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Improving photosynthesis throughout the full canopy rather than photosynthesis of only the top leaves of the canopy is central to improving crop yields. Many canopy photosynthesis models have been developed from physiological and ecological perspectives, however most do not consider heterogeneities of microclimatic factors inside a canopy, canopy dynamics and associated energetics, or competition among different plants, and most models lack a direct linkage to molecular processes. Here we described the rationale, elements, and approaches necessary to build a dynamic systems model of canopy photosynthesis. A systems model should integrate metabolic processes including photosynthesis, respiration, nitrogen metabolism, resource re-mobilization and photosynthate partitioning with canopy level light, CO(2), water vapor distributions and heat exchange processes. In so doing a systems-based canopy photosynthesis model will enable studies of molecular ecology and dramatically improve our insight into engineering crops for improved canopy photosynthetic CO(2) uptake, resource use efficiencies and yields., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: To explore the feasibility of burn denatured acellular dermal matrix (DADM) as dermal substitute in repairing wounds., Methods: (1) Nine Wistar rats received a deep partial-thickness scald on the back. Full-thickness wounded skin was collected on post scald day (PBD) 1, 2, and 3 (with 3 rats at each time point), and it was treated with 2.5 g/L trypsin/0.5% Triton X-100 to remove cells to prepare DADM, respectively called DADM-1 d, DADM-2 d, and DADM-3 d. Another 3 rats without scald injury were treated with the same method as above to prepare acellular dermal matrix (ADM) to serve as control. Gross and histological observations and microbiological and biomechanical tests, including ultimate tensile strength, maximum tension, stretched length at breaking, stress-strain relationship, were conducted for the resulting ADM and DADM. (2) Another 64 rats were divided into ADM group and DADM-1 d, DADM-2 d, and DADM-3 d groups according to the random number table, with 16 rats in each group. A skin flap in size of 2.0 cm×1.8 cm was raised on the back of each rat. The above-mentioned ADM, DADM-1 d, DADM-2 d, and DADM-3 d were cut into pieces in the size of 1.8 cm×1.5 cm, and they were respectively implanted under the skin flaps of rats in corresponding group. At post surgery week (PSW) 1, 3, 5, or 9, 4 rats in each group were used to observe wound healing condition and change in implants with naked eye, and histological observation of the implants was conducted. Data were processed with one-way analysis of variance and t test., Results: (1) The freshly prepared DADM was milky white, soft in texture with flexibility, but poor in elasticity as compared with ADM. No epithelial structure or cellular component was observed in ADM or DADM under light microscope. Collagen fibers of DADM were seen to be thickened unevenly and arranged in disorder and eosinophilic. All microbiological results of DADM were negative. There was no statistically significant difference among DADM-1 d, DADM-2 d, and DADM-3 d in levels of ultimate tensile strength, maximum tension, stretched length at breaking, and stress-strain relationship (with F values from 0.088 to 3.591, P values all above 0.05). Values of the above-mentioned four indexes were the highest in DADM-3 d, they were respectively (13.0 ± 2.4) MPa, (61 ± 4) N, (173 ± 7)%, (45.7 ± 2.0)%. Values of the four indexes of ADM were respectively (19.0 ± 2.6) MPa, (95 ± 4) N, (201 ± 5)%, (62.5 ± 2.2)%, which were higher than those of DADM-1 d, DADM-2 d, and DADM-3 d (with t values from 6.424 to 17.125, P values all below 0.01). (2) No exudate or swelling in the wounds of rats, and no contraction or curling of implants were observed in every group at PSW 1, but inflammatory cells infiltration and Fbs inward migration were observed in the wound. At PSW 3, the growth of hair was normal in the wound in DADM-1 d, DADM-2 d, and ADM groups, but few and scattered hair grew in DADM-3 d group. The inflammatory cells decreased, while Fbs increased, and new capillaries were found to grow inwardly in each group. The decrease in inflammatory cells was slightly delayed in DADM-3 d group. At PSW 5, hair growth became normal, and implants shrank and thinned with fiber membrane wrapped densely and bundles of ingrowing large caliber blood vessels in all groups. The dermal matrix in each group merged with the surrounding normal tissue. At PSW 9, ADM and DADM became white, thin, and soft tissue sheet which was closely connected with the inner side of the flap. There was no infiltration of inflammatory cells in implants in either group. The collagen fibers arranged regularly and densely, and they were integrated with normal collagen tissue., Conclusions: The burned DADM does not have obvious immunogenicity, but with good biocompatibility. It is prospective to become as a dermal substitute in repairing wounds.

Objective: To verify the impact of operation high water level on Oncomelania hupensis natural growth in the water diversion rivers of the east route of South-to-North Water Diversion Project., Methods: The data of the daily mean water level were investigated in the stilling pool of Jiangdu Pumping Station during the water diversion under the emergency anti-drought, and the water level data of the previous year served as the control. The dynamic of natural growth of O. hupensis snails was observed before and after the high water level in the beach wetlands of the stilling pool of Jiangdu Pumping Station. The water level of emergency anti-drought was as simulation operation water level of the east route of South-to-North Water Diversion Project in the stilling pool, and then the effects of operation water level on O. hupensis natural growth in the water diversion rivers of the east route of South-to-North Water Diversion Project were studied., Results: The altitude of the beach wetlands was 6.4 to 7.2 meters in the stilling pool of Jiangdu Pumping Station. The water diversion was 255 days continuously and the pumped water was 6.235 billion cubic meters in the Jiangdu Pumping Station from November 2010 to July 2011. There were 216, 136 days and 39 days when daily mean water level were more than or equal to 7.2, 7.6 and 8.0 meters during the water diversion, respectively. The snail densities were 0.856 snails/0.1m2 and 0.0153 snails/0.1m2, respectively, before and after the No.3 beach wetlands flooded in the stilling pool of Jiangdu Pumping Station. The densities of living snails decreased by 98.21%, and there was no any progeny of snail. The snails were not detected in other environment of the stilling pool., Conclusion: The operation high water level can effectively restrain snail breeding in the water diversion rivers of the east route of South-to-North Water Diversion Project.

Background: To investigate the expression of cyclin-dependent kinase 8 (CDK8) and β-catenin in colon cancer and evaluate the role of CDK8 in the proliferation, apoptosis and cell cycle progression of colon cancer cells, especially in HCT116 cell line., Methods: Colon cancer cell line HCT116 was transfected with small interfering RNA (siRNA) targeting on CDK8. After CDK8-siRNA transfection, mRNA and protein expression levels of CDK8 and β-catenin were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot assay in HCT116 cells. Cell proliferation was measured by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide Methylthiazolyl tetrazolium (MTT) assay, and cell cycle distribution and apoptosis were analyzed by flow cytometry analysis (FACS). CDK8 and β-catenin protein levels were also examined by real-time PCR and immunohistochemistry (IHC) in colon cancer tissues and adjacent normal tissues., Results: After CDK8 specific siRNA transfection, mRNA and protein expression levels of CDK8 and β-catenin in HCT116 cells were noticeably decreased (P < 0.05). CDK8 specific siRNA transfection inhibited HCT116 cells' proliferation and facilitated their apoptosis significantly (P < 0.05). In addition, the proportion of HCT116 cells in the G0/G1 phase was remarkably increased after CDK8-siRNA transfection (P < 0.05). The expression levels of CDK8 and β-catenin in adjacent normal tissues were lower than in tumor tissues (P < 0.05). Moreover, the expression of CDK8 was correlated with the expression of β-catenin in both tumor and adjacent normal tissues (P < 0.05)., Conclusions: CDK8 and β-catenin were expressed in colon cancer at a high frequency. CDK8 specific siRNA transfection down-regulated the expression of CDK8 in colon cancer cells, which was also associated with a decrease in the expression of β-catenin Moreover, CDK8 specific siRNA inhibited the proliferation of colon cancer cells, promoted their apoptosis and arrested these cells in the G0/G1 phase. Interference of CDK8 might be an effective strategy through β-catenin regulation of colon cancer.

Objective: To explore the model of Oncomelania snail survey in inland areas, so as to reduce the burden of farmers as well as to improve the quality of snail survey., Methods: A database of environment in snail survey was established, and specialized personnel were organized at town level. The general survey combined with survey in turn was used., Results: After the improvement of the survey model, the personnel numbers and amounts of labor used, especially the cost afforded at village level decreased significantly, without any influence on the quality of snail survey., Conclusions: The improvement of snail survey model can enhance the efficiency and quality of survey, and can reduce the burden of farmers, but careful organization, strengthened management, and standardized operations are needed in the procedure.

