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Neuroendocrine lesions of the thyroid are rare. The most common types are medullary thyroid carcinomas (MTCs) and C-cell hyperplasia. MTCs originate from thyroid parafollicular cells that secrete calcitonin which serves as a serum marker of MTCs. Here, the rare case of a calcitonin-negative neuroendocrine tumor (NET) derived from follicular lesions of the thyroid is described. A 34-year-old man presented at our hospital for the surgical management of an incidental thyroid nodule that was observed on an ultrasound sonography (USG) of the neck. Initially, USG-guided aspiration cytology was performed, and a MTC was suspected. The expressions of thyroglobulin and thyroid transcription factor-1, which are thyroid follicular cell markers, and synaptophysin and chromogranin A, which are neuroendocrine markers, was confirmed following surgical pathology. However, the staining of calcitonin, a marker of MTCs, was not observed. A nonmedullary NET of the thyroid is uncommon, and the distinction between calcitonin-negative NETs and MTCs of the thyroid may be important due to differences in their clinical courses and management.

Sialolipoma, a rare tumor of the salivary gland, is a recently described variant of salivary gland lipoma. Oncocytic sialolipoma was first described by Pusiol et al. in 2009. We report the case of an oncocytic sialolipoma of the submandibular gland in a 43-year-old female. Excision of the tumor was performed with preservation of the submandibular gland. The tumor had a thin, fibrous capsule and consisted of abundant adipose tissue, an oncocytic nodule, and scattered normal glandular structures surrounded by adipose tissue. Four cases of sialolipoma of the submandibular gland, including the present case, were reviewed. All 4 tumors were developed on the right submandibular glands, with a composition of adipose tissue as high as that of sialolipoma of the parotid gland; in contrast to previous reports, three cases were in females. As newly described tumor type, care should be taken to distinguish oncocytic sialolipoma from other salivary gland neoplasms such as simple lipoma, pleomorphic adenoma, or oncocytoma.

Time-resolved ground-state bleach and excited-state stimulated emission spectra have been measured for indocyanine green dissolved in methanol by employing spectrally resolved four wave mixing (SRFWM). The separation of the SRFWM signals into the ground-state bleach and excited-state stimulated emission contributions allows observation of intramolecular vibrational wave packet motions and intermolecular solvation dynamics upon impulsive excitation, while the molecule resides either in the ground or in the excited state. Frequencies of the indocyanine green intramolecular vibrational modes in the ground and excited states are practically the same. Vibrational dephasing times in the excited state range from a few hundred fs to ∼2 ps, and they are consistently shorter than those in the ground state. When excitation frequency is centered near the 0-0 transition, center frequencies of the stimulated emission redshift due to solvation of the excited state in nonequilibrium solvent configuration, whereas those of the ground-state bleach blueshift due to equilibrium fluctuation of the solvent molecules around the chromophore in the ground state. At early times, the solvation function obtained from the time-resolved ground-state bleach spectra is slower than the solvation function obtained from the time-resolved excited-state stimulated emission spectra.

Time-resolved ground-state bleach and excited-state stimulated emission spectra are measured for a cyanine dye, 3,3‘-diethylthiatricarbocyanine iodide, dissolved in methanol by spectrally resolving...

We report a third-order nonlinear time-domain method, coherence period (τ) resolved transient grating (TRTG), that gives accurate solvation dynamics free from population relaxation in a short data acquisition time. The validity of TRTG is established by theory and experiment. The TRTG signal is shown to follow the transition frequency correlation function by an analytic expression based on the response function theory for delta function pulses and by model numerical calculations including finite pulse durations. TRTG is demonstrated for two cyanine dyes IR144 and IR125 in methanol by using a diffractive-optics based four wave mixing apparatus. Solvation dynamics in methanol obtained from the TRTG are consistent with those reported previously confirming the validity of TRTG.

