Changes in tau phosphorylation levels in the hippocampus and frontal cortex following chronic stress

Studies have indicated that early-life or early-onset depression is associated with a 2- to 4-fold increased risk of developing Alzheimer's disease (AD). In AD, aggregation of an abnormally phosphorylated form of the tau protein may be a key pathological event. Tau is known to play a major role in promoting microtubule assembly and stabilization, and in maintaining the normal morphology of neurons. Several studies have reported that stress may induce tau phosphorylation. The main aim of the present study was to investigate possible alterations in the tau protein in the hippocampus and frontal cortex of 32 male Sprague-Dawley rats exposed to chronic unpredictable mild stress (CUMS) and then re-exposed to CUMS to mimic depression and the recurrence of depression, respectively, in humans. We evaluated the effects of CUMS, fluoxetine, and CUMS re-exposure on tau and phospho-tau. Our results showed that a single exposure to CUMS caused a significant reduction in sucrose preference, indicating a state of anhedonia. The change in behavior was accompanied by specific alterations in phospho-tau protein levels, but fluoxetine treatment reversed the CUMS-induced impairments. Moreover, changes in sucrose preference and phospho-tau were more pronounced in rats re-exposed to CUMS than in those subjected to a single exposure. Our results suggest that changes in tau phosphorylation may contribute to the link between depression and AD.

Mitigation of nutrient losses via surface runoff from rice cropping systems with alternate wetting and drying irrigation and site-specific nutrient management practices

Resource-conserving irrigation and fertilizer management practices have been developed for rice systems which may help address water quality concerns by reducing N and P losses via surface runoff. Field experiments under three treatments, i.e., farmers' conventional practice (FCP), alternate wetting and drying (AWD), and AWD integrated with site-specific nutrient management (AWD + SSNM) were carried out during two rice seasons at two sites in the southwest Yangtze River delta region. Across site years, results indicated that under AWD irrigation (i.e., AWD and AWD + SSNM), water inputs were reduced by 13.4~27.5 % and surface runoff was reduced by 30.2~36.7 % compared to FCP. When AWD was implemented alone, total N and P loss masses via surface runoff were reduced by 23.3~30.4 % and 26.9~31.7 %, respectively, compared to FCP. However, nutrient concentrations of surface runoff did not decrease under AWD alone. Under AWD + SSNM, total N and P loss masses via surface runoff were reduced to a greater extent than AWD alone (39.4~47.6 % and 46.1~48.3 % compared to FCP, respectively), while fertilizer inputs and N surpluses significantly decreased and rice grain yields increased relative to FCP. Therefore, by more closely matching nutrient supply with crop demand and reducing both surface runoff and nutrient concentrations of surface runoff, our results demonstrate that integration of AWD and SSNM practices can mitigate N and P losses via surface runoff from rice fields while maintaining high yields.

Local electrical conduction in polycrystalline La-doped BiFeO₃ thin films

Local electrical conduction behaviors of polycrystalline La-doped BiFeO3 thin films have been investigated by combining conductive atomic force microscopy and piezoelectric force microscopy. Nanoscale current measurements were performed as a function of bias voltage for different crystal grains. Completely distinct conducting processes and resistive switching effects were observed in the grain boundary and grain interior. We have revealed that local electric conduction in a grain is dominated by both the grain boundary and ferroelectric domain, and is closely related to the applied electric field and the as-grown state of the grain. At lower voltages the electrical conduction is dominated by the grain boundary and is associated with the redistribution of oxygen vacancies in the grain boundary under external electric fields. At higher voltages both the grain boundary and ferroelectric domain are responsible for the electrical conduction of grains, and the electrical conduction gradually extends from the grain boundary into the grain interior due to the extension of the ferroelectric domain towards the grain interior. We have also demonstrated that the conduction dominated by the grain boundary exhibits a much small switching voltage, while the conduction of the ferroelectric domain causes a much high switching voltage in the grain interior.

Cerebral and renal abscess and retino-choroiditis secondary to Candida albicans in preterm infants: eight case retrospective study

OBJECTIVES

To assess the tissues and organs commonly involved and the clinical features in the invasive fungal infection (IFI) of Candida albicans in the preterm infants.

