Hyun Joo Choi

Emphysematous gastritis associated with invasive gastric mucormycosis: a case report.

Emphysematous gastritis is a rare form of phlegmonous gastritis, characterized by air in the wall of the stomach due to invasion by gas-forming microorganisms. The most commonly involved microorganisms are streptococci, Escherichia coli, Pseudomonas aeruginosa, Clostrodium perfrigens and Staphylococcus aureus. Gastrointestinal mucormycosis is another rare condition, which is most frequently occurs in the stomach. Because emphysematous gastritis associated with invasive gastric mucormycosis is an extremely rare clinical condition and both are life-threatening diseases, early precise diagnosis and early treatment should be done to avoid mortality. Herein we present an extremely rare case of emphysematous gastritis associated with invasive gastric mucormycosis. A 43-yr-old man, suffering from alcoholism and diabetes, has experienced diffuse abdominal pain for 4 days. Abdominal computed tomography scan demonstrated gas within the stomach wall. A histologic examination of the total gastrectomy specimen showed several gas-filled bubbles in the wall, along with numerous fungal hyphae throughout the necrotic stomach wall. He died of multiorgan failure secondary to disseminated mucormycosis, despite the intensive medical therapy.

Expression of miRNAs and PTEN in endometrial specimens ranging from histologically normal to hyperplasia and endometrial adenocarcinoma

We investigated the relationship between frequently deregulated microRNAs (miRNAs) and enodometrial pathology in an attempt to find the most dependable miRNA or combination of miRNAs to identify normal, hyperplastic and malignant endometrial tissues. We also investigated the association between those miRNAs and PTEN status. We measured the expression of six miRNAs (miR-21, 182, 183, 200a, 200c and 205) in 75 formalin-fixed, paraffin-embedded normal, hyperplastic, and malignant endometrial tissue blocks using Taqman-based real-time PCR assays. PTEN loss of expression was assessed in the same endometrial tissues by immunohistochemistry. Expression of five miRNAs (miR-182, 183, 200a, 200c and 205) was significantly higher in endometrial carcinoma (CA) when compared with complex atypical hyperplasia (CAH), simple hyperplasia (SH) and normal endometrial tissue (P<0.05, respectively). Considering the likelihood ratio and number of parameters, the composite panel of six miRNAs was the best marker, revealing a sensitivity of 91% and a specificity of 94% in differentiating endometrial CA from endometrial hyperplasia or normal endometrium while the individual miRNAs exhibited 64–77% sensitivity and 66–91% specificity. Interestingly, in distinguishing endometrial CA from CAH, the composite panel of four miRNAs (miR-182, 183, 200a, 200c) was the best marker, producing 95% sensitivity and 91% specificity. The percentage of PTEN loss was significantly higher in endometrial CA compared with SH (68% vs 24%, P<0.05), and it was also higher in CAH compared with SH (71% vs 24%, P<005). Aberrant expression of miRNAs and loss of PTEN expression are common in endometrial hyperplasia and CA. They might serve to increase the diagnostic reproducibility and improve discrimination, especially, between CAH and CA by miRNA expression profiles and between simple and complex hyperplasia through PTEN expression patterns. Those expression profiles of biomarkers also might be used to predict the potential for progression from endometrial hyperplasia to invasive CA.

Reduced expression of TFF1 and increased expression of TFF3 in gastric cancer: correlation with clinicopathological parameters and prognosis.

Objectives: The trefoil factor family (TFF) is composed of three thermostable, and protease-resistant proteins, named TFF1, TFF2 and TFF3, and plays a role in gastrointestinal mucosal defence and repair. Recently, TFFs have been found to be related to the development of various types of cancer. This study assessed the relationship between the expression of TFF1 and TFF3 and the clinicopathological parameters in gastric carcinoma (GC). Materials and Methods: The expression of TFF1 and TFF3 was analyzed by immunohistochemistry in 292 GCs and 20 normal gastric tissues. Results: All normal gastric tissues expressed TFF1, but 53.8% of GCs showed reduced TFF1 expression. However, TFF3 was not detected in normal gastric tissues and 44.2% of GCs showed a high level of expression. Highly expressed TFF3 was significantly correlated with lymph node metastasis, lymphatic invasion, vein invasion, and advanced stage. The overall survival was shorter in patients with high expression of TFF3 than in those with low expression of TFF3 in 292 GCs and in 125 early GCs (EGCs). Moreover, in patients with EGCs, high expression of TFF3, associated with reduced expression of TFF1, was determined as an independent poor prognostic marker. Conclusions: Reduced expression of TFF1 and increased expression of TFF3 may play a role in the carcinogenesis of gastric cancer. Furthermore, high expression of TFF3 with reduced expression of TFF1 may be a marker of poor prognosis for patients with EGC.

