Research on the reactivation of Syk expression caused by the inhibition of DNA promoter methylation in the lung cancer

The aim of this study was to study the expression of Syk gene and methylation in its promoter region in the lung cancer and to investigate the relationship between silencing of the Syk gene and DNA methylation of the Syk promoter region in lung cancer cell lines. Real-time PCR and immunohistochemistry were used to examine the Syk expression in specimens from 3 lung cancer cell lines and 16 lung cancer patients (tumor tissues and adjacent normal tissues). MSP was used to analyze the methylation status of the Syk promoter region. We also investigated the role of restoring Syk expression by using a DNA methyltransferase inhibitor, 5-aza-CdR, in suppressing invasion of lung cancer cell lines. No expression of the Syk gene was detected in the 3 lung cancer cell lines. In the 16 lung cancer patient samples, Syk expression was significantly lower in the tumor tissues than that in their adjacent normal tissues (P<0.05). Consistently, immunohistochemistry analysis of Syk protein expression showed that in the lung cancer tissues Syk protein expression was also significantly lower than that in their adjacent normal tissues. In the two lung cancer cell lines (NL9980, YTMLC-9) that lack the endogenous Syk expression, 4uM demethylation agent 5-aza-CdR treatment was able to reactivate the Syk gene expression, but not NCI-H446. In conclusion, hypermethylation leads to silencing of the Syk gene in human lung carcinoma cell lines. Methylation of the Syk promoter and loss of Syk expression in lung cancer cell lines are independent biomarkers. Syk may be a potential tumor suppressor in human lung cancer.

Growth performance, digestibility, and gut development of broiler chickens on diets with inclusion of chicory (Cichorium intybus L.)

A total of 256 broiler chickens (1 d old) were used in a 32-d growth trial to study the effects of chicory (Cichorium intybus L.) forage and root inclusion on growth performance, digestibility, and gut development. The chicory forage originated from 2 harvests (June and September) and was included at 60 and 120 g/kg. The chicory root was included alone at 60 g/kg or together with chicory forage, from both harvests, in equal amounts (60 g/kg). The cereal-based control diet and 7 experimental diets were fed to each of 4 pens of chickens (8 chickens/pen). A higher BW gain and lower feed conversion ratio were found at 13 d of age in chickens fed the 60 g/kg chicory forage diet (P ≤ 0.05), whereas performance did not differ between the control and 60 g/kg chicory root diets. In contrast, a lower performance and digestibility of DM, organic matter, and AME as well as a thinner cecal mucosa layer were found for the 120 g/kg chicory forage diet (P ≤ 0.05). No diet effects on organ parameters or on pH of cecum digesta were detected. The soluble nonstarch polysaccharides fractions of chicory forage did not have any major negative effects on performance and gut development, and chicory forage from the September harvest was seen to have a higher nutritional value than that from the June harvest. Thus, results from the current study suggest that chicory forage is a potentially useful fiber-rich feed ingredient with high palatability for broiler chickens.

Effects of tripeptides and lactogenic hormones on oligopeptide transporter 2 in bovine mammary gland

This study was conducted to investigate the expression of oligopeptide transporter 2 (PepT2) and its potential function in bovine mammary gland. First, the PepT2 mRNA and protein were determined in cultured mammary epithelial cells. Then the effects of lactogenic hormones (prolactin, hydrocortisone or insulin) and substrate (threonyl-phenylalanyl-phenylalanine) on PepT2 were investigated. The PepT2 mRNA and protein were successfully detected in bovine mammary epithelial cells. PepT2 gene expression was enhanced by the addition of 50, 500 and 5000 ng/ml prolactin, 10 and 100 ng/ml hydrocortisone, and 50, 500, 5000 and 50,000 ng/ml insulin. PepT2 mRNA abundance was increased when 5, 10 and 15% of threonyl-phenylalanyl-phenylalanine was included. Responses of PepT2 to lactogenic hormones and oligopeptide inferred that it may play an important role in bovine mammary gland.

