Characterization of mGluR5R,a novel,metabotropic glutamate receptor 5-related gene

We report here the isolation of a novel gene termed mGluR5R (mGluR5-related). The N-terminus of mGluR5R is highly similar to the extracellular domain of metabotropic glutamate receptor 5 (mGluR5) whereas the C-terminus bears similarity to the testis-specific gene, RNF18. mGluR5R is expressed in the human CNS in a coordinate fashion with mGluR5. Although the sequence suggests that mGluR5R may be a secreted glutamate binding protein, we found that when expressed in HEK293 cells it was membrane associated and not secreted. Furthermore, mGluR5R was incapable of binding the metabotropic glutamate receptor class I selective agonist, quisqualate. Although mGluR5R could not form disulfide-mediated covalent homodimers, it was able to form a homomeric complex, presumably through noncovalent interactions. mGluR5R also formed noncovalent heteromeric associations with an engineered construct of the extracellular domain of mGluR5 as well as with full-length mGluR5 and mGluR1alpha. The ability of mGluR5R to associate with mGluR1alpha and mGluR5 suggests that it may be a modulator of class I metabotropic glutamate receptor function.     

Clinical outcome of elderly patients with Epstein–Barr virus positive diffuse large B‐cell lymphoma treated with a combination of rituximab and CHOP chemotherapy

Several studies have suggested the possibility of a prognostic relationship between Epstein–Barr virus (EBV) and diffuse large B‐cell lymphoma (DLBCL). The clinical outcome of EBV‐associated DLBCL is not clear, especially since the introduction of rituximab. We retrospectively analyzed 222 elderly patients (≥50 years) with DLBCL who received R‐CHOP chemotherapy and evaluated the state of EBV‐encoded RNA‐1 (EBER). Eighteen cases (8.1%) were EBER‐positive (+). After a median of six cycles of R‐CHOP chemotherapy, the response rate (≥partial response) was 72.2% (13/18) in the EBV (+) patients and 90.2% (184/204) in the EBV (?) DLBCL patients (P = 0.021). Four of 18 (22.2%) EBV (+) DLBCL patients received two or fewer cycles of R‐CHOP chemotherapy. R‐CHOP chemotherapy was also interrupted early more frequently compared with the EBV (?) group (2.5%) (P = 0.00). At a median follow‐up of 32.8 months, there was no significant difference in the overall survival between the groups (P = 0.627). The EBV (+) DLBCL patients with early interruption of R‐CHOP chemotherapy showed a trend toward a high EBV‐DNA titer (≥1,000 copies/mL) (P = 0.091). The results suggest that the EBV (+) tumoral status of elderly DLBCL patients who undergo R‐CHOP chemotherapy does not predict their survival but that their EBV status may contribute to the early interruption of R‐CHOP chemotherapy. Am. J. Hematol. 88:774–779, 2013. © 2013 Wiley Periodicals, Inc.     

Heterogeneity of macrolide-lincosamide-streptogramin B resistance phenotypes in enterococci

We determined the macrolide resistance phenotypes of 241 clinical isolates of erythromycin-resistant enterococci (MICs, > or = 1 microg/ml), including 147 Enterococcus faecalis strains and 94 Enterococcus faecium strains, collected from a hospital in Seoul, Korea, between 1999 and 2000. By the erythromycin (40 micro g)-josamycin (100 microg) double-disk test, 93 strains were assigned to the constitutive macrolide, lincosamide, and streptogramin B (MLS(B)) resistance (cMLS(B)) phenotype, and the remaining 148 strains were assigned to the inducible MLS(B) resistance (iMLS(B)) phenotype. Of the strains with the iMLS(B) phenotype, 36 exhibited a reversibly inducible MLS(B) (riMLS(B)) phenotype, i.e., blunting of the erythromycin zone of inhibition, which indicates that the 16-membered-ring macrolide josamycin is a more effective inducer than the 14-membered-ring macrolide erythromycin. Sequence analysis of the regulatory regions of the erm(B) genes from all of the strains exhibiting the riMLS(B) phenotype revealed not only erm(Bv) [where v represents variant; previously erm(AMR)] (n = 13), as reported previously, but also three kinds of erm(B) variants, which were designated erm(Bv1) (n = 17), erm(Bv2) (n = 3), and erm(Bv3) (n = 3), respectively. In lacZ reporter gene assays of these variants, the 16-membered-ring macrolide tylosin had stronger inducibility than erythromycin at > or = 0.1 microg/ml. These findings highlight the versatility of erm(B) in induction specificity.     