A facile and universal synthetic approach for preparing superlattice nanowire (SLNW) arrays is developed. In this method, two kinds of elements are alternately electrodeposited into the holes of the anodic alumina oxide (AAO) template, automatically in separate electrolytes by a programmed device. This method is not restricted by the relative values of the reduction potentials of the elements, and the deposition of each element can be controlled independently. Three kinds of representative SLNW arrays containing noble-metal material (Ag/Ni), thermoelectric material (Bi/Sb) and magnetic material (Ni/Cu) with adjustable segment length are fabricated successfully.

Background: Chloroplasts and mitochondria evolved from the endosymbionts of once free-living eubacteria, and they transferred most of their genes to the host nuclear genome during evolution. The mechanisms used by plants to coordinate the expression of such transferred genes, as well as other genes in the host nuclear genome, are still poorly understood., Results: In this paper, we use nuclear-encoded chloroplast (cpRPGs), as well as mitochondrial (mtRPGs) and cytoplasmic (euRPGs) ribosomal protein genes to study the coordination of gene expression between organelles and the host. Results show that the mtRPGs, but not the cpRPGs, exhibit strongly synchronized expression with euRPGs in all investigated land plants and that this phenomenon is linked to the presence of a telo-box DNA motif in the promoter regions of mtRPGs and euRPGs. This motif is also enriched in the promoter regions of genes involved in DNA replication. Sequence analysis further indicates that mtRPGs, in contrast to cpRPGs, acquired telo-box from the host nuclear genome., Conclusions: Based on our results, we propose a model of plant nuclear genome evolution where coordination of activities in mitochondria and chloroplast and other cellular functions, including cell cycle, might have served as a strong selection pressure for the differential acquisition of telo-box between mtRPGs and cpRPGs. This research also highlights the significance of physiological needs in shaping transcriptional regulatory evolution.

We previously showed that two thyroid hormone receptor (TR) isoforms--TRα1 and TRβ1--differentially regulate thyroid hormone (triiodothyroxine, T(3))-stimulated adipogenesis in vivo. This study aims to understand the role of the nuclear receptor corepressor, NCoR1, in TR isoform-dependent adipogenesis. We found that T(3)-stimulated adipogenesis of 3T3-L1 cells was accompanied by progressive loss of NCoR1 protein levels. In 3T3-L1 cells stably expressing a mutated TRα1, PV (L1-α1PV cells), the T(3)-stimulated adipogenesis was more strongly inhibited than that in 3T3-L1 cells stably expressing an identical mutation in TRβ1 (L1-β1PV cells). The stronger inhibition of adipogenesis in L1-α1PV cells was associated with a higher NCoR1 protein level. These results indicate that the degree of loss of NCoR1 correlates with the extent of adipogenesis. siRNA knockdown of NCoR1 promoted adipogenesis of control 3T3-L1 cells and reversed the inhibited adipogenesis of L1-α1PV and L1-β1PV cells, indicating that NCoR1 plays an essential role in TR isoform-dependent adipogenesis. An ubiquitin ligase, mSiah2, that targets NCoR1 for proteasome degradation was upregulated on day 1 before the onset of progressive loss of NCoR1. NCoR1 was found to associate with mSiah2 and with TR, TRα1PV, or TRβ1PV, but a stronger interaction of NCoR1 with TRα1PV than with TRβ1PV was detected. Furthermore, TRα1PV-NCoR1 complex was more avidly recruited than TRβ1PV-NCoR1 to the promoter of the C/ebpα gene, leading to more inhibition in its expression. These results indicate that differential interaction of NCoR1 with TR isoforms accounted for the TR isoform-dependent regulation of adipogenesis and that aberrant interaction of NCoR1 with TR could underlie the pathogenesis of lipid disorders in hypothyroidism.

Photosynthesis is limited by the conductance of carbon dioxide (CO(2)) from intercellular spaces to the sites of carboxylation. Although the concept of internal conductance (g(i)) has been known for over 50 years, shortcomings in the theoretical description of this process may have resulted in a limited understanding of the underlying mechanisms. To tackle this issue, we developed a three-dimensional reaction-diffusion model of photosynthesis in a typical C(3) mesophyll cell that includes all major components of the CO(2) diffusion pathway and associated reactions. Using this novel systems model, we systematically and quantitatively examined the mechanisms underlying g(i). Our results identify the resistances of the cell wall and chloroplast envelope as the most significant limitations to photosynthesis. In addition, the concentration of carbonic anhydrase in the stroma may also be limiting for the photosynthetic rate. Our analysis demonstrated that higher levels of photorespiration increase the apparent resistance to CO(2) diffusion, an effect that has thus far been ignored when determining g(i). Finally, we show that outward bicarbonate leakage through the chloroplast envelope could contribute to the observed decrease in g(i) under elevated CO(2). Our analysis suggests that physiological and anatomical features associated with g(i) have been evolutionarily fine-tuned to benefit CO(2) diffusion and photosynthesis. The model presented here provides a novel theoretical framework to further analyze the mechanisms underlying diffusion processes in the mesophyll.

Ever since the discovery of C(4) photosynthesis in the mid-1960s, plant biologists have envisaged the introduction of the C(4) photosynthetic pathway into C(3) crops such as rice and soybeans. Recent advances in genomics capabilities, and new evolutionary and developmental studies indicate that C(4) engineering will be feasible in the next few decades. Furthermore, better understanding of the function of C(4) photosynthesis provides new ways to improve existing C(4) crops and bioenergy species, for example by creating varieties with ultra-high water and nitrogen use efficiencies. In the case of C(4) engineering, the main enzymes of the C(4) metabolic cycle have already been engineered into various C(3) plants. In contrast, knowledge of the genes controlling Kranz anatomy lags far behind. Combining traditional genetics, high-throughput sequencing technologies, systems biology, bioinformatics, and the use of the new C(4) model species Setaria viridis, the discovery of the key genes controlling the expression of C(4) photosynthesis can be dramatically accelerated. Sustained investment in the research areas directly related to C(4) engineering has the potential for substantial return in the decades to come, primarily by increasing crop production at a time when global food supplies are predicted to fall below world demand.

Background: Several tools are available to identify miRNAs from deep-sequencing data, however, only a few of them, like miRDeep, can identify novel miRNAs and are also available as a standalone application. Given the difference between plant and animal miRNAs, particularly in terms of distribution of hairpin length and the nature of complementarity with its duplex partner (or miRNA star), the underlying (statistical) features of miRDeep and other tools, using similar features, are likely to get affected., Results: The potential effects on features, such as minimum free energy, stability of secondary structures, excision length, etc., were examined, and the parameters of those displaying sizable changes were estimated for plant specific miRNAs. We found most of these features acquired a new set of values or distributions for plant specific miRNAs. While the length of conserved positions (nucleus) in mature miRNAs were relatively longer in plants, the difference in distribution of minimum free energy, between real and background hairpins, was marginal. However, the choice of source (species) of background sequences was found to affect both the minimum free energy and miRNA hairpin stability. The new parameters were tested on an Illumina dataset from maize seedlings, and the results were compared with those obtained using default parameters. The newly parameterized model was found to have much improved specificity and sensitivity over its default counterpart., Conclusions: In summary, the present study reports behavior of few general and tool-specific statistical features for improving the prediction accuracy of plant miRNAs from deep-sequencing data.

Objective: To establish the index system of surveillance and early-warning on schistosomiasis and to provide the scientific basis for risk assessment and emergency plan in first phase of east route of South-to-North Water Diversion Project., Methods: The Delphi method and the multidimensional synthetic evaluation were used in the evaluation of indexes of surveillance and early-warning on schistosomiasis in the east route of the project., Results: There were 53 indexes evaluated in the index system, and among them, there were 3 first grade indexes, 10 second grade indexes and 40 third grade indexes. The indexes on Oncomelania snails were the most important. According to the habitation position of snails, the four grades on surveillance and early-warning of schistosomiasis were established in the east route. The grade I of the early-warning meant that snails crossed the first level of the pumping station. The grade II meant that snails crossed N 32 degrees 54'. The grade III meant that snails crossed N 33 degrees 03' or Jinhu pumping station. The grade IV meant that snails crossed N 33 degrees 15' or Hongze Station. Other 4 indexes on schistosome infection in people and livestock were confirmed as indicative indexes. According to the relationship among the indexes, the evaluation methods were determined on the risk of schistosomiasis transmission., Conclusions: The index system of surveillance and early-warning and the methods of risk assessment of schistosomiasis have been confirmed in first phase of east route of South-to-North Water Diversion Project. The primary index is related to snails and the supplementary is related to schistosome infection in people and livestock in the system.

