Prevalence of erosive esophagitis and Barrett's esophagus in the adult Chinese population

BACKGROUND AND STUDY AIM

The aim of this study was to determine the prevalence, characteristics, and risk factors of erosive esophagitis and Barrett's esophagus in an adult Chinese population without gastroesophageal reflux symptoms.

PATIENTS AND METHODS

Between March 2006 and February 2007, consecutive individuals aged between 18 and 75 years, who underwent routine upper endoscopy as part of their regular medical examination were recruited. Demographic and medical information were collected. Erosive esophagitis was defined endoscopically as visible breaks of the distal esophageal mucosa. Barrett's esophagus was diagnosed endoscopically and confirmed histologically. "Silent GERD" was defined when erosive esophagitis and/or Barrett's esophagus were present in an individual without reflux symptoms.

RESULTS

Among the 2580 individuals included, erosive esophagitis and Barrett's esophagus were found in 4.3 % (n = 110) and 1.0 % (n = 27), respectively. In individuals with erosive esophagitis and Barrett's esophagus, 33.6 % and 40.7 %, respectively, were asymptomatic. Thus, the prevalence of erosive esophagitis and Barrett's esophagus in individuals without GERS was 1.6 % and 0.5 %, respectively, giving an overall prevalence of silent GERD of 2.0 % (46 / 2270). Multivariate analysis identified that male sex (odds ratio [OR] = 2.87, 95 % confidence interval [CI] 1.24 - 6.66; P = 0.014), hiatus hernia (OR = 9.68, 95 %CI 5.00 - 17.95; P < 0.001), and alcohol consumption (OR = 3.17, 95 %CI 1.44 - 6.97; P = 0.004) were positively associated with erosive esophagitis, whereas Helicobacter Pylori infection (OR = 0.37, 95 %CI 0.14 - 0.98; P = 0.046) was negatively associated with erosive esophagitis. Alcohol consumption (OR = 5.32, 95 %CI 1.55 - 13.33; P = 0.008) was positively associated with Barrett's esophagus in asymptomatic individuals.

CONCLUSION

In this cohort of the adult Chinese population without reflux symptoms, the prevalence of erosive esophagitis and Barrett's esophagus is 1.6 % and 0.5 %, respectively, with an overall prevalence of silent GERD of 2.0 %. Male sex, hiatus hernia, and alcohol consumption are positively associated with erosive esophagitis, whereas a negative association exists for H. pylori infection. Alcohol consumption is positively associated with Barrett's esophagus.

Tapping mode microwave impedance microscopy

We report tapping mode microwave impedance imaging based on atomic force microscope platforms. The shielded cantilever probe is critical to localize the tip-sample interaction near the tip apex. The modulated tip-sample impedance can be accurately simulated by the finite-element analysis and the result agrees quantitatively to the experimental data on a series of thin-film dielectric samples. The tapping mode microwave imaging is also superior to the contact mode in that the thermal drift in a long time scale is totally eliminated and an absolute measurement on the dielectric properties is possible. We demonstrated tapping images on working nanodevices, and the data are consistent with the transport results.