Malignancy Risk Stratification in Thyroid Nodules with Benign Results on Cytology: Combination of Thyroid Imaging Reporting and Data System and Bethesda System

Background

The indications of repeat fine-needle aspiration (FNA) for thyroid nodules with benign results of the Bethesda system were investigated.

Methods

A total of 1,398 nodules were classified according to the Thyroid Imaging Reporting and Data System (TIRADS). TIRADS category 3 included nodules without solidity, hypoechogenicity or marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller-than-wide shape on ultrasonography (US). Categories 4a, 4b, 4c, and 5 included nodules with one, two, three or four, or five suspicious US features, respectively. The malignancy risks, and odds ratio (OR) with 95 % confidence interval (CI) were calculated. Analyses were performed for all nodules, nodules >10 mm, and nodules ≤10 mm.

Results

Of 1.398 nodules, 43 (3.1 %) were malignanct. The malignancy risks of benign nodules with categories 3, 4a, and 4b were 0.7, 1.2, and 0.7 %, respectively, whereas those for nodules with categories 4c and 5 were 9.8 and 22.2 %, respectively. The ORs of nodules with categories 4c and 5 were 19.4 (95 % CI 5.0–76.2) and 50.6 (95 % CI 10.4–245.0), respectively. In nodules >10 mm, the malignancy risks of categories 4c and 5 were 2.7 and 20 %, respectively, and the ORs were 10.7 (95 % CI 1.2–93.7) and 236.1 (95 % CI 12.6–4426.4), respectively. In nodules ≤ 10 mm, the malignancy risks of categories 4c and 5 were 12.6 and 22.6 %, respectively, and the ORs were 10.1 (95 % CI 1.3–78.0) and 18.9 (95 % CI 2.1–168.9), respectively.

Conclusions

Repeat US-guided FNA should be considered in benign thyroid nodules with three or more suspicious US features regardless of size.     

Preoperative Prediction of Central Lymph Node Metastasis in Thyroid Papillary Microcarcinoma Using Clinicopathologic and Sonographic Features

Background

The purpose of the present study was to evaluate the clinicopathologic factors and ultrasound (US) features predictive of central lymph node metastasis (LNM) in patients diagnosed with papillary thyroid microcarcinoma (PTMC).

Methods

From March 2008 to August 2008, the clinicopathologic features and preoperative US features of 483 patients who were diagnosed with conventional PTMC were included. Medical records, US features, and pathology reports of all patients were retrospectively reviewed. Univariate and multivariate analysis was performed to identify clinicopathological prognostic factors associated with central LNM. Odds ratios (OR) with relative 95 % confidence intervals (95 % CI) were calculated to determine the relevance of all potential predictors of central LNM.

Results

Among the 483 patients with PTMC, 139 (28.8 %) patients had central LNM. The OR of significant independent factors were 2.055 (95 % CI, 1.137–3.716), 2.075 (95 % CI, 1.27–3.39), 1.71 (95 % CI, 1.073–2.724), and 15.897 (95 % CI, 4.173–60.569), respectively, for bilaterality, larger tumor size (>5 mm), extracapsular invasion, and lateral LNM. No significant association was seen among the US features of PTMC with central LNM.

Conclusions

Central lymph node metastasis in patients with PTMC was significantly associated with various clinicopathological factors, including larger tumor size (>5 mm), bilaterality, extracapsular invasion, and lateral LNM. When these features are detected on preoperative US, selective central compartment dissection may be helpful in patients diagnosed with PTMC.     

Changing patterns in the clinical characteristics of Korean patients with breast cancer during the last 15 years