Graphene–ferroelectric metadevices for nonvolatile memory and reconfigurable logic-gate operations

Memory metamaterials are artificial media that sustain transformed electromagnetic properties without persistent external stimuli. Previous memory metamaterials were realized with phase-change materials, such as vanadium dioxide or chalcogenide glasses, which exhibit memory behaviour with respect to electrically/optically induced thermal stimuli. However, they require a thermally isolated environment for longer retention or strong optical pump for phase-change. Here we demonstrate electrically programmable nonvolatile memory metadevices realised by the hybridization of graphene, a ferroelectric and meta-atoms/meta-molecules, and extend the concept further to establish reconfigurable logic-gate metadevices. For a memory metadevice having a single electrical input, amplitude, phase and even the polarization multi-states were clearly distinguishable with a retention time of over 10 years at room temperature. Furthermore, logic-gate functionalities were demonstrated with reconfigurable logic-gate metadevices having two electrical inputs, with each connected to separate ferroelectric layers that act as the multi-level controller for the doping level of the sandwiched graphene layer.

Diagnostic utility of expression of claudins in non-small cell lung cancer : Different expression profiles in squamous cell carcinomas and adenocarcinomas

The claudins, members of a large family of adherent junction proteins, regulate the integrity and function of tight junctions. At present, at least 23 different claudins are known to exist in humans, and claudin gene expression is frequently altered in several human cancers. However, few studies have examined the expression of claudins in lung cancer. This study examined the expression of claudin-1, claudin-3, claudin-4, and claudin-5 proteins using immunohistochemical analysis in 14 normal lung tissue samples and 171 NSCLC samples. All of the claudin proteins examined were expressed in normal bronchial epithelial cells. In the normal peripheral parenchyma, only claudin-5 strongly stained most of the pneumocytes. Claudin-1 expression was stronger in squamous cell carcinomas than in adenocarcinomas, whereas claudin-4 and claudin-5 expression was stronger in adenocarcinomas. Clinically, expression of claudin proteins was not found to be associated with patient survival. These data suggest that the disruption of tight junction protein might be involved in the development of these tumors. Immunohistochemical evaluation of the different expression patterns of claudins in NSCLC suggests that claudin-4, in addition to 1 and 5, might be a useful differential diagnostic marker in Korean people.

Broadband Modulation of Terahertz Waves With Non-Resonant Graphene Meta-Devices

Single-layer graphene absorbs a small fraction of incident terahertz waves by intraband transition of Dirac fermions. The amounts of absorption, reflection, and transmission of terahertz waves depend on the doping level of graphene, i.e., the Fermi level, and they exhibit relatively weak frequency dependency at terahertz frequencies. By hybridizing gated single-layer graphene with a non-resonant meta-atom structure, we show that the effective surface conductivity of meta-atom hybridized graphene can be significantly enhanced, and large intensity modulation of transmitted terahertz waves can be achieved without sacrificing the broadband modulation feature of single-layer graphene. For a frequency insensitive response, the meta-atoms are designed so that their resonance is positioned outside the frequencies of interest. Exploiting the enhanced effective surface conductivity with a non-resonant feature, larger modulation was possible over broad operating frequency from 0.3 to 2.3 THz. We anticipate that this electrically controlled graphene meta-device may play an important role in the realization of practical terahertz modulators.

Hedgehog related protein expression in breast cancer: gli-2 is associated with poor overall survival.

Background The hedgehog (Hh) signaling pathway is known to play a critical role in various malignancies, but its clinicopathologic role in breast cancer is yet to be established. Methods Tissue microarray blocks from 334 cases of breast cancer were prepared. The expression of six Hh signaling proteins including sonic hedgehog (Shh), patched (Ptch), smoothened (Smo), and the glioma-associated oncogene (Gli)-1, Gli-2, and Gli-3 were analyzed immunohistochemically. Results The expression of Hh signaling proteins was significantly correlated with some prognostic factors including the correlation of lymph node metastasis with the expression of Shh (p=0.001) and Ptch (p=0.064), the correlation of the stages with Shh and Gli-3 expression (p=0.007 and p=0.024, respectively), the correlation of the nuclear grade with the Smo (p=0.004) and Gli-3 (p=0.000), and the correlation of the histologic grade with the Ptch (p=0.016), Smo (p=0.007), and Gli-3 (p=0.000). The Shh, Ptch, Smo, Gli-1, and Gli-2 expression was significantly different between the phenotypes (p=0.000, p=0.001, p=0.004, p=0.039, and p=0.031, respectively). Gli-2 expression was correlated with a worse overall survival outcome (p=0.012). Conclusions Hh pathway activation is correlated with a more aggressive clinical behavior in breast carcinomas. The comparison of phenotypes suggested that the Hh pathway may be a useful therapeutic target for breast carcinoma. Patients with Gli-2 expression had a significantly lower overall survival rate and, therefore, it showed promise as a prognostic marker.

MicroRNA expression profiling and Notch1 and Notch2 expression in minimal deviation adenocarcinoma of uterine cervix.