Past increases in yield potential of wheat have largely resulted from improvements in harvest index rather than increased biomass. Further large increases in harvest index are unlikely, but an opportunity exists for increasing productive biomass and harvestable grain. Photosynthetic capacity and efficiency are bottlenecks to raising productivity and there is strong evidence that increasing photosynthesis will increase crop yields provided that other constraints do not become limiting. Even small increases in the rate of net photosynthesis can translate into large increases in biomass and hence yield, since carbon assimilation is integrated over the entire growing season and crop canopy. This review discusses the strategies to increase photosynthesis that are being proposed by the wheat yield consortium in order to increase wheat yields. These include: selection for photosynthetic capacity and efficiency, increasing ear photosynthesis, optimizing canopy photosynthesis, introducing chloroplast CO(2) pumps, increasing RuBP regeneration, improving the thermal stability of Rubisco activase, and replacing wheat Rubisco with that from other species with different kinetic properties.

Photosynthesis produces the basic building block for crop biomass and yields; however, improving photosynthesis has not been effectively used as a breeding goal. More and more evidences suggested that improving photosynthesis can substantially increase crop yields. The complexity of photosynthesis however makes experimentally identifying new ways to engineer higher photosynthesis inherently time-consuming and costly. Combining systems modeling with evolutionary algorithm makes it possible to identify optimal engineering options for future global climate change scenarios and simultaneously consider environmental constraints, such as with constant or even decreasing nitrogen fertilizer application in the field. This method enables in silico examination of a large number of engineering options which natural selection has not explored, for higher photosynthetic energy conversion efficiency. The new approach comes particularly timely for now when our society is facing serious challenges in food security and global climate change. The traditional reductionist's approach will continue generating critical knowledge required to support this systems biology method to engineering higher photosynthesis., (Copyright 2010 Elsevier B.V. All rights reserved.)

Engineering the C4 photosynthetic pathway into C3 crops has the potential to dramatically increase the yields of major C3 crops. The genetic control of features involved in C4 photosynthesis are still far from being understood; which partially explains why we have gained little success in C4 engineering thus far. Next generation sequencing techniques and other high throughput technologies are offering an unprecedented opportunity to elucidate the developmental and evolutionary processes of C4 photosynthesis. Two contrasting hypotheses about the evolution of C4 photosynthesis exist, i.e. the master switch hypothesis and the incremental gain hypothesis. These two hypotheses demand two different research strategies to proceed in parallel to maximize the success of C4 engineering. In either case, systems biology research will play pivotal roles in identifying key regulatory elements controlling development of C4 features, identifying essential biochemical and anatomical features required to achieve high photosynthetic efficiency, elucidating genetic mechanisms underlining C4 differentiation and ultimately identifying viable routes to engineer C4 rice. As a highly interdisciplinary project, the C4 rice project will have far-reaching impacts on both basic and applied research related to agriculture in the 21st century.

C(4) photosynthesis drives productivity in several major food crops and bioenergy grasses, including maize (Zea mays), sugarcane (Saccharum officinarum), sorghum (Sorghum bicolor), Miscanthus x giganteus, and switchgrass (Panicum virgatum). Gains in productivity associated with C(4) photosynthesis include improved water and nitrogen use efficiencies. Thus, engineering C(4) traits into C(3) crops is an attractive target for crop improvement. However, the lack of a small, rapid cycling genetic model system to study C(4) photosynthesis has limited progress in dissecting the regulatory networks underlying the C(4) syndrome. Setaria viridis is a member of the Panicoideae clade and is a close relative of several major feed, fuel, and bioenergy grasses. It is a true diploid with a relatively small genome of ~510 Mb. Its short stature, simple growth requirements, and rapid life cycle will greatly facilitate genetic studies of the C(4) grasses. Importantly, S. viridis uses an NADP-malic enzyme subtype C(4) photosynthetic system to fix carbon and therefore is a potentially powerful model system for dissecting C(4) photosynthesis. Here, we summarize some of the recent advances that promise greatly to accelerate the use of S. viridis as a genetic system. These include our recent successful efforts at regenerating plants from seed callus, establishing a transient transformation system, and developing stable transformation.

Purpose: To investigate the efficacy of NG-methyl-L-arginine(L-NMMA) for treatment of indirect temporomandibular joint trauma in goats., Methods: Trauma to TMJ in 9 goats were exerted under an impact to the right and left mandibular angle with self-made device, L-NMMA (0.5 mL) were injected into the right TMJs after 3 hours, 7 days, 14 days, 21 days; the left TMJs were injected with normal saline and used as a control. The goats were killed after 3 months. The TMJs of goats were examined with scanning electron microscopy and light microscopy when sacrificed and scored in a subjective manner following the standard criteria which was a modification of the method by Mankin et al and Yoshimi et al. GLM model of SAS 9.0 software package was used to evaluate the scores of the treatment sides and control sides., Results: Under light microscopy and scanning electron microscopy, the left TMJ tissues showed severe osteoarthrotic changes in the temporal surface,disk and condyle, the right TMJ tissues showed significant improvement (P<0.05)., Conclusions: Repeated intra-articular injection of L-NMMA may reduce the destruction of indirect trauma on goat TMJs.

To understand the roles of thyroid hormone receptors (TRs) in adipogenesis, we adopted a loss-of-function approach. We generated 3T3-L1 cells stably expressing either TRalpha1 mutant (TRalpha1PV) or TRbeta1 mutant (TRbeta1PV). TRalpha1PV and TRbeta1PV are dominant negative mutations with a frameshift in the C-terminal amino acids. In control cells, the thyroid hormone, tri-iodothyronine (T(3)), induced a 2.5-fold increase in adipogenesis in 3T3-L1 cells, as demonstrated by increased lipid droplets. This increase was mediated by T(3)-induced expression of the peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT/enhancer-binding protein alpha (C/EBPalpha), which are master regulators of adipogenesis at both the mRNA and protein levels. In 3T3-L1 cells stably expressing TRalpha1PV (L1-alpha1PV cells) or TRbeta1PV (L1-beta1PV cells), adipogenesis was reduced 94 or 54% respectively, indicative of differential inhibitory activity of mutant TR isoforms. Concordantly, the expression of PPARgamma and C/EBPalpha at the mRNA and protein levels was more repressed in L1-alpha1PV cells than in L1-beta1PV cells. In addition, the expression of PPARgamma downstream target genes involved in fatty acid synthesis - the lipoprotein lipase (Lpl) and aP2 involved in adipogenesis - was more inhibited by TRalpha1PV than by TRbeta1PV. Chromatin immunoprecipitation assays showed that TRalpha1PV was more avidly recruited than TRbeta1PV to the promoter to preferentially block the expression of the C/ebpalpha gene. Taken together, these data indicate that impaired adipogenesis by mutant TR is isoform dependent. The finding that induction of adipogenesis is differentially regulated by TR isoforms suggests that TR isoform-specific ligands could be designed for therapeutic intervention for lipid abnormalities.

Aberrant expression and mutations of thyroid hormone receptor genes (TRs) are closely associated with several types of human cancers. To test the hypothesis that TRs could function as tumor suppressors, we took advantage of mice with deletion of all functional TRs (TRalpha1(-/-)TRbeta(-/-) mice). As these mice aged, they spontaneously developed follicular thyroid carcinoma with pathological progression from hyperplasia to capsular invasion, vascular invasion, anaplasia and metastasis to the lung, similar to human thyroid cancer. Detailed molecular analysis revealed that known tumor promoters such as pituitary tumor-transforming gene were activated and tumor suppressors such as peroxisome proliferator-activated receptor gamma and p53 were suppressed during carcinogenesis. In addition, consistent with the human cancer, AKT-mTOR-p70(S6K) signaling and vascular growth factor and its receptor were activated to facilitate tumor progression. This report presents in vivo evidence that functional loss of both TRalpha1 and TRbeta genes promotes tumor development and metastasis. Thus, TRs could function as tumor suppressors in a mouse model of metastatic follicular thyroid cancer.

