Temperature dependence of energy transfer between Nd3+ and Yb3+ ions in phosphate glass

The temperature dependence of energy transfer between Nd³⁺ and Yb³⁺ ions in phosphate glass was investigated with emission spectra, time-resolved spectroscopy, and luminescence lifetimes. The time-resolved spectrograms vividly displayed processes of both Nd³⁺→Yb³⁺ energy transfer and Yb³⁺→Nd³⁺ energy transfer. The impact of temperature on energy transfer rate has been studied by analyzing the cumulative rise times and decay times of Yb³⁺ upon excitation of Nd³⁺ and the cumulative rise times and decay times of Nd³⁺ upon excitation of Yb³⁺ at different temperatures. It has been found that both Nd³⁺→Yb³⁺ energy transfer and Yb³⁺→Nd³⁺ energy transfer are accelerated along with increasing temperatures in a certain temperature range.

Morin Protects Channel Catfish From Aeromonas hydrophila Infection by Blocking Aerolysin Activity

Aeromonas hydrophila (A. hydrophila) is an opportunistic bacterial pathogen widely distributed in the environments, particular aquatic environment. The pathogen can cause a range of infections in both human and animals including fishes. However, the application of antibiotics in treatment of A. hydrophila infections leads to the emergence of resistant strains. Consequently, new approaches need to be developed in fighting this pathogen. Aerolysin, the chief virulence factor produced by pathogenic A. hydrophila strains has been employed as target identifying new drugs. In our present study, we found that morin, a flavonoid without anti-bacterial activity isolated from traditional Chinese medicine, could directly inhibit the hemolytic activity of aerolysin. To determine the binding sites and the action of mechanism of morin against AerA, several assays were performed. Ser36, Pro347, and Arg356 were identified as the main binding sites affecting the conformation of AerA and resulted in block of the heptameric formation. Moreover, morin could protect Vero cells from cell injury mediated by aerolysin. In vivo study showed that morin could provide a protection to channel catfish against A. hydrophila infection. These results demonstrated that morin could be developed as a promising candidate for the treatment of A. hydrophila infections by decreasing the pathogenesis of A. hydrophila.

Recent insights into cotton functional genomics: progress and future perspectives

Functional genomics has transformed from futuristic concept to well-established scientific discipline during the last decade. Cotton functional genomics promise to enhance the understanding of fundamental plant biology to systematically exploit genetic resources for the improvement of cotton fibre quality and yield, as well as utilization of genetic information for germplasm improvement. However, determining the cotton gene functions is a much more challenging task, which has not progressed at a rapid pace. This article presents a comprehensive overview of the recent tools and resources available with the major advances in cotton functional genomics to develop elite cotton genotypes. This effort ultimately helps to filter a subset of genes that can be used to assemble a final list of candidate genes that could be employed in future novel cotton breeding programme. We argue that next stage of cotton functional genomics requires the draft genomes refinement, re-sequencing broad diversity panels with the development of high-throughput functional genomics tools and integrating multidisciplinary approaches in upcoming cotton improvement programmes.

The potential role of attitudes towards suicide between mental health status and suicidal ideation among Chinese children and adolescents

BACKGROUND

The objective of this study was to investigate the contributions of mental health status and attitudes towards suicide on suicidal ideation in a sample of 6568 Chinese children and adolescents in China. Attitudes towards suicide were investigated as a possible moderator and mediator of the influence of mental health status on suicidal ideation.

METHODS

Descriptive statistical analyses, Pearson correlation analyses and hierarchical regression analyses were adopted as methods of data analyses.

RESULTS

Approximately 35.38% of children and adolescents in our study reported having suicidal ideation. Mental health status and attitudes towards suicide both had an independent effect on the severity of suicidal ideation. Results indicated that mental health status was positively associated with suicidal ideation, while attitudes towards suicide were negatively associated with suicidal ideation. Moderation analysis showed that the impact of mental health status on suicidal ideation was significantly greater among children and adolescents who reported favourable attitudes towards suicide. Attitudes towards suicide partially mediated the link between mental health status and the severity of suicidal ideation. Specifically, students who experienced poorer mental health status might be more likely to report significantly more favourable attitudes towards suicide, which in turn promote greater suicidal ideation.

CONCLUSIONS

These results have implications for the prevention of youth suicide, suggesting that mental health status and attitudes towards suicide could be important targets for prevention and intervention for children and adolescents at risk of suicidal ideation.

[Determination of methylene bisthiocyanate in aquatic products by gas chromatography with pulsed-flame photometric detector]

A novel method was developed for the determination of methylene bisthiocyanate (MBT) in aquatic products by gas chromatography with pulsed-flame photometric detector (GC-PFPD). The samples were extracted by dichloromethane-n-hexane (1:1, v/v), concentrated and cleaned up by neutral-alumina SPE cartridges. The extracts were eluted with 8 mL dichloromethane, and blown to dryness by nitrogen at 35℃. The final extracts were redissolved with a mixture of dichloromethane-n-hexane (1:1, v/v), separated by an HP-5MS quartz capillary column (30 m×0.32 mm×0.25 μ m) and detected by PFPD with external standard method. Under the optimum experimental conditions, the standard curve was linear in the range of 1.0-20.0 mg/L with correlation coefficient of 0.9971. The limit of detection was 0.1 mg/kg. Recoveries ranged from 65.6% to 97.6% with RSDs of 6.32%-12.8% (n=7). The method has good innovative, advanced and practical values.

Spectral Properties of Er3+/Tm3+ Co-Doped ZBLAN Glasses and Fibers

A series of Er3+/Tm3+ co-doped fluoride (ZBLAN) glasses and fibers was prepared and their fluorescence spectra was measured under excitation at 793 nm and 980 nm. Correlation between the self-absorption effect of rare-earth ions and the shift of the emission peak was investigated. With the increasing length of fiber, the emission peaks red-shift when self-absorption occurs at the upper level of emission transition or blue-shift when that occurs at the lower level. As a result of the strong self-absorption effect, Er3+/Tm3+ co-doped fibers mainly yield 1390-1470, 1850-1980, and 2625-2750 nm emissions when excited at 793 nm, and 1480-1580, 1800-1980, and 2625-2750 nm emissions when excited at 980 nm. Further, a broadband emission in the range of 1410-1580 nm covering the S + C communication band was obtained by the dual-pumping scheme of 793 nm and 980 nm. Results suggest that the dual-pumping scheme would be more effective and important for an Er3+/Tm3+ co-doped fiber amplifier working in the S + C communication band.

