Modulated dye retention for the signal-on fluorometric determination of acetylcholinesterase inhibitor

A novel fluorometric assay method based on target-induced signal on was developed for acetylcholinesterase (AChE) inhibitor with obviously improved detection sensitivity. In this method, the AChE molecules catalyzed the hydrolysis of acetylthiocholine (ATCl) to form thiocholine, which in turn can specifically react with fluorescent squaraine derivative, a specific chemodosimeter for thiol-containing compounds, resulting in fluorescence quenching and offering a low fluorometric background for the further detection of AChE inhibitor. In the presence of AChE inhibitor, the catalytic hydrolysis of ATCl is blocked, and then the squaraine derivative remains intact and shows signal-on fluorescence. The amount of the remaining fluorescent squaraine derivative is positively correlated with that of the AChE inhibitor in solution. This new designed sensing system shows an obviously improved sensitivity toward target with a detection limit of 5 pg mL(-1) (0.018 nM) for the AChE inhibitor, comparing favorably with previously reported fluorometric methods. To our best knowledge, this new method is the first example of fluorometric enzymatic assay for AChE inhibitors based on such a signal-on principle and using a specific reaction, which has potential to offer an effective strategy for the detection of AChE inhibitors.

A low-dimensional deformation model for cancer cells in flow

A low-dimensional parametric deformation model of a cancer cell under shear flow is developed. The model is built around an experiment in which MDA-MB-231 adherent cells are subjected to flow with increasing shear. The cell surface deformation is imaged using differential interference contrast microscopy imaging techniques until the cell releases into the flow. We post-process the time sequence of images using an active shape model from which we obtain the principal components of deformation. These principal components are then used to obtain the parameters in an empirical constitutive equation determining the cell deformations as a function of the fluid normal and shear forces imparted. The cell surface is modeled as a 2D Gaussian interface which can be deformed with three active parameters: H (height), σ(x) (x-width), and σ(y) (y-width). Fluid forces are calculated on the cell surface by discretizing the surface with regularized Stokeslets, and the flow is driven by a stochastically fluctuating pressure gradient. The Stokeslet strengths are obtained so that viscous boundary conditions are enforced on the surface of the cell and the surrounding plate. We show that the low-dimensional model is able to capture the principal deformations of the cell reasonably well and argue that active shape models can be exploited further as a useful tool to bridge the gap between experiments, models, and numerical simulations in this biological setting.

Reutilization of immobilized fungus Rhizopus sp. LG04 to reduce toxic chromate

AIMS

Most of the researches investigating immobilized fungi in chromate [Cr(VI)] bioremediation have used dead cells to adsorb Cr(VI). Therefore, the aim was to identify a Cr(VI)-reducing fungus with the ability of reducing the toxic Cr(VI) into the much less toxic Cr(III) and to apply the immobilized living fungus in continual reduction of Cr(VI).

METHODS AND RESULTS

Cr(VI) reduction occurred using both free fungi and immobilized living Rhizopus sp. LG04. The Cr(VI) bioreduction by the free fungi was achieved mainly by bioreduction coupled with a small amount of biosorption on the cell surfaces. LG04 spores immobilized with 3% polyvinyl alcohol and 3% sodium alginate produced the most stable and efficient biobeads. When the LG04 biobeads were washed and transferred into fresh medium containing 42 mg l(-1) of Cr(VI), the biobeads could be reused to reduce Cr(VI) for more than 30 cycles during an 82-day operation period. Interestingly, as the cycles increased, the time required for complete reduction stabilized at approximately 2·5 days, which was faster than that obtained using the free fungi (4·5 days). The pH value of the solution decreased from 6·60 ± 0·10 to 3·85 ± 0·15 after each reduction cycle, which may be because the metabolic products of the fungus changed the environmental pH or because there was an accumulation of the organo-Cr(III) complex.

CONCLUSIONS

The results indicate that using the immobilized living fungus for the removal of Cr(VI) has the advantages in being stable, long-term treatment, easy to re-use and less biomass leakage.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this study reports the first successful use of immobilized living Rhizopus for the repeated reduction of Cr(VI).

