Photosystem II photochemistry, photoinhibition, and the xanthophyll cycle in heat-stressed rice leaves

To investigate how high light affects the responses of photosynthesis to heat stress, the effects of high temperature (25-42.5 degrees C) either in the dark or in the light (1000 micromol m(-2) s(-1)) on photosystem II (PSII) photochemistry and the xanthophyll cycle were investigated in rice plants. At temperatures higher than 35 degrees C, there was a decrease in the CO(2) assimilation rate, and this decrease was greater in the light than in the dark. The maximal efficiency of PSII photochemistry (F(v)/F(m)) showed no significant change in the dark, but did show a significant decrease in the light. In addition, there was an increase in non-photochemical quenching (NPQ) and this increase was greater in the light than in the dark. Furthermore, the de-epoxidation status of the xanthophyll cycle increased significantly with increasing temperature in the light. Compared to the control leaves, the dithiothreitol-fed leaves showed a greater decrease in F(v)/F(m) but a very small increase in NPQ and de-epoxidation status of the xanthophyll cycle at temperatures higher than 35 degrees C. On the other hand, the ascorbate-fed leaves showed less of a decrease in F(v)/F(m) but a greater increase in NPQ and the de-epoxidation status of the xanthophyll cycle. Ascorbate peroxidase and glutathione reductase activities in leaves and chloroplasts were enhanced and this enhancement was greater in the light than in the dark. Heat stress had no significant effect on the contents of ascorbate and glutathione in leaves and chloroplasts in the dark, but led to an increase in the contents of reduced ascorbate and glutathione in leaves and chloroplasts in the light at the temperatures higher than 35 degrees C. Our results suggest that the xanthophyll cycle plays an important role in protecting PSII against heat-induced photoinhibition by an increase in the ascorbate pool in the chloroplast.

Co-production of lactic acid and chitin using a pelletized filamentous fungus Rhizopus oryzae cultured on cull potatoes and glucose

AIMS

This paper developed a novel process for lactic acid and chitin co-production of the pelletized Rhzious oryzae NRRL 395 fermentation using underutilized cull potatoes and glucose as nutrient source.

METHODS AND RESULTS

Whole potato hydrolysate medium was first used to produce the highest pelletized biomass yield accompanying the highest chitin content in biomass. An enhanced lactic acid production then followed up using batch, repeated batch and fed batch culture with glucose as carbon source and mixture of ammonia and sodium hydroxide as neutralizer. The lactic acid productivity peaked at 2.8 and 3 g l(-1 )h(-1) in repeated batch culture and batch culture, respectively. The fed batch culture had the highest lactate concentration of 140 g l(-1).

CONCLUSIONS

Separation of the biomass cultivation and the lactic acid production is able to not only improve lactic acid production, but also enhance the chitin content. Cull potato hydrolysate used as a nutrient source for biomass cultivation can significantly increase both biomass yield and chitin content.

SIGNIFICANCE AND IMPACT OF THE STUDY

The three-step process using pelletized R. oryzae fermentation innovatively integrates utilization of agricultural residues into the process of co-producing lactic acid and chitin, so as to improve the efficiency, revenues and cost of fungal lactic acid production.

Polar metabolite of cholesterol induces rat cognitive dysfunctions

24-hydroxycholesterol, a major polar metabolite of brain cholesterol, has neurotoxic effects. However, little is known about the effects of this polar metabolite on the CNS. In the present study, the effects of 24-hydroxycholesterol on behavior changes were investigated. Rats were divided into three groups: (i) a control group; (ii) a sham group: 0.5 ml PBS was infused into the cerebral ventricle; (iii) a model group: 0.5 ml 24-hydroxycholesterol (10 microM) was infused into the cerebral ventricle. 24-hydroxycholesterol can obviously impair rats' acquisition and probe trial in the Morris Water Maze task. Compared with rats in the sham group, rats in the model group had longer escape latency time and traveled more distance, and performed worse in the probe trial task manifested by spending less time in the annulus and training quadrant, which probably was attributed to the neuronal degeneration in hippocampal CA1 area induced by 24-hydroxycholesterol as examined by histological assay and apoptotic assay. Our results revealed that the polar metabolites, such as 24-hydroxycholesterol, exert neurotoxic effects and exacerbate the neuron injury with their abnormal accumulation. These findings suggest that measures taken promptly to eliminate or inhibit the accumulation of polar metabolites should be a potential strategy to prevent neurological dysfunctions and promote the recovery of functional deficits after neurotoxic insult.

