Bong Kwon Chun

Pituitary Apoplexy Complicated by Chemical Meningitis and Cerebral Infarction

A 41-yr-old man was admitted with acute headache, neck stiffness, and febrile sensation. Cerebrospinal fluid examination showed pleocytosis, an increased protein level and, a decreased glucose concentration. No organisms were observed on a culture study. An imaging study revealed pituitary macroadenoma with hemorrhage. On the 7th day of the attack, confusion, dysarthria, and right-sided facial paralysis and hemiparesis were noted. Cerebral infarction on the left basal ganglia was confirmed. Neurologic deficits gradually improved after removal of the tumor by endoscopic transnasal transsphenoidal approach. It is likely that the pituitary apoplexy, aseptic chemical meningitis, and cerebral infarction are associated with each other. This rare case can serve as a prime example to clarify the chemical characteristics of pituitary apoplexy.

Detection of Pre-invasive Endobronchial Tumors with D-light/Autofluorescence System

Autofluorescence bronchoscopy (AFB) is one of the newly developed diagnostic tools to detect the pre-cancerous lesions in the bronchial tissue. The utility of D-Light/AFB in the detection of pre-cancerous lesions was compared to the standard white light bronchoscopy (WLB). In 113 patients (male 106, female 7), who visited hospital for evaluation of lung cancer, WLB and AFB were done and 364 biopsy specimens were obtained from November 2001 to August 2002. The bronchoscopic findings on WLB and AFB were compared to the pathological findings. The pathologic diagnoses of the specimens were as follows: normal in 96; hyperplasia in 69; metaplasia in 32; mild dysplasia in 13, moderate dysplasia in 6, severe dysplasia in 4; carcinoma in situ in 6; invasive carcinoma in 57. The relative sensitivity of adjunctive AFB to WLB vs. WLB alone was 1.5 in moderate dysplasia or worse lesions, and 3.2 in intraepithelial neoplasia. The specificity of adjunctive AFB and WLB alone were 0.91 and 0.5, respectively. The adjunctive AFB to the standard WLB increased the detection rate of the localized pre-invasive lesions. However, there was high rate of false positive in AFB.

Rabbit model of tracheal stenosis induced by prolonged endotracheal intubation using a segmented tube

OBJECTIVE Animal model of tracheal stenosis based on pathophysiology of prolonged endotracheal intubation has been rarely reported. We sought to verify the feasibility of inducing an animal model of tracheal stenosis by segmented endotracheal tube insertion in the New Zealand white rabbit model. METHODS Tracheal stenosis was induced by inserting a segmented endotracheal tube of 1.5cm length which was wrapped with a commercialized absorbable hemostat in 15 New Zealand white rabbits, while sham surgery controls (n=3) underwent tracheotomy and direct closure of tracheal exposure. The tube was removed transorally, 1 week after tube insertion. All rabbits were evaluated endoscopically at 1 week, 2 weeks and 3 weeks after the tube insertion. The rabbits were sacrificed 3 weeks after the surgery, and the excised tissue of trachea was processed along with the procedure of standard hematoxylin eosin staining and observed under a microscope. RESULTS Tracheal stenosis was induced in all rabbits (range 32-84% stenosis) with no death of rabbits during the study. The histological features of tracheal stenosis demonstrated thickening and fibrosis of lamina propria and submucosa with relatively intact cartilage framework. CONCLUSIONS We developed a rabbit model of tracheal stenosis induced by endotracheal intubation using a segmented tracheal tube. Since the model is based on the physiologic condition of prolonged endotracheal intubation, it may be used in variable studies related to tracheal stenosis.

Correlation of minimal extrathyroidal extension with pathologic features of lymph node metastasis in patients with papillary thyroid carcinoma

The impact of minimal extrathyroidal extension (mETE) to the prognosis of patients with papillary thyroid carcinoma (PTC) is controversial. In this study, we investigated whether mETE is related to the aggressive biology of metastatic lymph node (LN) in patients with PTC.

