A large quantity synthesis of ZnO nanoneedles and their polarity determination

A large quantity of uniform ZnO nanoneedles has been synthesized by thermal evaporation method. Both single and double tip ZnO nanoneedles were found coexistence in the as-synthesized products. The single tip nanoneedles are major products in the synthesis and a few double tip nanoneedles were also observed. The polarity of the nanoneedles was characterized by convergent beam electron diffraction (CBED) and the simulation results reveal that the polarity of the ZnO (0001) surface directs the preferential growth of the nanoneedles. It is also found that most of the double tip nanoneedles are originated from the joint growth of two single tip nanoneedles with a kink in the middle and smooth ones might be generated from forming thin layer of cubic structures in the double nanoneedle tips. A large quantity of ZnO nanorod building blocks without tips was also achieved by fast cooling. The formation of the nanoneedles and nanorods can be attributed to different cooling speeds in our experiments. The sharp single nanoneedle tip can be potentially used as scanning probe microscope or field-emission tips.

Irritant and adjuvant effects of gaseous formaldehyde on the ovalbumin-induced hyperresponsiveness and inflammation in a rat model

BACKGROUND

Formaldehyde (FA) is a common indoor air pollutant that can cause asthma in people experiencing long-term exposure. While FA and other man-made chemicals contribute to the stimulation of asthma in the general population, the underlying molecular pathogenesis of this relationship is not yet well understood.

OBJECTIVE

To explore FA as an irritant for the onset of asthma and as an adjuvant for the induction of allergy.

METHODS

In the present study, 40 Wistar rats in five experimental groups were exposed to: (i) saline; (ii) ovalbumin (OVA); (iii) OVA + FA at 417 ppb; (iv) OVA + FA at 2500 ppb; and (v) FA at 2500 ppb. Current and prior occupational exposure limits in China were established at 417 ppb and 2500 ppb, respectively. Gaseous FA was administrated to the animals for 6 h/day before and during OVA immunization or saline treatment. Measured outcomes included in situ lung function analysis, cytokine measurement, and histological changes in the rat lungs.

RESULTS

The airway reactivity, lung histological changes, pulmonary interleukin-4 secretion, and eosinophil infiltration in the OVA and FA exposed rats were significantly higher after gaseous FA exposures of 417 and 2500 ppb. While FA exposure alone did not induce significant structural changes to the airway, and the rate of inflammatory cell infiltration was the same as for the control group, pulmonary levels of interferon-gamma were significantly elevated in the exposed rats.

CONCLUSIONS

FA may be an irritant as well as serve as an adjuvant for the onset of asthma or asthma-like symptoms.

Steroid Receptor RNA Activator Protein (SRAP): A Potential New Prognostic Marker for Estrogen Receptor-Positive/Node-Negative/Younger Breast Cancer Patients

Purpose: The steroid receptor RNA activator (SRA) is a functional RNA suspected to participate in the mechanisms underlying breast tumor progression. This RNA is also able to encode for a protein, SRAP, whose exact function remains to be determined. Our aim was to assess, in a large breast cancer cohort, whether levels of this protein could be associated with outcome or established clinical parameters.Experimental Design: Following antibody validation, we have assessed SRAP expression by tissue-microarray (TMA) analysis of 372 tumors with known steroid receptor and node status. Clinical follow-up was available for all the corresponding patients. Immunohistochemical scores were independently determined by two investigators and averaged. Statistical analyses were performed using standard univariate and multivariate tests.Results: SRAP levels were significantly (Mann-Whitney rank sum test, P<0.05) higher in estrogen receptor-alpha positive (ER+, n = 273), in progesterone receptor positive (PR+, n= 256) and in older patients (age ≥ 65 years, n = 183). When considering ER+ tumors, PR+ tumors, or young patients (< 65 years), patients with high SRAP expression had a significantly (Mantel-Cox test, P < 0.05) worse breast cancer specific survival (BCSS) than patients with low SRAP levels. SRAP also appeared as a very powerful indicator of poor prognostic for BCSS in the subset of ER+, node negative and young breast cancer patients (Cox regression analysis, n = 60, BCSS Hazard Ratio=13.937, P<0.0001).Conclusion: Our data suggest that SRAP might be a new predictor of breast cancer specific survival in younger breast cancer patients with ER+/node negative tumors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2017.