MATERIALS AND METHODS

Eight preterm infants who developed IFI with positive blood culture for Candida albicans were retrospectively studied. All infants received selected clinical and laboratory parameters evaluation, such as blood culture, cerebral magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) biochemical test, routine urine test, urine culture, renal ultrasonography, renal computer tomography (CT), and fundus examination. The re-examinations were performed after one to two months follow-up.

RESULTS

Cerebral abscesses were detected in six infants. Five cases developed renal systemic fungal infection, among which one had renal abscess. Three cases were complicated with fungal retino-choroiditis.

CONCLUSIONS

Preterm infants, especially very-low-birthweight (VLBW) and extremely-low-birth-weight (ELBW) infants are susceptible to fungi. The majority of preterm late-onset fungal infections are due to Candida albicans. The organs commonly involved in the IFI of Candida albicans are central nervous system (CNS), kidney and fundus, among which renal systemic fungal infection are prone to recur, calling for a prolonged anti-fungi treatment course.

Scaling the dynamic electron scattering in imaging the graphene sheets by the high-angle annular dark-field microscopy

Employing the graphene sheets (GSs), the electron scattering constants are measured in the high-angle annular dark-field (HAADF) imaging by the scanning transmission electron microscopy. Single scattering is found to be dominant until the layer number of 200, complying with a simple relation of I = Io(1 - e(-tau/lambda)). The discrete layer counting of the GSs enables precise determination of incident depths. This work results values of lambda = 48.2, 61.4, 97.9 and 115.6 nm for 80, 120, 160 and 200 keV electrons, respectively. The uncertainties with the mean free paths and the cross sections are confined to 10 percent. The dependences on the electron beam energy and the collection angle are discussed based on a multislice simulation.

Transcription of promoter from the human APRIL gene regulated by Sp1 and NF-kB

A proliferation-inducing ligand (APRIL) which stimulates the cell proliferation is abundantly expressed in colorectal cancer (CRC) tumors. In this report, the promoter region of the APRIL gene was determined and the major transcription factor was investigated for the first time. Deletion analysis of 5'-flanking region of the human APRIL gene and transient transfection revealed that a 538 bp region (from -1539 to -1001) was essential for promoter activation of the APRIL gene. The data from electrophoretic mobility shift assays (EMSA) indicated that the 538 bp promoter region was responsive to the specificity protein 1 (Sp1) and nuclear factor kappa B (NF-kB). Overexpression of Sp1 or NF-kB increased the activity of the APRIL promoter. Mithramycin A (inhibitor of Sp1) and Bay11-7082 (inhibitor of NF-kB) exhibited an inhibitory activity to APRIL promoter. Our results will benefit to the APRIL gene regulation investigation and contribute to discover new drug target for the APRIL gene therapy of CRC.

Comparative pharmacokinetics of chlorogenic acid after oral administration in rats

The present study was aimed at the comparison of the pharmacokinetics of pure chlorogenic acid and extract of Solanum lyratum Thunb. The animals were allocated to two groups, and were administered chlorogenic acid or extract of S. lyratum Thunb. at a dose of 50.0 mg/kg orally. Blood samples were collected up to 8 h post-dosing. Plasma chlorogenic acid analyses were performed using an HPLC method with UV detector. The pharmacokinetic parameters were evaluated using non-compartmental assessment. Significant differences existed in the two groups for AUC_0−t, AUC_0−∞ and CLz/F. The reliable HPLC method was successfully applied to the determination of chlorogenic acid in rat plasma at dosage of 50.0 mg/kg.

