Intratympanic Botulinum Toxin Injection as a New Therapeutic Modality for Middle Ear Myoclonic Tinnitus.

OBJECTIVE: Middle ear myoclonic tinnitus (MEMT) is a disease caused by myoclonus or abnormal contractive movement of middle ear muscles (MEMs). This translational study was conducted to propose intratympanic botulinum toxin (IT-BTX) injection as a new therapeutic modality to treat MEMT. STUDY DESIGN: Animal experiment and nonrandomized controlled clinical trial. SETTING: Laboratory and medical center of an academic tertiary medical institution. METHODS: For the animal study, male Sprague-Dawley rats were divided into 4 subgroups according to the sacrificing day after IT-BTX injection. After initial hearing tests, randomly assigned experimental ears were intratympanically injected with 1 unit/100 µL of BTX-A, whereas control ears were injected with normal saline. Changes in the hearing thresholds, morphometry of the cochleae, electron microscopy study, and immunofluorescence analysis of MEMs were evaluated. For the human study, 10 intractable MEMT patients were enrolled. The hearing thresholds and the degree of tinnitus distress were observed for changes after IT-BTX injection. All patients were followed up for 3 months. RESULTS: As for the animal study, there were no significant changes in hearing thresholds and cochlear morphologies in all 4 subgroups of the rats. Significant MEM degenerations and immuno-detection of cleaved synaptosome-associated protein of 25 kDa (cSNAP-25) indicated the efficacy of IT-BTX. MEMT patients enrolled for the pilot clinical trial showed statistically significant improvement in tinnitus after IT-BTX injection. No major complications were noted. CONCLUSION: The new therapeutic modality of IT-BTX injection for the treatment of MEMT seems highly promising with an excellent result.

BLTR1 in Monocytes Emerges as a Therapeutic Target For Vascular Inflammation With a Subsequent Intimal Hyperplasia in a Murine Wire-Injured Femoral Artery.

Given the importance of high-mobility group box 1 (HMGB1) and 5-lipoxygenase (5-LO) signaling in vascular inflammation, we investigated the role of leukotriene signaling in monocytes on monocyte-to-macrophage differentiation (MMD) induced by HMGB1, and on vascular inflammation and subsequent intimal hyperplasia in a mouse model of wire-injured femoral artery. In cultured primary bone marrow-derived cells (BMDCs) stimulated with HMGB1, the number of cells with macrophage-like morphology was markedly increased in association with an increased expression of CD11b/Mac-1, which were attenuated in cells pre-treated with Zileuton, a 5-LO inhibitor as well as in 5-LO-deficient BMDCs. Of various leukotriene receptor inhibitors examined, which included leukotriene B4 receptors (BLTRs) and cysteinyl leukotriene receptors (cysLTRs), the BLTR1 inhibitor (U75302) exclusively suppressed MMD induction by HMGB1. The importance of BLTR1 in HMGB1-induced MMD was also observed in BMDCs isolated from BLTR1-deficient mice and BMDCs transfected with BLTR1 siRNA. Although leukotriene B4 (LTB4) had minimal direct effects on MMD in control and 5-LO-deficient BMDCs, MMD attenuation by HMGB1 in 5-LO-deficient BMDCs was significantly reversed by exogenous LTB4, but not in BLTR1-deficient BMDCs, suggesting that LTB4/BLTR1-mediated priming of monocytes is a prerequisite of HMGB1-induced MMD. In vivo, both macrophage infiltration and intimal hyperplasia in our wire-injured femoral artery were markedly attenuated in BLTR1-deficient mice as compared with wild-type controls, but these effects were reversed in BLTR1-deficient mice transplanted with monocytes from control mice. These results suggest that BLTR1 in monocytes is a pivotal player in MMD with subsequent macrophage infiltration into neointima, leading to vascular remodeling after vascular injury.

Clinical course and treatment outcomes of toxocariasis-related eosinophilic disorder.