Phase I-II clinical trial of hyaluronan-cisplatin nanoconjugate in dogs with naturally occurring malignant tumors

OBJECTIVE To conduct a phase I-II clinical trial of hyaluronan-cisplatin nanoconjugate (HA-Pt) in dogs with naturally occurring malignant tumors. ANIMALS 18 healthy rats, 9 healthy mice, and 16 dogs with cancer. PROCEDURES HA-Pt was prepared and tested by inductively coupled plasma mass spectrometry; DNA-platinum adduct formation and antiproliferation effects of cisplatin and HA-Pt were compared in vitro. Effects of cisplatin (IV) and HA-Pt (SC) in rodents were tested by clinicopathologic assays. In the clinical trial, dogs with cancer received 1 to 4 injections of HA-Pt (10 to 30 mg/m(2), intratumoral or peritumoral, q 3 wk). Blood samples were collected for pharmacokinetic analysis; CBC, serum BUN and creatinine concentration measurement, and urinalysis were conducted before and 1 week after each treatment. Some dogs underwent hepatic enzyme testing. Tumors were measured before the first treatment and 3 weeks after each treatment to assess response. RESULTS No adverse drug effects were detected in pretrial assessments in rodents. Seven of 16 dogs completed the study; 3 had complete tumor responses, 3 had stable disease, and 1 had progressive disease. Three of 7 dogs with oral and nasal squamous cell carcinoma (SCC) that completed the study had complete responses. Myelosuppression and cardiotoxicosis were identified in 6 and 2 dogs, respectively; none had nephrotoxicosis. Four of 5 dogs with hepatic enzymes assessed had increased ALT activities, attributed to diaquated cisplatin products in the HA-Pt. Pharmacokinetic data fit a 3-compartment model. CONCLUSIONS AND CLINICAL RELEVANCE HA-Pt treatment resulted in positive tumor responses in some dogs, primarily those with SCC. The adverse effect rate was high. IMPACT FOR HUMAN MEDICINE Oral SCC in dogs has characteristics similar to human head and neck SCC; these results could be useful in developing human treatments.

[Photodynamic therapy by topical drup for the treatment of juvenile onset laryngeal papillomatosis]

Objective:To observe the therapeutic effect of photodynamic therapy(PDT) on the treatment of juvenile onset laryngeal papillomatosis. Method:Twenty-eight cases of children with laryngeal papilloma were treated,only 2 cases for the first time, and the rest were repeatedly treated outside our hospital, the average hospital surgery were more than 4 times. Under self retaining laryngoscope and microscope and endoscope assisted by semiconductor laser and plasma and cold instrument method，visible tumor resection and local affixed deposited 20% 5-aminolevulinic acid(photosensitizer) 3 hours later, with 635 nm semiconductor laser photodynamic,200-280 mW and can volume density of 80 to 120 J/cm², 20 min irradiation. PDT should be repeated after 25 days until no visible tumor.Then,2 times PDT must be done. Result:In 28 cases, 24 cases were followed up for more than 1 years(12 cases were followed up for 3 years),19 had no recurrence, the cure rate was 79.2%(19/24)；5 cases recurrence, and the recurrence rate was 20.8%(5/24)，among them,2 cases were abandoned because of the relapse，the other 3 cases were cure after 3 times of PDT.The main complications were adhesion of larynx. Conclusion:The preliminary effect of PDT by topical drug for the treatment of juvenile onset laryngeal papillomatosis is encouraging. The principle of PDT and the principle of the recurrence of laryngeal papilloma in children were also introduced in this paper.

[Serological and pathological features of drug-induced liver injury and autoimmune hepatitis]

Objective: To investigate the differences and similarities between drug-induced liver injury (DILI) and autoimmune hepatitis (AIH) in serum biochemical parameters and liver pathology, and to provide some thoughts for clinical diagnosis and differentiation of these two diseases. Methods: A retrospective analysis was performed for the biochemical, immunological, autoantibody, and liver pathological data of 106 DILI patients and 63 AIH patients who were hospitalized, diagnosed, and treated in our hospital from January 2012 to October 2014. The patients' general data, biochemical parameters, immunological data, Ishak score, and qualitative changes in liver tissue were analyzed and compared. The Kruskal-Wallis test was used for comparison of nonparametric data between multiple groups, the Nemenyi test was used for comparison of nonparametric data between any two groups, the Wilcoxon rank sum test was used for comparison of Ishak scores, and the chi-square test was used for comparison of constituent ratio of categorical data. Results: There were significant differences between AIH group and DILI hepatocyte injury group/mixed-type DILI group in the following serum biochemical parameters: alanine aminotransferase (187.2 U/Lvs 1 326.5 U/L and 455.6,P< 0.05), aspartate aminotransferase (172.2 U/L vs 759.5 U/L and 349.5 U/L,P<0.05), alkaline phosphatase (209.3 U/L vs 157.3 U/L and 169.4 U/L,P< 0.05), gamma-glutamyl transferase (254.8 U/L vs 176.5 U/L and 170.5 U/L,P< 0.05), total bilirubin (37.2μmol/L vs 95.8μmol/L and 52.6μmol/L,P< 0.05), serum iron (18.9μmol/L vs 36.2μmol/L and 23.9μmol/L,P< 0.05), serum ferritin (122.5μmol/L vs 410.4μmol/L and 186.5μmol/L,P< 0.05), immunoglobulin G (18.4 g/L vs 12.6 g/L and 12.3 g/L,P< 0.05), and immunoglobulin M (1.8 g/L vs 1.3 g/L and 1.1 g/L,P< 0.05). There were also significant differences between AIH group and DILI hepatocyte injury group/mixed-type DILI group in the Ishak score for interface inflammation (2.2±0.8 vs 1.3±0.7 and 1.3±0.6,P< 0.05), Ishak score for portal inflammation (2.3±0.9 vs 1.5±0.7 and 1.4±0.8,P< 0.05), and fibrosis score (2.8±1.1 vs 1.5±0.7 and 1.3±0.7,P< 0.05). There were significant differences between AIH group and DILI hepatocyte injury group/mixed-type DILI group in the proportion of wax-like deposition (0 vs 29.2% and 34.5%, P <0.05) and proportion of iron deposition (11.1% vs 52.1% and 25.9%,P< 0.05). Conclusion: There are differences in biochemistry, immunology, and liver histology between DILI and AIH patients. AIH patients have more serious interface inflammation and portal inflammation and a higher fibrosis degree compared with DILI patients, while DILI patients have greater proportions of wax-like deposition and iron deposition compared with AIH patients.

[Pretreatment Research Based on Left and Right Hand Motor Imagery for Single-channel Electroencephalogram]

Most of electroencephalogram(EEG)acquired by multi-channels is difficult to be applied to the singlechannel brain-computer interface(BCI)in the EEG analysis method based on left and right hand motor imagery.The present research applied an improved independent component analysis(ICA)method to realize pretreatment of the EEG effectively.Firstly,data drift was removed through linear drift correction.Secondly,the number of virtual channels were increased by applying delayed window data and some EEG artifacts which are namely electrooculogram(EOG)and electrocardiogram(ECG)were removed by ICA.Finally,the average instantaneous energy characteristics were calculated and classified through the instantaneous amplitude which was solved by applying Hilbert-Huang transform(HHT).The experiment proves that the method completes the EEG pretreatment and improves classification ratio of single-channel EEG,and lays a foundation of single-channel and portable BCI.

