Dose effects associated with rivastigmine transdermal patch in patients with mild-to-moderate Alzheimer's disease

AIM

The cholinesterase inhibitor rivastigmine is available in both oral and transdermal forms. The efficacy of oral rivastigmine appears to be dose-dependent. The current analysis investigates the effect of dose on the efficacy of the rivastigmine transdermal patch.

METHODS

This was a retrospective analysis of a large, international, 24-week, randomised, placebo- and active-controlled trial (IDEAL, CENA713D2320) of rivastigmine in patients with mild-to-moderate Alzheimer's disease (AD). Patients received the 9.5 mg/24 h rivastigmine patch, the 17.4 mg/24 h rivastigmine patch, 12 mg/day rivastigmine capsules or placebo. Changes from baseline at week 24 on the AD Assessment Scale-cognitive subscale (ADAS-cog), AD Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) and the AD Cooperative Study-Activities of Daily Living (ADCS-ADL) scale were calculated based on the patient's mode and last prescribed patch dose. The analysis included the 4.6 mg/24 h and 13.3 mg/24 h patch doses, for which efficacy data have not previously been reported.

RESULTS

Significant differences (p<0.05 vs. placebo) were seen on the ADAS-cog and ADCS-ADL for all mode rivastigmine patch doses (except 4.6 mg/24 h) and all last prescribed rivastigmine patch doses (except 4.6 mg/24 h and 13.3 mg/24 h). Patients with a last prescribed/mode patch dose of 9.5 mg/24 h and 13.3 mg/24 h showed significant improvements (p<0.05 vs. placebo) on the ADCS-CGIC.

CONCLUSION

Rivastigmine patch doses higher than 9.5 mg/24 h may offer additional benefits. The 13.3 mg/24 h patch is worthy of further investigation.

Fabrication and evolution of multilayer silver nanofilms for surface-enhanced Raman scattering sensing of arsenate

Surface-enhanced Raman scattering (SERS) has recently been investigated extensively for chemical and biomolecular sensing. Multilayer silver (Ag) nanofilms deposited on glass slides by a simple electroless deposition process have been fabricated as active substrates (Ag/GL substrates) for arsenate SERS sensing. The nanostructures and layer characteristics of the multilayer Ag films could be tuned by varying the concentrations of reactants (AgNO3/BuNH2) and reaction time. A Ag nanoparticles (AgNPs) double-layer was formed by directly reducing Ag+ ions on the glass surfaces, while a top layer (3rd-layer) of Ag dendrites was deposited on the double-layer by self-assembling AgNPs or AgNPs aggregates which had already formed in the suspension. The SERS spectra of arsenate showed that characteristic SERS bands of arsenate appear at approximately 780 and 420 cm-1, and the former possesses higher SERS intensity. By comparing the peak heights of the approximately 780 cm-1 band of the SERS spectra, the optimal Ag/GL substrate has been obtained for the most sensitive SERS sensing of arsenate. Using this optimal substrate, the limit of detection (LOD) of arsenate was determined to be approximately 5 μg·l-1.

Enhanced production of aureofuscin by over-expression of AURJ3M, positive regulator of aureofuscin biosynthesis in Streptomyces aureofuscus

AIMS

 The production of aureofuscin is very low in the wild-type strain. We attempt to increase the production of aureofuscin by over-expression of a controlling gene in the wild-type strain.

METHODS AND RESULTS

The aurj3M gene was PCR-amplified from Streptomyces aureofuscus SYAU0709, ligated into vector pMD19 and sequenced. The predicted translation of the 579-bp cloned fragment was 97% similar to pimM from Streptomyces natalensis, which has an N-terminal PAS domain and a LuxR-type C-terminal helix-turn-helix. Recombinant bacterial strains were constructed by transforming SYAU0709 with an expression plasmid (pBJJ3M) that contained aurj3M, thereby increasing the number of aurj3M gene copies.