Chromosomal aberrations and gene expression profiles in non-small cell lung cancer

Alterations in genomic content and changes in gene expression levels are central characteristics of tumors and pivotal to the tumorigenic process. We analyzed 23 non-small cell lung cancer (NSCLC) tumors by array comparative genomic hybridization (array CGH). Aberrant regions identified included well-characterized chromosomal aberrations such as amplifications of 3q and 8q and deletions of 3p21.31. Less frequently identified aberrations such as amplifications of 7q22.3-31.31 and 12p11.23-13.2, and previously unidentified aberrations such as deletion of 11q12.3-13.3 were also detected. To enhance our ability to identify key acting genes residing in these regions, we combined array CGH results with gene expression profiling performed on the same tumor samples. We identified a set of genes with concordant changes in DNA copy number and expression levels, i.e. overexpressed genes located in amplified regions and underexpressed genes located in deleted regions. This set included members of the Wnt/beta-catenin pathway, genes involved in DNA replication, and matrix metalloproteases (MMPs). Functional enrichment analysis of the genes both overexpressed and amplified revealed a significant enrichment for DNA replication and repair, and extracellular matrix component gene ontology annotations. We verified the changes in expressions of MCM2, MCM6, RUVBL1, MMP1, MMP12 by real-time quantitative PCR. Our results provide a high resolution map of copy number changes in non-small cell lung cancer. The joint analysis of array CGH and gene expression analysis highlights genes with concordant changes in expression and copy number that may be critical to lung cancer development and progression.

Discovery and preliminary structure-activity relationship studies of novel benzotriazine based compounds as Src inhibitors

We report the discovery and preliminary SAR studies of a series of structurally novel benzotriazine core based small molecules as inhibitors of Src kinase. To the best of our knowledge, benzotriazine template based compounds have not been reported as kinase inhibitors. The 3-(2-(1-pyrrolidinyl)ethoxy)phenyl analogue (43) was identified as one of the most potent inhibitors of Src kinase.

Studies into Using Manure in a Biorefinery Concept

Animal manure is an underutilized biomass resource containing a large amount of organic carbon that is often wasted with the existing manure disposal practices. A research project funded by the US Department of Energy explored the feasibility of using manure via the sugar platform in a biorefinery, converting the carbon from fiber to biochemicals. The results showed that (1) fiber was the major component of manure dry material making up approx 50%, 40%, and 36% of the dry dairy, swine, and poultry manure material, respectively; within dairy manure, more than 56% of the dry matter was in particles larger than 1.680 mm; (2) in addition to being a carbon source, manure could provide a variety of nutrient for fungi T. reesei and A. phoenicis to produce cellulase; (3) the hemicellulose component in the manure fiber could be readily converted to sugar through acid hydrolysis; while concentrated acid decrystallization treatment was most effective in manure cellulose hydrolysis; (4) purification and separation was necessary for further chemical conversion of the manure hydrolysate to polyols through hydrogenation; and (5) the manure utilization strategy studied in this work is currently not profitable.

PET investigation of post-traumatic cerebral blood volume and blood flow

Hemodynamic changes following traumatic brain injury (TBI) may reflect cellular damage leading to secondary injury. The purpose of this study was to investigate the regional hemodynamic parameters acutely after TBI among regions in and around contusions. Sixteen patients (11 male, 5 female) showing evidence of contusion on CT and 18 normal volunteers (12 male, 6 female) underwent positron emission tomography (PET) with O-15 CO and O-15 H2O to estimate cerebral blood volume (CBV) and cerebral blood flow (CBF), respectively. A flow to volume ratio (FVR = CBF/CBV) was also calculated as an index of vasodilatation. The hemodynamic parameters were compared among contusion, pericontusion, and remote areas. Globally, hemodynamic parameters did not differ between patients and normal volunteers, and did not correlate with intracranial pressure (ICP). Regionally, contusional and pericontusional areas showed significantly lower CBF and FVR compared with normal volunteers, while CBV did not differ significantly. The correlation between CBF and CBV was significant (r = 0.37, p < 0.01). Remote areas did not show a significant difference in any of the PET parameters. In conclusion, regional brain edema is likely to occur in contusion and pericontusion areas, while some of the contusional tissue may show vascular engorgement.

[The development and application of computer-aided bone histomorphometry system]

The aim of this study is to develop a Computer-aided Bone Histomorphometry System. The method is based on the Micro-graphical Digital System composed of microscope, digital camera, computer and related programs. The methodology was developed to measure the basic data on each image of visual field of hard bone tissue with computer-assistance. Following this, the parameters of bone volume, bone structure and bone metabolism were calculated based on the standardization of bone histomorphometry. Such method has been used in the experimental and clinical studies of osteoporosis to predict the fracture risk and evaluate the drug effect.

