Correlation research of carotid arterial sclerosis and left ventricular diastolic function in hyperthyroidism

AIM

This study aims to investigate the correlation of carotid arterial sclerosis and left ventricular diastolic function in hyperthyroidism.

METHODS

A total of 70 patients with newly-diagnosed hyperthyroidism, including 32 patients clinically cured or improved after I131 therapy, were compared with 74 healthy cases in the control group. Bilateral carotid ultrasound and echocardiography were performed in all subjects. The carotid sclerosis index B, compliance coefficient CC, pulse wave velocity (PWV) and left ventricular diastolic function parameters (mitral valve diastolic peak velocity ratio E/A, mitral annulus tissue Doppler diastolic peak velocity ratio e/a and E/e) were obtained.

RESULTS

The B, CC, PWV and E/e exhibited correlation. Pre-treatment CC was negatively correlated with E/e (r=-0.325, P<0.01), whereas B and PWV were positively correlated with E/e (r=0.270 and 0.297, P < 0.05). Post-treatment CC was negatively correlated with E/e (r=-0.462, P<0.01), whereas B and PWV were positively correlated with E/e (r=0.513 and 0.479, P<0.01).

CONCLUSION

Carotid artery function and left ventricular diastolic function of hyperthyroid patients were damaged before the treatment and recovered after the treatment. Thus, a correlation existed between them. The early detection of carotid artery function could help the early detection of cardiovascular disease in the hyperthyroid patients.

Benzo(a)pyrene-7,8-diol-9,10-epoxide induced p53-independent necrosis via the mitochondria-associated pathway involving Bax and Bak activation

Benzo(a)pyrene-7,8-diol-9,10-epoxide (BPDE) is a highly reactive DNA damage agent and can induce cell death through both p53-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BPDE-induced cell death. To understand the p53-independent mechanisms, we have now examined BPDE-induced cytotoxicity in p53-deficient baby mouse kidney (BMK) cells. The results showed that BPDE could induce Bax and Bak activation, cytochrome c release, caspases activation, and necrotic cell death in the BMK cells. Bax and Bak, two key molecules of mitochondrial permeability transition pore, were interdependently activated by BPDE, with Bax and Bak translocation to and Bax/Bak homo-oligomerization in mitochondria, release of cytochrome c was induced. Importantly, cytochrome c release and necrotic cell death were diminished in BMK cells (Bax−/−), BMK cells (Bak−/−), and BMK cells (Bax−/−/Bak−/−). Furthermore, overexpression of Bcl-2 could ameliorate BPDE-induced cytochrome c release and necrosis. Together the findings suggested that BPDE-induced necrosis was modulated by the p53-independent pathway, which was related to the translocation of Bax and Bak to mitochondria, release of cytochrome c, and activation of caspases.

Family functioning in Asian families raising children with autism spectrum disorders: the role of capabilities and positive meanings

BACKGROUND

There has been increasing interest in exploring the factors contributing to successful adaptation and family functioning in ethnically and culturally diverse families who raise children with autism spectrum disorders (ASD), in order to inform more appropriate strength-based family support services. This pilot study used the Family Adjustment and Adaptation Response (FAAR) model as a theoretical framework to investigate the role of families' capabilities (coping strategies and resources of support) and positive meanings in raising a child with ASD in family functioning in an Asian context.

METHODS

Sixty-five Singaporean parents of 3- to 11-year-old children with ASD completed a series of questionnaires on demands, coping strategies, social support, positive meanings and family functioning.

RESULTS

Families reported a number of helpful coping strategies. Coping through family integration/optimism was most helpful, followed by understanding the condition and by developing esteem and psychological stability. Reported capabilities, but not positive meanings, mediated the relationship between demands and family functioning.

CONCLUSION

The findings are discussed in relation to existing literature, possible specific cultural issues, and the strengths and limitations of the study. Implications for supporting families of children with ASD in different social and cultural contexts are also discussed.