CONCLUSIONS

Bioassays for the antibiotic compound aureofuscin indicated that the recombinant bacteria had greater antifungal activity than the wild-type strain. Specifically, the recombinant strain produced approx. 600% more aureofuscin, as quantified by high-performance liquid chromatography analysis.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this approach has not been attempted in S. aureofuscus before and few genes in the aureofuscin pathway have been cloned and characterized.

Rule-based modelling and simulation of biochemical systems with molecular finite automata

The authors propose a theoretical formalism, molecular finite automata (MFA), to describe individual proteins as rule-based computing machines. The MFA formalism provides a framework for modelling individual protein behaviours and systems-level dynamics via construction of programmable and executable machines. Models specified within this formalism explicitly represent the context-sensitive dynamics of individual proteins driven by external inputs and represent protein-protein interactions as synchronised machine reconfigurations. Both deterministic and stochastic simulations can be applied to quantitatively compute the dynamics of MFA models. They apply the MFA formalism to model and simulate a simple example of a signal-transduction system that involves an MAP kinase cascade and a scaffold protein.

Removal of arsenate from water by adsorbents: a comparative case study

Laboratory and field filtration experiments were conducted to study the effectiveness of As(V) removal for five types of adsorbent media. The media included activated alumina (AA), modified activated alumina (MAA), granular ferric hydroxide (GFH), granular ferric oxide (GFO), and granular titanium dioxide (TiO₂). In laboratory batch and column experiments, the synthetic challenge water was used to evaluate the effectiveness for five adsorbents. The results of the batch experiments showed that the As(V) adsorption decreased as follows at pH 6.5: TiO₂ > GFO > GFH > MAA > AA. At pH 8.5, however, As(V) removal decreased in the following order: GFO = TiO₂ > GFH > MAA > AA. In column experiments, at pH 6.5, the adsorbed As(V) for adsorbents followed the order: TiO₂ > GFO > GFH, whereas at pH 8.5 the order became: GFO = TiO₂ > GFH when the challenge water containing 50 μg/L of As(V) was used. Field filtration experiments were carried out in parallel at a wellhead in New Jersey. Before the effluent arsenic concentration increased to 10 μg/L, approximately 58,000 and 41,500 bed volumes of groundwater containing an average of 47 μg/L of As(V) were treated by the filter system packed with GFO and TiO₂, respectively. The As(V) adsorption decreased in the following sequence: GFO > TiO₂ > GFH > MAA > AA. Filtration results demonstrated that GFO and TiO₂ adsorbents could be used as media in small community filtration systems for As(V) removal.

Low agreement between the T-SPOT®.TB assay and the tuberculin skin test among college students in China

T-SPOT®.TB and the tuberculin skin test (TST) were used to screen for latent tuberculosis infection among 899 Chinese college students. The positivity rates for T-SPOT®.TB and TST were respectively 13.0% (95% confidence interval [CI] 10.4-15.9) and 24.9% (95%CI 21.5-28.6) among students with a bacille Calmette-Guérin (BCG) scar (agreement of both tests 72.3%; 95%CI 68.6-75.8; κ = 0.118), and respectively 17.3% (95%CI 11.7-24.2) and 23.7% (95%CI 17.3-31.2) among those without a BCG scar (agreement 73.1%; 95%CI 65.4-79.9; κ = 0.179). These results demonstrate low agreement between the TST and T-SPOT.TB in the Chinese population studied.