BackgroundMicroRNA (miRNA) expression is known to be deregulated in cervical carcinomas. However, no data is available about the miRNA expression pattern for the minimal deviation adenocarcinoma (MDA) of uterine cervix. We sought to detect deregulated miRNAs in MDA in an attempt to find the most dependable miRNA or their combinations to understand their tumorigenesis pathway and to identify diagnostic or prognostic biomarkers. We also investigated the association between those miRNAs and their target genes, especially Notch1 and Notch2.MethodsWe evaluated miRNA expression profiles via miRNA microarray and validated them using.real-time PCR assays with 24 formalin-fixed, paraffin-embedded tissue blocks of MDA and 11 normal proliferative endocervical tissues as control. Expression for Notch1 and 2 was assessed by immunohistochemistry.ResultsMiRNA-135a-3p, 192-5p, 194-5p, and 494 were up-regulated, whereas miR-34b-5p, 204-5p, 299-5p, 424-5p, and 136-3p were down-regulated in MDA compared with normal proliferative endocervical tissues (all P <0.05). Considering the second-order Akaike Information Criterion consisting of likelihood ratio and number of parameters, miR-34b-5p showed the best discrimination power among the nine candidate miRNAs. A combined panel of miR-34b-5p and 194-5p was the best fit model to discriminate between MDA and control, revealing 100% sensitivity and specificity. Notch1 and Notch2, respective target genes of miR-34b-5p and miR-204-5p, were more frequently expressed in MDA than in control (63% vs. 18%; 52% vs. 18%, respectively, P <0.05). MiR-34b-5p expression level was higher in Notch1-negative samples compared with Notch1-positive ones (P <0.05). Down-regulated miR-494 was associated with poor patient survival (P = 0.036).ConclusionsMDA showed distinctive expression profiles of miRNAs, Notch1, and Notch2 from normal proliferative endocervical tissues. In particular, miR-34b-5p and 194-5p might be used as diagnostic biomarkers and miR-494 as a prognostic predictor for MDA. The miR-34b-5p/Notch1 pathway as well as Notch2 might be important oncogenic contributors to MDA.

Whole-exome sequencing identifies recurrent AKT1 mutations in sclerosing hemangioma of lung

Significance This report is an in-depth genetic profiling of pulmonary sclerosing hemangioma (PSH). We have discovered that PSH harbor recurrent AKT1 mutations (45.6%), most of which were AKT1 p.E17K mutations. This mutation may be the single-most common driver alteration to develop PSHs. In contrast to lung adenocarcinoma, PSH genomes harbor only a single driver mutation (AKT1 or β-catenin), which may provide clues to understanding the benign biology of PSH and for differential genomic diagnosis of lung tumors. Pulmonary sclerosing hemangioma (PSH) is a benign tumor with two cell populations (epithelial and stromal cells), for which genomic profiles remain unknown. We conducted exome sequencing of 44 PSHs and identified recurrent somatic mutations of AKT1 (43.2%) and β-catenin (4.5%). We used a second subset of 24 PSHs to confirm the high frequency of AKT1 mutations (overall 31/68, 45.6%; p.E17K, 33.8%) and recurrent β-catenin mutations (overall 3 of 68, 4.4%). Of the PSHs without AKT1 mutations, two exhibited AKT1 copy gain. AKT1 mutations existed in both epithelial and stromal cells. In two separate PSHs from one patient, we observed two different AKT1 mutations, indicating they were not disseminated but independent arising tumors. Because the AKT1 mutations were not found to co-occur with β-catenin mutations (or any other known driver alterations) in any of the PSHs studied, we speculate that this may be the single-most common driver alteration to develop PSHs. Our study revealed genomic differences between PSHs and lung adenocarcinomas, including a high rate of AKT1 mutation in PSHs. These genomic features of PSH identified in the present study provide clues to understanding the biology of PSH and for differential genomic diagnosis of lung tumors.

Fine needle aspiration cytology of thyroid follicular neoplasm: cytohistologic correlation and accuracy.

Background This study evaluated the accuracy of fine needle aspiration cytology (FNAC) in cases of follicular neoplasm (FN) on the basis of histologic diagnosis, and reviewed the cytologic findings of FN according to the FNAC. Methods Among the 66 cases diagnosed with thyroid FN by FNAC during the 7-year period from 2003 to 2009, 36 cases that had undergone thyroid surgery were available for review. Cytologic diagnosis was compared with the histologic diagnosis of each case. Results Among the 36 cases with a cytologic diagnosis of thyroid FN, histologic diagnosis was as follows: 20 follicular adenomas (55.6%), 3 Hurthle cell adenomas (8.3%), 2 follicular carcinomas (5.6%), 8 nodular goiters (22.2%), 2 papillary carcinomas (5.6%), and 1 Hashimotos thyroiditis (2.8%), resulting in a diagnostic accuracy of FNAC for thyroid FN of 69.5%. Conclusions This study shows that FNAC for thyroid FN is a useful primary screening method because when FN is diagnosed by FNAC, the rate of FN histologic diagnosis is relatively high, however, adequate sampling and experience is a prerequisite for this procedure.