HYPOTHESIS: Breast cancer has become the most common cancer in Korean women in recent years, with continuously increased incidence rates attributed to westernized lifestyles. DESIGN: Retrospective case series evaluating the changing patterns of clinical characteristics in breast cancer during the last 15 years. SETTING: Hospitalized patients with breast cancer in a university medical center. PATIENTS: A total of 5001 breast cancer patients who underwent surgery between July 1989 and March 2004 at the Asan Medical Center. MAIN OUTCOME MEASURE: Clinicopathologic data were collected using the online Korea Breast Cancer Registration Program, including factors such as age, symptoms, stage, surgery, reconstruction, risk factors, and survival. RESULTS: The median age of patients slightly increased from 44 years in 1991 to 46 years in 2003. The most frequent age group was the fifth decade (41.7%) and premenopausal women younger than 50 years (64.9%). The proportion of asymptomatic patients detected by screening mammography increased from 3.8% in 1991 to 21.0% in 2003 (P<.001). The proportion of early breast cancer (stages 0 and I) increased from 34.2% in 1991 to 48.8% in 2003 (P=.013). Breast-conserving surgery has increased continuously from 5.1% in 1991 to 39.1% in 2003 (P<.001). Twelve percent of all patients who underwent mastectomies had immediate reconstruction, and the proportion showed an increasing trend, especially in skin-sparing mastectomy and transverse rectus abdominis myocutaneous flap reconstruction. Five-year observed survival rates were 84.1%. Five-year survival rates according to stages were as follows: (1) 98.5%, stage 0; (2) 95.3%, stage I; (3) 86.0%, stage II; (4) 65.0%, stage III; and (5) 29.3%, stage IV. The number of patients with specific risk factors, such as early menarche and late first delivery, significantly increased. Of 263 high-risk patients examined for the BRCA mutation, mutations were found in 20 patients (7.6%), with 13 cases with BRCA1 and 7 cases with BRCA2. CONCLUSIONS: The present study showed a continuous increase in the number of patients with breast cancer; the proportion of young patients, asymptomatic patients, early breast cancer, breast-conserving surgery, and immediate reconstruction after mastectomy; and the number of patients with risk factors. These results suggest that the clinical characteristics of Korean breast cancer patients reflect the patterns of Western countries.     

Do allelic variants of the connexin37 1019 gene polymorphism differentially predict for coronary artery disease and myocardial infarction?

A C1019T polymorphism in the human connexin37 (hCx37) gene has been associated with cardiovascular risk, but it remains debatable whether the 1019C or the 1019T allele carries this risk. Here, we investigated whether these allelic variants are differentially predictive of increased risk for coronary artery disease (CAD) and myocardial infarction (MI). A total of 781 Swiss participants, including 597 patients diagnosed with CAD, 50% who reported previous MI, and 184 control subjects were genotyped. Patients in the +CAD group had a higher frequency of the Cx37-1019C allele (70.3% versus 65.0%, p=0.004). Multivariate analysis showed that the hCx37-C1019T polymorphism is an independent predictor of CAD (odds ratio=2.13, confidence interval=1.31-3.46 and p<0.01). Moreover, this polymorphism is not associated with any of the other characteristics examined, including gender, age, body-mass-index, diabetes, total/HDL/LDL-cholesterol, triglycerides, apoA-I, apoB, hypertension and cigarette smoking. In comparison with the -CAD group, we observed an increase of the Cx37-1019C allele in the +MI +CAD subgroup (71.2% versus 65.0%, p=0.002) but not in the -MI +CAD subgroup. Allelic frequency comparisons of these three subgroups predicted that this polymorphism is also an independent risk factor for MI. In conclusion, our results reveal the importance of screening the Cx37-1019C allele for both CAD and MI risk assessments.     

Altered pattern of vascular connexin expression in atherosclerotic plaques

Paracrine cell-to-cell interactions are crucial events during atherogenesis. However, little is known about the role of direct intercellular communication via gap junctions during this process. We have investigated the expression pattern of 3 vascular gap junction proteins (connexins) in mouse and human atherosclerotic plaques. Low density lipoprotein receptor-deficient mice were fed a high-fat diet for 0, 6, 10, or 14 weeks to induce different stages of atherosclerosis. Connexin37 (Cx37) and Cx40 were detected in the endothelium, and Cx43 was detected in the media of nondiseased aortas. In early atheromas, endothelial and medial connexin expression remained unchanged, and "islets" of Cx43 in smooth muscle cells and Cx37 in macrophages were observed in the neointima. In advanced atheromas, Cx37 was detected in medial smooth muscle cells and in macrophages in the lipid core but not in the endothelium covering the plaques. Cx40 could also no longer be detected in the endothelium covering the plaques. Cx43, on the other hand, was detected in the endothelium covering the shoulder of the plaques and also sparsely in neointimal smooth muscle cells. Similar results were obtained for human carotid arteries. In conclusion, vascular connexins are differentially expressed by atheroma-associated cells within lesions. These observations suggest a role for gap junctional intercellular communication during atherogenesis.