Cloning expression, monoclonal antibody preparation and serologic study of mammaglobin in breast cancer

Mammaglobin may be a potential serum biomarker for the differential diagnosis of breast cancer. 260 serum samples were collected from 127 untreated breast cancer patients and 133 healthy volunteers to analyze the sera expression of mammaglobin and its implications for both. The expression vector of pGEX-4T-2-Mammaglobin and pBVIL1-Mammaglobin were constructed and transformed into E.coli.HB101 for expression. The mice were immunized with the purified recombinant protein to prepare monoclonal antibody and to detect by ELISA the serum of normal people and breast cancer patients. Recombinant mammaglobin antigen was effectively expressed in E.coli. Two hybridoma cell lines were obtained after the mice were immunized by pGEX-4T-2-mammaglobin. 133 cases of normal serum and 127 cases of breast cancer serum were analyzed by ELISA. The sera expression level of mammaglobin in breast cancer group (average OD value 0.645±0.223) was significantly (p

KEYWORDS

mammaglobin; cloning expression; monoclonal antibody; serologic study; breast cancer.

Enhanced thermal stability of monodispersed silver cluster arrays assembled on block copolymer scaffolds

Triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) films with long-range ordered self-assembled nanopatterns are used as templates to selectively adsorb soft-landing silver clusters. Closely spaced cluster arrays with high monodispersity are formed through the confinement of the block copolymer scaffolds, and show a much enhanced thermal stability as compared with the cluster assemblies on the surfaces of covalent amorphous solids, or even on the disordered SBS films. Their morphologies are barely influenced by long time thermal annealing at a temperature as high as 180 degrees C, while in the latter case intense aggregations and coalescences of silver clusters are commonly observed upon annealing. The different thermal stabilities of the cluster assemblies also induce different evolutions of their optical extinction spectra under annealing. This promises a simple way to control the monodispersity and thermal stability of metal cluster assembly via self-assembled block copolymer template.

Improvements in renal osteodystrophy in patients treated with lanthanum carbonate for two years

AIMS

To investigate the evolution of renal osteodystrophy in patients on maintenance dialysis, treated with lanthanum carbonate (LC) vs. standard phosphate-binder therapy (Stx).

MATERIALS AND METHODS

This was a 2-year, randomized, prospective, open-label study during which patients on dialysis received LC titrated to a maximum of 3,000 mg/day or their previous phosphate binder treatment with the aim to achieve target phosphorus levels of < or = 5.9 mg/dl. Paired bone biopsy samples for histomorphometric analysis were available at baseline and 1 year (LC 32, Stx 33), and at baseline and 2 years (LC 32, Stx 24).

RESULTS

With similar phosphorus control, Stx was associated with numerically higher serum calcium levels at most visits. Results of osteocalcin and bone-specific alkaline phosphatase in LC patients were higher throughout the study and correlated with parameters of bone formation; however, the differences were not significant. Histological changes in bone turnover and volume were analyzed with respect to normal ranges. There was an improvement in bone turnover in the LC group, which was significant in the 1-year group, and an improvement in bone volume which was significant in the 2-year group. No significant changes in bone turnover or bone volume were observed in the Stx groups. In the 2-year LC group, 1 patient had osteomalacia at baseline and end of therapy, and a mineralization defect developed in 2 other patients. Several possible factors for a mineralization defect were present in these patients, but no single cause could be clearly identified. Histomorphometric parameters of bone, including formation and mineralization, did not correlate with bone lanthanum. No mineralization defect was observed in the Stx groups.

CONCLUSION

These findings show that similar phosphorus control with Stx and LC results in higher bone turnover after 1 year and higher bone volume after 2 years with LC.

Phytohemagglutinin improves efficiency of electrofusing mammary gland epithelial cells into oocytes in goats

The objective was to investigate the effect of phytohemagglutinin (PHA) on the fusion of mammary gland epithelial (MGE) cells into enucleated oocytes in goats. The toxicity of PHA was evaluated by testing its effect on the development of parthenogenetic caprine oocytes. The effective dose and duration of PHA treatment (100 microg/mL, 20 min incubation) was selected and used to compare fusion efficiency and embryo development following nuclear transfer. Two electrofusion protocols, chamber fusion (CF) and pressurized microelectrode fusion (pMEF), were also compared, when couplets were treated with and without PHA (100 microg/mL, 20 min). Fusion rate of couplets increased from 52.8 to 74.0% for the CF protocol (P<0.05), but was not significantly different for the pMEF protocol (72.7% vs. 78.1%) after PHA treatment. There were no significant differences between treated group and control in rates of subsequent cleavage or blastocyst development. Following transfer of the cloned blastocysts derived from the PHA-treated group and the control group into synchronized recipients, pregnancy rates (Day 30) were not significantly different between treated group and control (28.6% vs. 25.0%). However, all recipients aborted within 120d, microsatellite DNA analyses confirmed that the aborted fetuses were genetically identical to the donor goat. In conclusion, the fusion rate of caprine MGE cell couplets was improved by pre-incubating couplets in medium containing 100 microg/mL PHA prior to electrical pulsing, and embryos derived from PHA treatment established early pregnancies.