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Method for Quantitative Analysis of Platinum in Plasma, Urine, and Tissues

Cisplatin, a platinum chemotherapeutic, is one of the most commonly used chemotherapeutic agents for many solid tumors. In this work, we developed and validated an inductively coupled plasma mass spectrometry (ICP-MS) method for quantitative determination of platinum levels in rat urine, plasma, and tissue matrices including liver, brain, lungs, kidney, muscle, heart, spleen, bladder, and lymph nodes. The tissues were processed using a microwave accelerated reaction system (MARS) system prior to analysis on an Agilent 7500 ICP-MS. According to the Food and Drug Administration guidance for industry, bioanalytical validation parameters of the method, such as selectivity, accuracy, precision, recovery, and stability were evaluated in rat biological samples. Our data suggested that the method was selective for platinum without interferences caused by other presenting elements, and the lower limit of quantification was 0.5 ppb. The accuracy and precision of the method were within 15% variation and the recoveries of platinum for all tissue matrices examined were determined to be 85-115% of the theoretical values. The stability of the platinum-containing solutions, including calibration standards, stock solutions, and processed samples in rat biological matrices was investigated. Results indicated that the samples were stable after three cycles of freeze-thaw and for up to three months.

Ethanol impedes embryo transport and impairs oviduct epithelium

Most studies have demonstrated that alcohol consumption is associated with decreased fertility. The aim of this study was to investigate the effects of alcohol on pre-implantation embryo transport and/or early embryo development in the oviduct. We reported here that ethanol concentration-dependently suppressed the spontaneous motility of isolated human oviduct strips (EC50 50±6mM), which was largely attenuated in the present of L-NAME, a classical nitric oxide synthase(NOS) competitive inhibitor. Notably, either acute or chronic alcohol intake delayed egg transport and retarded early development of the embryo in the mouse oviduct, which was largely rescued by co-administration of L-NAME in a acute alcohol intake group but not in chronic alcohol intake group. It is worth mentioning that the oviductal epithelium destruction was verified by scanning electron microscope (SEM) observations in chronic alcohol intake group. In conclusion, alcohol intake delayed egg transport and retarded early development of the embryo in the oviduct by suppressing the spontaneous motility of oviduct and/or impairing oviductal epithelium. These findings suggested that alcohol abuse increases the incident of ectopic pregnancy.

Hyaluronan-Lysine Cisplatin Drug Carrier for Treatment of Localized Cancers: Pharmacokinetics, Tolerability, and Efficacy in Rodents and Canines

The purpose of this study was to develop a safe and efficacious drug delivery platform for sustained release of cisplatin after locoregional administration. We successfully synthesized hyaluronan-cisplatin nanoconjugates (HA-Lys-Pt) using an N-Ac-lysine linker, which formed a thermodynamically stable five-membered ring with the platinum. The conjugate was characterized for release kinetics, in vitro anti-proliferative activity, degradability, impurity content, formation of Pt-DNA adducts, pharmacokinetics, tolerability in rodents and canines, and for efficacy in rodents. The 75 kD HA-Lys-Pt (75HA-Lys-Pt) sustained release of platinum with a 69 h half-life in phosphate buffered saline without substantial burst release. Compared to intravenous cisplatin, subcutaneously injected 75HA-Lys-Pt formed 3.2-fold more Pt-DNA adducts in rat peripheral blood mononuclear cells compared to intravenous cisplatin over 96 h. Subcutaneous 75HA-Lys-Pt was tolerable in rats at 40 mg/kg (4 × LD50 of conventional cisplatin) and resulted in 62.5% partial response and 37.5% stable disease in murine xenografts of head and neck squamous cell cancer (20 mg/kg/wk × 3 weeks). 75HA-Lys-Pt demonstrated extended tmax and improved area-under-the-curve compared to cisplatin in rats and canines. Canine safety was demonstrated by liver enzyme and electrolyte levels, complete blood count, and urinalysis.

A retrospective clinical study of bevacizumab combined with gemcibabine or paclitaxel in the treatment of recurrent ovarian cancer

BACKGROUND

Bevacizumab, a recombinant humanized monoclonal antibody that blocks angiogenesis by inhibiting vascular endothelial growth factor A, was described to be effective in the treatment of recurrent or platinum-resistance ovarian cancer. The present retrospective study was performed to further evaluate the clinical efficacy and toxicity of bevacizumab in the treatment of Chinese recurrent ovarian cancer patients who had been previously treated by platinum-based chemotherapy.

MATERIALS AND METHODS

We reviewed the hospital database and finally included 26 recurrent ovarian cancer patients who were treated with bevacizumab combined with gemcibabine or paclitaxel or single agent. All included patients received >3 cycle of bevacizumab treatment. The tumor response, overall survival, and toxicities were documented.

RESULTS

Under the treatment of bevacizumab combined with gemcibabine or paclitaxel, 2 complete response (7.7%), 8 partial response (30.8%), 7 stable disease (26.9%) and 9 progression disease (34.6%) was documented with the objective response rate of 38.5% and disease control rate of 65.4%. The median overall survival from the first application of bevacizumab was 15.3 months [Figure 1] for all of the 26 patients. The median overall survival time was 16.2 and 14.0 months for bevacizumab + gemcitabine and bevacizumab + paclitaxel treatment schedule respectively. The overall survival was not different between bevacizumab + gemcitabine and bevacizumab + paclitaxel treatment regimen hazard ratio = 0.80 (95% confidence interval: 0.32-2, P = 0.64). The hypertension and proteinuria were the major bevacizumab related toxicities.

CONCLUSIONS

Bevacizumab combined with gemcibabine or paclitaxel was a promising treatment schedule for platinum-resistance recurrent ovarian cancer.

Preparation of LuAG Powders with Single Phase and Good Dispersion for Transparent Ceramics Using Co-Precipitation Method

The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG) powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC) was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h) with high terminal pH value (>7.80) resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders.

Nanomicellar TGX221 blocks xenograft tumor growth of prostate cancer in nude mice

BACKGROUND

Combination of androgen ablation along with early detection and surgery has made prostate cancer highly treatable at the initial stage. However, this cancer remains the second leading cause of cancer death among American men due to castration-resistant progression, suggesting that novel therapeutic agents are urgently needed for this life-threatening condition. Phosphatidylinositol 3-kinase p110β is a major cellular signaling molecule and has been identified as a critical factor in prostate cancer progression. In a recent report, we established a nanomicelle-based strategy to deliver p110β-specific inhibitor TGX221 to prostate cancer cells by conjugating the surface of nanomicelles with a RNA aptamer against prostate specific membrane antigen (PSMA) present in all clinical prostate cancers. In this study, we tested this nanomicellar TGX221 for its in vivo anti-tumor effect in mouse xenograft models.

METHODS

Prostate cancer cell lines LAPC-4, LNCaP, C4-2 and 22RV1 were used to establish subcutaneous xenograft tumors in nude mice. Paraffin sections from xenograft tumor specimens were used in immunohistochemistry assays to detect AKT phosphorylation, cell proliferation marker Ki67 and proliferating cell nuclear antigen (PCNA), as well as 5-bromo-2-deoxyuridine (BrdU) incorporation. Quantitative PCR assay was conducted to determine prostate-specific antigen (PSA) gene expression in xenograft tumors.