Multimodal imaging using optical coherence tomography and endolaryngeal ultrasonography in a new rabbit VX2 laryngeal cancer model.

Optical coherence tomography (OCT) provides ultrahigh‐resolution imaging of tissues within a depth of a few millimeters, whereas ultrasonography provides good imaging further below the surface. We aimed to develop a minimally invasive rabbit model of VX2 laryngeal cancer, suitable for these two imaging modalities through a transoral approach. We also sought to study the utility of combined OCT and endolaryngeal ultrasonography (EUS) for evaluation of early and advanced laryngeal cancer, using this model.

Optical imaging of subacute airway remodeling and adipose stem cell engraftment after airway injury

Acquired airway injury is frequently caused by endotracheal intubations, long-term tracheostomies, trauma, airway burns, and some systemic diseases. An effective and less invasive technique for both the early assessment and the early interventional treatment of acquired airway stenosis is therefore needed. Optical coherence tomography (OCT) has been proposed to have unique potential for early monitoring from the proliferative epithelium to the cartilage in acute airway injury. Additionally, stem cell therapy using adipose stem cells is being investigated as an option for early interventional treatment in airway and lung injury. Over the past decade, it has become possible to monitor the level of injury using OCT and to track the engraftment of stem cells using stem cell imaging in regenerative tissue. The purpose of this study was to assess the engraftment of exogenous adipose stem cells in injured tracheal epithelium with fluorescent microscopy and to detect and monitor the degree of airway injury in the same tracheal epithelium with OCT. OCT detected thickening of both the epithelium and basement membrane after tracheal scraping. The engraftment of adipose stem cells was successfully detected by fluorescent staining in the regenerative epithelium of injured tracheas. OCT has the potential to be a high-resolution imaging modality capable of detecting airway injury in combination with stem cell imaging in the same tracheal mucosa.

Preliminary study of optical coherence tomography imaging to identify microscopic extrathyroidal extension in patients with papillary thyroid carcinoma.

We evaluated the feasibility of using optical coherence tomography (OCT), to identify microscopic extrathyroidal extension (mETE) in ex vivo thyroidectomy specimens of patients who underwent thyroidectomy for the treatment of papillary thyroid carcinoma (PTC).

Correlation between 5-α reductase type 2 protein expression and methylation of 5-α reductase type 2 promotor gene of benign prostatic hyperplasia

PurposeThe enzyme 5-α reductase type 2 (5-AR 2) plays a key role in the development and maintenance of the prostate gland. We evaluated the level 5-AR 2 protein expression and the relationship between methylation of the 5-AR 2 gene-promoter and 5-AR 2 protein expression of benign prostatic hyperplasia (BPH).Materials and methodsA total of 37 prostate samples were evaluated. These included 22 samples from men undergoing transurethral prostate resections and 15 non-cancerous transition-zone human prostate tissue samples taken following radical prostatectomy. We quantified 5-AR 2 protein expression and gene-promoter methylation status using common assay procedures. Clinical variables included age, body mass index (BMI), prostate-specific antigen (PSA) levels, lipid profiles, and prostate volumes. Univariate and multivariate statistical analyses were performed followed by stepwise logistic regression modeling.ResultsWe were able to extract DNA from 36 of the 37 tissue samples and 10 of these (28%) did not express the 5-AR 2 protein. In total, 26 patients (72%) had methylated 5-AR 2 promoter-regions. There was a strong correlation between methylation of the 5-AR 2 promoter-regions and low-absent 5-AR 2 protein expression (p = 0.0003). Increasing age significantly predicted methylation status and protein expression level (p = 0.013).ConclusionsThe level of 5-AR 2 protein expression varies among prostate tissue samples. Methylation of the 5-AR 2 gene-promoter may account for low or absent expression of 5-AR 2 in adult human prostate tissues. Increased age correlates with increased 5-AR 2 gene-promoter methylation and decreased protein expression in men with BPH.