MTA2 is a metastasis promoter in breast cancer cells

Abstract #2047

Background: Breast cancer mortality is often the result of distant metastasis. It is believed that epigenetic regulation of gene expression plays an important roles in cancer biology. We have previously shown that metastasis tumor associated (MTA)2 is a repressor of estrogen signaling in estrogen receptor (ER) α-positive breast cancer cells and that overexpression of MTA2 rendered ERα-positive cells resistant to the effects of antiestrogens, such as tamoxifen. Knockdown of Rho GDP dissociation inhibitor (Rho GDIα), an inhibitor of the Rho family, conferred resistance to tamoxifen concomitant with MTA2 upregulation in ERα-positive cells. Furthermore, we found, using a retrospective cohort, that patients with high MTA2 and low Rho GDIα expression had poorer recurrence-free survival after tamoxifen treatment. Thus, MTA2 overexpression is associated with an aggressive, hormone-independent phenotype. We therefore hypothesize that MTA2 might similarly enhance the aggressiveness of ERα-negative breast cancer cells, and explored molecular mechanisms of metastasis.&#x2028; Materials and Methods: We compared the invasive and migratory phenotype of MDA-MB-231 cells stably overexpressing either MTA2 or empty vector using modified Boyden chamber invasion, wound healing, and soft agar colony formation assays. Immunoblot assay was used to assess changes in protein expression. MDA-MB-231 cells overexpressing MTA2 or vector were injected into the number four mammary gland as tumor xenografts in female athymic nude mice to test for changes in metastatic potential in vivo. Differential gene expression between the MTA2-overexpressing and vector control MDA-MB-231 cells was determined using Affymetrix microarray technology.&#x2028; Results: Stable MDA-MB-231 transfectants overexpressing MTA2 were generated. MTA2-overexpressing cells exhibited more cell to cell contacts, and fewer spindle-shaped cells than vector control. MTA2-overexpressing cells were approximately three times more invasive than vector control, and exhibited increased ability to form colonies in soft agar. However, they were less motile in wound healing assays. As xenografts, MTA2 stably transfected cells rapidly metastasized to the lung, lymph nodes, and skin. Metastases were not observed with vector control cells during the course of the experiment. Using microarray analysis, we identified enriched ontologies for a number of relevant pathways, including Rho signaling and cell adhesion. We have validated that MTA2-overexpressing cells have reduced expression of Rho GDIα, and we are exploring the role of Rho signaling as an effector of MTA2's impact on metastasis.&#x2028; Conclusion: MTA2 overexpression significantly alters the morphology and metastatic behavior of ERα-negative breast cancer cells. We hypothesize that MTA2 regulates pathways regulating cell adhesion, migration, and the Rho signaling pathway, thus increasing the metastatic ability of MTA2-overexpressing cells. In other models, MTA2's activity relies on its associated histone deacetylase activity, thus HDAC inhibitors may be able to block the effects of MTA2 overexpression, making MTA2 a potential therapeutic target.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2047.

Correlation of chromosomes 1p and 19q status and expressions of O6-methylguanine DNA methyltransferase (MGMT), p53 and Ki-67 in diffuse gliomas of World Health Organization (WHO) grades II and III: a clinicopathological study

AIMS

The objective of the present study was to verify the correlation of chromosomes 1p and 19q status and expressions of O(6)-methylguanine DNA methyltransferase (MGMT), p53 and Ki-67 in diffuse gliomas of World Health Organization grades II and III.

METHODS

A series of 146 diffuse gliomas, including 45 oligodendrogliomas, 42 oligoastrocytomas and 59 astrocytomas, were analysed by denaturing high-performance liquid chromatography for 1p and 19q status and by immunohistochemistry for MGMT, p53 and Ki-67 expression patterns. The molecular alterations were then correlated with clinicopathological characteristics and with each other.

RESULTS

Loss of heterozygosity (LOH) on 1p, combined LOH on 1p and 19q, low MGMT expression and high Ki-67 expression were associated with oligodendroglial tumours, whereas high p53 expression was associated with astrocytic and mixed tumours. LOH on 1p and low MGMT expression were associated with grade II oligodendroglial tumours, whereas high expressions of p53 and Ki-67 were associated with grade III oligodendroglial tumours. In addition, high Ki-67 expression was associated with grade III astrocytomas. LOH on 1p and LOH on 19q were associated with nontemporal oligodendroglial tumours. Nonrandom associations were found between LOH on 1p and LOH on 19q, MGMT expression and p53 expression, and MGMT expression and Ki-67 expression, whereas mutual exclusions were found between LOH on 1p and 19q and p53 expression, and LOH on 1p and Ki-67 expression.

CONCLUSIONS

The present study revealed significant interrelationships of the investigated molecular alterations and clinicopathological characteristics in diffuse gliomas of World Health Organization grades II and III, which support a promising role of molecular markers in the diagnostic assessment of these neoplasms.

Cloning, sequence analysis, and expression of cDNA coding for the major house dust mite allergen, Der f 1, in Escherichia coli

Our objective was to clone, express and characterize adult Dermatophagoides farinae group 1 (Der f 1) allergens to further produce recombinant allergens for future clinical applications in order to eliminate side reactions from crude extracts of mites. Based on GenBank data, we designed primers and amplified the cDNA fragment coding for Der f 1 by nested-PCR. After purification and recovery, the cDNA fragment was cloned into the pMD19-T vector. The fragment was then sequenced, subcloned into the plasmid pET28a(+), expressed in Escherichia coli BL21 and identified by Western blotting. The cDNA coding for Der f 1 was cloned, sequenced and expressed successfully. Sequence analysis showed the presence of an open reading frame containing 966 bp that encodes a protein of 321 amino acids. Interestingly, homology analysis showed that the Der p 1 shared more than 87% identity in amino acid sequence with Eur m 1 but only 80% with Der f 1. Furthermore, phylogenetic analyses suggested that D. pteronyssinus was evolutionarily closer to Euroglyphus maynei than to D. farinae, even though D. pteronyssinus and D. farinae belong to the same Dermatophagoides genus. A total of three cysteine peptidase active sites were found in the predicted amino acid sequence, including 127-138 (QGGCGSCWAFSG), 267-277 (NYHAVNIVGYG) and 284-303 (YWIVRNSWDTTWGDSGYGYF). Moreover, secondary structure analysis revealed that Der f 1 contained an a helix (33.96%), an extended strand (17.13%), a ss turn (5.61%), and a random coil (43.30%). A simple three-dimensional model of this protein was constructed using a Swiss-model server. The cDNA coding for Der f 1 was cloned, sequenced and expressed successfully. Alignment and phylogenetic analysis suggests that D. pteronyssinus is evolutionarily more similar to E. maynei than to D. farinae.