We present a converged spectroscopic system design for performing photoreflectance (PR), electroreflectance (ER), electroluminescence (EL), photoluminescence (PL) and photovoltage (PV) measurements of semiconductors. The design of the experimental setup is described in detail. To test the performance of the system, measurements of a series of In x Ga 1-x N/GaN light emitting semiconductor with different indium composition of InGaN layer are carried out by use of this system. The experimental reflection and luminescence spectra are analyzed and discussed. The experimental results demonstrate the performance of this system. Optical and electrical properties of In 0.15 Ga 0.85 N/GaN multi-quantum well (MQW) light-emitting diodes (LEDs) with different quantum well (QW) thicknesses were investigated by electric-field dependent ER spectroscopy. From the ER measurements, we have observed the well-resolved transition peaks related to InGaN QW. Furthermore, the transitions related to yellow luminescence (YL) from Si-doped GaN and blue luminescence (BL) from Mg-doped GaN were observed in the ER spectra of In 0.15 Ga 0.85 N/GaN MQW LEDs. With increasing QW thickness, the additional transitions related to InGaN QW can be attributed to the recombination of excitons localized at the shallow potential states in InGaN QW, originating from the In-poor InGaN regions caused by indium phase separation in InGaN QW. By applying a reverse bias voltage, the ER features related to InGaN QW were shifted to higher energy, resulting from the reduction of quantum confined Stark effect in InGaN QW with increasing reverse bias voltage. On the other hand, the ER features from YL and BL band related to the deep and the shallow impurity state exhibit redshift and broaden with reverse bias voltage. These results can be attributed to the reduction of Coulomb interaction between donor and acceptor caused by the increase of depletion regions with increasing reverse bias voltage.

OBJECTIVES: To assess the effectiveness of intraoral removal of submandibular calculi based on several factors that may influence the results of surgery. STUDY DESIGN AND SETTING: We retrospectively reviewed 172 patients who underwent intraoral removal of submandibular sialolithiasis. Results of surgery were divided into complete removal, partial removal, and failure. The effect of location, palpability, size, and presence of infection of the calculi on the results was estimated. RESULTS: Univariate analysis showed that palpability and presence of infection were statistically significant factors affecting intraoral removal. Palpability was the only significant factor after multivariate analysis. Twelve of 13 patients with recurrent calculi underwent repeat intraoral removal successfully. CONCLUSIONS: The palpability of submandibular calculi is the most important factor influencing their successful intraoral removal. SIGNIFICANCE: Intraoral removal can be performed successfully regardless of location, size, presence of infection, or recurrence of calculi, if the calculi are palpable.

Excitonic carrier dynamics taking place in In x Ga 1-x N/Gal4 multi-quantum-well systems have been studied by low temperature picosecond time resolved photoluminescence (LT-TRPL), HR-TEM, XPS, Dynamic TOF-SIMS, and quantum mechanical simulation methods. Both time-integrated and time-resolved photoluminescence spectra of In x Ga 1- x N/GaN multi-quantum-wells with different well thickness and Indium composition were measured at 10 K. We assigned the natural radiative lifetime of each sample from the time resolved PL. We observed that the natural radiative lifetime of In In x Ga 1-x N/GaN multi-quantum-wells depends strongly on the well thickness and Indium composition. To support the measured natural radiative lifetimes, excitonic oscillator strengths of the In x Ga 1-x N/GaN multi-quantum-wells were calculated by using a 2-D particle-in-a-box model as functions of well thickness and Indium composition. Values of the well thickness and Indium compositions from the HR-TEM and XPS compositional depth profiling were used to achieve more realistic computational results and to corroborate the measured natural radiative lifetimes of In x Ga 1-x N/GaN multi-quantum wells.

By use of precise controlled time delay between two pump pulses, four wave mixing experiments reveal some unknown features of ultrafast dynamics in solution. We investigate origin of coherent spike and nuclear wave packet dynamics and solvation dynamics which are very different between similar dye molecule used in this experiment.

Transient grating of a dye in liquid has been measured as a function of the electronic coherence period. A diffractive beam splitter and a pair of wedge prisms are implemented to achieve precise spatial phase overlap and interferometrically accurate control of the time delay between the pump pulses. As the electronic coherence period is varied, coherent interactions lead to an enhancement or loss of the sharp feature in the transient grating signal near time zero, which is usually called coherent spike. Sensitivity of the transient grating signal to the solvation process also changes by the coherence time delay. All the features can be accounted for by invoking third-order nonlinear response functions. Numerical simulations have been performed to corroborate our description. This work identifies a major source of the coherent spike in the transient grating and transient absorption experiments. In addition, it allows us to propose a method that measures the solvation function more efficiently than conventional transient grating technique does.

Ground state spectral hole and excited state particle dynamics are observed for a molecule in liquid by spectrally resolved four wave mixing. Detailed information on the intramolecular vibrations and solvation processes in each electronic state is obtained.

Ground state spectral hole and excited state particle dynamics are measured for molecules in liquid by frequency-time resolved four wave mixing. Nuclear wave packet motions in each electronic state are observed separately.

