Development of an ELISA screening test for nitroimidazoles in egg and chicken muscle

An antibody was generated that can bind metronidazole (MNZ), a nitroimidazole drug used in veterinary medicine to treat poultry for coccidiosis and histomoniasis. A direct competitive enzyme-linked immunosorbent assay (cELISA) is described. It was used to characterise binding of this antibody to a number of nitroimidazole drugs. It displayed cross-reactivity with dimetridazole (DMZ), ronidazole (RNZ), hydroxydimetridazole (DMZOH), and ipronidazole (IPZ).

Discovery of novel cathepsin S inhibitors by pharmacophore-based virtual high-throughput screening

The cysteine protease cathepsin S (CatS) is involved in the pathogenesis of autoimmune disorders, atherosclerosis, and obesity. Therefore, it represents a promising pharmacological target for drug development. We generated ligand-based and structure-based pharmacophore models for noncovalent and covalent CatS inhibitors to perform virtual high-throughput screening of chemical databases in order to discover novel scaffolds for CatS inhibitors. An in vitro evaluation of the resulting 15 structures revealed seven CatS inhibitors with kinetic constants in the low micromolar range. These compounds can be subjected to further chemical modifications to obtain drugs for the treatment of autoimmune disorders and atherosclerosis.

Rapid screening for monensin residues in poultry plasma by a dry reagent dissociation enhanced lanthanide fluoroimmunoassay.

Monensin, a carboxylic acid ionophore, is commonly fed to poultry to control coccidiosis. A method for rapid analysis of unextracted poultry plasma samples has been developed based on a novel immunoassay format: one-step all-in-one dry reagent time resolved fluorimetry. All assay specific components were pre-dried onto microtitration plate wells. Only addition of the serum sample diluted in assay buffer was required to perform analysis. Results were available one hour after sample addition. The limit of detection (mean + 3s) of the assay calculated from the analysis of 23 known negative samples was 14.2 ng ml(-1). Intra- and inter-assay RSD were determined as 15.2 and 7.4%, respectively, using a plasma sample fortified with 50 ng ml(-1) monensin. Eight broiler chickens were fed monensin at a dose rate of 120 mg kg(-1) feed for one week, blood sampled then slaughtered without drug withdrawal. Plasma monensin concentrations, as determined by the fluoroimmunoassay ranged from 101-297 ng ml(-1). This compared with monensin liver concentrations, determined by LC-MS, which ranged fi om 13-41 ng g(-1). The fluoroimmunoassay described is extremely user friendly, gives particularly rapid results and is suitable for the detection and quantification of plasma monensin residues. Data from medicated poultry suggest that analysis of plasma may be useful in predicting the extent of monensin liver residues.

Potentially Inappropriate Medications Defined by STOPP Criteria and the Risk of Adverse Drug Events in Older Hospitalized Patients

Background: Previous studies have not demonstrated a consistent association between potentially inappropriate medicines (PIMs) in older patients as defined by Beers criteria and avoidable adverse drug events (ADEs). This study aimed to assess whether PIMs defined by new STOPP (Screening Tool of Older Persons’ potentially inappropriate Prescriptions) criteria are significantly associated with ADEs in older people with acute illness.

Methods: We prospectively studied 600 consecutive patients 65 years or older who were admitted with acute illness to a university teaching hospital over a 4-month interval. Potentially inappropriate medicines were defined by both Beers and STOPP criteria. Adverse drug events were defined by World Health Organization–Uppsala Monitoring Centre criteria and verified by a local expert consensus panel, which also assessed whether ADEs were causal or contributory to current hospitalization. Hallas criteria defined ADE avoidability.Wecompared the proportions of patients taking Beers criteria PIMs
and STOPP criteria PIMs with avoidable ADEs that were causal or contributory to admission.