RESULTS

Although systemic delivery of unconjugated TGX221 significantly reduced xenograft tumor growth in nude mice compared to solvent control, the nanomicellar TGX221 conjugates completely blocked tumor growth of xenografts derived from multiple prostate cancer cell lines. Further analyses revealed that AKT phosphorylation and cell proliferation indexes were dramatically reduced in xenograft tumors received nanomicellar TGX221 compared to xenograft tumors received unconjugated TGX221 treatment. There was no noticeable side effect by gross observation or at microscopic level of organ tissue section.

CONCLUSION

These data strongly suggest that prostate cancer cell-targeted nanomicellar TGX221 is an effective anti-cancer agent for prostate cancer.

A Lanthanum-Tagged Chemotherapeutic Agent HA-Pt to Track the In Vivo Distribution of Hyaluronic Acid Complexes

Hyaluronic acid drug conjugates can target anti-cancer drugs directly to tumor tissue for loco-regional treatment with enhanced bioavailability, local efficacy and reduced toxicity. In this study, the distribution and pharmacokinetics of hyaluronic acid carrier and a conjugated cisplatin anti-cancer drug were tracked by lanthanum (III) [La(III)] affinity tagging of the nanocarrier. The strong binding affinity of La(III) to HA enabled the simple preparation of a physiologically stable complex HA-Pt-La and straightforward simultaneous detection of HA-La and Pt in biological matrices using inductively coupled plasma-mass spectrometry (ICP-MS). Consequently, after subcutaneous injection of HA-Pt-La nanoparticles in human head and neck squamous cell carcinoma (HNSCC) tumor-bearing mice, the HA and Pt content were detected and quantified simultaneously in the plasma, primary tumor, liver and spleen.

Cabozantinib Loaded DSPE-PEG2000 Micelles as Delivery System: Formulation, Characterization and Cytotoxicity Evaluation

Cabozantinib, a potent pan-tyrosine kinase inhibitor, has been reported to provide enhanced antitumor efficacy by simultaneously inhibiting both MET and VEGF pathways, which are critical to tumor angiogenesis, survival and migration. It's very poor water solubility prevents its administration by the intravenous route, which may be important in patients unable to take the drug orally. In this study, we developed an efficient PEG-lipid-based polymeric micelle formulation with enhanced drug solubility and stability for cabozantinib delivery. DSPE-PEG₂₀₀₀ micelles encapsulating cabozantinib were prepared by a thin-film rehydration method followed by a lyophilization process to generate the dry dosage form. The average hydrodynamic diameter of freshly prepared micelles was 11 nm with a narrow size distribution, and the dry micelle cake could be fully reconstituted by rehydration. Approximately 75% of the drug was encapsulated into the lyophilized cake, and a sustained drug release profile was observed in simulated normal physiological release medium. Compared with the free cabozantinib solution, the drug-loaded micelles displayed significantly enhanced intracellular accumulation and cytotoxicity in human glioblastoma cancer cells and non-small lung cancer cells. These results suggest that the micellar formulation of cabozantinib may serve as a promising nanocarrier in anticancer treatments.

New angle of view on the role of rho/rho kinase pathway in human diseases

Rho-kinase is an effector molecule of RhoA, a monomeric GTP-binding protein, and causes Ca2+ sensitization through inactivation of myosin phosphatase. The major physiological functions of Rho/Rho-kinase cascade include contraction, proliferation and migration in cells.There are some excellent reviews about Rho/Rho-kinase signal pathway, most of which focus on the specific proteins of the pathway including some upstream regulators and its final effects. But few articles cover signal pathways that can activate the signaling concerned, and/or the pathways that Rho/Rho-kinase can exactly activate. This review hence highlights the two questions after a profound survey of published literatures. Rho/Rho-kinase can exert positive feedback with just another kinase/signal transducers and activator of transcription, receptor tyrosine kinase signal pathways, even reactive oxygen species, which seem to comprise certain signal loops. The authors also presume, accordingly, that the positive feedback suggests a possible reason for exacerbation of some kind of inflammatory diseases including asthma, rheumatoid arthritis, multiple sclerosis, atherosclerosis, etc. This essay, therefore, provides a new angle of view for the therapy of these kinds of diseases.

Cellular uptake and internalization of hyaluronan-based doxorubicin and cisplatin conjugates

BACKGROUND

Hyaluronan (HA) is a ligand for the CD44 receptor which is crucial to cancer cell proliferation and metastasis. High levels of CD44 expression in many cancers have encouraged the development of HA-based carriers for anti-cancer therapeutics.

PURPOSE

The objective of this study was to determine whether HA conjugation of anticancer drugs impacts CD44-specific HA-drug uptake and disposition by human head and neck cancer cells.

METHODS

The internalization and cellular disposition of hyaluronan-doxorubicin (HA-DOX), hyaluronan-cisplatin (HA-Pt), and hyaluronan-cyanine7 (HA-Cy7) conjugates were investigated by inhibiting endocytosis pathways, and by inhibiting the CD44-mediated internalization pathways that are known to mediate hyaluronan uptake in vitro.

RESULTS

Cellular internalization of HA was regulated by CD44 receptors. In mouse xenografts, HA conjugation significantly enhanced tumor cell uptake compared to unconjugated drugs.

DISCUSSION

The results suggested that the main mechanism of HA-based conjugate uptake may be active transport via CD44 in conjunction with a clathrin-dependent endocytic pathway. Other HA receptors, hyaluronan-mediated motility receptor (RHAMM) and lymphatic vessel endothelial hyaluronan receptor (LYVE-1), did not play a significant role in conjugate uptake.

CONCLUSIONS

HA conjugation significantly increased CD44-mediated drug uptake and extended the residence time of drugs in tumor cells.

Development of 5Ns chromosome-specific SCAR markers for utilization in future wheat breeding programs

In previous studies, we developed a wheat-Psathyrostachys huashanica Keng disomic addition line 3-8-10-2, which exhibited high stripe rust resistance and could be used as a donor source for introducing novel disease resistance gene(s) into wheat in future breeding programs. It was identified using cytology, genomic in situ hybridization (GISH), EST-SSR, EST-STS and morphological analyses. However, these techniques are not suitable for breeding programs that require the rapid screening of large numbers of genotypes because they are highly technical and time-consuming. In this study, three Ns genome-specific SCAR markers were developed via random amplified polymorphic DNA (RAPD) markers. These SCAR markers were further validated using a complete set of wheat-P. huashanica disomic addition lines, which segregated the 5Ns disomic addition line individuals. Our results indicated that the SCAR markers associated with the 5Ns chromosome of P. huashanica and they provide a low cost, high efficiency, alternative tool for screening 5Ns chromosomes in a wheat background. These newly developed SCAR markers that species-specificity of the markers was proved by analysis of a wide range of cereal species, and specific for 5Ns chromosome, which should be useful in marker-assisted selection for wheat breeders who want to screen genotypes that may contain 5Ns chromatin.