Received October 24, 2010 Revised December 9, 2010 Accepted December 14, 2010 Address for correspondence June Sik Park, MD Department of OtolaryngologyHead and Neck Surgery, Kyungpook National University School of Medicine, 50 Samdeok-dong 2-ga, Jung-gu, Daegu 700-721, Korea Tel +82-53-420-5783 Fax +82-53-423-4524 E-mail junesik@knu.ac.kr Background and ObjectivesZZTherapeutic comprehensive neck dissection has been recommended for the patients with recurrent papillary thyroid carcinoma (PTC) confined to the neck after initial total thyroidectomy. However, the benefit of comprehensive neck dissection to remove asymptomatic metastatic lymph node towards improving clinical recurrences or survival is largely unproven. We analyzed the pattern of recurrence in the lateral compartment of neck and evaluated the possible application of limited lymph node dissection against comprehensive neck dissection. Subjects and MethodZZA retrospective review was carried out for 43 patients who underwent surgical treatment for recurrent PTC in the lateral neck from 2000 to 2005, and their clinicopathological results were stratified according to the extent of surgery into two groups, the limited surgery group and the comprehensive surgery group. ResultsZZRecurrence rate in lateral neck after initial total thyroidectomy was 14.5% (43/ 296), and the most common level of recurrence was level IV (50.9%). Although limited surgery group showed a tendency toward more frequent recurrence after treatment of the first recurrence than did the comprehensive surgery group, this tendency had no statistical significance. Moreover, no patients in either group have died of PTC during over a mean follow-up period of 80 months. In the aspect of factors associated with surgical morbidity, such as operating time, duration of admission, and complication, the limited surgery group had superior results when compared to the comprehensive group. ConclusionZZThe benefit of comprehensive neck dissection concerning recurrence and survival was not verified in the present study hence a more preservative approach could be applied to selective patients with recurrent PTC in the lateral compartment of neck. Korean J Otorhinolaryngol-Head Neck Surg 2011;54:62-8

Received April 19, 2011 Revised July 5, 2011 Accepted July 7, 2011 Address for correspondence Jin Ho Sohn, MD Department of OtolaryngologyHead and Neck Surgery, Kyungpook National University School of Medicine, 130 Dongdeok-ro, Jung-gu, Daegu 700-721, Korea Tel +82-53-200-3514 Fax +82-53-423-4524 E-mail sohnjh@knu.ac.kr Background and ObjectivesZZLeukoplakia is a clinical term solely designating a white patch or a plaque of the mucosa without considering its histological feature. Leukoplakia ranges microscopically from a hyperplasia to an invasive squamous cell carcinoma. This study attempted to find out the clinical progress and characteristics of leukoplakia in the larynx. Subjects and MethodZZIncluded in the study were 154 patients clinically diagnosed as leukoplakia from 1997 to 2010. We reviewed their medical records retrospectively for age, sex, smoking and drinking history, medical record, histopathologic finding, treatment method, and the follow-up records. ResultsZZHistopathologic findings of leukoplakia in the larynx showed hyperkeratosis (101 patients), invasive carcinoma (19 patients), dysplasia (14 patients), nodule (9 patients), papillomatosis (4 patients), chronic inflammation (4 patients) and tuberculosis (3 patients). Of the 128 patients, 39 patients who were diagnosed as hyperkeratosis, dysplasia, nodule or chronic inflammation in the larynx had recurrence and received re-biopsy over 2 times. Eight patients of these 39 who had recurrence had progression to invasive carcinoma. The mean interval between diagnosis of leukoplakia and invasive carcinoma was 53 months (ranged 7-114 month). Heavy smoking (more than 20 pack year) and drinking were significantly associated with recurrence or progression to invasive carcinoma. Age, gastroesophageal reflux disease and treatment method were not associated with recurrence. ConclusionZZLeukoplakia in the larynx led to various histopathologic diagnoses, high recurrence rate, and progressed to invasive carcinoma even after 5 years. Smoking and drinking should be managed and longterm follow-up is needed. Korean J Otorhinolaryngol-Head Neck Surg 2011;54:543-9