Nucleotide sequence analysis of a transforming gene isolated from nasopharyngeal carcinoma cell line CNE2: an aberrant human immunoglobulin kappa light chain which lacks variable region

A transforming gene, designated Tx, was isolated from a human nasopharyngeal carcinoma (NPC) cell line CNE2 by transfection and molecular cloning techniques. The Tx gene was analyzed using computer-based bioinformatics and compared with the known sequences in EMBL and GenBank databases. We found that Tx contains human immunoglobulin kappa light chain constant region, five intact joining regions J1-J5, five recombination signal sequences and an N-segment besides classic regulatory sequences such as TATA boxes, CAAT boxes, poly A signals, etc. Interestingly, Tx also contains several binding sites for nuclear transcription factors such as NF-kappaB, NF-IL6, TFIID, etc. In conclusion, there are only several base pairs mutations or deletions compared with normal Ig K JC gDNA fragment. In all, Tx is an aberrant human immunoglobulin kappa light chain that contains the constant region, five joining regions, which lacks the variable regions.

Catalytic, asymmetric synthesis of siphonarienal

This paper describes the synthesis of the marine natural product, siphonarienal. The key step of this synthesis is an aldol reaction that constructs most of the skeleton and sets all three stereocenters of the target in one step from commercially available starting materials. Deoxygenation and chain homologation steps complete the synthesis.

Effect of fetal spinal cord graft with different methods on axonal pathology after spinal cord contusion

OBJECTIVE

To investigate the effect of fetal spinal cord (FSC) graft with different methods on axonal pathology and neurological function recovery after spinal cord injury (SCI).

METHODS

Forty Wistar rats were divided into 4 groups. In Group A, the spinal cord was injured and hemisected. In Group B, fetal spinal cord (FSC) was transferred into the injured site. In Group C, after having done as Group B, the upper and lower spinal nerve roots were anastomosed. And in Group D, after having done as Group B, the pedicled omentum was transferred into the hemisection cavity. At 6 weeks after operation, light and electronic microscopes were used to examine the axonal pathology. The neurological function was assessed with inclined plane tests in the open field. The number of axons was quantitated by a computer image analysis system.

RESULTS

A greater loss of axons was observed in Group A than that of other groups at 6 weeks. The sequence of the reduced rate of the axons was as following, Group A>Group B>Group C>Group D (P<0.05). The remaining axons were paralleled with the significant improvement in neurological function recovery of the rats.

CONCLUSIONS

It indicates that FSC and pedicled omentum grafts after SCI can protect the axons and promote the neurological function recovery of the rats.

The essential role of MEKK3 in TNF-induced NF-kappaB activation

Activation of IkappaB kinase (IKK) is the key step in stimulation of the transcription factor NF-kappaB, which regulates many genes in the inflammatory response pathway. The molecular mechanism that underlies IKK activation in response to tumor necrosis factor (TNF) is still unknown. Using mitogen-activated protein kinase kinase kinase 3 (MEKK3)-deficient fibroblast cells, we found that MEKK3 plays a critical role in TNF-induced NF-kappaB activation. We have shown that MEKK3 is required for IKK activation and functions downstream of receptor-interacting protein (RIP) and TNF receptor- associated factor 2. We have also shown that MEKK3 interacts with RIP and directly phosphorylates IKK. The kinase activity of MEKK3 is pivotal to its function and, therefore, MEKK3 links RIP and IKK in TNF-induced NF-kappaB activation.

LMP1 activates NF-kappa B via degradation of I kappa B alpha in nasopharyngeal carcinoma cells

OBJECTIVE

To elucidate the mechanisms by which Epstein-Barr virus-encoded latent membrane protein 1 activates NF-kappa B in nasopharyngeal carcinoma cells.

METHODS

A tetracycline-regulated LMP1-expressing nasopharyngeal carcinoma cell line, Tet-on-LMP1-HNE2, was used as the cell model. The kinetics of the expression of proteins, including LMP1, I kappa B alpha and I kappa B beta, was analyzed by Western blotting. The subcellular localization of NF-kappa B (p65) was detected by indirect immunofluorescence assay. The NF-kappa B transactivity was studied by transient transfection and reporter gene assay.

RESULTS

I kappa B alpha was phosphorylated and degraded after the inducible expression of LMP1, although the total protein levels remained stable. The steady-state level of total I kappa B beta protein may have resulted from the initiation of an autoregulation loop after the activation of NF-kappa B. No change in the I kappa B beta level was detected. NF-kappa B (p65) was translocated from the cytoplasm to the nucleus following degradation of I kappa B alpha. After the introduction of the dominant-negative mutant of I kappa B alpha (Del 71) into Tet-on-LMP1-HNE2 cells, both nuclear translocation and transactivation of NF-kappa B induced by LMP1 was significantly inhibited.

