Adjuvant Radiotherapy for Dissected Parotid Lymph Nodes Containing Merkel Cell Carcinoma from an Unknown Primary Skin Site: 2 Case Reports.

BACKGROUND Merkel cell carcinoma (MCC) is an aggressive neuroendocrine malignancy that has increased in incidence in recent decades. The management of MCC should involve multidisciplinary experts to achieve optimal patient outcomes. Radiotherapy is commonly used as adjuvant therapy. Our literature review of MCC indicates that aggressive adjuvant radiotherapy might have a positive impact on overall local control and survival. CASE REPORT The first case is a 75-year-old male patient who discovered a right preauricular mass 2 weeks prior. He underwent right parotidectomy with tumor removal on 2012/07/09, and pathology revealed MCC in 3 lymph nodes. The patient received postoperative adjuvant radiotherapy (61.2 Gy) to the remaining right parotid tumor bed and right neck lymph nodes. The patient refused adjuvant chemotherapy. During long-term follow-up, the patient remained disease free for 10 years. The other case is a 73-year-old female patient with metastatic MCC in a left parotid lymph node. She also underwent left parotidectomy with tumor removal, and pathological staging performed according to the 8th edition of the AJCC staging system showed pTxN1aMx, stage IIIA. After the operation, she received postoperative adjuvant radiotherapy (56 Gy) to the remaining left parotid and left neck lymph nodes. The patient remained disease free for 14 months. CONCLUSIONS Metastatic MCC of the parotid lymph nodes without a detectable primary skin tumor is very rare. Adjuvant radiotherapy to the tumor bed and regional nodal basin might be beneficial for preventing disease recurrence despite the absence of systemic medical therapy.

Autoantibody of NRIP, a novel AChR-interacting protein, plays a detrimental role in myasthenia gravis.

BACKGROUND: Nuclear receptor interaction protein (NRIP) co-localizes with acetylcholine receptor (AChR) at the neuromuscular junction (NMJ), and NRIP deficiency causes aberrant NMJ architecture. However, the normal physiological and pathophysiological roles of NRIP in NMJ are still unclear. METHODS: We investigated the co-localization and interaction of NRIP with AChR-associated proteins using immunofluorescence and immunoprecipitation assay, respectively. The binding affinity of AChR-associated proteins was analysed in muscle-restricted NRIP knockout mice and NRIP knockout muscle cells (C2C12). We further collected the sera from 43 patients with myasthenia gravis (MG), an NMJ disorder. The existence and features of anti-NRIP autoantibody in sera were studied using Western blot and epitope mapping. RESULTS: NRIP co-localized with AChR, rapsyn and α-actinin 2 (ACTN2) in gastrocnemius muscles of mice; and α-bungarotoxin (BTX) pull-down assay revealed NRIP with rapsyn and ACTN2 in complexes from muscle tissues and cells. NRIP directly binds with α subunit of AChR (AChRα) in vitro and in vivo to affect the binding affinity of AChR with rapsyn and rapsyn with ACTN2. In 43 patients with MG (age, 58.4 ± 14.5 years; female, 55.8%), we detected six of them (14.0%) having anti-NRIP autoantibody. The presence of anti-NRIP autoantibody correlated with a more severe type of MG when AChR autoantibody existed (P = 0.011). The higher the titre of anti-NRIP autoantibody, the more severe MG severity (P = 0.032). The main immunogenic region is likely on the IQ motif of NRIP. We also showed the IgG subclass of anti-NRIP autoantibody mainly to be IgG1. CONCLUSIONS: NRIP is a novel AChRα binding protein and involves structural NMJ formation, which acts as a scaffold to stabilize AChR-rapsyn-ACTN2 complexes. Anti-NRIP autoantibody is a novel autoantibody in MG and plays a detrimental role in MG with the coexistence of anti-AChR autoantibody.

Collaborative localization in wireless sensor networks via pattern recognition in radio irregularity using omnidirectional antennas.

In recent years, various received signal strength (RSS)-based localization estimation approaches for wireless sensor networks (WSNs) have been proposed. RSS-based localization is regarded as a low-cost solution for many location-aware applications in WSNs. In previous studies, the radiation patterns of all sensor nodes are assumed to be spherical, which is an oversimplification of the radio propagation model in practical applications. In this study, we present an RSS-based cooperative localization method that estimates unknown coordinates of sensor nodes in a network. Arrangement of two external low-cost omnidirectional dipole antennas is developed by using the distance-power gradient model. A modified robust regression is also proposed to determine the relative azimuth and distance between a sensor node and a fixed reference node. In addition, a cooperative localization scheme that incorporates estimations from multiple fixed reference nodes is presented to improve the accuracy of the localization. The proposed method is tested via computer-based analysis and field test. Experimental results demonstrate that the proposed low-cost method is a useful solution for localizing sensor nodes in unknown or changing environments.