Effects of dietary supplementation of methionine and lysine on milk production and nitrogen utilization in dairy cows

The effect of the content of lysine and methionine in metabolizable protein (MP) on lactation performance and N utilization in Chinese Holstein cows was determined. A control diet (C) was formulated to be adequate in energy but slightly limiting in MP. The concentration of Met and Lys in MP was 1.87 and 5.93%, respectively. The treatments were as follows (% of Met or Lys in MP): L=diet C supplemented with L-lysine-HCl at 0.49% on a dry matter (DM) basis (Met, 1.87; Lys, 7.00); M=diet C supplemented with 2-hydroxy-4-(methylthio)-butanoic acid (HMB) at 0.15% (Met, 2.35; Lys, 5.93); ML=diet C supplemented with 0.49% L-lysine HCl and 0.15% HMB (Met, 2.39; Lys, 7.10). The diets were fed to 60 Chinese Holsteins in mid-lactation (average days in milk=120, and milk yield=32.0 kg/d) for 8 wk. Milk yield was increased by supplementation of either Lys (1.5 kg/d) or Met (2.0 kg/d), and supplementation of both Lys and Met further increased milk yield (3.8 kg/d). There was no significant difference in dry matter intake across treatment groups. Cows on treatments M (3.95%) and ML (3.90%) had higher milk fat content than those on C (3.60%) and L (3.67%), but there were no significant differences in milk protein and lactose contents or somatic cell count among treatments. Supplementation of Met or Lys significantly increased Met or Lys concentration in arterial plasma. Treatment ML had a higher conversion of intake N to milk N and lower urea N concentrations in serum, urine, and milk than did treatment C. Supplementing HMB and L-lysine-HCl to provide approximately 2.3% Met and 7.0% Lys of the MP in diets slightly limiting in MP increased milk production, milk protein yield, and N utilization efficiency.

Cadmium directly induced mitochondrial dysfunction of human embryonic kidney cells

Cadmium (Cd) is the major component of polluted environment, which has numerous undesirable effects on health. Cd could induce apoptosis of HEK293 cells, and the mitochondria may play a key role. However, the mode of action is unclear. In the present study, we aimed to evaluate the ability of the Cd to induce dysfunction of mitochondria. We examined the effect of cadmium chloride (1, 5 and 10 μM) on mitochondrial membrane permeability and potential as well as oxidative stress markers in mitochondria isolated from HEK293 cells. We found that Cd could directly increase in permeability and decrease in membrane potential of mitochondria, even resulted in mitochondrial swelling, and that Cd could inhibit the activities of ATPase, lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), enhanced the levels of reactive oxygen species (ROS) and lipid peroxidation (LPO). On the whole, the results show that Cd can directly lead to mitochondrial dysfunction of HEK293 cells, including increased permeability, inhibiting respiration and evoking oxidative stress. Thus, for the first time, this paper makes an overall analysis of Cd-induced changes of structure and function of isolated mitochondria. Our findings may also have general implications in Cd-induced apoptosis by mitochondria pathway.

Prognosis and Expression of Lambda Light Chains in Solitary Extramedullary Plasmacytoma of the Head and Neck: Two Case Reports and a Literature Review

Two cases of extramedullary plasmacytoma (EMP) of the head and neck, an uncommon plasma cell neoplasm, were studied. Both patients had good outcomes and have been followed for 17 and 12 years without recurrence or systemic disease. In these two cases, the tumours measured were 4 cm and 0.3 cm, and both cases were positive for lambda light chain restriction on immunohistochemistry. Prognostic factors were considered, based on a review of EMP of the head and neck, including published reports and the authors' clinical experience. Of all plasma cell tumours, EMP has the best prognosis, especially when located in the head and neck region. Variation in the biological behaviour of EMP and the limited number of documented cases make it difficult to determine prognostic factors. Some series have found that age, tumour size, site of origin (extramedullary versus bone), grade, M-protein, light chains and radiotherapy dose all influence the outcome in EMP patients.