CONCLUSIONS

The results indicated that in nasopharyngeal carcinoma cells, LMP1 activated NF-kappa B via phosphorylation and degradation of I kappa B alpha, but not I kappa B beta. The dominant-negative mutant of I kappa B alpha (Del 71) could completely inhibit both the nuclear translocation and transactivation of NF-kappa B induced by LMP1.

[Construction of Cryptococcus neoformans cap70 transformation system]

OBJECTIVE

To construct a transformation system of Cryptococcus neoformans capsule-deficient strain cap70.

METHODS

(1)Obtained ura5 mutants by screening the Cryptococcus neoformans cap70 using 5-fluoroorotic acid counter selection method, analyzed the obtaining strain by Southern blot and PCR; (2)Through the plasmid pCXJ18 and pCXJU which contained ura5 gene from Cryptococcus neoformans and ura3 from Kluyveromyces fragilils. as a selective marker, the ura5 strains were transformed by electrotransformation and chemical transformation.

RESULTS

Obtained ura5 mutants, they were detected as lack of ura function. The chemical transformation method was first be used in Cryptococcus neoformans transformation.

CONCLUSION

A transformation system of Cryptococcus neoformans cap70 has been established, which provides not only the basis for gene cloning from the species for studying gene function and gene expression.

Direct evidence for the size and conformational variability of the pyruvate dehydrogenase complex revealed by three-dimensional electron microscopy. The "breathing" core and its functional relationship to protein dynamics

Structural studies by three-dimensional electron microscopy of the Saccharomyces cerevisiae truncated dihydrolipoamide acetyltransferase (tE(2)) component of the pyruvate dehydrogenase complex reveal an extraordinary example of protein dynamics. The tE(2) forms a 60-subunit core with the morphology of a pentagonal dodecahedron and consists of 20 cone-shaped trimers interconnected by 30 bridges. Frozen-hydrated and stained molecules of tE(2) in the same field vary in size approximately 20%. Analyses of the data show that the size distribution is bell-shaped, and there is an approximately 40-A difference in the diameter of the smallest and largest structures that corresponds to approximately 14 A of variation in the length of the bridge between interconnected trimers. Companion studies of mature E(2) show that the complex of the intact subunit exhibits a similar size variation. The x-ray structure of Bacillus stearothermophilus tE(2) shows that there is an approximately 10-A gap between adjacent trimers and that the trimers are interconnected by the potentially flexible C-terminal ends of two adjacent subunits. We propose that this springlike feature is involved in a thermally driven expansion and contraction of the core and, since it appears to be a common feature in the phylogeny of pyruvate dehydrogenase complexes, protein dynamics is an integral component of the function of these multienzyme complexes.

Two-year results from the asthma self-management program: long-term impact on health care services, costs, functional status, and productivity

Participants in a variety of health plans, clinics and employer groups were invited to participate in the Asthma Self-Management Program (ASMP), an education program designed to improve self-management skills and daily functioning in individuals with asthma. The ASMP is an 8-week classroom program that provides information on the respiratory system, trigger avoidance, use of monitoring techniques and asthma medications. After program completion, graduates were contacted at scheduled intervals to reinforce performance of behaviors that are important to asthma self-management and to collect outcomes data. This paper reports the results of 2 years of follow-up with these individuals.

[Construction of attenuated Salmonella typhimurium vaccine strain expressing Helicobacter pylori catalase and observation on its protective immunity]

OBJECTIVE

To investigated the effect of attenuated Salmonella typhimurium vaccine strain expressing Helicobacter pylori (Hp) catalase (KatA) on protection against Hp infection.

METHODS

Recombinant plasmid expressing KatA was constructed. Expression of KatA was induced with IPTG, and analyzed by SDS-PAGE and Western blot. The recombinant plasmid were introduced into attenuated Salmonella typhimurium SL3261 strain to construct live oral vaccine strain. C57BL/6 mice was orally immunized with this vaccine strain and then given orogastric challenge with live Hp Sydney strain. The stomach samples were submitted to a rapid urease test and quantitative culture.

RESULTS

The SDS-PAGE showed a dominant additional protein with molecular weight of 79kDa which could specially react with antibody against GST and accounted for 19% of total bacteria proteins. Animal experiment indicated that this vaccine strain could protect mice against Hp infection.

CONCLUSION

Attenuated Salmonella typhimurium vaccine strain expressing KatA could induce effective immune response in protection against Hp infection,which may play an important role in preventing and treating Hp infection and related diseases.

One-pot, catalytic, asymmetric synthesis of polypropionates

[reaction: see text] The opening of methylketene dimer, followed by aldol reactions of the resulting enolate, provides a convenient access to syn,syn-dipropionate aldol adducts of a variety of aldehydes. These aldol adducts are useful precursors in the synthesis of complex polypropionates.