Characterization of the interaction between 8-bromoadenosine with human serum albumin and its analytical application

This study was designed to examine the interaction of 8-bromoadenosine with human serum albumin (HSA) by fluorescence spectroscopy in combination with molecular modeling under simulative physiological conditions. The results of fluorescence measurements indicate that 8-bromoadenosine has a strong ability to quench the intrinsic fluorescence of HSA through static quenching procedure. The binding constants (K) at different temperatures and thermodynamic parameters, enthalpy changes (DeltaH) and entropy changes (DeltaS) were calculated according to the fluorescence data. The results showed that the hydrophobic force played the major role in the binding of 8-bromoadenosine to HSA. The fluorescence experimental results were in agreement with the results obtained by molecular modeling study. The effects of some normal positive and negative ions on the binding constants were also discussed. Moreover, the synchronous fluorescence technique was used to characterize the interaction of 8-bromoadenosine to HSA and successfully applied to determine the total proteins in human serum, urine and saliva samples at room temperature under the optimum conditions with a wide linear range and satisfactory results.

Evaluation of the cytotoxicity of a two photon absorbing fluorescence compound on human HepG2 cells and its application to tracking human hepatic cancer cells in mice

Small organic dyes have been applied widely in fluorescence imaging techniques for biomedical research. We investigated the cytotoxicity of a novel fluorescent dye, trans-4-(N-2-hydroxyethyl-N-ethyl amino)-4'-(dimethyl amino) stilbene (DMAHAS), on human hepatocellular carcinoma (HepG2) cells using methyl thiazolyl tetrazolium(MTT), a neutral red assay, a Coomassie brilliant blue assay, and flow cytometric analysis. Our results showed that DMAHAS had live cell permeability, stable cytosolic localization and no significant cytotoxicity to HepG2 cells. We explored its application further for tumor cell tracking in a human liver tumor xenograft mouse model. Tumor xenografts were examined by fluorescence imaging and conventional histological methods. In addition, a method based on DMAHAS release was developed for tumor-specific cytotoxicity analysis. Our study indicated that DMAHAS is a reliable probe for tumor tracking and fluorescence imaging.

Inflammasomes are differentially expressed in cardiovascular and other tissues

To determine the expression of components in Toll-like receptors (TLRs)/Nod-like receptors (NLRs)/inflammasome/caspase-1/interleukin (IL-1)-beta pathway, we examined the expression profiles of those genes by analyzing the data from expression sequence tag cDNA cloning and sequencing. We made several important findings: firstly, among 11 tissues examined, vascular tissues and heart express fewer types of TLRs and NLRs than immune and defense tissues including blood, lymph nodes, thymus and trachea; secondly, brain, lymph nodes and thymus do not express proinflammatory cytokines IL-1beta and IL-18 constitutively, suggesting that these two cytokines need to be upregulated in the tissues; and thirdly, based on the expression data of three characterized inflammasomes (NALP1, NALP3 and IPAF inflammasome), the examined tissues can be classified into three tiers: the first tier tissues including brain, placenta, blood and thymus express inflammasome(s) in constitutive status; the second tier tissues have inflammasome(s) in nearly-ready expression status (with the requirement of upregulation of one component); the third tier tissues, like heart and bone marrow, require upregulation of at least two components in order to assemble functional inflammasomes. Our original model of three-tier expression of inflammasomes would suggest a new concept of tissue inflammation privilege, and provides an insight to the differences among tissues in initiating acute inflammation in response to stimuli.

A first-in-human phase I study to evaluate the pan-PI3K inhibitor GDC-0941 administered QD or BID in patients with advanced solid tumors

3501

Background: The PI3K-PTEN-AKT signaling pathway is deregulated in a wide variety of cancers. GDC-0941 is a potent and selective oral inhibitor of the class I PI3K with 3 nM IC50 for the p110-alpha subunit in vitro and 28 nM IC50 in a cell-based pAKT assay and demonstrates broad activity in breast, ovarian, lung, and prostate cancer models. Methods: A Phase I dose escalation study using a 3+3 design was initiated in patients (pts) with solid tumors. GDC-0941 was given on d1, followed by 1 wk washout to study single-dose PK and PD markers. GDC-0941 was then administered qd on a 3 wk on, 1 wk off, schedule. Steady-state PK and PD were evaluated after 1 wk of continuous dosing. A separate concurrent dose-escalation arm with bid dosing was initiated after the third qd cohort. Results: Nineteen pts have been enrolled in 5 successive dose-escalation cohorts in the qd arm with dose levels up to 80 mg daily. Seven pts were enrolled in 2 cohorts in the bid arm at total daily doses of 60 and 80 mg. The most frequently reported drug-related AEs were Grade 1/2 nausea, fatigue, diarrhea, peripheral edema, and dysgeusia; no drug related grade >3 events have been reported. PK data suggest dose-proportional increases in Cmax and AUC. Potential signs of anti-tumor activity have been observed with a soft tissue sarcoma pt on-study for >176 days with stable disease (30 mg qd), an ovarian cancer pt with an on-study 2.8-fold decrease in CA-125 response to normal levels (30 mg bid) and a pt with endometrial cancer with a decrease in tumor FDG-PET uptake (80 mg qd). Conclusions: GDC-0941 is generally well-tolerated with potential signs of anti-tumor activity. Preliminary PK data suggest dose-proportional increases in exposure over the dose levels evaluated. Dose-escalation on both the qd and bid schedules continues with updated data to be presented.

