Effects of short-term high-fat overfeeding on genome-wide DNA methylation in the skeletal muscle of healthy young men

AIMS/HYPOTHESIS

Energy-dense diets that are high in fat are associated with a risk of metabolic diseases. The underlying molecular mechanisms could involve epigenetics, as recent data show altered DNA methylation of putative type 2 diabetes candidate genes in response to high-fat diets. We examined the effect of a short-term high-fat overfeeding (HFO) diet on genome-wide DNA methylation patterns in human skeletal muscle.

METHODS

Skeletal muscle biopsies were obtained from 21 healthy young men after ingestion of a short-term HFO diet and a control diet, in a randomised crossover setting. DNA methylation was measured in 27,578 CpG sites/14,475 genes using Illumina's Infinium Bead Array. Candidate gene expression was determined by quantitative real-time PCR.

RESULTS

HFO introduced widespread DNA methylation changes affecting 6,508 genes (45%), with a maximum methylation change of 13.0 percentage points. The HFO-induced methylation changes were only partly and non-significantly reversed after 6-8 weeks. Alterations in DNA methylation levels primarily affected genes involved in inflammation, the reproductive system and cancer. Few gene expression changes were observed and these had poor correlation to DNA methylation.

CONCLUSIONS/INTERPRETATION

The genome-wide DNA methylation changes induced by the short-term HFO diet could have implications for our understanding of transient epigenetic regulation in humans and its contribution to the development of metabolic diseases. The slow reversibility suggests a methylation build-up with HFO, which over time may influence gene expression levels.

Developmental changes of <i>GHR</i> and <i>IGF-I</i> mRNA expression in lamb rumen

Abstract. Lambs from birth (0-day-old) to 56-day-old were selected in present study to investigate developmental changes of growth hormone receptor (GHR) and insulin-like growth factor I (IGF-I) mRNA expression in their rumen tissue. Forty-five lambs (5 lambs per group) were slaughtered at 0, 7, 14, 21, 28, 35, 42, 49, 56 days of age respectively for sampling the tissue of the rumen dorsal sac. The abundance of GHR and IGF-I mRNA were detected through real-time quantitative PCR method. The results indicated that the expression levels of GHR and IGF-I mRNA had similar change tendency in rumen tissue that the GHR and IGF-I mRNA abundance decreased with age from birth to 56-day-old. There was significant positive correlation between the two gene mRNA expression levels. The results suggested that GHR and IGF-I gene expression levels had the specific developmental pattern in rumen tissue.

One-way transmission of linearly polarized light in plasmonic subwavelength metallic grating cascaded with dielectric grating

We show that optical transmission of linearly polarized light through a plasmonic subwavelength metallic grating cascaded with a dielectric grating at a 45° angle to each other is asymmetric in opposite directions. A key characteristic of this asymmetric transmission is that the polarization of the transmitted light is changed. Simulation results reveal that transmission of 0.92 in one direction and 10(-5) in the opposite direction can be obtained at normal incidence at a wavelength of 1550 nm. Because of their high optical performance and loose fabrication requirements, the structures may provide practical applications in the control of light transmission.

A study on indoor environment contaminants related to dust mite in dwellings of allergic asthma patients and of healthy subjects

This study investigated the pollution of dust mite allergens in the houses of 30 families and their infection to young allergic asthma patients in Shanghai. Medical records, family information, and dust samples were collected from the dwellings of 15 young allergic asthma patients and 15 healthy subjects. Der 1 allergen, which is a common allergen causing allergic asthma, was measured in collected dust samples using the Pharmacia Uni-CAP System. A significant correlation was found between the number of Der 1 allergens collected from floor surfaces and the number of Der 1 allergens collected from bed surfaces. Some factors influencing Der 1 allergen levels were found in this study. Relative humidity in dwellings was found to be most influential to the allergen levels. The findings suggested that traditional reduction methods for coarse particles, such as opening windows and periodic cleaning of beddings, may be effective in removing dust mite allergens.

Effects of hepatocyte growth factor on wound healing of rabbit maxillary sinus mucosa

OBJECTIVE

The purpose of this study was to investigate the effects of hepatocyte growth factor (HGF) on healing of the sinonasal mucosa.

METHODS

A 6 mm wound was created in the bilateral maxillary sinuses of 16 New Zealand White rabbits, and 8 mm diameter absorbable gelatin sponge with 25 μL HGF (case) and 25 μL saline (control) were randomly assigned to each side for wound treatment. On the third and seventh days after the procedure, the average decreased diameter was recorded. On the seventh day, the medial wall of the maxillary sinus was taken for histologic analysis (including scanning electron microscopy of two rabbits). The maximal thickness of fibrous tissue and no epithelium coverage of the wound were detected. In the second, third, and fourth weeks, another 3 rabbits were randomly selected for photographs under a scanning electron microscope.