Increasing the yield potential of the major food grain crops has contributed very significantly to a rising food supply over the past 50 years, which has until recently more than kept pace with rising global demand. Whereas improved photosynthetic efficiency has played only a minor role in the remarkable increases in productivity achieved in the last half century, further increases in yield potential will rely in large part on improved photosynthesis. Here we examine inefficiencies in photosynthetic energy transduction in crops from light interception to carbohydrate synthesis, and how classical breeding, systems biology, and synthetic biology are providing new opportunities to develop more productive germplasm. Near-term opportunities include improving the display of leaves in crop canopies to avoid light saturation of individual leaves and further investigation of a photorespiratory bypass that has already improved the productivity of model species. Longer-term opportunities include engineering into plants carboxylases that are better adapted to current and forthcoming CO(2) concentrations, and the use of modeling to guide molecular optimization of resource investment among the components of the photosynthetic apparatus, to maximize carbon gain without increasing crop inputs. Collectively, these changes have the potential to more than double the yield potential of our major crops.

Various Mg-based nanoparticles were prepared by evaporating bulk magnesium in the atmospheres of Ar, Ar+N2 and CH4, respectively. The formations, phases, morphologies, thermal properties and corrosion behaviors of these kinds of nanocomposite particles were investigated by means of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), thermogravimetric-differential thermal analysis (TG/DTA) and potentiodynamic polarisation scan (PPS). It is shown that the Mg-based nanoparticles produced in Ar and Ar+N2 atmospheres have hexangular crystal habits with particles' sizes ranging from 50 to 400 nm, while the nanoparticles produced in CH4 atmosphere have amorphous carbon out layers with particles' sizes among 20-100 nm. TG/DTA results show that two-steps oxidation process can be confirmed for all samples, which may be attributed to the oxidations of out layer and core of nanoparticle. The CH4 atmosphere-prepared nanoparticles exhibit better corrosion resistance properties due to its peculiar carbon doping.

Objective: To evaluate the clinical therapeutic effect of electroacupuncture for treatment of catatonic schizophrenia., Methods: Eighty cases were randomly divided into an observation group and a control group, 40 cases in each group. The observation group was treated with electroacupuncture, Baihui (GV 20) and Taiyang (EXHN 5) were selected, once daily; the control group was treated with modified electric convulsive therapy (MECT), the treatment was given once every 2 days or 3 days, 14 to 21 days constituted one course in the two groups., Results: The markedly effective rate and total effective rate were 72.5% and 92.5% in the observation group, 77.5% and 97.5% in the control group, respectively, there was no significant difference between the two groups (both P>0.05)., Conclusion: The therapeutic effect of electroacupuncture is similar to that of MECT.

Thyroid carcinomas, the most common endocrine tumors in humans, have an increasing incidence in the U.S. and worldwide. There are four major types of thyroid cancers: papillary, follicular, anaplastic, and medullary carcinomas. In recent years, significant progress has been made in the identification of genetic alterations in thyroid carcinomas, particularly, papillary and medullary thyroid cancers. Mouse models of thyroid cancer are valuable tools in elucidating molecular genetic changes underlying thyroid carcinogenesis and in identifying potential molecular targets for therapeutic intervention. Representative mouse models of papillary, follicular, and medullary carcinomas are reviewed here with particular emphasis on those for follicular thyroid carcinomas. Challenges for further development in the modeling of thyroid cancer will also be discussed.

Thyroid hormone receptors (TRs) play critical roles in energy homeostasis. To understand the role of TRs in lipid homeostasis in vivo, we adopted the loss-of-function approach by creating knock-in mutant mice with targeted mutation in the TRalpha gene (TRalpha1PV mouse) or TRbeta gene (TRbetaPV mouse). The PV mutation, identified in a patient with resistance to thyroid hormone, exhibits potent dominant-negative activity. Here we show that in contrast to TRalpha1PV mouse, TRbetaPV mice exhibited no significant reduction in WAT but had significant increases in serum free fatty acids and total triglycerides. Moreover, the liver of TRbetaPV mice was markedly increased (33%) with excess lipid accumulation, but the liver mass of TRalpha1PV mouse was decreased (23%) with paucity of lipids. These results indicate that apo-TRbeta and apo-TRalpha1 exerted distinct abnormalities in lipid metabolism. Further biochemical analyses indicate that increased lipogenic enzyme expression, activated peroxisome proliferator-activated receptor gamma (Ppargamma) signaling, and decreased fatty acid beta-oxidation activity contributed to the adipogenic steatosis and lipid accumulation in the liver of TRbetaPV mice. In contrast, the expression of lipogenic enzymes and Ppargamma was decreased in the liver of TRalpha1PV mice. These results suggest that the regulation of genes critical for lipid metabolism by TRs in the liver is isoform dependent. These results indicate that apo-TRbeta and apo-TRalpha1 had different effects on lipid metabolism and that both TR isoforms contribute to the pathogenesis of lipid metabolism in hypothyroidism.

Chloroplasts evolved as a result of endosymbiosis, during which sophisticated mechanisms evolved to translocate nucleus-encoded plastid-targeted enzymes into the chloroplast to form the chloroplast metabolic network. Given the constraints and complexity of endosymbiosis, will preferential attachment still be a plausible mechanism for chloroplast metabolic network evolution? We answer this question by analysing the metabolic network properties of the chloroplast and a cyanobacterium, Synechococcus sp. WH8102 (syw). First, we found that enzymes related to more ancient pathways are more connected, and synthetases have the highest connectivity. Most of the enzymes shared by the two densest cores between the chloroplast and syw are synthetases. Second, the highly conserved functional modules mainly consist of highly connected enzymes. Finally, isozymes and enzymes from endosymbiotic gene transfer (EGT) were distributed mainly in conserved modules and showed higher connectivity than nonisozymes or non-EGT enzymes. These results suggest that even with severe evolutionary constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network. However, the current analysis may not completely differentiate whether the chloroplast network properties reflect the evolution of the chloroplast network through preferential attachment or has been inherited from its cyanobacterial ancestor. To fully differentiate these two possibilities, further analyses of the metabolic network structure properties of organisms at various intermediate evolutionary stages between cyanobacteria and the chloroplast are needed.

Unlabelled: Nonsteroidal anti-inflammatory drugs inhibit cell proliferation and induce apoptosis in various cancer cell lines, which is considered to be an important mechanism for their anti-tumor activity and cancer prevention. However, the molecular mechanisms through which these compounds induce apoptosis are not well understood., Aim: to determine the effects of nonselective cyclooxygenase-2 (COX-2) inhibitor, aspisol on breast cancer cells in vitro and in vivo., Methods: The cytotoxic activity of aspisol was evaluated by MTT assay. The apoptosis index of cells was measured by flow cytometry. Immunohistochemical staining was used to detect expressions of COX-2 and caspase-3 in MDA-MB-231 cells. The expression of bcl-2 and bax was analyzed by Western blot analysis. The content of prostaglandin E2 (PGE2) in MDA-MB-231 cells was estimated by ELISA. In vivo apoptosis of the tumor cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)., Results: Our results showed that aspisol reduced viability of MDA-MB-231 cells in time- and dose- dependent fashions and induced apoptosis by increase of caspase-3 and bax expressions while decrease of COX-2 and bcl-2 expression in vitro. In addition, exposure to aspisol decreased the basal release of PGE2. In vivo, aspisol also inhibited the proliferation of breast cancer cells and induced their apoptosis., Conclusions: Our in vitro and in vivo data indicated that the antitumor effects of aspisol on breast cancer cells was probably mediated by the induction of apoptosis, and it could be linked to the downregulation of the COX-2 or bcl-2 expression and up-regulation of caspase-3 or bax expression.