Epigenetic synergies between biotin and folate in the regulation of pro-inflammatory cytokines and repeats

The protein biotin ligase, holocarboxylase synthetase (HLCS), is a chromatin protein that interacts physically with the DNA methyltransferase DNMT1, the methylated cytosine-binding protein MeCP2 and the histone H3 K9-methyltransferase EHMT1, all of which participate in folate-dependent gene repression. Here we tested the hypothesis that biotin and folate synergize in the repression of pro-inflammatory cytokines and long-terminal repeats (LTRs), mediated by interactions between HLCS and other chromatin proteins. Biotin and folate supplementation could compensate for each other's deficiency in the repression of LTRs in Jurkat and U937 cells. For example, when biotin-deficient Jurkat cells were supplemented with folate, the expression of LTRs decreased by >70%. Epigenetic synergies were more complex in the regulation of cytokines compared with LTRs. For example, the abundance of TNF-α was 100% greater in folate- and biotin-supplemented U937 cells compared with biotin-deficient and folate-supplemented cells. The NF-κB inhibitor curcumin abrogated the effects of folate and biotin in cytokine regulation, suggesting that transcription factor signalling adds an extra layer of complexity to the regulation of cytokine genes by epigenetic phenomena. We conclude that biotin and folate synergize in the repression of LTRs and that these interactions are probably mediated by HLCS-dependent epigenetic mechanisms. In contrast, synergies between biotin and folate in the regulation of cytokines need to be interpreted in the context of transcription factor signalling.

Abstract P3-07-08: Breast cancer in China reveals transcriptomic likeness to Caucasian breast cancer

The incidence of breast cancer among Chinese women has been historically much lower than that of Caucasian women but has increased dramatically over the past 30 years in urban areas of China, an increase likely to continue in the next decades across China with progressive urbanization and economic development. However, it is still unclear whether differences in breast cancer incidence between Chinese and Caucasian women reflect differences in disease biology in addition to environmental factors. To address this question, we compared consecutive cohorts of Chinese and Italian breast cancer patients who underwent surgical resection in the years 2005-2007 at Fudan Cancer Center of Shanghai (China) and Fondazione IRCCS Istituto Tumori of Milan (Italy), respectively, two comprehensive cancer centers with similar inpatients and outpatients recruited in a large area. Analyses of clinico-pathological characteristics of 1563 Chinese and 1052 Italian consecutive breast cancer patients revealed that 50% of patients in the Chinese cohort were younger than 50 years versus 29% of Italian patients, indicating that Chinese women develop breast cancer earlier than Italian patients, with a peak of frequency at 50-60 years. Among Chinese breast tumors, 63% were estrogen receptor (ER)-positive versus 85% of the Italians, and the prevalence of ER-positive tumors was equivalent in pre- and postmenopausal Chinese cases, suggesting the same hormonal features in tumors of younger and older patients, consistent with findings in the Italian cohort.

Microarray-based gene and miRNA expression profiling was then conducted on 80 Chinese and 97 Italian samples using Illumina Gene and MicroRNA expression technologies. To minimize potential bias and artifact due to variability in specimen collection, storage, processing and analysis of high-throughput results, samples initially collected in the Chinese and Italian hospitals were all stored, randomly processed and analyzed in the Italian center. Analysis revealed a comparable pattern of gene and miRNA expression in the 2 cohorts with unsupervised hierarchical clustering of 12,338 genes and 858 miRNAs, and similar expression of intrinsic and extracellular matrix (ECM) genes led to a similar partition in intrinsic and ECM subtypes, indicating molecular similarity among Chinese and Caucasian breast cancers.

Supported by Ministero Affari Esteri (Italy-China significant bilateral project).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-07-08.

Abstract P4-07-13: High microRNA-621 level predicts a better response to neoadjuvant chemotherapy in breast cancer patients

Purpose: Weekly paclitaxel plus carboplatin (PCb) regimen is an effective neoadjuvant chemotherapy for breast cancer. However, some patients respond to this regimen poorly and suffer from side effects. In this study, we aimed to define the microRNA (miRNA) biomarker for predicting sensitivity to PCb chemotherapy in breast cancer patients, and to explore the potential molecular mechanisms.