Blood eosinophilia is a common clinical finding. Helminthic infections, including toxocariasis, are a common cause of eosinophilia; however, the clinical course of toxocariasis associated with eosinophilia is not fully understood. Thus, controversies exist regarding treatment indications.To evaluate the clinical features and natural course of various types of eosinophilia, with a particular focus on toxocariasis, we retrospectively reviewed the medical records of 1000 patients with peripheral blood eosinophilia who were referred to the allergy clinic at Asan Medical Center between 2007 and 2012. Clinical parameters and imaging study findings were evaluated. The treatment response to albendazole and resulting changes in eosinophilia and imaging studies were analyzed in patients diagnosed with toxocariasis.Among the 1000 subjects, toxocariasis was the most common cause of eosinophilia (n = 534; 53.4%), followed by allergic disease and adverse drug reactions. The majority of patients with toxocariasis were men, and they were mostly asymptomatic. More than one-third of patients (n = 215; 40.3%) with toxocariasis exhibited organ involvement, particularly hepatic involvement. In most cases of eosinophilia and organ involvement due to toxocariasis, the symptoms normalized regardless of treatment.Most cases of eosinophilia related to toxocariasis displayed a self-remitting course regardless of treatment. With the exception of several clinical situations, including ocular involvement, the clinical need for anti-helminthic therapy in toxocariasis is not that significant.

Grb2-associated binder-1 is required for extrafusal and intrafusal muscle fiber development.

The neuregulin-1 (NRG1) signaling pathway plays an important role in the development of the peripheral neuromuscular system, including in muscle spindle and postnatal myelination. We previously showed that NRG1 on the axonal membrane regulates peripheral nerve myelination through Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling. Here, we determined the role of Gab1 in the development of muscles and the muscle spindle using muscle-specific conditional Gab1 knockout mice. The mutant mice showed general retardation in muscular growth and hypotrophy of extrafusal muscle fibers. In addition, the muscle-specific Gab1 knockout mutant exhibited significant underdevelopment of muscle spindles, which are normally regulated by NRG1, and abnormal proprioceptive behavior. Furthermore, the selective knockdown of Gab1 in C2C12 muscle cells reduced NRG1-induced expression of Egr3, a critical transcription factor for muscle spindle development. However, Gab2 knockout mice did not show any defects in the development of muscles or muscle spindles. Our findings suggest that Gab1 is an essential signaling molecule in mediating axonal NRG1 signaling for the development of both extrafusal and intrafusal muscle fibers.

Characteristic MR image finding of squatting exercise-induced rhabdomyolysis of the thigh muscles.

OBJECTIVE: To describe the characteristic MRI appearance of squatting-induced rhabdomyolysis involving the thigh muscles. METHODS: This study consisted of 10 cases obtained at 3 institutions from 2005 to 2015. A retrospective review was performed to obtain clinical information and MR scans for rhabdomyolysis of the thigh muscles. MRI was analyzed according to the distribution and degree of muscle involvement; the degree was assessed and graded as normal, mild or prominent. RESULTS: The mean patient age was 20.2 years (range, 15-24 years), and 7 of the 10 patients were male. All patients had history of excessive squatting action, suffered clinically from bilateral thigh pain and were confirmed to have rhabdomyolysis through analysis of serum creatine kinase (CK) levels. All of the patients (10/10) exhibited diffuse mild to prominent degree involvement of the anterior thigh muscles according to fluid-sensitive MR sequences. Among the anterior thigh muscles, the rectus femoris was spared in 8 patients (8/10) and mild degree involved in 2 patients (2/10). Thus, no cases exhibited prominent degree involvement of the rectus femoris muscle. CONCLUSION: Preservation of the rectus femoris muscle on MRI in squatting-induced rhabdomyolysis may be useful for differentiating rhabdomyolysis from other aetiologies. Advances in knowledge: Preservation of rectus femoris on MRI is distinguishable finding in squatting-induced rhabdomyolysis and reflects the functional anatomy of anterior thigh muscles.

