Development and evaluation of endothelin-A receptor (radio)ligands for positron emission tomography

The expression and function of endothelin (ET) receptors are abnormal in cardiovascular diseases, tumor progression, and tumor metastasis. A previously reported promising radioligand for positron emission tomography (PET) based on the non-peptide ET(A) receptor antagonist PD 156707 showed specific binding to target receptors in the myocardium but high accumulation in bile and intestine, probably because of its high lipophilicity. In this study we describe the synthesis of a series of fluorinated derivatives with hydrophilic building blocks. All compounds were evaluated as high affinity ET(A) receptor ligands (16, 17, 23-26, K(i) = 1.4-7.9 nM) with high subtype selectivity over the ET(B) receptor. [(18)F]3-Benzo[1,3]dioxol-5-yl-4-{3-[1-(2-{2-[2-(2-fluoroethoxy)ethoxy]ethoxy}ethyl)-1H-[1,2,3]triazol-4-ylmethoxy]-4,5-dimethoxybenzyl}-5-hydroxy-5-(4-methoxyphenyl)-5H-furan-2-one ([(18)F]17) was synthesized as one of the radioligands of this series that possesses a higher hydrophilicity and an excellent stability in human serum. Improved clearance properties and specific uptake in target organs have been confirmed by biodistribution studies and small animal PET imaging.     

A monograph assignment as an integrative application of evidence-based medicine and pharmacoeconomic principles

Objective

To describe the development and assessment of monographs as an assignment to incorporate evidence-based medicine (EBM) and pharmacoeconomic principles into a third-year pharmacoeconomic course.

Design

Eight newly FDA-approved drugs were assigned to 16 teams of students, where each drug was assigned to 2 teams. Teams had to research their drug, write a professional monograph, deliver an oral presentation, and answer questions posed by faculty judges. One team was asked to present evidence for inclusion of the drug into a formulary, while another team presented evidence against inclusion.

Assessment

The teams'' average score on the written report was 99.1%; on the oral presentation, 92.5%, and on the online quiz given at the end of the presentations, 77%.

Conclusions

Monographs are a successful method of incorporating and integrating learning across different concepts, as well as increasing relevance of pharmacoeconomics in the PharmD curriculum.     

Stability of Ibuprofen solutions in normal saline or 5% dextrose in water

Background:

A shortage of the standard medication for treatment of patent ductus arteriosus has necessitated use of parenteral ibuprofen, which is equally efficacious for this indication. The beyond-use date recommended by the manufacturer is very short and has implications for resource allocation and wastage.

Objective:

To evaluate the stability of ibuprofen (undiluted or diluted in either 0.9% sodium chloride [normal saline; NS] or 5% dextrose in water [D5W]) with storage for up to 21 days under refrigeration or at room temperature in glass vials or polypropylene syringes.

Methods:

Six glass vials, each containing undiluted ibuprofen (5 mg/mL), were prepared. In addition, ibuprofen was diluted to 2.5 mg/mL in NS or D5W, and 6 syringes were prepared for each diluent (total of 12 syringes). Finally, 6 extension tubes were each primed with 1 mL of ibuprofen (duplicates of undiluted solution and solutions diluted to 2.5 mg/mL in NS or D5W). Half of the vials, syringes, and tubes were stored under refrigeration (4°C) and the other half at room temperature (23°C). The concentration of ibuprofen was determined by a validated, stability-indicating liquid chromatographic method on study days 0, 1, 2, 3, 6, 8, 10, 13, 17, and 21 for samples stored in vials and syringes, or at time 0, 6, 24, and 30 h for samples stored in tubes.

Results:

Analysis of variance showed differences in the percentage of ibuprofen remaining due to study day (p < 0.001) and diluent (p < 0.005), but no differences due to concentration (p = 0.06) or temperature (p = 0.12). All solutions of ibuprofen were stable throughout the study period, retaining at least 90% of their initial concentration.

Conclusions:

Undiluted ibuprofen (5 mg/mL) stored in glass vials and ibuprofen diluted to 2.5 mg/mL with either NS or D5W and stored in polypropylene syringes will retain more than 92% of its initial concentration with storage for up to 14 days at 4°C. A beyond-use date of 14 days would allow for up to 24 h storage at 23°C during this 14-day period. Storage of ibuprofen solutions in extension tubing should not exceed 29 h at 4°C or 17 h at 23°C. Beyond-use dates should be applied only after consideration of US Pharmacopeia Revised General Chapter <797> guidelines for compounding of sterile preparations.     