[Table: see text]

A phase I study evaluating the pharmacokinetics (PK) and pharmacodynamics (PD) of the oral pan-phosphoinositide-3 kinase (PI3K) inhibitor GDC-0941

3538

Background: The PI3K-PTEN-AKT signaling pathway is deregulated in a wide variety of cancers. GDC-0941 is a potent and selective oral inhibitor of class I PI3K and demonstrates activity in a broad range of preclinical models (breast, ovarian, lung, and prostate). Methods: Patients (pts) with histologically confirmed advanced solid tumors and ECOG PS 0–1 were treated with GDC-0941 using a 3+3 escalation design at a single institution. Treatment was a single dose with 1wk washout, followed by GDC-0941 qd on a 3wk on, 1wk off schedule. Objectives were to determine MTD and DLT, evaluate PD endpoints in surrogate (pAKT in platelet rich plasma) and tumor (pAKT and pS6 in paired tumor biopsies and FDG uptake via PET imaging) tissues, and describe anti-tumor activity. Results: Thirteen patients have been enrolled in 4 successive cohorts (15–60 mg qd). GDC-0941 was generally well-tolerated with no drug related Grade 3 or 4 AEs or DLTs to date. Grade 1 diarrhea, nausea, dysgeusia, peripheral sensory neuropathy, dry mouth, thrombocytopenia, and increased aspartate aminotransferase have been observed. Preliminary PK data suggest dose-proportional increases in fasting mean Cmax and AUC. Preliminary PD data show decreased levels of pAKT in platelet rich plasma correlated with GDC-0941 plasma concentrations. GDC-0941 effects on FDG-PET imaging is being assessed, with 1 patient with HER2+ metastatic breast cancer showing a reduction in FDG uptake and improvement of a chest wall lesion (dose level 60 mg qd). Evaluation of PI3K pathway modulation from paired tumor biopsies is underway. Conclusions: GDC-0941 is generally well tolerated when administered qd at doses associated with inhibition of pAKT in surrogate tissues. Evidence of PD activity in tumor tissue has also been observed. Dose-escalation continues and updated PK/PD data will be presented.

[Table: see text]

Formation of an intermediate compound with a B12H12 cluster: experimental and theoretical studies on magnesium borohydride Mg(BH4)2

Experimental and theoretical studies on Mg(BH4)2 were carried out from the viewpoint of the formation of the intermediate compound MgB12H12 with B12H12 cluster. The full dehydriding and partial rehydriding reactions of Mg(BH4)2 occurred according to the following multistep reaction: Mg(BH4)2 -->1/6MgB12H12 + 5/6MgH2 + 13/6H2 <--> MgH2 + 2B + 3H2 <--> Mg + 2B + 4H2. The dehydriding reaction of Mg(BH4)2 starts at approximately 520 K, and 14.4 mass% of hydrogen is released upon heating to 800 K. Furthermore, 6.1 mass% of hydrogen can be rehydrided through the formation of MgB12H12. The mechanism for the formation of MgB12H12 under the present rehydriding condition is also discussed.

CD25high T cells with a prolonged survival inhibit development of diabetes

The goal of this study is to examine a novel hypothesis that the progression of diabetes is partially due to the weakened survival of CD25high T cells, and prolonging survival of CD25high T cells inhibits the development of diabetes. Since CD28 co-stimulation is essential for the survival of CD4+CD25high T cells, we determined whether CD28-upregulated translationally controlled tumor protein (TCTP) prolongs the survival of CD4+CD25high regulatory T cells (Tregs) by a transgenic approach. The TCTP transgene prevents Tregs from undergoing apoptosis induced by interleukin-2 withdrawal-, dexamethasone-, cyclophosphamide-, and anti-Fas treatment in vitro. In addition, transgenic Tregs express higher levels of FOXP3 than wild-type counterparts and maintain suppressive activity, suggesting that TCTP promotes Tregs escape from thymic negative selection, and that prolonged survival does not attenuate Treg suppression. Moreover, TCTP transgenic Tregs inhibit the development of autoimmune diabetes due to increased survival of suppressive Tregs and decreased expression of pancreatic TNF-alpha. Promoting the survival of CD25high T cells leads to prolonged survival of Tregs but not activated CD25+ non-Treg T cells. Thus, we propose a new model of "two phase survival" for Tregs. Our results suggest that modulation of Treg survival can be developed as a new therapy for autoimmune diseases.