Clinical, Hormonal, and Genetic Evaluation of Idiopathic Nonobstructive Azoospermia and Klinefelter Syndrome Patients.

To investigate the clinical, hormonal, and genetic factors in infertile men with idiopathic nonobstructive azoospermia (NOA) or azoospermic Klinefelter syndrome (KFS), a total of 556 and 96 patients, respectively, were included in this study. All patient samples were analyzed cytogenetically. Serum reproductive hormone levels were measured. Microdeletions in the azoospermia factor (AZF) region of the Y chromosome were detected by multiplex PCR using 16 specific sequence-tagged sites. FSH and LH levels in both NOA and KFS patients were significantly higher than the normal range, and the testosterone level in KFS patients was significantly lower. Ninety-two (95.8%) of the KFS patients showed non-mosaic 47,XXY karyotypes and 47,XXY,inv(9)(p11.1q13); the other KFS patients had mosaic karyotypes of 47,XXY/46,XY, 47,XXY/46,XX, and 47,XXY/48,XXXY/46,XX. Among the 556 idiopathic NOA patients with normal karyotypes, 67 (12.05%) had microdeletions in the AZF region of the Y chromosome. Microdeletions were most frequently detected in the AZFc region, followed by AZFa, AZFb, AZFbc, and partial AZFc deletions. However, Y chromosome microdeletions were not found in any of the azoospermic KFS patients. In view of the hormonal and genetic abnormalities in infertile men with idiopathic NOA and with azoospermic KFS, genetic testing for karyotype, Y chromosome microdeletions, and hormonal parameters is advocated.

Predictive markers for abnormal glucose intolerance in women with polycystic ovary syndrome.

BACKGROUND: The purpose of this study is to identify predictive markers for abnormal glucose metabolism in Korean women with polycystic ovary syndrome (PCOS). METHODS: A total of 312 PCOS patients were evaluated. All patients underwent 75g oral glucose tolerance tests. The 2 hour plasma glucose level was used to categorize subjects as impaired glucose tolerance (IGT) or non-insulin-dependent diabetes mellitus (NIDDM). Areas under the receiver operating characteristic (ROC) curves were used to compare the power of serum markers. Multiple linear regression analysis was used to evaluate the contribution of each confounding factor to the 2 hour post-load glucose value. RESULTS: 285 PCOS women with normal glucose tolerance (91.3%) and 27 PCOS patients with abnormal glucose metabolism (8.7%) (IGT/NIDDM) were evaluated. Area under the curve (AUC) of hemoglobin(Hb) A1c, high sensitivity C-reactive protein (hs- CRP), lipid accumulation product(LAP) index, and triglyceride (TG) were 0.780, 0.772, 0.762, and 0.758 respectively. ROC analysis suggested a threshold value of 5.45 in HbA1c (71.4% sensitivity and 70.0% specificity), a value of 1.16 in high sensitivity CRP (70.3% sensitivity and 80.1% specificity), a value of 12.98 in LAP index (88.5% sensitivity and 52.3% specificity) and a value of 88.0 in TG (77.8% sensitivity and 63.5% specificity) to predict for abnormal glucose metabolism. CONCLUSION: HbA1c, hs-CRP, LAP index, and TG could be useful predictive markers for abnormal glucose metabolism (IGT/NIDDM) in Korean PCOS women.

SIRT1 attenuates PAF-induced MMP-2 production via down-regulation of PAF receptor expression in vascular smooth muscle cells.