A computer-controlled whole-body inhalation exposure system for the oil dispersant COREXIT EC9500A

An automated whole-body inhalation exposure system capable of exposing 12 individually housed rats was designed to examine the potential adverse health effects of the oil dispersant COREXIT EC9500A, used extensively during the Deepwater Horizon oil spill. A computer-controlled syringe pump injected the COREXIT EC9500A into an atomizer where droplets and vapor were formed and mixed with diluent air. The aerosolized COREXIT EC9500A was passed into a customized exposure chamber where a calibrated light-scattering instrument estimated the real-time particle mass concentration of the aerosol in the chamber. Software feedback loops controlled the chamber aerosol concentration and pressure throughout each exposure. The particle size distribution of the dispersant aerosol was measured and shown to have a count median aerodynamic diameter of 285 nm with a geometric standard deviation of 1.7. The total chamber concentration (particulate + vapor) was determined using a modification of the acidified methylene blue spectrophotometric assay for anionic surfactants. Tests were conducted to show the effectiveness of closed loop control of chamber concentration and to verify chamber concentration homogeneity. Five automated 5-h animal exposures were performed that produced controlled and consistent COREXIT EC9500A concentrations (27.1 ± 2.9 mg/m(3), mean ± SD).     

MicroRNA in colorectal cancer: from benchtop to bedside

Colon carcinogenesis represents a stepwise progression from benign polyps to invasive adenocarcinomas and distant metastasis. It is believed that these pathologic changes are contributed by aberrant activation or inactivation of protein-coding proto-oncogenes and tumor suppressor genes. However, recent discoveries in microRNA (miRNA) research have reshaped our understanding of the role of non-protein-coding genes in carcinogenesis. In this regard, a remarkable number of miRNAs exhibit differential expression in colon cancer tissues. These miRNAs alter cell proliferation, apoptosis and metastasis through their interactions with intracellular signaling networks. From a clinical perspective, polymorphisms within miRNA-binding sites are associated with the risk for colon cancer, whereas miRNAs isolated from feces or blood may serve as biomarkers for early diagnosis. Altered expression of miRNA or polymorphisms in miRNA-related genes have also been shown to correlate with patient survival or treatment outcome. With further insights into miRNA dysregulation in colon cancer and the advancement of RNA delivery technology, it is anticipated that novel miRNA-based therapeutics will emerge.     

Quantum rods as nanocarriers of gene therapy

Both antisense oligonucleotides (ASODN) and small interfering RNA (siRNA) have enormous potential to selectively silence specific cancer-related genes and could therefore be developed to be important therapeutic anti-cancer drugs. The use of nanotechnology may allow for significant advancement of the therapeutic potential of ASODN and siRNA, due to improved pharmacokinetics, bio-distribution and tissue specific targeted therapy. In this mini-review, we have discussed the advantages of using a nanocarrier such as a multimodal quantum rod (QR) complexed with siRNA for gene delivery. Comparisons are made between ASODN and siRNA therapeutic efficacies in the context of cancer and the enormous application potential of nanotechnology in oncotherapy is discussed. We have shown that a QR-interleukin-8 (IL-8) siRNA nanoplex can effectively silence IL-8 gene expression in the PC-3 prostate cancer cells with no significant toxicity. Thus, nanocarriers such as QRs can help translate the potent effects of ASODN/siRNA into a clinically viable anti-cancer therapy. Drug delivery for cancer therapy, with the aid of nanotechnology is one of the major translational aspects of nanomedicine, and efficient delivery of chemotherapy drugs and gene therapy drugs or their co-delivery continue to be a major focus of nanomedicine research.     

The role of MAPK and Nrf2 pathways in ketanserin-elicited attenuation of cigarette smoke-induced IL-8 production in human bronchial epithelial cells

Cigarette smoking is a major risk factor in chronic obstructive pulmonary disease (COPD) with chronic airway inflammation as a key feature. Blockade of serotonin receptor 2A (5-HTR(2A)) with ketanserin has been found to improve lung function in COPD patients. Furthermore, ketanserin has been shown to possess anti-inflammatory properties in vivo. In this study, we investigated the antioxidative and anti-inflammatory properties of ketanserin and its underlying mechanism of action on cigarette smoke-induced interleukin (IL)-8 release in vitro. Primary normal human bronchial epithelial cells and human bronchial epithelial cell line (BEAS-2B) were treated with or without ketanserin prior to exposure to cigarette smoke medium (CSM). Exposure to CSM caused elevation of both mRNA and release of IL-8 with increased phosphorylation of p38 and extracellular signal-regulated kinases 1 and 2 (ERK1/2). Consistently, CSM-induced IL-8 release was blocked by SB203580, U0126, or MEK1 small interfering RNA (siRNA) but not SP600125. On the other hand, CSM caused a dose-dependent decrease in the ratio of reduced glutathione to oxidized glutathione (rGSH/GSSG) together with an increased translocation of Nrf2 to the nucleus demonstrated by Western blot analysis. Knock down of Nrf2 by siRNA completely blocked CSM-induced IL-8 release. Ketanserin suppressed CSM-induced IL-8 release by inhibiting p38, ERK1/2 MAPK, and Nrf2 signaling pathways and partially inhibited CSM-induced reduction of rGSH/GSSG ratio. Our data demonstrated the novel antioxidative and anti-inflammatory role of ketanserin via the Nrf2 signaling pathway in CSM-exposed human bronchial epithelial cells. This may open up new perspectives in the development of novel therapeutic targets in the treatment of cigarette smoke-related COPD.