Inclusion of the female condom in a male condom-only intervention in the sex industry in China: a cross-sectional analysis of pre- and post-intervention surveys in three study sites

OBJECTIVES

To describe female condom (FC) use, male condom (MC) use and overall levels of protected sex before, during and after FC education and promotion (using the original prototype FC) combined with MC promotion among female sex workers in three rural or small urban settings in southern China.

STUDY DESIGN

The 1-year FC intervention was conducted by local health workers through outreach to establishments where sex work is conducted. Three serial cross-sectional surveys were conducted in each study town before, during and after the intervention along with process documentation throughout the intervention period.

METHODS

Cross-sectional data from pre-intervention (baseline) and 6-month and 12-month post-intervention surveys from three study sites are used in a descriptive comparison of the context of the sex industry, outreach in two phases of intervention, and FC adoption after the intensive intervention phase in each site.

RESULTS

Approximately 75-80% of eligible women working in sex establishments, varying from 74 to 155 participants for each survey, were recruited from three study sites. After introduction and promotion of the FC along with the MC during the community public health intervention, between one-fifth and one-half of the study participants had tried the FC in the three study sites by the time of the 6-month and 12-month cross-sectional surveys. Among them, 10-30% had used the FC more than once. FC awareness increased following the intervention with much less variation across the three study sites. At baseline, 31-54% of participants across the three sites reported 100% protected sex in the last 30 days with all types of partners. At one of the sites with relatively low MC use before the intervention, the proportion of women reporting 100% protected sex in the last 30 days increased by 15%, and the proportion reporting nil protected sex in the last 30 days decreased by 13% between baseline and 12-month post-intervention surveys. More complex profiles of FC and MC use and protected sex were shown at the other two study sites, where a higher level of protection had been reached before the project started.

CONCLUSIONS

Different levels of FC adoption were identified after the 1-year FC promotion intervention through outreach to sex establishments. The input, output and outcomes of the intervention may be associated with women's demographic and risk characteristics, the local capacities of intervention staff, and other contextual factors. Further analysis of these factors will help establish the role of the FC in increasing protected sex, and provide insight into how to achieve greater FC use.

Ultrasound-guided percutaneous cryotherapy of hepatocellular carcinoma

BACKGROUND

Reports on percutaneous cryoablation to treat patients with HCC are sparse in the medical literature. This study aimed to determine the safety and efficacy of percutaneous cryotherapy for unresectable or recurrent hepatocellular carcinoma (HCC).

METHODS

The results of 40 patients with unresectable HCC and 26 patients with recurrent HCC treated with ultrasound-guided percutaneous cryotherapy from January 2006 to June 2009 were retrospectively analyzed.

RESULTS

We used percutaneous cryotherapy to treat 76 tumors in 40 patients with unresectable and 76 tumors in 26 patients with recurrent HCC. The size of the tumors was 2.8 ± 1.7 cm (mean ± S.D.). The mean number of treatment sessions for unresectable and recurrent HCC were 1.7 and 1.4, respectively. All cryotherapy procedures were technically successful. No procedure-related death was observed. The overall complication rate was 12.1%. Patients with unresectable HCC had 1-, and 3-year overall survival rates of 81.4%, and 60.3%, while the disease-free survival rates at 1 year and 3 years were 67.6% and 20.8%, respectively. Patients with recurrent HCC had 1-, and 3-year overall survival rates of 70.2%, and 28.8%, while the disease-free survival rates at 1 year and 3 years were 53.8% and 7.7%, respectively.

CONCLUSION

Ultrasound-guided percutaneous cryotherapy was safe and efficacious in the treatment of unresectable and recurrent HCC. Further randomized trials are needed to compare the safety and efficacy of cryotherapy with other forms of percutaneous treatment so that an unbiased therapeutic strategy can be devised.