Long lifetimes of quantum-dot intersublevel transitions in the terahertz range

Carrier relaxation is a key issue in determining the efficiency of semiconductor optoelectronic device operation. Devices incorporating semiconductor quantum dots have the potential to overcome many of the limitations of quantum-well-based devices because of the predicted long quantum-dot excited-state lifetimes. For example, the population inversion required for terahertz laser operation in quantum-well-based devices (quantum-cascade lasers) is fundamentally limited by efficient scattering between the laser levels, which form a continuum in the plane of the quantum well. In this context, semiconductor quantum dots are a highly attractive alternative for terahertz devices, because of their intrinsic discrete energy levels. Here, we present the first measurements, and theoretical description, of the intersublevel carrier relaxation in quantum dots for transition energies in the few terahertz range. Long intradot relaxation times (1.5 ns) are found for level separations of 14 meV (3.4 THz), decreasing very strongly to approximately 2 ps at 30 meV (7 THz), in very good agreement with our microscopic theory of the carrier relaxation process. Our studies pave the way for quantum-dot terahertz device development, providing the fundamental knowledge of carrier relaxation times required for optimum device design.

Fast optical preparation, control, and readout of a single quantum dot spin

We propose and demonstrate the sequential initialization, optical control, and readout of a single spin trapped in a semiconductor quantum dot. Hole spin preparation is achieved through ionization of a resonantly excited electron-hole pair. Optical control is observed as a coherent Rabi rotation between the hole and charged-exciton states, which is conditional on the initial hole spin state. The spin-selective creation of the charged exciton provides a photocurrent readout of the hole spin state.

Effects of daidzein on messenger ribonucleic Acid expression of gonadotropin receptors in chicken ovarian follicles

Effects of daidzein on expression of mRNA of gonadotropin receptors [follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR)] were evaluated in ovarian follicles of ISA laying hens that were 13 mo old in the postpeak period of egg laying. The hens were randomly allocated as control and daidzein-treated groups, with daidzein supplemented to the basal diet at the level of 10 mg/kg for 7 wk. The granulosa layers of preovulatory follicles (F1, F2, F3, F4, F5) and follicular layers of the small yellow follicle (SYF), large white follicle (LWF), and atretic follicle were collected. The mRNA expression of related genes was measured by semiquantitative reverse transcription PCR. Results showed that daidzein significantly increased the egg-laying rate (P < 0.05) and the number of SYF and LWF (P < 0.05). The relative abundance of the FSHR mRNA decreased in the granulosa layers from F5 to F1, but LHR mRNA displayed the opposite trend in developmental changes. Treatment with daidzein resulted in increased expression of FSHR mRNA in LWF, SYF, and granulosa layers of F4 to F2 and LHR mRNA in granulosa layers of F4 and F1 (P < 0.05). These results indicated that dietary supplementation of daidzein upregulated mRNA expression of gonadotropin receptors to improve follicle development in chicken developing follicles and laying performance after the peak laying period.

The Isoflavonoid Daidzein Attenuates the Oxidative Damage Induced by Polychlorinated Biphenyls on Cultured Chicken Testicular Cells

The soy isoflavonoid daidzein (DAI) is one of the most abundant phenolic compounds in the human diet and in animal feedstuffs. Daidzein possesses a wide spectrum of physiological and pharmacological functions related to human health. The aim of this study was to evaluate the effect of DAI on oxidative damage induced by a potential carcinogen, polychlorinated biphenyl. Testicular cells were dispersed from 18-d-old chicken embryos and exposed to DAI alone or in combination with a mixture of polychlorinated biphenyls, Aroclor 1254 (A1254), in culture. Oxidative damage was estimated by measuring the lipid peroxidation and superoxide dismutase activities and glutathione content. Results showed that DAI (10 microg/mL) increased germ cell numbers, which were inhibited by cotreatment with the estrogen receptor antagonist tamoxifen at 0.1 microg/mL. Exposure to A1254 (10 microg/mL) reduced superoxide dismutase activity and glutathione content but increased lipid peroxidation significantly. However, simultaneous supplementation with 10 microg/mL of DAI restored these parameters. The above results indicated that DAI may exert weak estrogenic activity, and more important, that DAI may display an antioxidant effect to prevent oxidative damage induced by the oxidant A1254.