Experimental Design: 81 patients with stages II and III breast cancer, who received four cycles of weekly PCb regimen preoperative chemotherapy, were included. Gene expression profiles from 31 patients was used as training set to determine differentially expressed genes (DEGs) and to predict miRNAs that may be associated with chemotherapeutic sensitivity. The other 50 patients were analyzed as validation set to test the accuracy of DEG identification and miRNAs prediction by quantitative real-time PCR. In parallel, in vitro and in vivo analyses were carried out to determine the potential mechanisms of miRNA-dependent drug sensitivity.

Results: Gene profiling analyses in the training set revealed significant correlation between high expression level of miR-345 and miR-621 and pathologic complete response (pCR) in breast cancer patients. We further validated that the expression level of miR-621 was significantly higher in tumor tissues of pCR patients than that in non-pCR patients (P = 0.01). In breast cancer cell lines, ectopic overexpression of miR-621 promoted apoptosis and increased chemosensitivity to paclitaxel and carboplatin both in vitro and in vivo. The potential miR-621-target genes were determined by TargetScan and miRNA CLIP-seq database, which were further confirmed as DEGs reversely-correlated to miR-621 in breast cancer patient samples. Among those, FBXO11 was verified as one of the direct targets of miR-621 in breast cancer cells, whose expression level negatively associated with chemosensitivity in breast cancer patients. The molecular mechanisms by which miR-621/FBXO11 axis regulates chemosensitivity may involve regulation of p53 transcriptional activity and epithelial-mesenchymal transition (EMT) in breast cancer cells.

Conclusions: Our study revealed a strong correlation between miR-621 expression and chemosensitivity in breast cancers. High level of miR-621 predicts sensitivity to PCb regimen neoadjuvant chemotherapy in breast cancer patients who tend to achieve pCR. The increased chemosensitivity may be mediated by down-regulation of FBXO11 gene, which leads to enhanced p53 transactivity and reduced EMT in breast cancer cells. Therefore, miR-621 may be used as predictive biomarker and the potential therapeutic target in breast cancer treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-07-13.

Genome-wide screening for components of small interfering RNA (siRNA) and micro-RNA (miRNA) pathways in the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

The brown planthopper (BPH), Nilaparvata lugens, is a major rice pest in Asia, and accumulated evidence indicates that this species is susceptible to RNA interference (RNAi); however, the mechanism underlying RNAi and parental RNAi has not yet been determined. We comprehensively investigated the repertoire of core genes involved in small interfering RNA (siRNA) and micro-RNA (miRNA) pathways in the BPH by comparing its newly assembled transcriptome and genome with those of Drosophila melanogaster, Tribolium castaneum and Caenorhabditis elegans. Our analysis showed that the BPH possesses one drosha and two Dicer (dcr) genes, three dsRNA-binding motif protein genes, two Argonaute (ago) genes, two Eri-1-like genes (eri-1), and a Sid-1-like gene (sid-1). Additionally, we report for first time that parental RNAi might occur in this species, and siRNA pathway and Sid-1 were required for high efficiency of systemic RNAi triggered by exogenous dsRNA. Furthermore, our results also demonstrated that the miRNA pathway was involved in BPH metamorphosis as depletion of the ago1 or dcr1 gene severely impaired ecdysis. The BPH might be a good model system to study the molecular mechanism of systemic RNAi in hemimetabolous insects, and RNAi has potential to be developed to control this pest in agricultural settings.