RESULTS

On the third and seventh days after injury, the average decreased diameters were 2.05 ± 0.56 mm and 1.56 ± 0.80 mm, 3.90 ± 0.76 mm, and 3.29 ± 0.70 mm on the case and control sides, respectively. On day 7 after injury, the maximal thickness of fibrous tissue was 324.8 ± 93.1 μm and 432.8 ± 106.3 μm, and the wound without epithelium coverage was 345.7 ± 114.6 μm and 508.6 ± 157.2 μm on case and control sides, respectively, and there were significant differences (p < .05).

CONCLUSIONS

HGF can promote wound healing and ciliogenesis and inhibit fibrosis in the maxillary sinus mucosa, especially in the first 3 days. This finding suggests that HGF plays a potential role in reepithelialization and cilium hyperplasia.

Associations between testosterone, bone mineral density, vitamin D and semen quality in fertile and infertile Chinese men

Testosterone (T) and vitamin D (VD) interact in androgen deficient men, however, this interaction and subsequent semen quality and bone mineral density (BMD) status is not clear in infertile men. Our objective was to investigate T, VD, semen quality, BMD and their relationships in Chinese infertile men. We conducted a cross-sectional study of 559 men aged 20-40 years, including 195 fertile men, 9 infertile men with known risk factors for osteoporosis (WR) and 355 infertile men without known risk factors for osteoporosis (WOR). WOR infertile men constituted 314 oligo-, astheno-, teratospermic or normospermic infertile men (OATN men) and 41 non-obstructive azoospermic men (NOA men). Differences of parameters were assessed, and the relationships were adjusted by multiple linear regression. WOR infertile men had significantly lower T, lumbar spine and total hip BMD than fertile men (all p < 0.05). Bioavailable T (Bio-T) and 25-hydroxyvitamin D [25(OH)D] were independent determinants of BMD in WOR infertile men (all p < 0.01) but not in fertile men. After stratifying Bio-T, WOR infertile men had lower BMD than fertile men (all p < 0.05) in low Bio-T subgroups (Bio-T ≤ 11.6 nmol/L), but not high Bio-T subgroups (Bio-T > 11.6 nmol/L). 25(OH)D was an independent determinant of sperm motility and morphology in WOR OATN men (all p < 0.05), with only borderline significance in fertile men(motility: p = 0.047; morphology: p = 0.056). T determined sperm concentration (square root) and morphology in WOR OATN men (all p < 0.001). No correlations between T and 25(OH)D were found in all groups. We suggest that infertile men have lower T and BMD than fertile men. 25(OH)D and T were associated with low BMD and poor semen quality in infertile men.

[The application septonasal bidirectional mucoperiosteal flap in treatment of refractory choanal atresia in adults]

OBJECTIVE

To explore the effects of septonasal bidirectional mucoperiosteal flap in the treatment of refractory choanal atresia in adults.

METHOD

Analysis of 9 cases for choanal atresia was conducted. Two cases were of congenital origin and 7 cases of acquired origin, which was a complication of radiotherapy for nasopharyngeal carcinoma. The patients received transnasal endoscopic surgery using the septonasal bidirectional mucoperiosteal flap, without positioning the postoperative expansion tube. After the operation, the changes of symptoms were observed and the recurrent rate of restenosis or atresia was investigated in the follow-up time.

RESULT

The symptoms of nasal obstruction and mouth breathing improved significantly in the 9 patients. At an average follow-up time of 19.3 months, the new forming posterior nare remained patent. The mucoperiosteal flap had no shift or necrosis. No restenosis or atresia happened. Nasal adhesion occurred in two patients. Granulation tissue hyperplasia was found in 1 patient, who underwent endoscopic revision without recurrence.

CONCLUSION

The application of mucoperiosteal flap in transnasal endoscopic surgery for the choanal atresia can reduce the incidence of restenosis or atresia. Postoperative expansion tube is not mandatory.