Abstract P2-09-32: Estrogen Receptor-Related Genes Are Important Predictors of Response to Neo-Adjuvant Chemotherapy in Breast Cancer

Background: Clinical data suggest a contribution of estrogen receptor (ER) to chemotherapy response. However, ER status alone is not perfectly predictive, and there is an urgent need for more reliable markers of chemotherapy responsiveness. In this study, we set out to find novel ER-related genes in predicting chemotherapy response by microarrays, hoping to provide more robust multi-variable prediction to chemotherapy. Material and Methods: One hundred and ten patients with stage II-III breast cancer were included, receiving preoperative four cycles of weekly PCb (paclitaxel plus carboplatin) regimen. Pretreatment gene expression profiling was performed with gene microarrays on core biopsy specimens. 55 training cases were used for marker discovery and to identify any ER-related genes that might be associated with response (“training cases”), and the other 55 patients were available as an independent validation set (“validation cases”) to test whether the ER-related genes do predict pCR in protein levels by immunohistochemistry (IHC). Results: In the training cases, the yield of total RNA was insufficient to assay in 16 patients and 8 chips failed in the quality check (QC) process. Therefore, gene expression profile from 31 samples were available for this study. The overall pCR rate in the 86 patients was 19.7% (n=17, 6 cases of pCR in training set and 11 pCR in validation set). In the training set, by Significance Analysis of Microarrays (SAM), 300 probes (231 genes) were identified as differentially expressed between pCR versus non-pCR when fold change &gt; 2. There were 20 differentially expressed genes, setting fold change &gt; 3. Among these 20 genes, TFF1, ESR1, GATA3, TFF3 were found as ER-related. In 55 independent validation cases, univariate analysis indicated that clinical variables and ER-related genes, including ER, PR, GATA3, TFF1 and TFF3 were all significantly associated with pCR (Pearson x2, P&lt;0.001, P=0.013, P&lt;0.001, P&lt;0.001, P&lt;0.001). Multivariate logistic regression model showed that ER (P=0.016) remained significantly associated with complete remission. In spearman analysis, these 5 ER-related genes were significantly correlated with each other (P&lt;0.05). It was found that pCR rate was as high as 80% (4/5) when these 5 factors were all negative. In contrast, these 5 factors were all positive in 7 of 9 PD/SD patients.

Discussion: ER combined with ER-related genes expression status may provide important predictive value of response to neoadjuvant chemotherapy and allows to identify a subgroup of patients who might highly benefit from chemotherapy and who might be resistant to it.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-32.

Two-fold elevation of expression of FoxM1 transcription factor in mouse embryonic fibroblasts enhances cell cycle checkpoint activity by stimulating p21 and Chk1 transcription

OBJECTIVES

Forkhead Box M1 (FoxM1) transcription factor regulates expression of cell cycle effective genes and is stabilized by checkpoint kinase 2 (Chk2) to stimulate expression of DNA repair enzymes in response to DNA damage. This study intended to test whether FoxM1 is involved in cell cycle checkpoint pathways.

MATERIALS AND METHODS

Analysis of senescence and cell proliferation in FoxM1 transgenic (TG) mouse embryonic fibroblasts (MEFs) with 2-fold elevation of FoxM1, and overexpression or knockdown of FoxM1 in an inducible FoxM1 expression cell line, or FoxM1 siRNA. Chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assays (EMSA), and cotransfection to determine FoxM1 transcription targets, as well as RNase protection assays and western blot analysis, were performed.

RESULTS

Two-fold elevation of FoxM1 in FoxM1-TG-MEFs resulted in low levels of cell proliferation and increase in permanent cell cycle arrest at early passages (from passage 6 to 9). These phenotypes correlated with increased phosphorylation of p53 on Ser15, elevated expression of cell cycle inhibitor p21 and Chk1 at passage 3. FoxM1 was stabilized in response to DNA damage in MEFs and FoxM1 overexpression induced p21. Knockdown of FoxM1 resulted in decrease in Chk1. ChIP, EMSA and cotransfection assays confirmed that FoxM1 stimulated promoters of p21 and Chk1.

CONCLUSIONS

Chk1 and p21 are direct transcription targets of FoxM1 and FoxM1 participates in transcriptional responses to stress in normal cells.

