Essential Role of Protein Arginine Methyltransferase 1 in Pancreas Development by Regulating Protein Stability of Neurogenin 3

BACKGROUND: Protein arginine methyltransferase 1 (PRMT1) is a major enzyme responsible for the formation of methylarginine in mammalian cells. Recent studies have revealed that PRMT1 plays important roles in the development of various tissues. However, its role in pancreas development has not yet been elucidated. METHODS: Pancreatic progenitor cell-specific Prmt1 knock-out (Prmt1 PKO) mice were generated and characterized for their metabolic and histological phenotypes and their levels of Neurog3 gene expression and neurogenin 3 (NGN3) protein expression. Protein degradation assays were performed in mPAC cells. RESULTS: Prmt1 PKO mice showed growth retardation and a severely diabetic phenotype. The pancreatic size and β-cell mass were significantly reduced in Prmt1 PKO mice. Proliferation of progenitor cells during the secondary transition was decreased and endocrine cell differentiation was impaired. These defects in pancreas development could be attributed to the sustained expression of NGN3 in progenitor cells. Protein degradation assays in mPAC cells revealed that PRMT1 was required for the rapid degradation of NGN3. CONCLUSION: PRMT1 critically contributes to pancreas development by destabilizing the NGN3 protein.

Recurrent Eosinophilic Pneumonia Associated with Mesalazine Suppository in a Patient with Ulcerative Colitis / 대한소화기학회지

Mesalazine suppositories are widely used to treat ulcerative colitis and have a guaranteed safety profile, but although rare, they can cause pulmonary toxicity. A 35-year-old woman with ulcerative colitis was diagnosed to have acute eosinophilic pneumonia after 29 days of oral mesalazine use and improved after mesalazine and corticosteroid were withdrawn. Reintroduction of mesalazine suppositories resulted in acute eosinophilic pneumonia recurrence after 28 days. Mesalazine re-administration (even via a different route) in patients with a history of mesalazine-induced eosinophilic pneumonia should be undertaken cautiously, because eosinophilic pneumonia may recurrence.

Negative pressure is not necessary for using fine-needle aspiration biopsy to diagnose suspected thyroid nodules: a prospective randomized study

PURPOSE: Fine-needle aspiration biopsy (FNAB) can be used to diagnose thyroid cancer and other tumors. Although FNAB without negative pressure (FNAB−P) reduces the risk of blood contamination, FNAB with negative pressure (FNAB+P) increases the sensitivity of the biopsy results. Therefore, we performed a randomized study of FNAB with or without negative pressure to identify the better diagnostic method. METHODS: Between March 2016 and February 2017, 172 consecutive patients were enrolled to investigate >0.5 cm nodules with indeterminate or suspicious malignant features. Patients were randomly assigned to the FNAB+P group (a 50 mL syringe was used to provide negative pressure) or to the FNAB−P group (passive collection of blood in the needle's hub). The 2 methods' diagnostic adequacy and quality were evaluated using an objective scoring system. The study's protocol was registered with the World Health Organization Clinical Research Information Service (http://cris.nih.go.kr/cris, KCT0001857). RESULTS: The patients were randomly assigned to the FNAB+P group (n = 86) or the FNAB−P group (n = 86). There were no significant intergroup differences in nodule position, size, age, consistency, calcification, BRAF mutation, or pathology. Evaluation of diagnostic adequacy parameters revealed no significant differences in background blood/clot (P = 0.728), amount of cellular material (P = 0.052), degree of cellular degeneration (P = 0.622), degree of cellular trauma (P = 0.979), or retention of appropriate architecture (P = 0.487). Furthermore, there was no significant intergroup difference in the diagnostic quality (P = 0.634). CONCLUSION: This prospective randomized study failed to detect significant differences in the diagnostic adequacy and quality of FNAB with or without negative pressure. Therefore, the examiner may select whichever FNAB method they prefer.

A Rare Case of Primary Spinal Cord Germinoma Treated with Single Radiation Therapy after Surgery / 대한내과학회지

A 32-year old male came to our hospital with chief complaint of paraplegia. He had symptom of radiating pain to right leg 3 months ago before paraplegic symptom appeared. Magnetic resonance (MR) imaging from outside hospital showed intramedullary mass involving from T8 to T10 level of spinal cord. According to the imaging result, tumor removal with total laminectomy was performed between T8 and T10 level in our hospital. Pathologic result was compatible with germinoma. Spine radiation (39.6 Gy/22 fx) from T7 to T12 level without chemotherapy was performed 3 weeks later since tumor removal. Follow-up MR imaging showed no recurrence without any distant metastasis. And our patient's neurologic symptom had been improved. According to this case, postoperative radiotherapy is thought to be effective to primary spinal germinoma.