Reversing adriamycin resistance of human breast cancer cells by hyperthermia combined with Interferon alpha and Verapamil

One of the major obstacles related to chemotherapy is resistance against anticancer drugs, including Adriamycin (ADM). The purpose of the present work is to investigate the reversal effects on ADM resistance by hyperthermia (42.5 degrees C) combined with two reversal agents (Interferon alpha and Verapamil) in MCF-7/ADR (ADM-resistant MCF-7 breast cancer cell line), and its relevant molecular mechanism of action. The cell survival rate and ADM IC50 of different experiment groups were measured by MTT test. The quantitative expression of MDR1 gene in cells was detected by Real-time PCR, and the expression of P-glycoprotein (P-gp) on the cells surface and the intracellular ADM accumulation was detected by flow cytometry (FCM). The ADM IC50 of the MCF-7/ADR cells decreased 830-fold after combined with Interferon alpha (IFN-alpha) and Verapamil (VRP). Although there was no distinction in the mRNA expression of MDR1, the P-gp on the MCF-7/ADR cell membrane was significantly reduced and the cellular ADM uptake increased markedly as compared to pretreatment. Our results suggeste that hyperthermia induces a considerably reversal activity against ADM resistance synergizing other reversal agents (IFN-alpha and VRP). The reversal mechanism needs further study. However, these features of hyperthermia may be exploited in clinical cancer chemotherapy.

VEGF-Targeted RNA Interference Suppresses Angiogenesis and Tumor Growth of Retinoblastoma

Vascular endothelial growth factor (VEGF) is one of the most important angiogenic growth factors for tumor angiogenesis which has been verified to be involved in neovascularization of retinoblastoma. Here, we sought to explore whether RNA interference (RNAi) targeting VEGF could inhibit retinoblastoma angiogenesis and tumor growth. Stable transfection of the two human retinoblastoma cell lines SO-RB50 and HXO-RB44 with VEGF-targeted small interfering RNA (siRNA) expression plasmid significantly inhibited VEGF expression determined by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay and Western blot, whereas the control transfection showed no effects. The chemically synthesized VEGF siRNA dramatically suppressed tumor angiogenesis (CD34 immunohistochemistry) and tumor growth in the SO-RB50 subcutaneous xenograft model. Significant downregulation of VEGF expression both on messenger RNA and protein levels in VEGF-siRNA-treated SO-RB50 subcutaneous xenograft was confirmed by real-time PCR and Western blot compared to control. Our data demonstrate the suppression function on angiogenesis and tumor growth of retinoblastoma by VEGF-targeted RNAi. This novel therapeutic strategy promises to play a part in the clinical management of retinoblastoma.

Quantitative trait Loci mapping for adult-plant resistance to powdery mildew in bread wheat

ABSTRACT Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a major disease to wheat (Triticum aestivum) worldwide. Use of adult-plant resistance (APR) is an effective method to develop wheat cultivars with durable resistance to powdery mildew. In the present study, 432 molecular markers were used to map quantitative trait loci (QTL) for APR to powdery mildew in a doubled haploid (DH) population with 107 lines derived from the cross Fukuho-komugi x Oligoculm. Field trials were conducted in Beijing and Anyang, China during 2003-2004 and 2004-2005 cropping seasons, respectively. The DH lines were planted in a randomized complete block design with three replicates. Artificial inoculation was carried out in Beijing with highly virulent isolate E20 of B. graminis f. sp. tritici and the powdery mildew severity on penultimate leaf was evaluated four times, and the maximum disease severity (MDS) on penultimate leaf was investigated in Anyang under natural inoculation in May 2004 and 2005. The heritability of resistance to powdery mildew for MDS in 2 years and two locations ranged from 0.82 to 0.93, while the heritability for area under the disease progress curve was between 0.84 and 0.91. With the method of composite interval mapping, four QTL for APR to powdery mildew were detected on chromosomes 1AS, 2BL, 4BL, and 7DS, explaining 5.7 to 26.6% of the phenotypic variance. Three QTL on chromosomes 1AS, 2BL, and 7DS were derived from the female, Fukuho-komugi, while the one on chromosome 4BL was from the male, Oligoculm. The QTL on chromosome 1AS showed high genetic effect on powdery mildew resistance, accounting for 19.5 to 26.6% of phenotypic variance across two environments. The QTL on 7DS associated with the locus Lr34/Yr18, flanked by microsatellite Xgwm295.1 and Ltn (leaf tip necrosis). These results will benefit for improving powdery mildew resistance in wheat breeding programs.