Cytogenetic and molecular identification of a wheat-Leymus mollis alien multiple substitution line from octoploid Tritileymus x Triticum durum

Leymus mollis (Trin.) Pilger (NsNsXmXm, 2n = 28), a wild relative of common wheat, possesses many traits that are potentially valuable for wheat improvement. In order to exploit and utilize the useful genes of L. mollis, we developed a multiple alien substitution line, 10DM50, from the progenies of octoploid Tritileymus M842-16 x Triticum durum cv. D4286. Genomic in situ hybridization analysis of mitosis and meiosis (metaphase I), using labeled total DNA of Psathyrostachys huashanica as probe, showed that the substitution line 10DM50 was a cytogenetically stable alien substitution line with 36 chromosomes from wheat and three pairs of Ns genome chromosomes from L. mollis. Simple sequence repeat analysis showed that the chromosomes 3D, 6D, and 7D were absent in 10DM50. Expressed sequence tag-sequence tagged sites analysis showed that new chromatin from 3Ns, 6Ns, and 7Ns of L. mollis were detected in 10DM50. We deduced that the substitution line 10DM50 was a multiple alien substitution line with the 3D, 6D, and 7D chromosomes replaced by 3Ns, 6Ns, and 7Ns from L. mollis. 10DM50 showed high resistance to leaf rust and significantly improved spike length, spikes per plant, and kernels per spike, which are correlated with higher wheat yield. These results suggest that line 10DM50 could be used as intermediate material for transferring desirable traits from L. mollis into common wheat in breeding programs.

In vivo efficacy of nano hyaluronan-conjugated cisplatin for treatment of murine melanoma

BACKGROUND

Melanoma is a deadly skin cancer with rapidly rising incidence. While localized melanoma can be treated with excision, there are at present no similarly effective treatments for regional and distant disease, so survival rates are low. One problem is that melanoma is chemo-resistant, and most chemotherapy doses are limited by systemic toxicity. A method for delivering high-dose chemotherapy directly to tumors and draining lymph nodes could have the advantage of allowing much higher effective doses with reduced systemic exposure.

METHODS

Human melanoma cell line A-2058 tumor cells were injected into athymic mice. After tumors grew to 50~100 mm³ mice were divided into five groups: (1) nontreated (2) intravenous (i.v.) cisplatin, (3) i.v. nano hyaluronan-conjugated cisplatin (HA-Pt), (4) subcutaneous (s.c.) peri-tumoral cisplatin, and (5) s.c. peri-tumoral HA-Pt. All treatment groups received 3 weekly doses of 10 mg/kg.

RESULTS

Tumors grew progressively in all control, i.v. cisplatin, and s.c. cisplatin groups. Tumors showed a trend toward slower growth in the i.v. HA-Pt group, but all animals died or were euthanized per protocol within 3 weeks of treatment. Tumors showed shrinkage only in the subcutaneous peri-tumoral HA-cisplatin group; one of these mice appeared to be cured.

CONCLUSIONS

Peri-tumoral HA-cisplatin may be shown potential as a therapeutic option in treatment of certain types of melanoma.

A novel SCAR marker for detecting Psathyrostachys huashanica Keng chromatin introduced in wheat

In this study, we cloned and sequenced a 938-base pair polymorphic band, pHs27, in the tightly linked random amplified polymorphic DNA marker OPU10 and converted it into a sequence-characterized amplified region (SCAR) marker referred to as RHS141, which was specific for the Ns genome of Psathyrostachys huashanica. A GenBank basic local alignment search tool search showed that the sequence of pHs27 had no primary sequence homology with known sequences, and Southern blotting confirmed this result. This SCAR marker was used to detect Ns genome chromatin in wheat, and it was successfully amplified in P. huashanica itself, a complete set of wheat-P. huashanica disomic addition lines (1Ns-7Ns), and undetermined homoeologous group addition lines. This SCAR marker will be a powerful tool for the marker-assisted selection of P. huashanica chromosome(s) in a wheat background, and it should also allow wheat breeders to screen for the excellent traits found in P. huashanica chromatin.

Temperature dependent emission and absorption cross section of Yb3+ doped yttrium lanthanum oxide (YLO) ceramic and its application in diode pumped amplifier

Temperature dependent absorption and emission cross-sections of 5 at% Yb(3+) doped yttrium lanthanum oxide (Yb:YLO) ceramic between 80K and 300 K are presented. In addition, we report on the first demonstration of ns pulse amplification in Yb:YLO ceramic. A pulse energy of 102 mJ was extracted from a multi-pass amplifier setup. The amplification bandwidth at room temperature confirms the potential of Yb:YLO ceramic for broad bandwidth amplification at cryogenic temperatures.

Forelimb amputation-induced reorganization in the cuneate nucleus (CN) is not reflected in large-scale reorganization in rat forepaw barrel subfield cortex (FBS)

We examined reorganization in cuneate nucleus (CN) in juvenile rat following forelimb amputation (n=34) and in intact controls (n=5) to determine whether CN forms a substrate for large-scale reorganization in forepaw barrel subfield (FBS) cortex. New input from the shoulder first appears in the FBS 4 weeks after amputation, and by 6 weeks, the new shoulder input comes to occupy most of the FBS. Electrophysiological recording was used to map CN in controls and in forelimb amputees during the first 12 weeks following deafferentation and at 26 and 30 weeks post-amputation. Mapping was confined to a location 300 μm anterior to the obex where a medial-to-lateral row of electrode penetrations traversed through a complete complement of cytochrome-oxidase stained clusters (called barrelettes) that are associated with the representation of the glabrous forepaw digits and pads and adjacent non-cluster zones that are associated with the representation of the wrist, arm, and shoulder. Following amputation, non-cluster zones became occupied with new input from the body/chest and head/neck, while the cluster zone remained largely devoid of new input except at the border. A regression analysis comparing controls and amputees over the first 12 weeks post-amputation found significant differences for the total area of new input from the body/chest and head/neck in the non-cluster zones, while no significant differences were found for any new input into the cluster zone. When the averaged areas of a body-part representation were re-examined as a percentage of the averaged zonal area, a non-significant increase in new input from the body was observed within the cluster zone during post-amputation weeks 2-3 that returned to baseline in the subsequent weeks. In contrast, significant differences in averaged area of body-part representations for body/chest and head/neck were found in non-cluster zones over the first 12 weeks post-amputation. The present findings suggest that reorganization occurs only within the non-cluster zones whereby new input from the body/chest and head/neck moves in and occupies the deafferented territory immediately after amputation. Additionally, the lack of significant differences in new shoulder input in either cluster or non-cluster zones over the first 12 weeks after amputation suggests that CN provides an unlikely substrate for large-scale reorganization in the FBS.