Electrocatalytic Properties of Nanocrystalline Calcium-Doped Lanthanum Cobalt Oxide for Bifunctional Oxygen Electrodes

Calcium-doped lanthanum cobalt oxide is a promising electrocatalyst for oxygen evolution and oxygen reduction in rechargeable metal-air batteries and water electrolyzers operating with alkaline electrolyte. Nanocrystalline perovskite of composition La0.6Ca0.4CoO3 with a unique cellular internal structure was prepared at 350 °C and then annealed in air at progressively higher temperatures in the range of 600-750 °C. The samples were characterized by electrochemical techniques and X-ray photoelectron spectroscopy. The area-specific electrocatalytic activity for oxygen evolution/oxygen reduction, the oxidation state of cobalt, and the crystallite size increased with annealing temperature, while the Tafel slope remained constant. These trends provide new insights into the role of the cobalt center in oxygen evolution and oxygen reduction, and how preparation conditions can be altered to tune the activity of the cobalt center for electrocatalysis. We expect these findings to guide the design of electrocatalysts for bifunctional oxygen electrodes, in general.

Structural changes and relaxations monitored by luminescence

Luminescence data have often been used to study imperfections and to characterize lattice distortions because the signals are sensitive to changes of structure and composition. Previous studies have included intentionally added probe ions such as rare earth ions to sense distortions in local crystal fields caused by modified structural environments. An under-exploited extension of this approach was to use luminescence to monitor crystalline phase changes. A current overview of this new and powerful technique shows that continuous scanning of the sample temperatures immediately offered at least three types of signatures for phase transitions. Because of high sensitivity, luminescence signals were equally responsive to structural changes from inclusions and nanoparticles. These coupled to the host material via long-range interactions and modified the host signals. Two frequently observed examples that are normally overlooked are from nanoparticle inclusions of water and CO2. Examples also indicated that phase transitions were detected in more diverse materials such as superconductors and fullerenes. Finally, luminescence studies have shown that in some crystalline examples, high dose ion implantation of surface layers could induce relaxations and/or structural changes of the entire underlying bulk material. This was an unexpected result and therefore such a possibility has not previously been explored. However, the implications for ion implication are significant and could be far more general than the examples mentioned here.

Functional scaffold-free 3-D cardiac microtissues: a novel model for the investigation of heart cells

To bridge the gap between two-dimensional cell culture and tissue, various three-dimensional (3-D) cell culture approaches have been developed for the investigation of cardiac myocytes (CMs) and cardiac fibroblasts (CFs). However, several limitations still exist. This study was designed to develop a cardiac 3-D culture model with a scaffold-free technology that can easily and inexpensively generate large numbers of microtissues with cellular distribution and functional behavior similar to cardiac tissue. Using micromolded nonadhesive agarose hydrogels containing 822 concave recesses (800 μm deep × 400 μm wide), we demonstrated that neonatal rat ventricular CMs and CFs alone or in combination self-assembled into viable (Live/Dead stain) spherical-shaped microtissues. Importantly, when seeded simultaneously or sequentially, CMs and CFs self-sorted to be interspersed, reminiscent of their myocardial distribution, as shown by cell type-specific CellTracker or antibody labeling. Microelectrode recordings and optical mapping revealed characteristic triangular action potentials (APs) with a resting membrane potential of -66 ± 7 mV (n = 4) in spontaneously contracting CM microtissues. Under pacing, optically mapped AP duration at 90% repolarization and conduction velocity were 100 ± 30 ms and 18.0 ± 1.9 cm/s, respectively (n = 5 each). The presence of CFs led to a twofold AP prolongation in heterogenous microtissues (CM-to-CF ratio of 1:1). Importantly, Ba(2+)-sensitive inward rectifier K(+) currents and Ca(2+)-handling proteins, including sarco(endo)plasmic reticulum Ca(2+)-ATPase 2a, were detected in CM-containing microtissues. Furthermore, cell type-specific adenoviral gene transfer was achieved, with no impact on microtissue formation or cell viability. In conclusion, we developed a novel scaffold-free cardiac 3-D culture model with several advancements for the investigation of CM and CF function and cross-regulation.

Metallic nanofilm half-wave plate based on magnetic plasmon resonance

We proposed and fabricated a nanofilm half-wave plate consisting of periodic arrays of orthogonally coupled slit-hole resonator structures in Au film. Experimental results reveal that 95.2% of energy of the incident linearly polarized light is converted to the perpendicular polarization direction after reflection from the nanostructure. The wave plate is single layer with only 180 nm thickness, which is much thinner than the operation wavelength. Our method can be expanded to other resonant structures or transmitted case.

Short- and long-term hemodynamic and clinical effects of carotid artery stenting

BACKGROUND AND PURPOSE

Stenosis of the carotid artery may cause reduced hemodynamic and neural function that may be ameliorated with CAS. The goal of this study was to evaluate short- and long-term hemodynamic and clinical effects after CAS.