Fracture spacing in layered materials and pattern transition from parallel to polygonal fractures

We perform three-dimensional simulations of fracture growth in a three-layered plate model with an embedded heterogeneous layer under horizontal biaxial stretch (representing stretch from directional to isotropic) by the finite element approach. The fractures develop under a quasistatical, slowly increasing biaxial strain. The material inhomogeneities are accounted for by assigning each element a failure threshold that is defined by a given statistical distribution. A universal scale law of fracture spacing to biaxial strain in terms of principal stress ratio is well demonstrated in a three-dimensional fashion. The numerically obtained fracture patterns show a continuous pattern transition from parallel fractures, laddering fracture to polygonal fractures, which depends strongly on the far-field loading conditions in terms of principal stress ratio lambda = sigma(2)/sigma(1), from uniaxial (lambda = 0), anisotropic (0 < lambda < 1) to isotropic stretch (lambda = 1). We find that, except for further opening of existing fractures after they are well-developed (saturation), new fractures may also initiate and propagate along the interface between layers, which may serve as another mechanism to accommodate additional strain for fracture saturated layers.

Grain yield responses to moisture regimes in a rice population: association among traits and genetic markers

Drought is a major constraint to rice (Oryza sativa L.) production in rainfed and poorly irrigated environments. Identifying genomic regions influencing the response of yield and its components to water deficits will aid our understanding of the genetic mechanism of drought tolerance (DT) of rice and the development of DT varieties. Grain yield (GY) and its components of a recombinant inbred population developed from a lowland rice and an upland rice were investigated under different water levels in 2003 and 2004 in a rainout DT screening facility. Correlation and path analysis indicated that spikelet fertility (SF) was particularly important for grain yield with direct effect (P=0.60) under drought stress, while spikelet number per panicle (SN) contributed the most to grain yield (P=0.41) under well-watered condition. A total of 32 quantitative trait loci (QTLs) for grain yield and its components were identified. The phenotypic variation explained by individual QTLs varied from 1.29% to 14.76%. Several main effect QTLs affecting SF, 1,000-grain weight (TGW), panicle number (PN), and SN were mapped to the same regions on chromosome 4 and 8. These QTLs were detected consistently across 2 years and under both water levels in this study. Several digenic interactions among yield components were also detected. The identification of genomic regions associated with GY and its components under stress will be useful to improve drought tolerance of rice by marker-aided approaches.

Spin waves in nickel nanorings of large aspect ratio

The spin dynamics of high-aspect-ratio nickel nanorings in a longitudinal magnetic field have been investigated by Brillouin spectroscopy and the results are compared with a macroscopic theory and three-dimensional micromagnetic simulations. Good agreement is found between the measured and calculated magnetic field dependence of the spin wave frequency. Simulations show that as the field decreases from saturation, the rings switch from a "bamboo" to a novel "twisted bamboo" state at a certain critical field, and predict a corresponding dip in the dependence of the spin wave frequency on the magnetic field.

Effect of cordycepin on Hantaan virus 76-118 infection of primary human embryonic pulmonary fibroblasts--characterization of apoptotic effects

The cDNA microarray technique was used to study gene epression in human embryonic pulmonary fibroblasts (HEPF) infected with Hantaan virus (HTNV) under the influence of cordycepin (Cor), an inhibitor of post-transcriptional pre-mRNA polyadenylation. Four apoptotic genes, the insulin-like growth factor binding protein 1, NFkB inhibitor alpha, caspase-3 and NFkB1 were up-regulated in both infected and uninfected Cor-treated cells and two cell cycle-associated genes, CDC-like kinase and beta-induced transforming growth factor were up-regulated in Cor-untreated cells but down-regulated in Cor-treated cells. Cell morphology examination, quantitative RT-PCR, and immunofluorescence (IF) test suggested that following the Cor treatment the HTNV infection took place, but late viral gene expression was slightly reduced. Three parameters, namely caspase-3 activity, annexin V binding, and cell cycle were used to detect apoptosis. The results suggested that the induction of apoptosis in HEPF by HTNV started at 6 hrs post infection (p.i.). Following the Cor treatment, however, the caspase-3 activity began to increase at 24 hrs p.i. Thus it is suggested that inhibition of de novo late viral protein synthesis by Cor changes the apoptosis pathway and cell cycle by delaying caspase-3 gene expression and by up/down-regulating of expression of other apoptotic and cell cycle-associated genes. This implicates that HTNV can induce apoptosis in HEPF even without de novo viral protein synthesis and with a reduced and slowed viral maturation.