Inheritance and fine mapping of a restorer-of-fertility (Rf) gene for the cytoplasmic male sterility in soybean

The cytoplasmic male sterility (CMS) line FuCMS5A and its restorer line FuHui9 were crossed to produce a segregating F(2) population for pollen fertility assay and the genetic mapping of restorer-of-fertility (Rf) gene. Results showed that the individual F(2) plants were fertile or semi-fertile based on their pollen fertility characteristics. The average ratios of viable pollen were 96.90% and 50.00% for each class of individuals. The segregation of F(2) plants showed a good fit to a 1:1 ratio, which reflects a typical heredity pattern of gametophytic CMS with fertility restorer being controlled by a single dominant gene. Using bulk segregation analysis (BSA) and genetic mapping, the Rf gene was mapped on molecular linkage group J (chromosome 16), between the simple sequence repeat (SSR) makers BARCSOYSSR-16-1064 and BARCSOYSSR-16-1082 with the distances of 0.59 and 0.83 cM, respectively. Four SSR markers (BARCSOYSSR-16-1070, Sctt011, BARCSOYSSR-16-1076 and BARCSOYSSR-16-1077) were cosegregating with this Rf gene in the mapping population. These makers will greatly facilitate the maker assisted selection procedures in CMS breeding programs and it lays a foundation for further map-base cloning of the Rf gene.

Lymphatic trafficking kinetics and near-infrared imaging using star polymer architectures with controlled anionic character

Targeted lymphatic delivery of nanoparticles for drug delivery and imaging is primarily dependent on size and charge. Prior studies have observed increased lymphatic uptake and retentions of over 48 h for negatively charged particles compared to neutral and positively charged particles. We have developed new polymeric materials that extend retention over a more pharmaceutically relevant 7-day period. We used whole body fluorescence imaging to observe in mice the lymphatic trafficking of a series of anionic star poly-(6-O-methacryloyl-D-galactose) polymer-NIR dye (IR820) conjugates. The anionic charge of polymers was increased by modifying galactose moieties in the star polymers with succinic anhydride. Increasing anionic nature was associated with enhanced lymphatic uptake up to a zeta potential of ca.-40 mV; further negative charge did not affect lymphatic uptake. Compared to the 20% acid-conjugate, the 40-90% acid-star-polymer conjugates exhibited a 2.5- to 3.5-fold increase in lymphatic uptake in both the popliteal and iliac nodes. The polymer conjugates exhibited node half-lives of 2-20 h in the popliteal nodes and 19-114 h in the deeper iliac nodes. These polymer conjugates can deliver drugs or imaging agents with rapid lymphatic uptake and prolonged deep-nodal retention; thus they may provide a useful vehicle for sustained intralymphatic drug delivery with low toxicity.

Functional and structural organization of the forelimb representation in cuneate nucleus in rat

We examined the physiological representation of the forelimb in the cuneate nucleus (CN) of forelimb-intact young adult rats (n=38) as the first part in a series of studies aimed at understanding the possible role that CN plays in delayed cortical reorganization that follows forelimb amputation. Metabolic labeling with cytochrome oxidase (CO) and electrophysiological mapping were used to examine the relationship between the structural and functional organization of CN. CN is a cylinder-shaped structure that lies bilaterally in the brainstem and extends nearly 4mm in the rostrocaudal direction. The forelimb is represented along the rostrocaudal extent. CN contains three zones; the rostral and caudal zones receive input largely from deep muscle and joint receptors and a middle zone, in the vicinity of the obex, receives input primarily from cutaneous receptors in the skin. The middle zone is somatotopically organized with the glabrous digits represented centrally, bordered on the medial side by ulnar wrist, ulnar forearm, and posterior upper arm representations; on the lateral side by radial wrist, radial forearm, and anterior upper arm representations; and on dorsal side by the dorsal digits and dorsal hand. The middle zone also contains well-defined CO-filled glomerular structures, called barrelettes, which are located within a homogenously stained field. The barrelettes are associated with the representation of the glabrous digits, with D5 represented most dorsal followed sequentially in a ventral-to-lateral direction by the representation of D4, D3, D2, and D1. The digit representations are topographically organized with the distal digit surface represented laterally with respect to the more medially lying proximal digit surface. The digit and palmar pads are also represented by barrelettes located on the medial side of CN. In contrast, the dorsal digit surfaces are represented dorsally and the dorsal hand is represented directly beneath the cuneate fasciculus, in a region devoid of barrelettes. The representations of the ulnar and radial wrist, forearm, and upper arm also lie within the homogeneously stained field in CN. The forelimb representation is bordered on the medial side by representation of trunk and hindlimb, and on the lateral side by representation of shoulder, ear, and head. While the present findings support and extend previous electrophysiological and anatomical studies of CN in the rat, they also provide a detailed physiological description of the functional organization of CN that is necessary for subsequent understanding of the functional reorganization of CN that may result following forelimb amputation.

Multi-arm polymeric nanocarrier as a nitric oxide delivery platform for chemotherapy of head and neck squamous cell carcinoma

Nitric oxide is a cell signaling molecule that can be a potent inducer of cell death in cancers at elevated concentrations. However, NO is also toxic to normal tissues and chronic exposure at low levels can induce tumor growth. We have designed a polymeric carrier system to deliver nitric oxide locoregionally to tumorigenic tissues at micromolar concentrations. A highly water solubility and biodegradable multi-arm polymer nanocarrier, sugar poly-(6-O-methacryloyl-d-galactose), was synthesized using MADIX/RAFT polymerization, and utilized to deliver high concentrations of nitric oxide to xenografts of human head and neck squamous cell carcinoma (HNSCC). The in vitro release of the newly synthesized nitric oxide donor, O(2)-(2,4-dinitrophenyl) 1-[4-(2-hydroxy)ethyl]-3-methylpiperazin-1-yl]diazen-1-ium-1,2-diolate and its corresponding multi-arm polymer-based nanoconjugate demonstrated a 1- and 2.3-fold increase in half-life, respectively, compared to the release half-life of the nitric oxide-donor prodrug JS-K. When administered to tumor-bearing nude mice, the subcutaneously injected multi-arm polymer nitric oxide nanoparticles resulted in 50% tumor inhibition and a 7-week extension of the average survival time, compared to intravenous JS-K therapy. In summary, we have developed an effective nitric oxide anti-cancer chemotherapy that could be administered regionally to provide the local disease control, improving prognosis for head and neck cancers.

In vivo photoacoustic imaging of chemotherapy-induced apoptosis in squamous cell carcinoma using a near-infrared caspase-9 probe

Anti-cancer drugs typically exert their pharmacological effect on tumors by inducing apoptosis, or programmed cell death, within the cancer cells. However, no tools exist in the clinic for detecting apoptosis in real time. Microscopic examination of surgical biopsies and secondary responses, such as morphological changes, are used to verify efficacy of a treatment. Here, we developed a novel near-infrared dye-based imaging probe to directly detect apoptosis with high specificity in cancer cells by utilizing a noninvasive photoacoustic imaging (PAI) technique. Nude mice bearing head and neck tumors received cisplatin chemotherapy (10 mg/kg) and were imaged by PAI after tail vein injection of the contrast agent. In vivo PAI indicated a strong apoptotic response to chemotherapy on the peripheral margins of tumors, whereas untreated controls showed no contrast enhancement by PAI. The apoptotic status of the mouse tumor tissue was verified by immunohistochemical techniques staining for cleaved caspase-3 p11 subunit. The results demonstrated the potential of this imaging probe to guide the evaluation of chemotherapy treatment.