Silent mating type information regulation 2 homolog 1 (SIRT1) is known as a key regulator in the protection of various vascular disorders, however, no direct evidences have been reported in the progression of atherosclerosis. Considering the pivotal role of matrix metalloproteinase-2 (MMP-2) in plaque destabilization, this study investigated the role of SIRT1 on MMP-2 production in vascular smooth muscle cells (VSMCs) induced by platelet activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine). In VSMCs stimulated with resveratrol, SIRT1 activator, PAF receptor (PAFR) was internalized and then its protein levels were diminished. It was attenuated in cells pretreated with proteasome or lysosome inhibitor. Also, the degradation of PAFR in SIRT1-stimulated cells was significantly attenuated by ß-arrestin2 depletion. In cells treated with nicotinamide, SIRT1 deacetylase inhibitor, PAFR internalization by resveratrol or reSIRT1 was inhibited, demonstrating that deacetylation of SIRT1 is an important step in SIRT1-induced PAFR down-regulation. Moreover, PAF-induced MMP-2 production in VSMCs and aorta was attenuated by resveratrol. In the aorta of SIRT1 transgenic mice, the PAF-induced MMP-2 expression was prominently attenuated compared to that in wild type mice. Taken together, it was suggested that SIRT1 down-regulated PAFR in VSMCs via ß-arrestin2-mediated internalization and degradation, leading to an inhibition of PAF-induced MMP-2 production.

Differential diagnosis between tuberculous spondylodiscitis and pyogenic spontaneous spondylodiscitis: a multicenter descriptive and comparative study.

BACKGROUND CONTEXT: Although tuberculous and pyogenic spondylodiscitis are common causes of spinal infections, their protean manifestation complicates differential diagnosis. PURPOSE: The clinical, laboratory, and radiologic characteristics of tuberculous and pyogenic spontaneous spondylodiscitis were compared in this study. STUDY DESIGN: This multicenter retrospective study was conducted in 11 teaching hospitals in the Republic of Korea from January 2011 to December 2013. PATIENT SAMPLE: Study subjects included adult patients (≥18 years) diagnosed with tuberculous (n=60) or pyogenic (n=117) spontaneous spondylodiscitis. OUTCOME MEASURES: Risk factors for tuberculous spondylodiscitis were determined, and their predictive performance was evaluated. METHODS: Multivariate logistic regression analysis was performed to determine predictors independently associated with tuberculous spondylodiscitis. Receiver-operating characteristic curve analysis using the presence or absence of risk factors was used to generate a risk index to identify patients with increased probability of tuberculous spondylodiscitis. RESULTS: Of 177 patients, multivariate logistic regression analysis showed that patients with tuberculous spondylodiscitis (n=60) were more frequently women, with increased nonlumbar spinal involvement and associated non-spinal lesions, delayed diagnosis, higher serum albumin levels, reduced white blood cell counts, and lower C-reactive protein and procalcitonin levels. Among 117 patients with pyogenic spondylodiscitis, the most frequent causative microorganism was Staphylococcus aureus (64.1%). The mean diagnostic delay was significantly shorter, which may reflect higher clinical expression leading to earlier diagnosis. A combination of clinical data and biomarkers had better predictive value for differential diagnosis compared with biomarkers alone, with an area under the curve of 0.93, and sensitivity, specificity, and positive and negative predictive values of 95.0%, 79.5%, 70.4%, and 96.9%, respectively. CONCLUSIONS: This study provides guidance for clinicians to predict the causative organisms of spondylodiscitis in uncertain situations and before culture or pathologic examinations. Clinical data and single biomarkers combined can be useful for differential diagnoses between tuberculous and pyogenic spondylodiscitis.

Hepatic STAMP2 alleviates high fat diet-induced hepatic steatosis and insulin resistance.