First Report of Syringa oblata and S. reticulata Leafroll Disease in China

Syringa oblata is an important ornamental tree widely grown in China. In September of 2008, S. oblata plants exhibiting symptoms of leafroll and yellowing were found in a garden on the Northwest A&F University campus. Samples were collected from this site. Total DNA was extracted from 0.5 g of phloem tissue from leaf midribs and stems of each sample. DNA samples were analyzed with a nested PCR assay using phytoplasma 16S rDNA universal primers R16mF2/R16mR1 followed by specific primers R16F2n/R16R2 (1), which amplified a 1,452- and 1,246-bp product, respectively. We tested all 30 lilac samples, 20 of which had symptoms of leafroll and yellowing. These produced the expected 1,452- and 1,246-bp PCR products In contrast, the remaining 10 samples from symptomless trees yielded no PCR products. We also surveyed another lilac variety (Syringa reticulata), which is widely grown on the campus, and tested 50 samples with the above method. Again, 1.4- and 1.2-kb PCR products were amplified from all 30 trees displaying leafroll and yellowing symptoms, but not from the other 20 samples from symptomless trees. A comparative analysis of sequences derived from the two hosts showed that the phytoplasmas infecting them were most similar (>99%) to paulownia witches'-broom (PaWB) phytoplasma (GenBank Accession No. EF199937). Restriction fragment length polymorphism (RFLP) analysis of the nested 1.2-kb 16S rDNA products with endonucleases AluI and MseI indicated that all symptomatic plants were infected by the phytoplasmas belonging to aster yellow group (16SrI) subgroup D (16SrI-D) PaWB phytoplasma (2). 16S rDNA sequence comparisons and RFLP analysis of the cloned 16S rDNA from S. oblata (GenBank Accession No. FJ445224) and S. reticulate (GenBank Accession No. FJ445225) indicated that the phytoplasmas infecting them were nearly identical (99.8% identity). To our knowledge, this is the first report of the presence of the phytoplasma associated with a leafroll disease of S. oblata and S. reticulata in China. References: (1) D. E. Gundersen and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (2) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.

Efficacy and safety of ginsenoside-Rd for acute ischaemic stroke: a randomized, double-blind, placebo-controlled, phase II multicenter trial

BACKGROUND AND PURPOSE

Ginsenoside-Rd is a selective competitive Ca2+ receptor antagonist. A phase II randomized, double-blind, placebo-controlled, multicenter study was conducted to examine the efficacy and safety of ginsenoside-Rd in patients with acute ischaemic stroke.

METHODS

A total of 199 patients were randomized equally to receive a 14-day infusion of placebo (group B), ginsenoside-Rd 10 mg (group A) or ginsenoside-Rd 20 mg (group C). Primary end-points were National Institutes of Health Stroke Scale (NIHSS) scores at 15 days. Secondary end-points were NIHSS scores and the Barthel Index at 8 days, the Barthel Index and the modified Rankin scale at 15 days and 90 days. The safety end-points included serious and non-serious adverse events, laboratory values and vital signs. Analysis was by intention to treat.

RESULTS

For the primary study outcome, there is significant difference amongst the three groups at 15 days in NIHSS scores (P = 0.0003). Comparing group A with B and group B with C, the difference in the mean for NIHSS was significant in statistics (P = 0.0004, P = 0.0009 respectively). This is no significant difference between group A and C (P = 0.9640). For the secondary study outcome, ginsenoside-Rd did not improve neurological functioning. Incidence of serious and non-serious adverse events was similar amongst the three groups.

CONCLUSIONS

Ginsenoside-Rd may be of some benefit in acute ischaemic stroke.

Physical activity and colon cancer prevention: a meta-analysis

Although an inverse association between physical activity and risk of colon cancer is well established, a formal estimate of the magnitude of this risk reduction that includes recent studies is not available. This analysis examines the association by sex and study design, restricting analyses to studies where data for colon cancer alone were available. The authors reviewed published studies through June 2008 examining the association between physical activity and risk of colon cancer. Heterogeneity and publication bias were evaluated and random effects models used to estimate relative risks (RR). Differences by sex and study design were evaluated. A total of 52 studies were included. An inverse association between physical activity and colon cancer was found with an overall relative risk (RR) of 0.76 (95% confidence interval (CI): 0.72, 0.81). For men, the RR was 0.76 (95% CI: 0.71, 0.82); for women, this was little different, (RR=0.79, 95% CI: 0.71, 0.88). The findings from case-control studies were stronger (RR=0.69, 95% CI: 0.65, 0.74) than for cohort studies (RR=0.83, 95% CI: 0.78, 0.88). This study confirms previous studies reporting an inverse association between physical activity and colon cancer in both men and women, and provides quantitative estimates of the inverse association.