Results: A total of 329 ADEs were detected in 158 of 600 patients (26.3%); 219 of 329 ADEs (66.6%) were considered causal or contributory to admission. Of the 219 ADEs, 151(68.9%)considered causal or contributory to admission were avoidable or potentially avoidable. After adjusting for age, sex, comorbidity, dementia, baseline activities of daily living function, and number of medications, the likelihood of a serious avoidable ADE increased significantly when STOPP PIMs were prescribed (odds ratio, 1.847; 95% confidence interval [CI], 1.506-2.264; P.001); prescription of Beers criteria PIMs did not significantly increase ADE risk (odds ratio, 1.276; 95% CI, 0.945-1.722; P=.11).

Conclusion: STOPP criteria PIMs,unlike Beers criteria PIMs, are significantly associated with avoidable ADEs in older people that cause or contribute to urgent hospitalization.

Recent Innovations in Antibody-Mediated, Targeted Particulate Nanotechnology and Implications for Advanced Visualisation and Drug Delivery

Research into the targeting of drug substances to a specific disease site has enjoyed sustained activity for many decades. The reason for such fervent activity is the considerable clinical advantages that can be gained when the delivery system plays a pivotal role in determining where the drug is deposited. When compared to conventional formulations where no such control exists, such as parenteral and oral systems, the sophisticated targeting device can reduce side effects and limit collateral damage to surrounding normal tissue. No more so is this important than in the area of oncology when dose-limiting side effects are often encountered as an ever present difficulty. In this review, the types of colloidal carrier commonly used in targeted drug delivery are discussed, such as gold and polymeric colloids. In particular, the process of attaching targeting capabilities is considered, with reference to antibody technologies used as the targeting motifs. Nanotechnology has brought together a means to carry both a drug and targeting ligand in self-contained constructs and their applications to both clinical therapy and diagnosis are discussed.

Screening and confirmatory determination of ractopamine residues in calves treated with growth promoting doses of the beta-agonist

Ractopamine (RCT) is a phenethanolamine member of the family of beta-adrenergic agonists (beta-agonists), This class of compounds have become notable for their properties of enhancing the growth rates of farm animal species but are not licensed for use in Europe. An ELISA procedure employing a polyclonal antibody raised in a goat was developed to detect RCT residues in bovine urine samples, The assay had a high sensitivity (calibration curve mid-point of 22 pg per well), allowing the analysis of urine samples without the need for sample clean-up. In addition, an LC-MS-MS confirmatory procedure was developed which was able to act as a confirmatory procedure for the ELISA results. Four calves were orally treated with RCT (0.1 mg kg(-1) body mass for 17 d) and urine samples collected were assayed by both analytical procedures. It was observed that RCT residues were excreted mainly in the form of glucuronides and deconjugation could be achieved using two different sources of the enzyme beta-glucuronidase (Helix pomatia and Escherichia coli), High concentrations of RCT residues were found throughout the medication period (44-473 ng ml(-1); LC-MS-MS data) and remained present for several days following removal of the drug from the diet, RCT residues were no longer detectable 2 weeks after withdrawal, Good agreement (r(2) = 0.73) was achieved between the ELISA and LC-MS-MS results, especially when sample deconjugation was applied to the urine samples for both sets of analyses, The results show that an effective screening and confirmatory system was devised to detect RCT residues in urine samples taken during treatment and close to withdrawal, However, alternative matrices may have to be selected to allow the illegal use of the substance to be detected following prolonged withdrawal times.

Synthesis and SAR of novel, 4-(phenylsulfamoyl)phenylacetamide mGlu(4) positive allosteric modulators (PAMs) identified by functional high-throughput screening (HTS)

Herein we disclose the synthesis and SAR of a series of 4-(phenylsulfamoyl)phenylacetamide compounds as mGlu(4) positive allosteric modulators (PAMs) that were identified via a functional HTS. An iterative parallel approach to these compounds culminated in the discovery of VU0364439 (11) which represents the most potent (19.8 nM) mGlu(4) PAM reported to date. (C) 2010 Elsevier Ltd. All rights reserved.