Increased Immunoreactivity of LGR4 in Histologically Aggressive Basal Cell Carcinoma

No abstract available.

Morphological and Functional Changes in the Thyroid Follicles of the Aged Murine and Humans

BACKGROUND: Although both thyroid histology and serum concentrations of hormones are known to change with age, only a few reports exist on the relationship between the age-related structural and functional changes of the thyroid follicles in both mice and humans. Our objectives were to investigate age-related histological changes of the thyroid follicles and to determine whether these morphological changes were associated with the functional activity of the follicles. METHODS: The thyroid glands of mice at 18 weeks and at 6, 15, and 30 months of age were histologically examined, and the serum levels of thyroid hormones were measured in 11-week-old and 20-month-old mice. Samples of human thyroid tissue from 10 women over 70 years old and 10 women between 30 and 50 years of age were analyzed in conjunction with serum thyroid hormone level. RESULTS: The histological and functional changes observed in the thyroid follicles of aged mice and women were as follows: variable sizing and enlargement of the follicles; increased irregularity of follicles; Sanderson’s polsters in the wall of large follicles; a large thyroglobulin (Tg) globule or numerous small fragmented Tg globules in follicular lumens; oncocytic change in follicular cells; and markedly dilated follicles empty of colloid. Serum T3 levels in 20-month-old mice and humans were unremarkable. CONCLUSIONS: Thyroid follicles of aged mice and women show characteristic morphological changes, such as cystic atrophy, empty colloid, and Tg globules.

Concurrent Mucosal Melanoma and Angiofibroma of the Nose

Malignant melanoma rarely develops in the paranasal sinuses, and generally has a poor prognosis. However, mucosal melanoma can masquerade both clinically and histopathologically as a benign lesion, rendering accurate early diagnosis difficult. On the other hand, angiofibroma, a benign tumor, is more easily diagnosed than a mucosal melanoma, because the former exhibits specific histopathological features. No cases of concurrent angiofibroma and mucosal melanoma have been reported to date. We describe such a case below.

Mitochondrial Energy Metabolism and Thyroid Cancers

Primary thyroid cancers including papillary, follicular, poorly differentiated, and anaplastic carcinomas show substantial differences in biological and clinical behaviors. Even in the same pathological type, there is wide variability in the clinical course of disease progression. The molecular carcinogenesis of thyroid cancer has advanced tremendously in the last decade. However, specific inhibition of oncogenic pathways did not provide a significant survival benefit in advanced progressive thyroid cancer that is resistant to radioactive iodine therapy. Accumulating evidence clearly shows that cellular energy metabolism, which is controlled by oncogenes and other tumor-related factors, is a critical factor determining the clinical phenotypes of cancer. However, the role and nature of energy metabolism in thyroid cancer remain unclear. In this article, we discuss the role of cellular energy metabolism, particularly mitochondrial energy metabolism, in thyroid cancer. Determining the molecular nature of metabolic remodeling in thyroid cancer may provide new biomarkers and therapeutic targets that may be useful in the management of refractory thyroid cancers.

NAD(P)H: Quinone Oxidoreductase 1 and NRH:Quinone Oxidoreductase 2 Polymorphisms in Papillary Thyroid Microcarcinoma: Correlation with Phenotype

PURPOSE: NAD(P)H:Quinone Oxidoreductase 1 (NQO1) C609T missense variant (NQO1*2) and 29 basepair (bp)-insertion/deletion (I29/D) polymorphism of the NRH:Quinone Oxidoreductase 2 (NQO2) gene promoter have been proposed as predictive and prognostic factors for cancer development and progression. The purpose of this study is to investigate the relationship between NQO1/NQO2 genotype and clinico-pathological features of papillary thyroid microcarcinoma (PTMC). MATERIALS AND METHODS: Genomic DNA was isolated from 243 patients; and clinical data were retrospectively analyzed. NQO1*2 and tri-allelic polymorphism of NQO2 were investigated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. RESULTS: PTMC with NQO1*2 frequently exhibited extra-thyroidal extension as compared to PTMC with wild-type NQO1 (p=0.039). There was a significant relationship between I29/I29 homozygosity of NQO2 and lymph node metastasis (p=0.042). Multivariate analysis showed that the I29/I29 genotype was associated with an increased risk of lymph node metastasis (OR, 2.24; 95% CI, 1.10-4.56; p=0.026). CONCLUSION: NQO1*2 and I29 allele of the NQO2 are associated with aggressive clinical phenotypes of PTMC, and the I29 allele represents a putative prognostic marker for PTMC.