[Tissue distribution and excretion of 5-fluorouracil from indomethacin 5-fluorouracil-1-ylmethylester in rats]

To study the tissue distribution and excretion of indomethacin 5-fluorouracil-1-ylmethyl ester (IFM) metabolite 5-fluorouracil in rats, an accurate and specific high performance liquid chromatography method for quantifying IFM in rat plasma and tissues was developed. Biological samples were prepared by liquid-liquid extraction and separated on a Diamonsil C18 column (250 mm x 4.6 mm ID, 5 microm). The mobile phase for tissue samples, plasma samples and feces samples were composed of methanol-water-36% acetic acid (3:96.9:0.1, v/v) and the mobile phase for urine samples was a mixture of methanol-water-36% acetic acid (10:89.9:0.1, v/v). The eluate was monitored by UV absorbance at 260 nm. After a single ig dose of 100 mg x kg(-1) IFM in rats, 5-Fu was mainly distributed in stomach, small intestine, and liver. The concentrations of 5-fluorouracil in other tissues and plasma were low. The excretion of 5-Fu in urine and feces amounted to 0.0065% and 0.063% of the dose, respectively. The method is shown to be accurate and specific, and suitable for preclinical pharmacokinetic studies of IFM.

Structural and electronic properties of TaSi(n) (n=1-13) clusters: a relativistic density functional investigation

The TaSi(n) (n=1-13) clusters with doublet, quartet, and sextet spin configurations have been systematically investigated by a relativistic density functional theory with the generalized gradient approximation available in Amsterdam density functional program. The total bonding energies, equilibrium geometries, Mulliken populations as well as Hirshfeld charges of TaSi(n) (n=1-13) clusters are calculated and presented. The emphasis on the stabilities and electronic properties is discussed. The most stable structures of the small TaSi(n) (n=1-6) clusters and the evolutional rule of low-lying geometries of the larger TaSi(n) (n=7-13) clusters are obtained. Theoretical results indicate that the most stable structure of TaSi(n) (n=1-6) clusters keeps the similar framework as the most stable structure of Si(n+1) clusters except for TaSi(3) cluster. The Ta atom in the lowest-energy TaSi(n) (n=1-13) isomers occupies a gradual sinking site, and the site moves from convex, to flatness, and to concave with the number of Si atom varying from 1 to 13. When n=12, the Ta atom in TaSi(12) cluster completely falls into the center of the Si frame, and a cagelike TaSi(12) geometry is formed. Meanwhile, the net Mulliken and Hirsheld populations of the Ta atom in the TaSi(n) (n=1-13) clusters vary from positive to negative, manifesting that the charges in TaSi(n) (n>/=12) clusters transfer from Si atoms to Ta atom. Additionally, the contribution of Si-Si and Si-Ta interactions to the stability of TaSi(n) clusters is briefly discussed. Furthermore, the investigations on atomic averaged binding energies and fragmentation energies show that the TaSi(n) (n=2,3,5,7,10,11,12) clusters have enhanced stabilities. Compared with pure silicon clusters, a universal narrowing of highest occupied molecular orbital-lowest unoccupied molecular orbital gap in TaSi(n) clusters is found.