MATERIALS AND METHODS

Hemodynamic parameters were acquired by PCT within 1 week before CAS and at 1 week and 1 year (10-13 months) after CAS. In ACA territory, MCA territory, PCA territory, basal ganglia, anterior and posterior CWS and IWS, the rCBF, rCBV, and rMTT were determined in 20 patients with unilateral carotid artery stenosis who underwent CAS. MR and noncontrast CT were performed within 1 week before CAS. Noncontrast CT and carotid arteriography were performed immediately after CAS. Carotid arteriography was performed 1 year after CAS. MRS was performed in 3 measurements. The variance analysis was performed to determine whether there were significant differences among the 3 measurements.

RESULTS

No significant differences were found among rCBV in any territory (P > .05). In the non-PCA territories, rMTT decreased and rCBF increased at 1 week after CAS (P < .01), but there was no significant difference between 1-week and 1-year effects (P > .05). For MR spectroscopy, no significant differences were found between 1 week after CAS and pretreatment (P > .05); the 1-year scores improved significantly (P < .01).

CONCLUSIONS

The long-term hemodynamic and clinical results after treatment validated that CAS is a durable procedure. The 1-week hemodynamic effects can predict long-term effects.

Cell-substrate interaction with cell-membrane-stress dependent adhesion

Cell-substrate interaction is examined in a two-dimensional mechanics model. The cell and substrate are treated as a shell and an elastic solid, respectively. Their interaction through adhesion is treated using nonlinear springs. Compared to previous cell mechanics models, the present model introduces a cohesive force law that is dependent not only on cell-substrate distance but also on internal cell-membrane stress. It is postulated that a living cell would establish focal adhesion sites with density dependent on the cell-membrane stress. The formulated mechanics problem is numerically solved using coupled finite elements and boundary elements for the cell and the substrate, respectively. The nodes in the adhesion zone from either side are linked by the cohesive springs. The specific cases of a cell adhering to a homogeneous substrate and a heterogeneous bimaterial substrate are examined. The analyses show that the substrate stiffness affects the adhesion behavior significantly and regulates the direction of cell adhesion, in good agreement with the experimental results in the literature. By introducing a reactive parameter (i.e., cell-membrane stress) linking biological responses of a living cell to a mechanical environment, the present model offers a unified mechanistic vehicle for characterization and prediction of living cell responses to various kinds of mechanical stimuli including local extracellular matrix and neighboring cells.

Anti-epidermal growth factor receptor therapy for advanced head and neck squamous cell carcinoma: a meta-analysis

OBJECTIVE

To assess the efficacy and safety of anti-epidermal growth factor receptor (EGFR) therapy versus non-anti-EGFR therapy for advanced head and neck squamous cell carcinoma (HNSCC).

METHODS

The Cochrane Central Register of Controlled Trials, Medline, and Embase databases were searched for relevant reports. Quantitative analysis was carried out to evaluate the overall response rate (ORR), overall survival (OS), progression free survival (PFS), and grade 3-4 adverse effects.

RESULTS

Ten reports involving 2,396 patients were included. Primary meta-analysis indicated that anti-EGFR therapy could improve ORR [relative risk (RR) 1.36, 95% confidence interval (CI) 1.12-1.67] and PFS [hazard ratio (HR) 0.63, 95% CI 0.55-0.71), but failed to improve OS (HR 0.88, 95% CI 0.74-1.03). In subgroup analyses, we found that monoclonal antibodies (Mabs) could improve ORR, OS, and PFS for both locoregionally advanced (LA) (ORR: 1.21, 1.08-1.37; OS: 0.72, 0.59-0.89; PFS: 0.66, 0.53-0.83) and recurrent/metastatic (RM) HNSCC (ORR: 1.88, 1.40-2.54; OS: 0.79, 0.67-0.94; PFS: 0.61, 0.52-0.71), while tyrosine kinase inhibitors (TKIs) did not improve any of these in patients with either LA (ORR: 1.09, 0.91-1.32; OS: 0.7, 0.31-1.63; PFS: 0.71, 0.34-1.52) or RM (ORR: 1.65, 0.84-3.24; OS: 1.13, 0.97-1.31; PFS: not available) HNSCC. Analysis of adverse effects demonstrated that rash (RR 14.34, 95% CI 5.02-41.02), diarrhea (2.36, 1.15-4.87), and anorexia (2.49, 1.11-5.56) were significantly associated with anti-EGFR therapy.

CONCLUSIONS

Anti-EGFR Mabs are effective for both LA and RM HNSCC. In contrast, TKIs were unsuitable for treatment of advanced HNSCC. During anti-EGFR therapy, rash and some gastrointestinal reactions, such as diarrhea and anorexia, should be carefully monitored.