BACKGROUND & AIMS: Most studies on the role of STAMP2 in metabolism have used adipose tissue. Little knowledge exists concerning the role of STAMP2 in the liver, which is a metabolically central target. We hypothesized that STAMP2 is involved in non-alcoholic fatty liver disease (NAFLD) pathogenesis. METHODS: We examined our hypothesis using human NAFLD patient pathology samples and a high-fat diet (HFD)-induced NAFLD mouse model. The molecular mechanism underlying hepatic STAMP2-mediated lipid imbalance was explored using an oleic acid (OA)-induced NAFLD in vitro model. RESULTS: Noticeably, the expression level of STAMP2 protein was reduced in the livers obtained from NAFLD patients and HFD-induced NAFLD mice. In vivo knockdown of hepatic STAMP2 by siRNA accelerated hepatic steatosis and insulin resistance in mice fed a HFD. Conversely, the delivery of adenoviral STAMP2 (Ad-STAMP2) improved hepatic steatosis in HFD-induced NAFLD mice. The expression of lipogenic or adipogenic factors was increased in both in vitro and in vivo NAFLD models but was reversed by Ad-STAMP2. Adenoviral overexpression of STAMP2 improved insulin resistance in the HFD-induced NAFLD mice. In vivo and in vitro assays demonstrated that STAMP2 modulates insulin sensitivity and glucose metabolism and that STAMP2 counteracts OA-induced insulin resistance by modulating insulin receptor substrate-1 stability. CONCLUSIONS: The present study revealed that hepatic STAMP2 plays a pivotal role in preventing HFD-induced NAFLD and that STAMP2 overexpression improves hepatic steatosis and insulin resistance in NAFLD. Our findings indicate that STAMP2 may represent a suitable target for interventions targeting NAFLD.

PAF enhances MMP-2 production in rat aortic VSMCs via a ß-arrestin2-dependent ERK signaling pathway.

Platelet-activating factor (PAF), 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, is a potent phospholipid mediator and has been reported to be localized in atherosclerotic plaque. However, its role in the progression of atherosclerosis remains unclear. In the present study, we investigated the role of PAF in the production of matrix metalloproteinase (MMP) in primary vascular smooth muscle cells (VSMCs). When rat aortic primary VSMCs were stimulated with PAF (1 nmol/l), the expressions of MMP-2 mRNA and protein, but not of MMP-9, were significantly increased, and these upregulations were markedly attenuated by inhibiting extracellular signal-regulated kinases (ERKs) using molecular and pharmacological inhibitors, but not by using inhibitors of p38 mitogen-activated protein kinase or c-Jun N-terminal kinase. Likewise, ERK phosphorylation was markedly enhanced in PAF-stimulated VSMCs, and this was attenuated by WEB2086, but not by EGF receptor inhibitor, demonstrating the specificity of PAF receptor (PAFR) in PAF-induced ERK phosphorylation. In immunofluorescence studies, ß-arrestin2 in PAF-stimulated VSMCs colocalized with PAFR and phosphorylated ERK (P-ERK). Coimmunoprecipitation results suggest that ß-arrestin2-bound PAFRs existed as a complex with P-ERK. In addition, PAF-induced ERK phosphorylation and MMP-2 production were significantly attenuated by ß-arrestin2 depletion. Taken together, the study shows that PAF enhances MMP-2 production in VSMCs via a ß-arrestin2-dependent ERK signaling pathway.

Histomorphological factors in the risk prediction of lymph node metastasis in papillary thyroid carcinoma.

AIMS: Few clinicopathological parameters have been identified as independent predictive factors for lymph node metastasis. This study evaluated the predictive ability of three histological characteristics of PTC in lymph node metastases: hobnail features, loss of cohesiveness/polarity (LOCP) and micropapillary structures. METHODS AND RESULTS: Tissue specimens from 153 patients with histologically confirmed PTC including 112 cases of papillary thyroid microcarcinoma (PTMC) were enrolled in this study. Three histological characteristics (hobnail features, LOCP and micropapillary structures) and several clinicopathological parameters were evaluated for their value in predicting lymph node metastasis. Hobnail features, LOCP and micropapillary structures were each significantly associated with and found to be independent predictive factors for lymph node metastasis (P < 0.05). These three histological characteristics were closely correlated with one another (P < 0.001). Six of the seven possible combinations of these three histological characteristics were independently correlated with lymph node metastasis (P < 0.05). Among these combinations, the coincidence of all three histological parameters represented the strongest independent predictive factor for lymph node metastasis (OR: 3.270, P = 0.006). CONCLUSIONS: Our study demonstrates that hobnail features, LOCP and micropapillary structures, either alone or in combinations, represent strong independent predictive factors for lymph node metastasis in PTC.