Aim: To detect the expression of DPC4 in malignant and non-malignant specimens of human pancreas, and observe the inhibition of retroviral pLXSN containing DPC4 on pancreatic carcinoma cells in vitro., Methods: The expression of DPC4 was determined in 40 pancreatic adenocarcinoma and 36 non-malignant pancreatic specimens by reverse-transcriptase polymerase chain reaction (RT-PCR) and immunohisto-chemistry. Furthermore, we constructed retroviral vectors containing DPC4, which then infected the pancreatic carcinoma cell line BxPC-3. Cell growth in vitro after being infected was observed, and the vascular endothelial growth factor (VEGF) mRNA level in the daughter cells was determined by semi-quantitative PCR assay., Results: The RT-PCR assay showed a positive rate of DPC4 mRNA in 100% (36/36) of normal specimens, compared to 40% (16/40) in adenocarcinoma specimens. The regional and intense positive cases of DPC4 expression in adenocarcinoma detected by immunohistochemistry were 10 and four, whereas it was all positive expression in normal tissues. There was a significant difference of DPC4 expression between them. The stable expression of DPC4 in the pancreatic carcinoma cells BxPC-3 could be resumed by retroviral vector pLXSN transfection, and could inhibit cell growth in vitro. Rather, DPC4 could decrease VEGF mRNA transcription levels., Conclusion: The deletion of DPC4 expression in pancreatic carcinoma suggests that loss of DPC4 may be involved in the development of pancreatic carcinoma. The retroviral vector pLXSN containing DPC4 can inhibit the proliferation of pancreatic carcinoma cells, and down-regulate the level of VEGF.

Background: Pancreatic cancer is a highly malignant tumor affecting an ever increasing number of patients with a mean 5-year survival rate below 4%. Therefore, gene therapy for cancer has become a potential novel therapeutic modality. In this study we sought to determine the inhibitory effects of adenovirus-mediated human interleukin-24 (AdhIL-24) on pancreatic cancer., Methods: Human interleukin-24 gene was cloned into replication-defective adenovirus specific for patu8988 tumor cells by virus recombination technology. Reverse transcription-polymerase chain reaction and Western blotting analysis were used to determine the expression of human interleukin-24 mRNA in patu8988 cells in vitro. Induction of apoptosis by overexpression of human interleukin-24 in patu8988 cells was determined by flow cytometry. In vivo efficacy of adenoviral delivery of human interleukin-24 was assessed in nude mice (n = 10 for each group) bearing patu8988 pancreatic cancer cell lines by determining inhibition of tumor growth, endothelial growth factor and CD34 expression, and intratumoral microvessel density (MVD)., Results: The recombinant adenovirus vector AdVGFP/IL-24 was constructed with a packaged recombinant retrovirus titer of 1.0 x 10(10) pfu/ml and successfully expressed of both mRNA and protein in patu8988 cells. The AdVGFP/IL-24 induced apoptosis of patu8988 tumor cells in vitro and significantly inhibited tumor growth in vivo (P < 0.05). The intratumoral MVD decreased significantly in the treated tumors (P < 0.05)., Conclusion: The recombinant adenovirus AdGFP/IL-24 can effectively express biologically active human interleukin-24, which results in inhibition of pancreatic cancer growth.

Postsynaptic density (PSD)-93, a neuronal scaffolding protein, binds to and clusters N-methyl-D-aspartate receptor (NMDAR) subunits NR2A and NR2B at cellular membranes in vitro. However, the roles of PSD-93 in synaptic NR2A and NR2B targeting in the central nervous system and NMDAR-dependent physiologic and pathologic processes are still unclear. We report here that PSD-93 deficiency significantly decreased the amount of NR2A and NR2B in the synaptosomal membrane fractions derived from spinal cord dorsal horn and forebrain cortex but did not change their levels in the total soluble fraction from either region. However, PSD-93 deficiency did not markedly change the amounts of NR2A and NR2B in either synaptosomal or total soluble fractions from cerebellum. In mice deficient in PSD-93, morphine dose-dependent curve failed to shift significantly rightward as it did in wild type (WT) mice after acute and chronic morphine challenge. Unlike WT mice, PSD-93 knockout mice also showed marked losses of NMDAR-dependent morphine analgesic tolerance and associated abnormal sensitivity in response to mechanical, noxious thermal, and formalin-induced inflammatory stimuli after repeated morphine injection. In addition, PSD-93 knockout mice displayed dramatic loss of jumping activity, a typical NMDAR-mediated morphine withdrawal abstinence behavior. These findings indicate that impaired NMDAR-dependent neuronal plasticity following repeated morphine injection in PSD-93 knockout mice is attributed to PSD-93 deletion-induced alterations of synaptic NR2A and NR2B expression in dorsal horn and forebrain cortex neurons. The selective effect of PSD-93 deletion on synaptic NMDAR expression in these two major pain-related regions might provide the better strategies for the prevention and treatment of opioid tolerance and physical dependence.

Application of the widely used Farquhar model of photosynthesis in interpretation of gas exchange data assumes that photosynthetic properties are homogeneous throughout the leaf. Previous studies showed that heterogeneity in stomatal conductance (g(s)) across a leaf could affect the shape of the measured leaf photosynthetic CO(2) uptake rate (A) versus intercellular CO(2) concentration (C(i)) response curve and, in turn, estimation of the critical biochemical parameters of this model. These are the maximum rates of carboxylation (V(c,max)), whole-chain electron transport (J(max)), and triose-P utilization (V(TPU)). The effects of spatial variation in V(c,max,) J(max), and V(TPU) on estimation of leaf averages of these parameters from A-C(i) curves measured on a whole leaf have not been investigated. A mathematical model incorporating defined degrees of spatial variability in V(c,max) and J(max) was constructed. One hundred and ten theoretical leaves were simulated, each with the same average V(c,max) and J(max), but different coefficients of variation of the mean (CV(VJ)) and varying correlation between V(c,max) and J(max) (Omega). Additionally, the interaction of variation in V(c,max) and J(max) with heterogeneity in V(TPU), g(s), and light gradients within the leaf was also investigated. Transition from V(c,max)- to J(max)-limited photosynthesis in the A-C(i) curve was smooth in the most heterogeneous leaves, in contrast to a distinct inflection in the absence of heterogeneity. Spatial variability had little effect on the accuracy of estimation of V(c,max) and J(max) from A-C(i) curves when the two varied in concert (Omega = 1.0), but resulted in underestimation of both parameters when they varied independently (up to 12.5% in V(c,max) and 17.7% in J(max) at CV(VJ) = 50%; Omega = 0.3). Heterogeneity in V(TPU) also significantly affected parameter estimates, but effects of heterogeneity in g(s) or light gradients were comparatively small. If V(c,max) and J(max) derived from such heterogeneous leaves are used in models to project leaf photosynthesis, actual A is overestimated by up to 12% at the transition between V(c,max)- and J(max)-limited photosynthesis. This could have implications for both crop production and Earth system models, including projections of the effects of atmospheric change.

Photosynthesis is the source of our food and fiber. Increasing world population, economic development, and diminishing land resources forecast that a doubling of productivity is critical in meeting agricultural demand before the end of this century. A starting point for evaluating the global potential to meet this goal is establishing the maximum efficiency of photosynthetic solar energy conversion. The potential efficiency of each step of the photosynthetic process from light capture to carbohydrate synthesis is examined. This reveals the maximum conversion efficiency of solar energy to biomass is 4.6% for C3 photosynthesis at 30 degrees C and today's 380 ppm atmospheric [CO2], but 6% for C4 photosynthesis. This advantage over C3 will disappear as atmospheric [CO2] nears 700 ppm.

Background: Transcription factors (TFs) have multiple combinatorial forms to regulate the transcription of a target gene. For example, one TF can help another TF to stabilize onto regulatory DNA sequence and the other TF may attract RNA polymerase (RNAP) to start transcription; alternatively, two TFs may both interact with both the DNA sequence and the RNAP. The different forms of TF-TF interaction have different effects on the probability of RNAP's binding onto the promoter sequence and therefore confer different transcriptional efficiencies., Results: We have developed an analytical method to identify the thermodynamic model that best describes the form of TF-TF interaction among a set of TF interactions for every target gene. In this method, time-course microarray data are used to estimate the steady state concentration of the transcript of a target gene, as well as the relative changes of the active concentration for each TF. These estimated concentrations and changes of concentrations are fed into an inference scheme to identify the most compatible thermodynamic model. Such a model represents a particular way of combinatorial control by multiple TFs on a target gene., Conclusions: Applying this approach to a time-course microarray dataset of embryonic stem cells, we have inferred five interaction patterns among three regulators, Oct4, Sox2 and Nanog, on ten target genes.

