Alternative Polyadenylation in Human Diseases

Varying length of messenger RNA (mRNA) 3′-untranslated region is generated by alternating the usage of polyadenylation sites during pre-mRNA processing. It is prevalent through all eukaryotes and has emerged as a key mechanism for controlling gene expression. Alternative polyadenylation (APA) plays an important role for cell growth, proliferation, and differentiation. In this review, we discuss the functions of APA related with various physiological conditions including cellular metabolism, mRNA processing, and protein diversity in a variety of disease models. We also discuss the molecular mechanisms underlying APA regulation, such as variations in the concentration of mRNA processing factors and RNA-binding proteins, as well as global transcriptome changes under cellular signaling pathway.

Osteoma of the External Auditory Canal / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Osteoma of the external auditory canal is an uncommon benign lesion and represents as a unilateral pedunculated mass in the outer half of the bony canal. The aim of this study is to evaluate the clinical, histopathological characteristics of osteoma and its treatment outcomes. MATERIAL AND METHODS: We have operated 9 patients who visited Chungnam National Universitv Hospital in the past 10 years with the complaints of osteoma arising from the external auditory canal. The medical records were retrospectively reviewed with regard to clinical characteristics, surgical findings, histopathological features and treatment outcomes. RESULTS: One patient showed regrowth of the tumor after surgery and CT scans demonstrated a hidden lobe embedded in soft tissue of the bony-cartilaginous junction. Five patients have had no connection with regard to tympanosquamous or tympanomastoid suture line, which had been known as the predilection site. CONCLUSION: Osteoma of the external auditory canal is a distinct benign tumor which can be removed easily. A precise preoperative evaluation of the extent of the tumor and a complete surgical removal under adequate exposure is the best way to ensure no recurrence or complication.

Leiomyosarcoma of the Nose and Paranasal Sinuses / 대한이비인후과학회지

Leiomyosarcoma is an uncommon tumor of smooth-muscle origin, and has rarely been described in reference to the head and neck region. There have been 30 previously reported cases of this tumor involving the sinonasal tract in the literature. We present a case of leiomyosarcoma involving the nasal cavity, ethmoid, and sphenoid sinus. We also review here the characteristics, diagnosis and treatment of this tumor.

Effect of Panax Ginseng Saponin on Salicylate Ototoxicity in Guinea Pigs / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Large doses or long-term use of salicylate may cause reversible tinnitus and hearing loss. The exact cause of salicylate ototoxicity in unknown. Decreased cochlear blood flow following reversible biochemical changes in the cochlea seems to play an important role in salicylate ototoxicity. Protopanaxatriol and protopanaxadiol saponin of the Panax ginseng are known to have a vasodilatory effect. We investigated the effect of Panax ginseng saponin on salicylate induced hearing loss in guinea pigs. MATERIALS AND METHODS: Guinea pigs were divided into two groups. The control group was injected with salicylate (300 mg/kg, IM) and the experimental group was pretreated with Panax ginseng saponin (100 mg/kg, IP) before salicylate injection. ABR threshold was measured hourly after salicylate injection. RESULTS: The control group showed a maximal hearing loss (20+/-3.54 dBnHL) in 3 hours after the salicylate injection. Comparing with the control group, the experimental group revealed a significantly different maximal hearing loss (5+/-3.54 dBnHL). CONCLUSION: These results suggest that the protopanaxatriol and protopanaxadiol saponin of the Panax ginseng can attenuate salicylate induced hearing loss.

Recurrent Myxoma of Maxilla / 대한이비인후과학회지

Myxoma is a relatively rare tumor of mesenchymal origin that can be found in numerous sites throughout the body including heart, skin, and subcutaneous tissue along with various sites in the head and neck. It is presumed to be originated from dental malformation or missing teeth, but occasionally myxoma without dental abnormalities is found giving arguments for its embryogenesis. Myxoma in the head and neck is usually managed by radical operation in order to prevent the possible recurrence. A case of recurrent myxoma of maxilla is described, which was treated with en-bloc removal via lateral rhinotomy incision. The purpose of this article is to present a case of myxoma of maxilla with a review of the literature and is to give a special emphasis on the proper modalities of treatment which minimizes recurrence and functional deficit.