Adrenomedullin regulates sperm motility and oviductal ciliary beat via cyclic adenosine 5'-monophosphate/protein kinase A and nitric oxide

Cilium and flagellum beating are important in reproduction and defects in their motion are associated with ectopic pregnancy and infertility. Adrenomedullin (ADM) is a polypeptide present in the reproductive system. This report demonstrates a novel action of ADM in enhancing the flagellar/ciliary beating of human spermatozoa and rat oviductal ciliated cells. At the concentration found in the seminal plasma, it increases the progressive motility of spermatozoa. ADM binds to its classical receptor, calcitonin receptor-like receptor/receptor activity-modifying protein complex on spermatozoa. ADM treatment increases the protein kinase A activities, the cyclic adenosine monophosphate, and nitric oxide levels of spermatozoa and oviductal cells. Pharmacological activators and inhibitors confirmed that the ADM-induced flagella/ciliary beating was protein kinase A dependent. Whereas nitric oxide donors had no effect on sperm motility, they potentiated the motility-inducing action of protein kinase A activators, demonstrating for the first time the synergistic action of nitric oxide and protein kinase A signaling in flagellar/ciliary beating. The ADM-induced motility enhancement effect in spermatozoa also depended on the up-regulation of intracellular calcium, a known key regulator of sperm motility and ciliary beating. In conclusion, ADM is a common activator of flagellar/ciliary beating. The study provides a physiological basis on possible use of ADM as a fertility regulation drug.

Downregulation of the Novel Candidate Tumor Suppressor Gene NCOR2/SMRT in Human Breast Cancer Progression

Background: We recently described a number of DNA copy number changes that differentiated low grade ductal carcinoma in situ (DCIS) lesions with and without associated invasive carcinoma. One of the invasion-associated candidate genes was Nuclear Corepressor 2/Silencing Mediator of Retinoid and Thyroid Receptors (NCOR2/SMRT). This gene is a component of a repressing nuclear receptor complex and a mediator of ER activity. It facilitates recovery from DNA double strand breaks. Previous studies showed that downregulation of the gene was associated with transformation of non-Hodgkin lymphomas.Materials and Methods: Genomic DNA was extracted from microdissected paraffin sections of formalin fixed low grade DCIS lesions with an invasive component (n=42), as well as morphologically similar DCIS lesions without associated invasion within at least 5 years (n=38). Comparative PCR was performed with GAPDH as the reference gene. In addition, we assayed tissue microarrays (TMAs) by immunohistochemistry using two anti-Smrt antibodies. Three TMAs included 162 interpretable cases of invasive breast carcinoma from Roswell Park Cancer Institute (RPCI). One additional TMA included 73 interpretable breast cancers from a previously described cohort from Vienna, Austria. Nuclear staining in neoplastic cells was scored as positive, reduced (significantly weaker compared to admixed benign cells), and negative. Ncor2/Smrt expression was correlated with various patho-biologic variables.Results: Allelic loss of NCOR2/SMRT was observed in 79% (33/42) of DCIS lesions with associated invasion, but in only 26% (10/38) of pure DCIS cases (p<0.01). In the RPCI breast cancer cohort, nuclear Ncor2/Smrt protein was absent or downregulated in 73% (119/162) of tumors. In the Vienna cohort, there was no or markedly reduced nuclear staining in 48% (35/73) of cases. In both cohorts, loss of nuclear reactivity was more common in ER-negative breast cancers. In the Vienna series, Ncor2/Smrt loss was more frequent in PR-negative tumors as well. In the RPCI cohort, Ncor2/Smrt downregulation was more common in ductal (81%, 109/135) than in lobular (37%, 10/27) carcinomas. Neither series showed a significant association between Ncor2/Smrt expression and tumor grade or HER2/neu status.Discussion: Allelic loss of NCOR2/SMRT was significantly more common in DCIS lesions associated with stromal invasion. In invasive tumors, the protein downregulation rate was between 48% and 73%. The gene was more commonly downregulated in ER-negative carcinomas, consistent with its role as a modulator of ER function. Our data provide new evidence that NCOR2/SMRT may play an important part in early breast cancer progression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3150.