Neurexins are cell adhesion molecules that help to specify and stabilize synapses and provide receptors for neuroligins, neurexophilins, dystroglycans and alpha-latrotoxins. We previously reported significant allele frequency differences for single nucleotide polymorphisms (SNPs) in the neurexin 3 (NRXN3) gene in each of two comparisons between individuals who were dependent on illegal substances and controls. We now report work clarifying details of NRXN3's gene structure and variants and documenting association of NRXN3 SNPs with alcohol dependence. We localize this association signal with the vicinity of the NRXN3 splicing site 5 (SS#5). A splicing site SNP, rs8019381, that is located 23 bp from the SS#5 exon 23 donor site displays association with P = 0.0007 (odds ratio = 2.46). Including or excluding exon 23 at SS#5 produces soluble or transmembrane NRXN3 isoforms. We thus examined expression of these NRXN3 isoforms in postmortem human cerebral cortical brain samples from individuals with varying rs8019381 genotypes. Two of the splice variants that encode transmembrane NRXN3 isoforms were expressed at significantly lower levels in individuals with the addiction-associated rs8019381 'T' allele than in CC homozygotes. Taken together with recent reports of NRXN3 association with nicotine dependence and linkage with opiate dependence, these data support roles for NRXN3 haplotypes that alter expression of specific NRXN3 isoforms in genetic vulnerabilities to dependence on a variety of addictive substances.

The distribution of resources between enzymes of photosynthetic carbon metabolism might be assumed to have been optimized by natural selection. However, natural selection for survival and fecundity does not necessarily select for maximal photosynthetic productivity. Further, the concentration of a key substrate, atmospheric CO(2), has changed more over the past 100 years than the past 25 million years, with the likelihood that natural selection has had inadequate time to reoptimize resource partitioning for this change. Could photosynthetic rate be increased by altered partitioning of resources among the enzymes of carbon metabolism? This question is addressed using an "evolutionary" algorithm to progressively search for multiple alterations in partitioning that increase photosynthetic rate. To do this, we extended existing metabolic models of C(3) photosynthesis by including the photorespiratory pathway (PCOP) and metabolism to starch and sucrose to develop a complete dynamic model of photosynthetic carbon metabolism. The model consists of linked differential equations, each representing the change of concentration of one metabolite. Initial concentrations of metabolites and maximal activities of enzymes were extracted from the literature. The dynamics of CO(2) fixation and metabolite concentrations were realistically simulated by numerical integration, such that the model could mimic well-established physiological phenomena. For example, a realistic steady-state rate of CO(2) uptake was attained and then reattained after perturbing O(2) concentration. Using an evolutionary algorithm, partitioning of a fixed total amount of protein-nitrogen between enzymes was allowed to vary. The individual with the higher light-saturated photosynthetic rate was selected and used to seed the next generation. After 1,500 generations, photosynthesis was increased substantially. This suggests that the "typical" partitioning in C(3) leaves might be suboptimal for maximizing the light-saturated rate of photosynthesis. An overinvestment in PCOP enzymes and underinvestment in Rubisco, sedoheptulose-1,7-bisphosphatase, and fructose-1,6-bisphosphate aldolase were indicated. Increase in sink capacity, such as increase in ADP-glucose pyrophosphorylase, was also indicated to lead to increased CO(2) uptake rate. These results suggest that manipulation of partitioning could greatly increase carbon gain without any increase in the total protein-nitrogen investment in the apparatus for photosynthetic carbon metabolism.

Background & Objective: Cyclooxygenase (COX) plays an important role in tumorigenesis and development. Many inhibitors of COX could inhibit proliferation and induce apoptosis of cancer cells. This study was to observe the inhibitory effect of Aspisol on growth of transplanted breast cancer in C3H mice and the effects of Aspisol on tumor cell apoptosis and the expression of Caspase-3 and COX-2, and explore the mechanisms., Methods: The suspension of breast cancer cells was injected subcutaneously into forelimb axillas of C3H mice to establish xenograft models. From the next day, the mice received intraperitoneal injection of different concentrations of Aspisol once a day for 28 days; the mice received injection of 5-fluorouracil (5-FU) were used as positive controls, and the mice received injection of normal saline (NS) were used as negative controls. The inhibition rate of tumor growth was calculated. Tumor cell apoptosis was detected by TUNEL assay. The expression of Caspase-3 and COX-2 was detected by immunohistochemistry., Results: The inhibition rate of tumor growth was 38.9% in 175 mg/kg Aspisol group, 48.2% in 350 mg/kg Aspisol group, 47.0% in 700 mg/kg Aspisol group, and 60.4% in 10 mg/kg 5-FU group. Typical apoptotic morphologic changes were seen in the 4 groups. Caspase-3 expression was significantly higher and COX-2 expression was significantly lower in Aspisol groups than in NS group., Conclusions: Aspisol may inhibit the growth of transplanted breast cancer in C3H mice, and induce tumor cell apoptosis. The mechanism may be correlated to down-regulation of COX-2 and up-regulation of Caspase-3.

Background: Chloroplasts descended from cyanobacteria and have a drastically reduced genome following an endosymbiotic event. Many genes of the ancestral cyanobacterial genome have been transferred to the plant nuclear genome by horizontal gene transfer. However, a selective set of metabolism pathways is maintained in chloroplasts using both chloroplast genome encoded and nuclear genome encoded enzymes. As an organelle specialized for carrying out photosynthesis, does the chloroplast metabolic network have properties adapted for higher efficiency of photosynthesis? We compared metabolic network properties of chloroplasts and prokaryotic photosynthetic organisms, mostly cyanobacteria, based on metabolic maps derived from genome data to identify features of chloroplast network properties that are different from cyanobacteria and to analyze possible functional significance of those features., Results: The properties of the entire metabolic network and the sub-network that consists of reactions directly connected to the Calvin Cycle have been analyzed using hypergraph representation. Results showed that the whole metabolic networks in chloroplast and cyanobacteria both possess small-world network properties. Although the number of compounds and reactions in chloroplasts is less than that in cyanobacteria, the chloroplast's metabolic network has longer average path length, a larger diameter, and is Calvin Cycle -centered, indicating an overall less-dense network structure with specific and local high density areas in chloroplasts. Moreover, chloroplast metabolic network exhibits a better modular organization than cyanobacterial ones. Enzymes involved in the same metabolic processes tend to cluster into the same module in chloroplasts., Conclusion: In summary, the differences in metabolic network properties may reflect the evolutionary changes during endosymbiosis that led to the improvement of the photosynthesis efficiency in higher plants. Our findings are consistent with the notion that since the light energy absorption, transfer and conversion is highly efficient even in photosynthetic bacteria, the further improvements in photosynthetic efficiency in higher plants may rely on changes in metabolic network properties.

Objective: Antisense CDK4 was transfected into human colorectal cancer cells HT29 to examine the effect of it on the growth and proliferation of HT29 cells., Methods: Antisense CDK4 transfected the HT29 cells with lipofectamine. The transfected effects were verified by the Northern blot, Western blot, morphological method, flow cell measure, etc., Results: The transformant cells showed the expression of exogenous antisense CDK4 mRNA, and downmodulation of endogenous CDK4 mRNA expression and inhibition of its protein synthesis. The transformant cells exhibited the partial reversion of the malignant phenotype and behavior, and that the cell growth and the ability of colony formation in soft agar were inhibited. The arrest of G1 phase was also revealed. the apoptosis rate is higher in HT29-asCDK4., Conclusion: The antisense CDK4 gene can inhibited the cell growth and proliferation, and induce the cell apoptosis. It might provide a new way to gene therapy of the colorectal carcinoma.