Structural genomics efforts at the Chinese Academy of Sciences and Peking University

Structural genomics efforts at the Chinese Academy of Sciences and Peking University are reported in this article. The major targets for the structural genomics project are targeted proteins expressed in human hematopoietic stem/progenitor cells, proteins related to blood diseases and other human proteins. Up to now 328 target genes have been constructed in expression vectors. Among them, more than 50% genes have been expressed in Escherichia coli, approximately 25% of the resulting proteins are soluble, and 35 proteins have been purified. Crystallization, data collection and structure determination are continuing. Experiences accumulated during this initial stage are useful for designing and applying high-throughput approaches in structural genomics.

First Report of the Occurrence of Tomato chlorosis virus and Tomato infectious chlorosis virus in Taiwan

Pronounced yellowing symptoms on the lower leaves of tomato plants, similar to those caused by nitrogen deficiency, were observed in the spring of 1998 in The Asian Vegetable Research and Development Center and in farmers' fields in southern Taiwan. However, the brittleness of the discolored leaves, occasional upward leaf rolling, and abundance of whiteflies on these plants suggested the involvement of Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) that belong to the group of whitefly-transmitted, phloem-limited criniviruses (family Closteroviridae). Leaves of symptomatic and healthy plants were collected, and total nucleic acids were extracted from 0.2 g of leaf tissue (1). The total nucleic acids were precipitated by ethanol and dissolved in 160 μl of sterile water. Eight microliters of total nucleic acids were observed on positively charged nylon membranes (Roche Diagnostic GmbH, Roch Applied Science, Germany). Two digoxigenin-labeled riboprobes, transcribed from pTIC8-44 (complementary to the 3'-end region of TICV RNA 1) and pToC 78 (corresponding to the coat protein region of ToCV RNA 2), were used in hybridization tests to detect TICV and ToCV, respectively (2). Six of seventeen symptomatic tomato plant samples were positive with the ToCV probe, whereas none of the 13 samples reacted with the TICV probe. Similar symptoms as described above for tomato were observed on zinnia plants in the same locations. Five of eight zinnia samples gave a positive reaction with the ToCV probe. One of the ToCV positive samples also gave a positive reaction with the TICV probe. Electron microscopic examination from leaf-dip preparations of ToCV-positive leaf tissues, stained in 1% uranyl acetate, showed the presence of flexuous filamentous particles approximately 800 to 850 nm long. To our knowledge, this is the first evidence of the presence of ToCV and TICV in zinnia and ToCV in tomato in Taiwan. References: (1) A. Hadidi et al. J. Virol. Methods 30:261, 1990. (2) G. C. Wisler et al. Phytopathology 88:402, 1998.

Hydrogen-based tubular catalytic membrane for removing nitrate from groundwater

A porous tubular ceramic membrane coated with palladium-cupper (Pd-Cu) catalyst on its surface was prepared and evaluated for catalytic reduction of nitrate from groundwater. Nitrate reduction activity and selectivity with the catalytic membrane were compared with Pd-Cu/Al2O3 catalyst particles. The catalytic membrane reactor exhibited a better selectivity by enabling an effective control of hydrogen gas, thus minimizing ammonium production. No leaching of palladium and copper into aqueous phase was observed, thereby indicating a high chemical stability of the metallic ions on the carrier support. This was also evidenced by the X-ray photoelectron spectroscopy (XPS) profiles of fresh and used catalysts, which showed no significant difference in surface compositions. Due to its higher selectivity in nitrate reduction and better flexibility in terms of operating conditions, the tubular catalytic ceramic membrane could be useful in removing nitrate from groundwater.