tomography revealed right-sided aortic arch and aberrant left subclavian artery with no signs of complete situs inversus viscerum, suggesting possible left NRLN. Left hemithyroidectomy was performed using nerve monitoring system. Intraoperatively, left recurrent laryngeal nerve was not identified along tracheoesophageal groove, but directly originated from vagal nerve and was running horizontally to larynx. Mobility of vocal cords were not impaired and postoperative course was uneventful. During thyroid surgery for the patients with right-sided aortic arch, meticulous care should be taken using nerve monitoring system to avoid nerve injury.