The yield potential (Yp) of a grain crop is the seed mass per unit ground area obtained under optimum growing conditions without weeds, pests and diseases. It is determined by the product of the available light energy and by the genetically determined properties: efficiency of light capture (epsilon i), the efficiency of conversion of the intercepted light into biomass (epsilon c) and the proportion of biomass partitioned into grain (eta). Plant breeding brings eta7 and epsilon i close to their theoretical maxima, leaving epsilon c, primarily determined by photosynthesis, as the only remaining major prospect for improving Yp. Leaf photosynthetic rate, however, is poorly correlated with yield when different genotypes of a crop species are compared. This led to the viewpoint that improvement of leaf photosynthesis has little value for improving Yp. By contrast, the many recent experiments that compare the growth of a genotype in current and future projected elevated [CO2] environments show that increase in leaf photosynthesis is closely associated with similar increases in yield. Are there opportunities to achieve similar increases by genetic manipulation? Six potential routes of increasing epsilon c by improving photosynthetic efficiency were explored, ranging from altered canopy architecture to improved regeneration of the acceptor molecule for CO2. Collectively, these changes could improve epsilon c and, therefore, Y p by c. 50%. Because some changes could be achieved by transgenic technology, the time of the development of commercial cultivars could be considerably less than by conventional breeding and potentially, within 10-15 years.

Aim: To observe biological characteristics of hepatocarcinoma cells before and after CD80 transfection and to compare the effect of CD80-transfected hepatocarcinoma cells on T lymphocyte activation., Methods: Retro virus vector carrying CD80 gene was transfected into HepG2 cells to establish CD80-transfected hepatocarcinoma cells (HepG2/hCD80). Flow cytometry (FCM) was performed to detect CD80 expression in the transfected cells. RT-PCR was used to evaluate CD80 expression at mRNA level. In the presence of anti-CD3 mAb, the proliferation of T lymphocyte was observed by MTT. Meanwhile, the expression of activated molecule marker CD25 was analyzed through FCM., Results: A stable cell line HepG2/hCD80 expressing the human CD80 was established. Growth curve showed that the molecule CD80 could obviously decrease the growth of tumor cells. HepG2/hCD80 was evidenced to have a potency to enhance T cell proliferation and upregulate CD25 expression., Conclusion: CD80 transfection can lower malignant phenotype of hepatocarcinoma cells. CD80 transfection has a down-regulatory effect to activated T cells in vitro.

Results from studies using molecular and genetic methods in humans and rodents suggest that brain-derived neurotrophic factor (BDNF) is involved in the behavioral effects of abused drugs, making understanding of its genomic structure and regulation of substantial interest. Recently, we have reported that the human BDNF gene contains seven upstream exons that can each be spliced independently to the major BDNF coding exon to form diverse bipartite BDNF transcripts. We also identified a novel "BDNFOS" gene that is transcribed to produce alternatively spliced natural antisense transcripts (NATs); its fifth exon overlaps with the protein coding exon VIII of human BDNF. To better understand BDNF's genomic structure and differential regulation, we now describe the rodent BDNF gene and transcripts. This gene includes six bipartite transcripts that are generated by six independently transcribed exons, each of which is spliced to a major coding exon and a tripartite transcript that is composed of two upstream exons and one coding exon. In addition, we found no evidence for antisense, opposite strand BDNFOS gene transcripts in mice or rats. The BDNF rodent splice variants display specific patterns of differential expression in different brain regions and peripheral tissues. Acute cocaine administration increased striatal expression of a specific BDNF4 splice variant by up to 5-fold. Interestingly, however, neither experimenter- nor self-administered chronic cocaine administration enhanced striatal BDNF expression. These data suggest a role of specific BDNF promoter regions and regulatory sequences in stimulant-induced alterations in BDNF expression, and in the alterations that changed BDNF expression is likely to confer in the brain.

Chlorophyll a fluorescence induction (FI) is widely used as a probe for studying photosynthesis. On illumination, fluorescence emission rises from an initial level O to a maximum P through transient steps, termed J and I. FI kinetics reflect the overall performance of photosystem II (PSII). Although FI kinetics are commonly and easily measured, there is a lack of consensus as to what controls the characteristic series of transients, partially because most of the current models of FI focus on subsets of reactions of PSII, but not the whole. Here we present a model of fluorescence induction, which includes all discrete energy and electron transfer steps in and around PSII, avoiding any assumptions about what is critical to obtaining O J I P kinetics. This model successfully simulates the observed kinetics of fluorescence induction including O J I P transients. The fluorescence emission in this model was calculated directly from the amount of excited singlet-state chlorophyll in the core and peripheral antennae of PSII. Electron and energy transfer were simulated by a series of linked differential equations. A variable step numerical integration procedure (ode15s) from MATLAB provided a computationally efficient method of solving these linked equations. This in silico representation of the complete molecular system provides an experimental workbench for testing hypotheses as to the underlying mechanism controlling the O J I P kinetics and fluorescence emission at these points. Simulations based on this model showed that J corresponds to the peak concentrations of Q(-)AQB (QA and QB are the first and second quinone electron acceptor of PSII respectively) and Q(-)AQ(-)B and I to the first shoulder in the increase in concentration of Q(-)AQ(2-)B. The P peak coincides with maximum concentrations of both Q(-)AQ(2-)B and PQH2. In addition, simulations using this model suggest that different ratios of the peripheral antenna and core antenna lead to differences in fluorescence emission at O without affecting fluorescence emission at J, I and P. An increase in the concentration of QB-nonreducing PSII centers leads to higher fluorescence emission at O and correspondingly decreases the variable to maximum fluorescence ratio (F v/F m).

Objective: To investigate the effect of exogenous carbon monoxide (CO) in inhibiting the sequestration of polymorphonuclear neutrophils (PMNs) in the lung following limb ischemia-reperfusion (IR) and the mechanism thereof., Methods: PMNs of peripheral blood were isolated from the venous blood of a healthy volunteer. Serum was collected from a patient undergoing bilateral knee joint replacement as IR serum. Human pulmonary microvascular endothelial cells (PMVECs) were cultured and divided into 4 groups: control group (cultured under the condition of room air containing 5% CO2 for 5 h and cultured in normal human serum instead of medium during the last 4 hours of experiment), IR group (cultured under the condition of air containing 5% CO2 for 5h and cultured in the serum of IR patient during the last 4 hours), IR + CO group (cultured under the condition of air containing 0.025% CO and 5% CO2 for 5 hours and cultured in IR serum during the last 4 hours), and control + CO group (cultured under the condition of air containing and 0.025% CO and 5% CO2 for 5 hours and cultured in normal human serum during the last 4 hours). Immunofluorescence flow cytometry was used to detect the expression of intercellular adhesion molecule (ICAM)-1 and integrin CD11b in the PMVECs. Human PMVECs were put into the wells of a 96-well plate and added with PMNs to calculate the PMVEC-PMN adhesion rate. Tourniquettes were bound at the bilateral hind thighs of 32 healthy male SD rats for 4 hours so as to establish a rate IR model. The rats were randomly divided into 4 equal groups: control group (undergoing the same operation without causing limb ischemia and exposed to room air), IR group (undergoing bilateral hind limb ischemia for 4 h and reperfusion for 4 h and exposed to room air), IR + CO group (exposed to the containing 0.025% CO one hour before reperfusion till 4 hours after reperfusion), and control + CO group (exposed to air containing 0.025% CO at the corresponding time point as that of the IR + CO group). Then the rats were killed and their middle pulmonary lobes were taken out for microscopy and calculation of the number of PMNs in alveolar septum. Western blotting was used to examine the ICAM-1 protein expression in the lung., Results: The ICAM-1 expression and integrin CD11b expression of the IR group PMVECs were significantly stronger than those of the IR + CO group PMVECs (both P < 0.05) and there were no significant differences in the ICAM-1 expression and CD11b expression between the control + CO and control groups (both P > 0.05). The PMN-PMVEC adhesion rate of the IR group PMVECs was 30 +/- 2.9%, significantly higher than those of the IR + CO group and control group PMVECs (19.8 +/- 1.5% and 13.4 +/- 1.1% respectively, both P < 0.05) and there was no significant difference in the PMN-PMVEC adhesion rate between the CO + control group and control group (P > 0.05). The lung tissues of the IR group rats showed edema and hemorrhage. The number of PMNs in the alveolar septum was 60.6 +/- 1.7/10 high power fields, significantly higher than those of the IR + CO group and control group (36.4 +/- 1.6 and 22.5 +/- 1.6 respectively, both P < 0.05) and there was no significant difference between the latter 2 groups (P > 0.05). The ICAM-1 protein expression in the lung of the IR group was the strongest, followed by the IR + CO group, control + CO group, and control group., Conclusion: Exogenous CO inhibits the limb/IR-induced PMN sequestration in the lung, probably by the mechanism of down-regulation of the expression of adhesion molecules and suppression of the PMN\PMVEC adhesion following IR.