Tracheal cartilage regeneration by progenitor cells derived from the perichondrium

The regenerative potential of adult tracheal cartilage is very limited which makes repair of this cartilage extremely challenging. However, the perichondrium has a large quantity of progenitor cells that differentiate directly into chondrocytes. Bone morphogenetic protein (BMP) stimulates chondrogenesis by inducing the differentiation of progenitor cells into chondrocytes which makes it a potential therapeutic agent for cartilage regeneration. In this present study, we investigated the mesenchymal stem cell characterization of progenitor cells from the perichondrial tissue of tracheal cartilage and the efficiency of the perichondrium for tracheal cartilage regeneration by evaluating the effect of BMP on cartilage regeneration in perichondrial progenitor cells. Progenitor cells were isolated from the fibrous perichodrial tissue of tracheal cartilage and cultured for phenotypic characterization of mesenchymal stem cells. Next, a 0.3–0.5 mm gap was made in the mid-ventral portion of the tracheal cartilages. In the control group (n=5), the resulting gap was left untreated (without perichondrial replacement). In the perichondrial group (n=15), the gap was replaced by fibrous perichondrial tissue. We euthanized all mice in each group (n=5) at 2, 4, and 20 weeks after the perichondrial replacement and examined the replacement site microscopically. The immunohistochemistry for BMP-2 was performed in progenitor cells from perichondrial tissue. The primary cultured cells from fibrous perichondrial tissue were positive for CD29, CD90, and CD105, but negative for CD45. The progenitor cells were capable of multipotent differentiation towards adipogenic and osteogenic lineages. The control group showed no regenerated cartilage 2 weeks after injury. The experimental group demonstrated proliferation of progenitor cells between both stumps at 2 weeks and regenerated hyaline cartilage was observed at 4 and 20 weeks. Regenerated cartilage was observed as separated islets between the ends of the host cartilage stumps. The gaps were nearly filled with regenerated cartilage at 20 weeks. BMP-2 was expressed in both fibrous and cabial perichondria chondrogenesis. The progenitor cells from perichondrial tissue had mesenchymal stem cell-like features and might play a crucial role in tracheal cartilage regeneration and repair. Expression of BMP-2 may induce formation of structural cartilage in a tracheal injury model.

Subacute lymphocytic thyroiditis after lobectomy in a patient with papillary thyroid carcinoma: a case report

IntroductionSubacute lymphocytic thyroiditis is anautoimmune thyroid disease presenting with transient thyrotoxicosis as well as transient hypothyroidism. Several factors have been thought to be the initiating event in subacute lymphocytic thyroiditis. However, subacute lymphocytic thyroiditis that develops after thyroid lobectomy has not yet been reported in the literature. We report a case of subacute lymphocytic thyroiditis after lobectomy in a patient with papillary thyroid carcinoma.Case presentationA 30-year-old Korean woman was referred to our center for thyroid tumor operation. She was diagnosed with suspicious papillary thyroid carcinoma by fine needle aspiration at a local medical clinic. The thyroid ultrasonography demonstrated a diffusely enlarged thyroid gland with a 0.4×0.3cm sized hypoechoic nodule in the left lobe. Left thyroid lobectomy by endoscopic thyroidectomy was performed via a transaxillary approach, and the nodule was confirmed to be a papillary thyroid carcinoma. On postoperative day 1, a thyroid function test revealed hyperthyroidism, and on postoperative day 8, a thyroid function test again revealed hyperthyroidism with decreased radioactive iodine uptake. Thyroid function tests showed euthyroid on postoperative day 48 and hypothyroidism on postoperative day 86. She was treated with levothyroxine.ConclusionSubacute lymphocytic thyroiditis can develop after thyroid lobectomy. Thyroid autoantigen released during thyroid lobectomy may cause the onset or exacerbation of the destructive process.