Aberrant promoter methylation of the TPEF gene in esophageal squamous cell carcinoma

Aberrant methylation of tumor suppressor genes plays an important role in the development of esophageal squamous cell carcinoma (ESCC). The purpose of the present study was to identify the epigenetic changes in ESCC. Methylation-sensitive arbitrarily primed polymerase chain reaction (MS AP-PCR) analysis was used on 22 matched ESCC tumors and adjacent normal tissues. Through this screen we identified a frequently methylated fragment that showed a high homology to the 5'-CpG island of the gene encoding a transmembrane protein containing epidermal growth factor and follistatin domains (TPEF). The methylation status of the TPEF gene was then detected by bisulfite sequencing and the levels of TPEF mRNA were detected by RT-PCR. In addition, the effects of a methylation inhibitor 5-aza-2'-deoxycytidine on TPEF mRNA expression was determined in cells of ESCC cell lines. Hypermethylation of the 5'-CpG island of TPEF was found in 12 of 22 (54.5%) primary tumors. Reverse transcription PCR analysis demonstrated that TPEF mRNA expression was significantly lower in tumors than in adjacent normal tissues, which is associated with promoter hypermethylation. In addition, treatment of ESCC cell lines with 5-aza-2'-deoxycytidine led to re-expression of the TPEF transcript. In conclusion, we observed promoter of TPEF gene is frequently hpermethylated, and is associated with the loss of TPEF mRNA expression in ESCC samples. Promoter hypermethylation of TPEF gene may play a role in the development of ESCC.

Inclusive K(S);(0)K(S);(0) resonance production in ep collisions at HERA

Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.

Surface plasmon resonance in CdSe semiconductor coated with gold nanoparticles

We have grown CdSe semiconductor films on glass substrates and the films were coated with Au nanoparticles of 10 nm in size by the pulsed-laser deposition technique. The films demonstrate a large enhancement of Raman intensity and photoluminescence of CdSe semiconductor via excitation of surface plasmon resonances in proximate gold metal nanoparticles deposited on the surface of CdSe film. These observations suggest a variety of approaches for improving the performance of devices such as photodetectors, photovoltaics, and related devices, including biosensors.

Urinary 8-hydroxydeoxyguanosine levels in diabetic retinopathy patients

PURPOSE

Involvement of oxidative stress in the pathogenesis of diabetic microvascular complications has been proposed. Recently, 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been reported to serve as a new sensitive biomarker of the oxidative DNA damage in vivo. This study was undertaken to investigate whether the urinary levels of 8-OHdG are altered in patients with type 2 diabetes. The authors also attempted to analyze the relationship between 8-OHdG levels and other clinical parameters of patients with diabetes, especially the relationship between oxidative DNA damage and the severity of the retinal lesions in patients with diabetic retinopathy.

METHODS

The authors studied 60 patients with type 2 diabetes and compared them with 35 nondiabetic control subjects. Urinary 8-OHdG concentrations were assayed using competitive enzymelinked immunosorbent assay.

RESULTS

The patients with type 2 diabetes had significantly higher concentrations of 8-OHdG in their urine than the control subjects (19.6+/-6.7 vs 11.9+/-4.9 ng/mgCr; p<0.05). The authors could not find any correlation between urinary 8-OHdG levels and age, duration of diabetes, or serum lipids. However, HbA1c values were significantly correlated with 8-OHdG values. Among the patients with diabetes, those with proliferative retinopathy had significantly higher 8-OHdG levels than those with nonproliferative retinopathy or without retinopathy.

CONCLUSIONS

The authors' findings show that measuring urinary 8-OHdG is a novel convenient method for evaluating oxidative DNA damage in patients with diabetes, and it is also suggested that 8-OHdG could be a sensitive biomarker and may be helpful for the early diagnosis and treatment of patients with diabetic retinopathy.