Population pharmacokinetic modeling for intravenous temsirolimus and sirolimus metabolite in subjects with various solid tumors

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Background: Temsirolimus (TEMSR) is an mTOR inhibitor approved for treatment of patients with advanced renal cell carcinoma, and under development for relapsed/refractory mantle cell lymphoma (MCL). In MCL, TEMSR showed a dose-related increase in median progression-free survival [4.8 vs. 3.4 mo] and objective response rate [22% vs 6%] for 175 mg x 3 wks then 75 or 25 mg weekly regimens (175/75-mg and 175/25-mg), respectively. We aim to characterize the population pharmacokinetic exposure, covariate influence, and differences afforded by these regimens. Methods: Nonlinear mixed-effects models of TEMSR and sirolimus (SIR; major active metabolite) blood concentrations were defined in healthy subjects and patients. Modeling for TEMSR employed a 4-compartment model with saturable distribution to red cells and peripheral tissue, and modeling for SIR utilized a linear 2- compartment model with factor for dose. Covariates included demographic factors, clinical labs, and disease condition. Following validation, simulations with variability were used to evaluate effects of covariates on exposure. Results: Final datasets comprised 1342 observations from 150 subjects (TEMSR) and 1648 observations from 279 subjects (SIR). In a typical patient (56-year-old male weighing 76.5 kg), disease affected TEMSR clearance (62.4 L/h in MCL, 92.1 L/h in breast cancer vs. 112 L/h for other subjects). Dose, single vs. multiple, and body weight affected SIR apparent clearance. Simulations for the 175/75-mg regimen indicate that significant covariates yield only modest differences on blood exposures. For MCL (175/75-mg regimen), TEMSR Cmax (week 3) was 2574 ng/mL and SIR Ctrough (week 6) was 10.7 ng/mL. AUC for the 75-mg maintenance arm was ∼2.3-fold (TEMSR) and ∼3.5-fold higher (SIR) than respective values of the 25-mg arm. Correlation of average AUC to clinical response was not apparent. Conclusions: No significant differential effects were observed for age, gender, race, or hepatic and renal laboratory measures. Covariates of disease, while significant, have only modest effects on the exposure profile. Higher clinical responses observed with the 175/75-mg regimen as compared with the 175/25-mg regimen may critically derive from differences in exposure.

[Table: see text]

Preoperative assessment and staging of hilar cholangiocarcinoma with 16-multidetector computed tomography cholangiography and angiography

BACKGROUND/AIMS

To evaluate prospectively the preoperative use of 16-multidetector computed tomography (MDCT) with cholangiography and angiography in determining the resectability of hilar cholangiocarcinoma.

METHODOLOGY

From January 2002 to January 2008, 75 consecutive patients with hilar cholangiocarcinoma underwent preoperative MDCT with cholangiography and angiography. 3D images of the portal vein, hepatic artery, and bile ducts were created and viewed simultaneously. The accuracy of MDCT with cholangiography and angiography was determined by comparison with intraoperative and pathologic findings.

RESULTS

All patients tolerated the CT imaging well and without serious complication. The sensitivity, specificity, and accuracy rates were 92.9%, 100%, and 96% for portal vein invasion and 83.3%, 100%, and 93.3% for hepatic arterial invasion. The accuracy rate of longitudinal tumor extension, using the modified Bismuth-Corlette classification, was 96%. The sensitivity, specificity, and accuracy of prediction of resectability were 95.7%, 82.1%, and 90.7%, respectively.

CONCLUSIONS

Preoperative MDCT with cholangiography and angiography gave a good assessment of the degree of biliary and vascular involvement of hilar cholangiocarcinoma. It also accurately predicted resectability.

Dominant local binary patterns for texture classification

This paper proposes a novel approach to extract image features for texture classification. The proposed features are robust to image rotation, less sensitive to histogram equalization and noise. It comprises of two sets of features: dominant local binary patterns (DLBP) in a texture image and the supplementary features extracted by using the circularly symmetric Gabor filter responses. The dominant local binary pattern method makes use of the most frequently occurred patterns to capture descriptive textural information, while the Gabor-based features aim at supplying additional global textural information to the DLBP features. Through experiments, the proposed approach has been intensively evaluated by applying a large number of classification tests to histogram-equalized, randomly rotated and noise corrupted images in Outex, Brodatz, Meastex, and CUReT texture image databases. Our method has also been compared with six published texture features in the experiments. It is experimentally demonstrated that the proposed method achieves the highest classification accuracy in various texture databases and image conditions.