Neuroprotective effect of resveratrol on arsenic trioxide–induced oxidative stress in feline brain

Arsenic trioxide (As2O3) is a known environmental toxicant and potent chemotherapeutic agent. Significant correlation has been reported between arsenic exposure (including consumption of arsenic-contaminated water and clinical use of As2O3) and dysfunction in the nervous system. In this study, we aimed to elucidate the effect of resveratrol with neuroprotective activities on As2O3-induced oxidative damage and cerebral cortex injury. Twenty-four healthy Chinese Dragon Li cats of either sex were randomly divided into four groups: control (1 ml/kg physiological saline), As2O3 (1 mg/kg), resveratrol (3 mg/kg) and As2O3 (1 mg/kg) + resveratrol (3 mg/kg). As2O3+resveratrol-treated group were given resveratrol (3 mg/kg) 1 h before As2O3 (1 mg/kg) administration. Pretreatment with resveratrol upregulated the activities of antioxidant enzymes and attenuated As2O3-induced increases in reactive oxygen species and malondialdehyde production. In addition, resveratrol attenuated the As2O3-induced reduction in the level of reduced glutathione and the ratio of reduced glutathione to oxidised glutathione, and accumulation of arsenic in the cerebral cortex. These findings support neuroprotective effect of resveratrol on As2O3 toxicity in feline brain and provide a better understanding of the mechanism that resveratrol modulates As2O3-induced oxidative damage and a stronger rational for clinical use of resveratrol to protect brain against the toxicity of arsenic.

Inbreeding and genetic diversity in three imported Swine breeds in china using pedigree data

The accumulation of inbreeding and the loss of genetic diversity is a potential problem in the modern swine breeds in China. Therefore, the purpose of this study was to analyze the pedigrees of Chinese Duroc (CD), Landrace (CL) and Yorkshire (CY) swine to estimate the past and current rates of inbreeding, and to identify the main causes of genetic diversity loss. Pedigree files from CD, CL and CY containing, 4529, 16,776 and 22,600 records, respectively, were analyzed. Pedigree completeness indexes of the three breeds, accounting for one generation back, were 83.72, 93.93 and 93.59%, respectively. The estimated average annual inbreeding rates for CD, CL and CY in recent three years were 0.21, 0.19 and 0.13%, respectively. The estimated average percentage of genetic diversity loss within each breed in recent three years was about 8.92, 2.19, and 3.36%, respectively. The average relative proportion of genetic diversity loss due to unequal contributions of founders in CD, CL and CY was 69.09, 57.95 and 60.57%, and due to random genetic drift was 30.91, 42.05 and 39.43%, respectively. The estimated current effective population size for CD, CL and CY was 76, 117 and 202, respectively. Therefore, CD has been found to have lost considerable genetic diversity, demanding priority for optimizing the selection and mating to control future coancestry and inbreeding. Unequal contribution of founders was a major cause of genetic diversity loss in Chinese swine breeds and random genetic drift also showed substantial impact on the loss of diversity.

X-ray microdiffraction, TEM characterization and texture analysis of human dentin and enamel

Human tooth is a complex bioceramic composite, which consists of enamel, dentin and the interface, the dentin-enamel junction (DEJ). The crystal properties and ultrastructure of the inorganic phase through the thickness of healthy human molar teeth were investigated using X-ray microdiffraction (μXRD), electron diffraction and transmission electron microscopy (TEM) techniques. The XRD data were analysed using the Le Bail profile fitting approach. The size and the texture of the crystallites forming enamel and dentin in the crown part of teeth were measured using both techniques and then compared. Results showed that the thickness of dentin crystallites was found to decrease towards the DEJ, whereas the thickness of the enamel crystallites increased from the DEJ towards the outer layers. It was demonstrated that enamel exhibited an increase of texture in 002 lattice planes from the DEJ towards the outer layers. Texture was also detected in 102 lattice planes. The texture effect in 002 planes at the scale of less than 1 μm was also demonstrated in dentin. The variation of lattice parameters as a function of the position within the thickness of dentin and enamel was also observed. The values of the nonuniform microstrain in the dentin and enamel crystallites were from 1.40 × 10(-6) % to 4.44 × 10(-5) %. The good correlation between XRD and TEM indicated that μXRD is a useful technique to study crystallography and microstructure of heterogeneous enamel and dentin. The observed gradient characteristics of texture and crystallite size in enamel and dentin maybe an evolutionary outcome to resist wear and fracture, thereby contributing to the excellent mechanical properties of teeth.