Relativistic Computational Investigation: The Geometries and Electronic Properties of TaSin+ (n = 1−13, 16) Clusters

The equilibrium geometries, stabilities, and electronic properties of the TaSi(n)+ (n = 1-13, 16) clusters are investigated systematically by using the relativistic density functional method with generalized gradient approximation. The small-sized TaSi(n)+ clusters with slight geometrical adjustments basically keep the frameworks that are analogous to the neutrals while the medium-sized charged clusters significantly deform the neutral geometries, which are confirmed by the calculated AIP and VIP values. Furthermore, the optimized geometries of the charged clusters agree with the experimental results of Hiura and co-workers (Hiura, H.; Miyazaki, T.; Kanayama, T. Phys. Rev. Lett. 2001, 86, 1733). The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) gaps of the charged clusters are generally increased as the cluster size goes from n = 1 to 13; and the large HOMO-LUMO gaps of charged clusters resulting from the positive charge indicate that their chemical stabilities are stronger than their neutral counterparts, especially for n = 4, 6, and 7 clusters. Additionally, the contributions of the d orbitals of the Ta atom to the HOMO and LUMO reveal that the chemical activity of the d orbitals of the Ta atom decreases gradually as the number of silicon atoms increases. This interesting finding is in good agreement with the recent experimental results on the reactive activities of the H2O and transition-metal silicon clusters (Koyasu, K.; Akutsu, M.; Mitsui, M.; Nakajima, A. J. Am. Chem. Soc. 2005, 127, 4998). Generally, the positive charge significantly influences the electronic and geometric structures of the charged clusters. Finally, the most stable neutral and charged TaSi16 clusters are found to be fullerene-like structures and the HOMO-LUMO gap in charged form is detectable experimentally.

Two-point, high-repetition-rate Rayleigh thermometry in flames: techniques to correct for apparent dissipation induced by noise

High-repetition-rate, two-point Rayleigh thermometry is used to measure the thermal dissipation in turbulent nonpremixed jet flames. Scalar-dissipation measurements are very important in turbulent combustion but are often strongly influenced by noise effects. Dissipation is proportional to the squared gradient of the scalar, and noise produces an "apparent dissipation" that can dominate the measured dissipation, particularly at high resolution. Two independent techniques are presented that enable correction for the apparent thermal dissipation, provided that the smallest spatial scales are resolved. A model for shot-noise-limited data is developed that predicts the magnitude of the apparent dissipation at any measurement location and gives the minimum value of the apparent dissipation for measurements that are not shot-noise limited. These techniques are applied to the Rayleigh thermometry data, and they are shown to be largely self-consistent and consistent with theoretical expectations. The apparent dissipation is significantly larger than the true dissipation, demonstrating the importance of data correction in this noise-limited, fully spatially resolved regime.

Local atomic structures of palladium nanowire

In this paper, investigation of the structure of palladium nanowire has been performed by using genetic algorithm simulation based on the molecular dynamics. Our calculation employs a well-fitted, tight-binding many-body potential for Pd atoms. Some local atomic structures and defects in nanowires have been reported. The melting behavior of palladium nanowire has also been investigated. An interesting result is that the diffusion of the central atoms results in the beginning of the melting. The moving central atoms build up a monostrand atomic chain during the melting process. The single atomic chain is very stable which can exist in a wide temperature region (800-950 K). The formation of the single atomic chain causes some new defects in the nanowire. And the new defects result in the decrease of the thermal stability of the nanowire. Interestingly, the liquid from the nanowire melting has a supercooled feature because the splitting of the second peak of pair correlation function is observed. The curves of the internal energy and the local cluster are used to monitor the phase transition. The melting of the nanowire is not only due to the single atomic diffusion, but also the diffusion of the local clusters.

Real-time studies on microalgae under microgravity

Using remote sensing technique, we investigated real-time Nostoc sphaeroides Kütz (Cyanobacterium) in Closed System under microgravity by SHENZHOU-2 spacecraft in January 2001. The experiments had 1 g centrifuges in space for control and ground control group experiments were also carried out in the same equipments and under the same controlled condition. The data about the population growth of Nostoc sp. of experiments and temperature changes of system were got from spacecraft every minute. From the data, we can find that population growth of Nostoc sp. in microgravity group was higher than that of other groups in space or on ground, even though both the control 1 g group in space and 1 g group on ground indicated same increasing characteristics in experiments. The growth rate of 1.4 g group (centrifuged group on ground) was also promoted during experiment. The temperature changes of systems are also affected by gravity and light. Some aspects about those differences were discussed. From the discussion of these results during experiment, it can be found that gravity is the major factor to lead to these changes.