Lymphatic drug delivery using engineered liposomes and solid lipid nanoparticles

The lymphatic system plays a crucial role in the immune system's recognition and response to disease, and most solid cancers initially spread from the primary site via the tumor's surrounding lymphatics before hematological dissemination. Hence, the lymphatic system is an important target for developing new vaccines, cancer treatments, and diagnostic agents. Targeting the lymphatic system by subcutaneous, intestinal, and pulmonary routes has been evaluated and subsequently utilized to improve lymphatic penetration and retention of drug molecules, reduce drug-related systemic toxicities, and enhance bioavailability of poorly soluble and unstable drugs. Lymphatic imaging is an essential tool for the detection and staging of cancer. New nano-based technologies offer improved detection and characterization of the nodal diseases, while new delivery devices can better target and confine treatments to tumors within the nodal space while sparing healthy tissues. This manuscript reviews recent advances in the field of lymphatic drug delivery and imaging and focuses specifically on the development of liposomes and solid lipid nanoparticles for lymphatic introduction via the subcutaneous, intestinal, and pulmonary routes.

A sensitive near-infrared fluorescent probe for caspase-mediated apoptosis: Synthesis and application in cell imaging

Near-infrared (NIR) absorbing dyes represent an intriguing avenue for extracting biological information from living subjects since they can be monitored with noninvasive optical imaging techniques. We designed and synthesized an imaging agent which contains a NIR fluorochrome (IR780) and peptidyl fluoromethyl ketone (FMK) for caspase-9 imaging of cells undergoing apoptosis. The IR780-FMK fluorescent probe had a Strokes shift of 79 nm and quantum yield 0.75. Prostate cancer DU145 cells undergoing apoptosis were successfully imaged using as little as 0.1 μM of IR780-FMK.

Derp2-mutant gene vaccine inhibits airway inflammation and up-regulates Toll-like receptor 9 in an allergic asthmatic mouse model

BACKGROUND

A DNA vaccine encoding the whole segment of the Derp2 allergen could prevent allergic airway inflammation in a Derp2 allergen-induced allergic airway inflammation mouse model.

OBJECTIVE

This study investigated the effect of DNA vaccine encoding Derp2-mutant gene in which an IgE epitope was deleted on airway inflammation and the role of TLR9 in the asthmatic mouse model.

METHODS

A Derp2-mutant DNA vaccine was constructed. Mice were immunized, sensitized and challenged. Airway inflammation, airway hyper reactivity (AHR) and serum antibody were tested. The expression of Toll like receptor9 (TLR9) was detected with western-blot and immunehistochemistry.

RESULTS

We demonstrated that the Derp2-mutant-DNA induced IgG2a and inhibited IgE production, inhibited airway allergenic inflammation and AHR. Derp2-mutant-DNA vaccine induce TLR9 expression in lung tissue.

CONCLUSIONS

The data indicate that allergen DNA vaccine deleted IgE epitope could prevent allergenic airway inflammation, AHR, and upregulate lung TLR9 express.

Prenatal alcohol exposure reduces the size of the forelimb representation in motor cortex in rat: an intracortical microstimulation (ICMS) mapping study

Children with fetal alcohol spectrum disorder (FASD) often exhibit sensorimotor dysfunctions that include deficits in motor coordination and fine motor control. Although the underlying causes for these motor abnormalities are unknown, they likely involve interactions between sensory and motor systems. Rodent animal models have been used to study the effects of prenatal alcohol exposure (PAE) on skilled reaching and on the development and organization of somatosensory barrel field cortex. To this end, PAE delayed the development of somatosensory cortex, reduced the size of whisker and forelimb representations in somatosensory barrel field cortex, and delayed acquisition time to learn a skilled reaching task. However, whether PAE also affects the motor cortex (MI) remains to be determined. In the present study, we investigated the effect of PAE on the size of the forelimb representation in rat MI, thresholds for activation, and the overlap between motor and sensory cortical forelimb maps in sensorimotor cortex. Pregnant Sprague-Dawley rats were assigned to alcohol (Alc), pair-fed (PF), and chow-fed (CF) groups on gestation day 1 (GD1). Rats in the Alc group (n=4) were chronically intubated daily with binge doses of alcohol (6g/kg body weight) from GD1 to GD20 that resulted in averaged blood alcohol levels measured on GD10 (mean=191.5+/-41.9mg/dL) and on GD17 (mean=247.0+/-72.4mg/dL). PF (n=2) and CF (n=3) groups of pregnant rats served as controls. The effect of PAE on the various dependent measures was obtained from multiple male offspring from each dam within treatment groups, and litter means were compared between the groups from alcohol-treated and control (Ct: CF and PF) dams. At approximately 8 weeks of age, rats were anesthetized with ketamine/xylazine and the skull opened over sensorimotor cortex. A tungsten microelectrode was then inserted into the depths of layer V and intracortical microstimulation was used to deliver trains of pulses to evoke muscle contractions and/or movements; maximum stimulating < or =100microA. When a motor response was observed, the threshold for movement was measured and the motor receptive field projected to the cortical surface to serve as representative point for that location. A motor map for the forelimb representation was generated by systematically stimulating at adjacent sites until current thresholds reached the maximum and/or motor responses were no longer evoked. The major findings in this study were as follows: (1) PAE significantly reduced the area of the forelimb representation in the Alc offspring (6.01mm(2), standard error of the mean=+/-0.278) compared with the Ct offspring (8.03mm(2)+/-0.586), (2) PAE did not significantly reduce the averaged threshold for activation of movements between groups, (3) PAE significantly reduced the percent overlap (Alc=31.1%, Ct=55.4%) between the forelimb representation in sensory and motor cortices, and (4) no significant differences were observed in averaged body weight, hemisphere weight, or age of animal between treatment groups. These findings suggest that the effects of PAE are not restricted to somatosensory barrel field cortex but also involve the MI and may underlie deficits in motor control and sensorimotor integration observed among children with FASD.

Identification and Distribution of Soybean mosaic virus Strains in Southern China

From 1,417 leaf samples with Soybean mosaic virus (SMV)-like symptoms collected from about 1,500 fields of 117 counties of 13 provinces in Southern China during 2004 to 2006, 201 SMV isolates were obtained after biological purification with single-lesion isolation and serological determination. Based on disease reactions on 10 differentials used in China as a representative from various reported differential cultivar systems, the isolates were grouped into 12 strains. Among them, eight were the same as those previously reported from Northeast China and the Huang-Huai Valleys while the other four were new and were designated as SC18, SC19, SC20, and SC21. Strains SC15 and SC18, which were predominant and widespread in Southern China, accounted for 32.3 and 26.4% of the total isolates and were distributed in 9 and 10 provinces, respectively. Thus far, 21 strains have been identified in the three soybean-producing regions in China under the uniform differentials system. According to their responses on the 10 differentials, the strains were clustered into five groups at similarity coefficient 0.6. Among them, SC15 in cluster V is the most virulent strain because it infects all differentials. Therefore, specific attention should be placed on control of its prevalence in soybean production.