최근 20여 년 사이 경부 초음파 및 전산화단층촬영, 갑상선 스캔 등 갑상선 관련 진단 기술의 비약적인 발전에 따라 전세 계적으로 갑상선 질환의 빈도 또한 기하급수적으로 늘어나고 있으며, 이와 더불어 무증상의 선천성 갑상선 기형 및 이형성 증에 대한 보고도 증가하는 추세이다. 이 중 갑상선 양엽의 비대칭은 갑상선 수술을 하거나 갑상선 스캔 및 경부 전산화 단층촬영을 판독하는 많은 임상의들이 경험하게 되는 소견 으로서, 주로 우측엽이 좌측엽에 비해 크고 또한 높이 위치하 는 것으로 알려져 있다. 갑상선 반쪽 무형성증은 이러한 갑상 선 비대칭의 극단적인 경우로 갑상선 일측엽의 발생 실패에 기 인하는 선천성 이상으로 생각되나, 그 자세한 기전은 아직 분 명히 밝혀져 있지 않다. 갑상선 반쪽 무형성증은 1866년 Handfield-Jones가 처음 이에 대한 증례를 기술한 이후 현재까지 전 세계적으로 300예 미만이 보고된 드문 선천성 기형이나, 최근 갑상선 질환에 대한 관심이 많아지고, 진단적 기술 또한 발달 함에 따라 그 유병률 역시 점차 증가하고 있다. 국내에서는 본 저자들이 한국의학논문 데이터베이스, 대한 의학학술지편집인협의회, 그리고 각 학회지 검색을 통한 결과 2011년 1월 현재 총 16예의 국내 갑상선 반쪽 무형성증 증례 를 확인할 수 있었으며, 이 중 남아 있는 반대쪽 갑상선에 유 두암이 동반된 경우는 4예에서만 찾을 수 있었다. 또한 국 외 학술지 검색에서도 갑상선 반쪽 무형성증과 동반한 유두 암의 국외 증례는 단지 10예 미만에서만 찾을 수 있었다. 본 저자들은 이처럼 흔하지 않은 갑상선 유두암을 동반한 갑상선 반쪽 무형성증을 경험하였기에 이를 문헌 고찰과 함 께 보고하는 바이다. Case Report Korean J Otorhinolaryngol-Head Neck Surg 2011;54:557-9 / pISSN 2092-5859 / eISSN 2092-6529 http://dx.doi.org/10.3342/kjorl-hns.2011.54.8.557

Absence of major salivary glands, especially those of occurring unilaterally or secondary to Wharton’s duct stone, is a rare disorder, A case of unilateral submandibular gland absence occurring secondary to Wharton’s duct stone was presented in a 51-year-old male. Using the ultrasonography (USG) and computerized tomography (CT), the absence of the submandibular gland was confirmed. The patient had long-term history of sialolithiasis of the right subman dibular gland, so the right submandibular gland was suspected of having acquired a change due to sialolithiasis. The present case would be a second report demonstrating a case of unilateral submandibular gland absence occurring secondary to stones, suggesting that, without ligation of submandibular nerves, the obstruction of excretory duct of a submandibular gland could lead to a complete atrophy of the gland in human. � Korean J Otorhinolaryngol-Head Neck Surg 2011;54:154-7

Mouse and human melanoma cells metastatic to the brain express degradative enzyme activities that are used for invasion of brain basement membrane and parenchyma. Compared to poorly metastatic or lung- or ovary-metastatic murine melanoma lines, the brain-metastatic sublines secreted higher levels of a variety of degradative enzymes. Brain-metastatic murine and human melanoma cells also degraded subendothelial basement membrane and reconstituted basement membrane at rates higher than other metastatic melanoma cells. In some cases these degradative activities in mouse and human melanoma cells can be induced by paracrine factors known to be present in the brain parenchyma, such as nerve growth factor (NGF). NGF stimulates the expression of degradative enzymes, such as the endo-beta-glucuronidase heparanase, that are important in basement membrane penetration but this factor does not stimulate melanoma cell growth. The growth of brain-metastasizing melanoma cells appears to be stimulated by other paracrine growth factors, such as paracrine transferrin. Melanoma cells metastatic to brain express higher numbers of transferrin receptors and respond and proliferate at lower concentrations of transferrin than do melanoma cells metastatic to other sites or poorly metastatic melanoma cells. The results suggest that degradation and invasion of brain basement membrane and responses to paracrine neurotrophins and paracrine transferrins are important properties in brain metastasis of murine and human malignant melanoma cells.

The piezoelectric fields of localized states in trapezoidal InGaN quantum wells (QWs) were investigated using electric field dependent electroreflectance (ER) spectroscopy. From the energy shift in ER peak in a bias range from 0 to −24 V, the piezoelectric field of the dominant QWs was estimated to be −1.22 MV/cm. In contrast, the localized states exhibited a piezoelectric field that was about 30%–60% weaker than for the dominant QW states. The reduced piezoelectric field in the localized states can be attributed to the partial release of compressive strain in the local InGaN regions, along with a relative reduction in the effective reverse-bias. The relative decrease in the reverse-bias can be explained by the voltage drop in the localized states that is caused by an increase in the leakage current under a reverse-bias.