The pharmacokinetics of nitazoxanide active metabolite (tizoxanide) in goats and its protein binding ability in vitro

The pharmacokinetics of tizoxanide (T), the active metabolite of nitazoxanide (NTZ), and its protein binding ability in goat plasma and in the solutions of albumin and alpha-1-acid-glycoprotein were investigated. The plasma and protein binding samples were analyzed using a high-performance liquid chromatography (HPLC) assay with UV detection at 360 nm. The plasma concentration of T was detectable in goats up to 24 h. Plasma concentrations vs. time data of T after 200 mg/kg oral administration of NTZ in goats were adequately described by one-compartment open model with first order absorption. As to free T, the values of t(1/2Ka), t(1/2Ke), T(max), C(max), AUC, V/F((c)), and Cl((s)) were 2.51 +/- 0.41 h, 3.47 +/- 0.32 h, 4.90 +/- 0.13 h, 2.56 +/- 0.25 microg/mL, 27.40 +/- 1.54 (microg/mL) x h, 30.17 +/- 2.17 L/kg, and 7.34 +/- 1.21 L/(kg x h), respectively. After beta-glucuronidase hydrolysis to obtain total T, t(1/2ke), C(max), T(max), AUC increased, while the V/F((c)) and Cl((s)) decreased. Study of the protein binding ability showed that T with 4 microg/mL concentration in goat plasma and in the albumin solution achieved a protein binding percentage of more than 95%, while in the solution of alpha-1-acid-glycoprotein, the percentage was only about 49%. This result suggested that T might have much more potent binding ability with albumin than with alpha-1-acid-glycoprotein, resulting from its acidic property.

Population pharmacokinetic modeling of pantoprazole in pediatric patients from birth to 16 years

The population pharmacokinetics of pantoprazole was characterized in pediatric patients from birth to 16 years using NONMEM and evaluated via bootstrap and predictive check. Data were described using a 2-compartment model with a typical parameterized in terms of clearance (CL) (95% CI) of 1.93 L per hour (1.53, 2.61), given the reference covariates (female, full term, extensive/unknown CYP2C19 metabolizer status, non-African American, 10 kg weight, intravenous or tablet administration). Pantoprazole pharmacokinetic parameters appear to be similar in pediatric patients compared to adults when allometrically scaled. The effect of age on allometrically scaled CL was best described by a sigmoid Emax model with the age effect reaching an asymptote approximately equal to the adult CL by 1 year. CYP2C19 poor metabolizers exhibited reduced CL with the point estimate and 95% CI more than 70% lower than the typical value. Simulations from the final model indicated that the 1.2-mg/kg dose provides the best comparison to adults.

1,5-Anhydroglucitol attenuates cytokine release and protects mice with type 2 diabetes from inflammatory reactions

1,5-anhydroglucitol (1,5-AG) decreases in diabetic patients and is used as a marker of glycemic control. Type 2 diabetic patients are susceptibile to lipopolysaccharides (LPS), which stimulate macrophages to release large quantities of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6. This study examines the effects of 1,5-AG on lung inflammation induced by LPS and consequent systemic inflammation to determine whether the decrease of 1,5-AG concentration induces susceptibility to LPS. Before the challenge with LPS (1 mg/kg in vivo and 500 ng/ml in vitro), we pretreated db/db mice and RAW264.7 cells with 1,5-AG at 38.5 mg/kg and 500 microg/ml, respectively. The levels of IL-6, TNF-alpha, macrophage chemoattractant protein (MCP)-1 and IL-1beta in the serum and in the cell supernatants were measured. We also measured macrophage recruitment and the expression of inducible nitric oxide synthase (iNOS) in pulmonary tissues. We found that 1,5-AG attenuated serum cytokine release and protected db/db mice from LPS-induced pulmonary inflammation. In addition, 1,5-AG suppressed cytokine release and iNOS expression by suppressing Akt/NF-kB activity in RAW264.7 cells. These results suggest that 1,5-AG may be a mediator in, as well as marker for diabetes, and 1,5-AG intake may confer tolerance to LPS in patients with type 2 diabetes.