Spectroscopic properties and near-infrared broadband luminescence of Bi-doped SrB4O7 glasses and crystalline materials

Spectroscopic properties of Bi-doped SrB(4)O(7) glasses, sintered compounds, polycrystalline materials, and single crystals were investigated. Broadband near-infrared luminescence was realized in Bi-doped SrB(4)O(7) glasses with basicity and polycrystalline materials with non-bridging oxygens. In Bi:SrB(4)O(7) single crystals, only visible luminescence of Bi(3+) and Bi(2+) was observed, but no near-infrared. The rigid three-dimensional network of SrB(4)O(7) crystal is proved to be unfavorable for accommodation of Bi(+) ions.

Electronic structure and magnetic properties of Co-doped CeO(2): based on first principle calculation

The electronic structure and magnetic properties of Co-doped CeO(2) are theoretically investigated by first principles calculations based on the density functional theory + U (DFT+U) methods, using the WIEN2k package. With the presence of oxygen vacancies (V(O)) in CeO(2), d and f orbits of Ce are obviously pulled closer to the Fermi level, but without spin polarization. On the other hand, in Co-doped CeO(2), V(O) defects can lead to strong ferromagnetic coupling between the nearest neighboring Co ions. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Co 3d states, via electrons trapped in V(O). The results provide direct evidence for the F-center mediated exchange interaction in oxide-based magnetic semiconductors.

[Effect of age on body composition in healthy Beijing women]

OBJECTIVE

To observe the effect of age and menstrual status on body composition in healthy Beijing women.

METHODS

We measured body composition with dual-energy X-ray (GE Lunar Prodigy) in 316 healthy Beijing females aged 20 to 74 years (5-7 cases per age). Parameters provided by the software were as following: total body bone mineral content, lean mass, fat mass and fat percentage (%fat). Local regions measured included arm, leg, trunk, android region and gynoid region. Body mass index (BMI), fat mass index (FMI), free fat mass index (FFMI) and A/G were calculated. Volunteers were assigned to 6 groups according age by every ten years a group.

RESULTS

BMC peaked during the 4th decade, LM peaked during the 5th decade, with a decline of 18.1% and 5.2% respectively at age 74 years. Total body fat mass and %fat showed a general increase with aging throughout the studied age range. Total body fat mass increased from 16+/-5 kg at age 20-29 years to 24+/-6 kg at age 70-74 years, while %fat increased from 31.3% to 39.5%. All local region %fat increased with aging at different extents. Android region %fat showed the largest raise extent (32.2%). BMI increased gradually from 21.1 kg/m2 at age 20-29 years to 26.1 kg/m2 at age 70-74 years. FMI changed more obviously than FFMI. A/G increased from 0.85 at age 20-29 years to 1.02 at age 70-74 years. Different menstrual status in women of 40-59 years had obvious effect on A/G and BMC (P<0.05), while it had no significant effect on BMI, body weight and waist circumference (P>0.05).

CONCLUSIONS

Aging and menstrual status have evident effect on body composition distribution in healthy Beijing women.

Tests of trait—haplotype association when linkage phase is ambiguous, appropriate for matched case-control and cohort studies with competing risks

The impact of competing risks on tests of association between disease and haplotypes has been largely ignored. We consider situations in which linkage phase is ambiguous and show that tests for disease-haplotype association can lead to rejection of the null hypothesis, even when true, with more than the nominal 5 per cent frequency. This problem tends to occur if a haplotype is associated with overall mortality, even if the haplotype is not associated with disease risk. A small simulation study illustrates the magnitude of bias (high type I error rate) in the context of a cohort study in which a modest number of disease cases (about 350) occur over time. The bias remains even if the score test is based on a logistic model that includes age as a covariate. For cohort studies, we propose a new test based on a modification of the proportional hazards model and for case-control studies, a test based on a conditional likelihood that have the correct size under the null even in the presence of competing risks, and that can be used when haplotype is ambiguous.

Influence of maturation on constrictive response to stimulation of C-fiber afferents in isolated guinea pig airways

We investigated whether the airway constrictive response to stimulation of bronchopulmonary C-fiber afferents is altered during the maturation process. Isometric tension was measured in airway rings isolated from three tracheobronchial locations (intrathoracic trachea and main and hilar bronchi) and compared in mature [M, 407 ± 10 (SE) g body wt, n = 36] and immature (IM, 161 ± 5 g body wt, n = 35) guinea pigs. Our results showed no difference in the ACh (10−5 M)- or KCl (40 mM)-induced contraction between M and IM groups, regardless of the airway location. In sharp contrast, the concentration-response curves of 10−8–10−6 M capsaicin were distinctly lower in IM hilar bronchi; for example, response to the same concentration of capsaicin (10−6 M) was 89.2 ± 15.3% of the response to 10−5 M ACh in IM and 284.7 ± 43.2% in M animals. Similar, but smaller, differences in the bronchoconstrictive response to capsaicin between IM and M groups were also observed in the trachea and main bronchus. Electrical field stimulation induced airway constriction in all three locations in M and IM groups. However, after administration of 10−6 M atropine and 10−6 M propranolol, electrical field stimulation-induced contraction was significantly smaller in the hilar bronchus of IM than M animals, and this difference was not prevented by pretreatment with 5 × 10−5 M indomethacin. Although radioimmunoassay showed no difference in the tissue content of substance P between M and IM airways, the constrictive responses to exogenous substance P and neurokinin A were markedly greater in M airways at all three locations. In conclusion, the constriction of isolated airways evoked by C-fiber stimulation was significantly weaker in the IM guinea pigs, probably because of a less potent effect of tachykinins on the airway smooth muscle.

Involvement of the chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase sequence His444-Arg-Glu-Arg in modulation of the bisphosphatase activity by its kinase domain

The bisphosphatase activity of the hepatic bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase is repressed by its kinase domain, and regulated by cAMP-dependent protein kinase (PKA)-catalysed phosphorylation. In the present study, the mechanism by which the bisphosphatase activity is repressed by the kinase domain and regulated by phosphorylation was investigated. We found that truncation of the C-terminus of the enzyme by 25, but not 20, amino acids dramatically enhanced the catalytic rate of the bisphosphatase, abrogated the inhibition by the kinase domain, and eliminated the effect of PKA-mediated phosphorylation on activity. In addition, mutation of His444-Arg-Glu-Arg to Ala-Ala-Glu-Ala had similar effects as the deletion. Moreover, the mutations also significantly affected the phosphorylation-mediated regulation of the kinase activity of the enzyme. Furthermore, the mutations altered the pH-dependence of the bisphosphatase, and the mutant bisphosphatases were more sensitive to modification by diethyl pyrocarbonate and guanidine-induced inactivation than the wild-type enzyme. Taken together, these results demonstrate that the sequence His444-Arg-Glu-Arg plays a critical role in repression of the bisphosphatase activity by both the N-terminal kinase domain and the C-terminal tail itself. These results also explain the activation of the bisphosphatase activity by PKA-catalysed phosphorylation, by suggesting that phosphorylation may relieve the inhibitory effect of the kinase domain that is mediated by the three basic residues in this sequence.