Background and Objectives : Laser cordectomy has been widely acknowledged to have advantages for the treatment of early glottic carcinoma. This study was performed to assess the results of laser cordectomy for its oncologic safeness, time-effectiveness, and to report a few interesting precancerous cases that have progressed to glottic cancer. Subjects and Method : Subjects (47) who had undergone laser cordectomy for the treatment of early glottic cancer from April 2006 to July 2009 were enrolled in this study. We analyzed the oncologic outcomes, the duration of hospital treatment after the surgery, and postoperative complications by reviewing of medical records. Results : For 47 cases, the mean age was 66 years and the mean follow up period was 22.6 months. The mean duration of treatment was 1.9 days. Among them, 24 cases were classified into T1a, 12 T1b, and 2 T2. Local recurrence was observed in 2 cases, so salvage treatments, such as radiation therapy or near total laryngectomy, were performed, and both of them were alive in the disease-free state. The most common complication was anterior commissure web, which was observed in 6 cases (15.8%), followed by granuloma observed in 5 cases (13.1%). Serious complications such as aspiration, respiratory distress, and dysphagia were not found in any of 47 cases. Also, we could observe 3 cases in which the precancerous glottic lesion had progressed to glottic carcinoma over a long period of time. Conclusion : Laser cordectomy might be the treatment of choice for patient's convenience because of its excellent oncologic outcomes, low morbidity, and time-effectiveness.

Uniformity of luminescence properties in blue InGaN light-emitting diodes has been studied and analyzed by local time-resolved photoluminescence and microelectroluminescence measurements at different biasing. For studied structures, some nonuniform distribution of photoluminescence properties has been observed at reverse biasing conditions. This nonuniformity revealed inhomogeneous distribution of electric field over the active region. It is supposed that nonuniform distribution of acceptors concentration in p-GaN is a source of electric field fluctuations. Microelectroluminescence measurements showed that areas with locally lower acceptor concentration in p-GaN layer emit lower electroluminescence intensity. This was caused by limited hole injection efficiency into multiple quantum wells region at high current.

Recent studies have suggested a probable association between Epstein-Barr virus (EBV) and nasal/nasopharyngeal T cell lymphomas but the role of oncogenes or tumor suppressor genes is poorly understood. We have studied the frequency of p53 expression and its relation to the EBV infection in 33 Korean patients with head and neck (H&N) lymphomas. All cases (23 B cell & 10 T cell) were immunostained for p53 protein using the mAb D07 (Novocastra) and the avidin biotin peroxidase method. EBER in situ hybridization was performed using a fluorescein conjugated EBV oligonucleotide probe (Dako). Among 33 lymphomas, 16 cases stained positively for p53 protein. P53 expression was frequent both in higher grade lymphomas and in advanced stage. Nine cases were EBER positive, EBER was more commonly found in T cell lymphomas than in B cell lymphomas (70% vs 8.7%). EBER positive lymphomas showed a higher frequency of p53 positivity than EBER negative lymphomas (78% vs 38%), although the difference was not statistically significant (p = 0.095). These findings indicate altered expression of p53 protein occurs in H&N lymphomas, especially in late event lymphoma progression and appears to play a role in the development of EBER positive T cell lymphomas.

Bromodeoxyuridine, an analogue of thymidine, can be detected by means of monoclonal antibodies and utilized as a marker of the S-phase of the cell cycle. In vitro immunohistochemical application of the BrdU/anti-BrdU-MAb method permits a quantitative assessment of the proliferative activity of a tissue as well as the direct location of the actively replicating cells in histological sections. In this paper, a method for the detection of the labeling index of S-phase cells in normal and neoplastic tissues with in vitro BrdU labeling and standard immunohistochemical techniques using anti-BrdU-MAb and avidin-biotin peroxidase complex is described. We have employed this method in 47 human solid tumor samples, including squamous cell carcinomas of head and neck and cervix uteri, adenocarcinomas and malignant lymphomas, and also evaluated the possible application of the BrdU labeling index to estimate the cycling S-phase cells in neoplastic cell populations. In our data, the in vitro labeling index varied greatly in an individual case (3.56-29.2%) and from an area to an area within the same case. Squamous cell carcinomas of the head and neck showed higher LI than those of the cervix uteri. A case of metastatic carcinoma to the lung from ductal carcinoma of the breast had the highest LI (29.2%), in contrast to the low LI (3.6%) in the primary ductal carcinoma of breast.