A comparison of the application of STOPP/START to patients' drug lists with and without clinical information

Background A European screening tool (STOPP/START) has been formulated to identify the prescribing of potentially inappropriate medicines (PIMs) and potential prescribing omissions (PPOs). Pharmacists working in community pharmacies could use STOPP/START as a guide to conducting medication use reviews; however, community pharmacists do not routinely have access to patients' clinical records. Objective To compare the PIM and PPO detection rates from application of the STOPP/START criteria to patients' medication details alone with the detection rates from application of STOPP/START to information on patients' medications combined with clinical information. Setting Community Pharmacy. Method Three pharmacists applied STOPP/START to 250 patient medication lists, containing information regarding dose, frequency and duration of treatment. The PIMs and PPOs identified by each pharmacist were compared with those identified by consensus agreement of two other pharmacists, who applied STOPP/START criteria using patients' full clinical records. Main outcome measure The main outcome measures were: (1) PIM and PPO detection rates among pharmacists with access to patients' clinical information compared to PIM and PPO detection rates among pharmacists using patients' medication information only, and (2) the levels of agreement (calculated using Cohen's kappa statistic (k)) for the three most commonly identified PIMs and PPOs. Results Pharmacists with access to patients' clinical records identified significantly fewer PIMs than pharmacists without (p = 0.002). The three most commonly identified PIMs were benzodiazepines, proton pump inhibitors and duplicate drug classes, with kappa (k) statistic agreement ranges of 0.87-0.97, 0.60-0.68 and 0.39-0.85 respectively. PPOs were identified more often (p 

Non-steroidal anti-inflammatory drug and aspirin use and the risk of head and neck cancer

Background: Evidence for non-steroidal anti-inflammatory drugs (NSAIDs) preventing head and neck cancer (HNC) is inconclusive; however, there is some suggestion that aspirin may exert a protective effect.

Methods: Using data from the United States National Cancer Institute Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, we examined the association between aspirin and ibuprofen use and HNC.

Results: Regular aspirin use was associated with a significant 22% reduction in HNC risk. No association was observed with regular ibuprofen use.

Conclusion: Aspirin may have potential as a chemopreventive agent for HNC, but further investigation is warranted.

Combined genomic and phenotype screening reveals secretory factor SPINK1 as an invasion and survival factor associated with patient prognosis in breast cancer

Secretory factors that drive cancer progression are attractive immunotherapeutic targets. We used a whole-genome data-mining approach on multiple cohorts of breast tumours annotated for clinical outcomes to discover such factors. We identified Serine protease inhibitor Kazal-type 1 (SPINK1) to be associated with poor survival in estrogen receptor-positive (ER+) cases. Immunohistochemistry showed that SPINK1 was absent in normal breast, present in early and advanced tumours, and its expression correlated with poor survival in ER+ tumours. In ER- cases, the prognostic effect did not reach statistical significance. Forced expression and/or exposure to recombinant SPINK1 induced invasiveness without affecting cell proliferation. However, down-regulation of SPINK1 resulted in cell death. Further, SPINK1 overexpressing cells were resistant to drug-induced apoptosis due to reduced caspase-3 levels and high expression of Bcl2 and phospho-Bcl2 proteins. Intriguingly, these anti-apoptotic effects of SPINK1 were abrogated by mutations of its protease inhibition domain. Thus, SPINK1 affects multiple aggressive properties in breast cancer: survival, invasiveness and chemoresistance. Because SPINK1 effects are abrogated by neutralizing antibodies, we suggest that SPINK1 is a viable potential therapeutic target in breast cancer.

Cancer drug resistance:an evolving paradigm

Resistance to chemotherapy and molecularly targeted therapies is a major problem facing current cancer research. The mechanisms of resistance to 'classical' cytotoxic chemotherapeutics and to therapies that are designed to be selective for specific molecular targets share many features, such as alterations in the drug target, activation of prosurvival pathways and ineffective induction of cell death. With the increasing arsenal of anticancer agents, improving preclinical models and the advent of powerful high-throughput screening techniques, there are now unprecedented opportunities to understand and overcome drug resistance through the clinical assessment of rational therapeutic drug combinations and the use of predictive biomarkers to enable patient stratification.