Aim: To investigate the expression of mitogen-activated protein kinases (MAPKs) and its upstream protein kinase in human gastric cancer and to evaluate the relationship between protein levels and clinicopathological parameters., Methods: Western blot was used to measure the expression of extracellular signal-regulated kinase (ERK)-1, ERK-2, ERK-3, p38 and mitogen or ERK activated protein kinaseMEK-1 proteins in surgically resected gastric carcinoma, adjacent normal mucosa and metastatic lymph nodes from 42 patients. Immunohistochemistry was employed for their localization., Results: Compared with normal tissues, the protein levels of ERK-1 (integral optical density value 159 526+/-65 760 vs 122 807+/-65 515, P = 0.001), ERK-2 (168 471+/-95 051 vs 120 469+/-72 874, P<0.001), ERK-3 (118 651+/-71 513 vs 70 934+/-68 058, P<0.001), P38 (104 776+/-51 650 vs 82 930+/-40 392, P = 0.048) and MEK-1 (116 486+/-45 725 vs 101 434+/-49 387, P = 0.027) were increased in gastric cancer tissues. Overexpression of ERK-3 was correlated to TNM staging (average ratio of integral optic density (IOD)(tumor): IOD(normal) in TNM I, II, III, IV tumors was 1.43+/-0.34, 5.08+/-3.74, 4.99+/-1.08, 1.44+/-1.02, n = 42, P = 0.023) and serosa invasion (4.31+/-4.34 vs 2.00+/-2.03, P = 0.037). In poorly differentiated cancers (n = 33), the protein levels of ERK-1 and ERK-2 in stage III and IV tumors were higher than those in stage I and II tumors (2.64+/-3.01 vs 1.01+/-0.33, P = 0.022; 2.05+/-1.54 vs 1.24+/-0.40, P = 0.030). Gastric cancer tissues with either lymph node involvement (2.49+/-2.91 vs 1.03+/-0.36, P = 0.023; 1.98+/-1.49 vs 1.24+/-0.44, P = 0.036) or serosa invasion (2.39+/-2.82 vs 1.01+/-0.35, P = 0.022; 1.95+/-1.44 vs 1.14+/-0.36, P = 0.015) expressed higher protein levels of ERK-1 and ERK-2. In Borrmann II tumors, expression of ERK-2 and ERK-3 was increased compared with Borrmann III tumors (2.57+/-1.86 vs 1.23+/-0.60, P = 0.022; 5.50+/-5.05 vs 1.83+/-1.21, P = 0.014). Borrmann IV tumors expressed higher p38 protein levels. No statistically significant difference in expression of MAPKs was found when stratified to tumor size or histological grade (P>0.05). Protein levels of ERK-2, ERK-3 and MEK-1 in metastatic lymph nodes were 2-7 folds higher than those in adjacent normal mucosa. The immunohistochemistry demonstrated that ERK-1, ERK-2, ERK-3, p38 and MEK-1 proteins were mainly localized in cytoplasm. The expression of MEK-1 in gastric cancer cells metastasized to lymph nodes was higher than that of the primary site., Conclusion: MAPKs, particularly ERK subclass are overexpressed in the majority of gastric cancers. Overexpression of ERKs is correlated to TNM staging, serosa invasion, and lymph node involvement. The overexpression of p38 most likely plays a prominent role in certain morphological subtypes of gastric cancers. MEK-1 is also overexpressed in gastric cancer, particularly in metastatic lymph nodes. Upregulation of MAPK signal transduction pathways may play an important role in tumorigenesis and metastatic potential of gastric cancer.

Objective: To study the change and role of heme oxygenase-1 (HO-1) in injured lungs following limb ischemia/reperfusion in rats., Methods: A total of 96 healthy male Sprague-Dawley rats, weighing 250-300 g, were used in this study. Hind limb ischemia was made on 40 rats through clamping the infrarenal aorta for 2 hours with a microvascular clip, then limb reperfusion for 0, 4, 8, 16 and 24 hours (n=8 in each time point) was performed, respectively. Other 8 rats undergoing full surgical operation including isolation of the infrarenal aorta without occlusion were taken as the sham operation group. Lung tissues were obtained from the 48 animals and Northern blotting and Western blotting were employed to measure the changes of HO-1 mRNA and protein expression, respectively. Immunohistochemistry technique was used to determine the cell types responsible for HO-1 expression after limb ischemia/reperfusion. Then hind limb ischemia was made on other 12 rats through clamping the infrarenal aorta for 2 hours with a microvascular clip, among whom, 6 rats were given zinc protoporphyrin (ZnPP), an inhibitor of HO. Then limb reperfusion for 16 hours was performed on all the 12 rats. And other 12 rats underwent full surgical operation including isolation of the infrarenal aorta without occlusion, among whom, 6 rats were then given ZnPP. Then lung tissues were obtained from the 24 animals and lung injury markers, lung histology, polymorphonuclear leukocyte (PMN) count and malondialdehyde (MDA) content were detected, respectively. HO activity was determined through measuring the carboxyhemoglobin (COHb) level in artery blood with a CO-oximeter after limb ischemia/reperfusion. And the animal mortality was observed on the other 24 rats., Results: Northern blotting analysis showed that HO-1 mRNA increased significantly at 4 hours after reperfusion, peaked at 16 hours, and began to decrease at 24 hours. In contrast, no positive signal was observed in the sham and simple ischemia animals. Increased HO-1 mRNA levels were accompanied by similar increases in HO-1 protein. Lung PMNs and MDA content increased significantly at 4, 8, 16 and 24 hours after reperfusion, compared with the sham controls (P<0.001), while they decreased in rats with reperfusion for 16 hours when compared with rats with reperfusion for 4 hours (P<0.001). Immunohistochemical studies showed that HO-1 was expressed in a variety of cell types, including the airway epithelia, alveolar macrophages and vascular smooth muscular cells. The blood COHb level and animal mortality increased significantly after limb ischemia/reperfusion compared with the sham controls (P<0.001). ZnPP administrated to the ischemia/reperfusion animals led to a decrease in the COHb level and an increase in lung PMN number, MDA content and animal mortality (P<0.001 compared with ischemia/reperfusion group), and the lung injury was aggravated., Conclusions: Limb ischemia/reperfusion up-regulates pulmonary HO-1 expression, which serves as a compensatory protective response to the ischemia/reperfusion-induced lung injury in rats.

Regulated thermal dissipation of absorbed light energy within the photosystem II antenna system helps protect photosystem II from damage in excess light. This reversible photoprotective process decreases the maximum quantum yield of photosystem II (Fv)/Fm) and CO2 assimilation (phiCO2), and decreases the convexity of the non-rectangular hyperbola describing the response of leaf CO2 assimilation to photon flux (theta). At high light, a decrease in phiCO2 has minimal impact on carbon gain, while high thermal energy dissipation protects PSII against oxidative damage. Light in leaf canopies in the field is continually fluctuating and a finite period of time is required for recovery of phiCO2 and when light drops below excess levels. Low phiCO2) and can limit the rate of photosynthetic carbon assimilation on transfer to low light, an effect prolonged by low temperature. What is the cost of this delayed reversal of thermal energy dissipation and phiCO2 recovery to potential CO2 uptake by a canopy in the field? To address this question a reverse ray-tracing algorithm for predicting the light dynamics of 120 randomly selected individual points in a model canopy was used to describe the discontinuity and heterogeneity of light flux within the canopy. Because photoprotection is at the level of the cell, not the leaf, light was simulated for small points of 10(4) micro m rather than as an average for a leaf. The predicted light dynamics were combined with empirical equations simulating the dynamics of the light-dependent decrease and recovery of phiCO2 and and their effects on the integrated daily canopy carbon uptake (A'c). The simulation was for a model canopy of leaf area index 3 with random inclination and orientation of foliage, on a clear sky day (latitude 44 degrees N, 120th day of the year). The delay in recovery of photoprotection was predicted to decrease A'c by 17% at 30 degrees C and 32% at 10 degrees C for a chilling-susceptible species, and by 12.8% at 30 degrees C and 24% at 10 degrees C for a chilling-tolerant species. These predictions suggest that the selection, or engineering, of genotypes capable of more rapid recovery from the photoprotected state would substantially increase carbon uptake by crop canopies in the field., (Copyright 2004 Society for Experimental Biology)