Melting behavior of one-dimensional zirconium nanowire

In this paper, we analyze the melting behavior of zirconium nanowire using the results of a series of molecular dynamics simulations. Our calculation employs a well-fitted, tight-binding many-body potential for zirconium atoms. The melting point of the nanowire is predicted by the root-mean-square displacements for inner and outer shells. Our simulations predict two melting behaviors: one is the inner melting and the other is the outer melting. Our results reveal that the melting of nanowire starts from the inner shell atoms. The melting point of zirconium nanowire is lower than the bulk value (2125 K). Moreover, the melting point of the inner shell is lower than that of the outer shell. A coexistence of crystal and liquid units is observed in the melting process of nanowire. An investigation of local clusters is carried out to further analyze the melting mechanism of the nanowire. The presence of the local clusters 1331, 1321, 1211, etc. is an indication of disordered structures. The pair and angular correlation functions are also presented for the analysis of the melting behavior. It is not only the diffusion of single atom but the diffusion of clusters result in the occurrence of the melting.

Binding of FADD and caspase-8 to molluscum contagiosum virus MC159 v-FLIP is not sufficient for its antiapoptotic function

Molluscum contagiosum virus (MCV), a member of the human poxvirus family, encodes the MC159 protein that inhibits Fas-, tumor necrosis factor (TNF)-, and TNF-related apoptosis-inducing ligant (TRAIL)-induced apoptosis. We used site-directed mutagenesis to change charged or hydrophobic amino acid residues to alanines to identify regions of MC159 that are critical for protection from apoptosis and for protein-protein interactions. Surprisingly, while MC159 is thought to block apoptosis by binding to Fas-associated death domain (FADD) or caspase-8, several mutants that lost apoptosis blocking activity still bound to both FADD and caspase-8. Mutations in the predicted hydrophobic patch 1 and alpha2 regions of both death effector domains (DEDs) within MC159 resulted in loss of the ability to bind to FADD or caspase-8 and to block apoptosis. Amino acid substitutions in the RXDL motif located in the alpha6 region of either DED resulted in loss of protection from apoptosis induced by Fas, TNF, and TRAIL and abolished the ability of MC159 to block death effector filament formation. Thus, charged or hydrophobic amino acids in three regions of the MC159 DEDs (hydrophobic patch 1, alpha2, and alpha6) are critical for the protein's ability to interact with cellular proteins and to block apoptosis.

[Construction of linkage map and mapping resistance gene of Scterotinia scterotiorum in Brassica napus]

Scterotinia scterotiorum (Lib.) de by is a world-wide disease, which seriously decreases the yield and the quality of oil of rapeseed. Mapping resistance genes of S. scterotiorum is of vital effect to breed new elite cultivars resisting the disease. In this paper, we reported that a RAPD linkage map was constructed, including 193 RAPD markers, 19 linkage groups and covering 1,324 cM, by using Mapmaker 3.0. On the basis of map, and resistance genes, Sc1, Sc2 and Sc3, were located in 4th, 8th and 18th linkage groups. Among three QTLs, Sc2 has the characteristics of major gene with explained 29%. The three QTLs together explained about 56% of phenotypic variation.

New cytotoxic sesquiterpenes from the gorgonian Isis hippuris

Five new suberosane sesquiterpenes, suberosenol A (1), suberosenol B (2), suberosanone (3), suberosenol A acetate (4), and suberosenol B acetate (5), along with the known sesquiterpene subergorgic acid (6), have been isolated from the gorgonian Isis hippuris. The structures of these metabolites were established by spectroscopic and chemical methods. Metabolites 1 and 3-5 were found to exhibit potent cytotoxicity toward P-388, A549, and HT-29 cancer cell lines.