Syntheses of optically pure, conformationally constrained, and highly hydrophobic unusual amino acids: 2-amino-3, 3-diarylpropionic acids*

A series of optically pure, conformationally constrained, and highly hydrophobic unusual aromatic amino acids, 2-amino-3,3-diarylpropionic acids, were synthesized via asymmetric 1,4-Michael addition reaction/azidation reactions in seven steps with overall yields of 20-30%.

Role of retinoic acid inducible gene-I in human metapneumovirus-induced cellular signalling

Human metapneumovirus (HMPV) is a recently discovered pathogen that causes a significant proportion of respiratory infections in young infants, the elderly and immunocompromised patients. Very little is known regarding the cellular signalling elicited by this virus in airway epithelial cells, the target of HMPV infection. In this study, we investigated the role of the RNA helicases retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-associated gene-5 (MDA-5) as the main pattern recognition receptors (PRRs) involved in viral detection and subsequent expression of proinflammatory and antiviral genes. HMPV infection readily induced RIG-I and MDA-5 gene and protein expression in A549 cells, a type II-like alveolar epithelial cell line. Expression of dominant-negative (DN) RIG-I or downregulation of RIG-I gene expression using small interfering RNA (siRNA) significantly decreased HMPV-induced beta interferon (IFN-beta), interleukin (IL)-8 and RANTES gene transcription, by inhibiting viral-induced activation of nuclear factor (NF)-kappaB and interferon regulatory factor (IRF), leading to enhanced viral replication. On the other hand, MDA-5 did not seem to play a significant role in HMPV-induced cellular responses. Mitochondrial antiviral signalling protein (MAVS), an adaptor protein linking both RIG-I and MDA-5 to downstream activation of IRF-3 and NF-kappaB, was also necessary for HMPV-induced cellular signalling. Expression of a DN MAVS significantly reduced IFN-beta and chemokine gene transcription, by inhibiting NF-kappaB- and IRF-dependent gene transcription, in response to HMPV infection. Our results show that HMPV activates the RIG-I-MAVS signalling pathway in airway epithelial cells, leading to the expression of important proinflammatory and antiviral molecules involved in the innate immune response to viruses.

Markers of angiogenesis in cervical cancer: A Gynecologic Oncology Group study

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Background: Extensive tumor angiogenesis has correlated with poorer progression-free and overall survival in cervical cancer; however, specific markers of angiogenesis have not been studied prospectively. Methods: Cervical cancer patients with high-risk features on radical hysterectomy were eligible for randomization to adjuvant pelvic irradiation ± radiosensitizing platinum. Following central pathology review, formalin-fixed, paraffin-embedded tumors were sectioned into 4-micron specimens. Semi-quantitative immunohistochemisty (IHC) was performed using previously validated antibodies against mutant p53 (mp53), vascular endothelial growth factor (VEGF), thrombospondin-1 (TSP-1), and endothelial markers CD 31 and CD 105. Tumoral histoscores (HS) were calculated for mp53 and VEGF using the formula: [% cells positive × (intensity +1)], with a 5% threshold for positivity and intensity ranging 1–4+ (3+ = intensity of positive control). Intensity scores (0–4+) were assigned to TSP-1 specimens referencing the positive control (3+). MVD “hotspots” were counted in a 20X high-power field. HS and MVD counts were considered as continuous variables and TSP-1 intensity as an ordinal variable. Associations between markers were determined by Pearson’s and Spearman’s correlation tests, between markers and clinico-pathologic variables by Wilcoxon rank test, and between markers and survival by Cox regression modeling. Results: One hundred seventy-six specimens were analyzed. Acquisition of mp53 and increased VEGF expression were associated with increased MVD assessed by both CD31 (p=0.08 and p=0.002, respectively) and CD105 (p=0.02 and p=0.012, respectively). Statistically significant associations between markers and high-risk pathologic factors included: low-level TSP-1 and high CD-105 counts with lymph node metastases; high VEGF scores with advanced stage, non-squamous histologic subtype, and depth of tumor invasion; and high CD 31 counts with parametrial metastases. Survival analysis is currently being performed. Conclusions: Angiogenesis occurs early in cervical carcinogenesis, and may be a rational target for biologic therapy in cervical cancer.

No significant financial relationships to disclose.