Real-Time Ultrasound/MRI Fusion for Suprasacral Parallel Shift Approach to Lumbosacral Plexus Blockade and Analysis of Injectate Spread:An Exploratory Randomized Controlled Trial

Fused real-time ultrasound and magnetic resonance imaging (MRI) may be used to improve the accuracy of advanced image guided procedures. However, its use in regional anesthesia is practically nonexistent. In this randomized controlled crossover trial, we aim to explore effectiveness, procedure-related outcomes, injectate spread analyzed by MRI, and safety of ultrasound/MRI fusion versus ultrasound guided Suprasacral Parallel Shift (SSPS) technique for lumbosacral plexus blockade. Twenty-six healthy subjects aged 21–36 years received two SSPS blocks (20 mL 2% lidocaine-epinephrine [1 : 200,000] added 1 mL diluted contrast) guided by ultrasound/MRI fusion versus ultrasound. Number (proportion) of subjects with motor blockade of the femoral and obturator nerves and the lumbosacral trunk was equal (ultrasound/MRI, 23/26 [88%]; ultrasound, 23/26 [88%]; p=1.00). Median (interquartile range) preparation and procedure times (s) were longer for the ultrasound/MRI fusion guided technique (686 [552–1023] versus 196 [167–228], p<0.001 and 333 [254–439] versus 216 [176–294], p=0.001). Both techniques produced perineural spread and corresponding sensory analgesia from L2 to S1. Epidural spread and lidocaine pharmacokinetics were similar. Different compartmentalized patterns of injectate spread were observed. Ultrasound/MRI fusion guided SSPS was equally effective and safe but required prolonged time, compared to ultrasound guided SSPS. This trial is registered with EudraCT (2013-004013-41) and ClinicalTrials.gov (NCT02593370)

Readings in Advanced Pharmacokinetics

This book, “Readings in Advanced Pharmacokinetics - Theory, Methods and Applications”, covers up to date information and practical topics related to the study of drug pharmacokinetics in humans and in animals. The book is designed to offer scientists, clinicians and researchers a choice to logically build their knowledge in pharmacokinetics from basic concepts to advanced applications. This book is organized into two sections. The first section discusses advanced theories that include a wide range of topics; from bioequivalence studies, pharmacogenomics in relation to pharmacokinetics, computer based simulation concepts to drug interactions of herbal medicines and veterinary pharmacokinetics. The second section advances theory to practice offering several examples of methods and applications in advanced pharmacokinetics

Pharmacokinetic and Pharmacodynamic Evaluation of Cocaine Hydrolases for the Treatment of Cocaine Overdose and Cocaine Addiction Using Rodent Models

Overdose and addiction are two medical complications of cocaine abuse. To date, there is no FDA approved pharmacotherapy specific for cocaine abuse. Cocaine hydrolases (CocHs) have been extensively investigated for its potential in anti-cocaine therapy. Previous studies have demonstrated that CocHs efficiently hydrolyze cocaine to generate biologically inactive metabolites both in vivo and in vitro. However, it has not been studied whether there is gender difference in the therapy using CocHs. In addition, the effectiveness of CocHs is unknown for treating cocaine toxicity when alcohol is co-administered. The main purpose of this dissertation is to characterize and evaluate efficient CocHs for cocaine overdose and cocaine addiction treatment. In the first set of studies, the effectiveness of human serum albumin-fused CocH1 were studied in male and female rats. The pharmacokinetic profiles, as well as the pharmacodynamic effects of CocH1-HSA were compared in male and female rats. The obtained data clearly demonstrated that CocH1-HSA was equally effective in both genders. The second set of studies investigated the efficiency of Fc-fused CocH5 in reversing cocaine toxicity in rats receiving simultaneous administration of cocaine and alcohol. Results showed that CocH5-Fc rapidly hydrolyzed cocaine and cocaine’s toxic metabolites in rats, and demonstrated that CocH5-Fc was efficient in treating cocaine toxicity when alcohol was simultaneously administered. In later studies to investigate the effects of CocH5-Fc for the treatment of cocaine addiction, a mathematical model was developed and validated to predict the effects of CocH5-Fc on the disposition of cocaine in rat blood and brain. This model adequately described the effects of CocH5-Fc in accelerating the elimination of cocaine and its toxic metabolites in both rat blood and brain. In conclusion, the studies within the current dissertation demonstrate the clinical potential of CocHs for the treatment of both cocaine overdose and cocaine addiction

Video-Rate Fluorescence Molecular Tomography for Hand-held and Multimodal Molecular Imaging

In the United States, cancer is the second leading cause of death following heart disease. Although, a variety of treatment regimens are available, cancer management is complicated by the complexity of the disease and the variability, between people, of disease progression and response to therapy. Therefore, advancements in the methods and technologies for cancer diagnosis, prognosis and therapeutic monitoring are critical to improving the treatment of cancer patients. The development of improved imaging methods for early diagnosis of cancer and of near real-time monitoring of tumor response to therapy may improve outcomes as well as the quality of life of cancer patients. In the last decade, imaging methods including ultrasound, computed tomography: CT), magnetic resonance imaging: MRI), single photon emission computed tomography: SPECT), and positron emission tomography: PET), have revolutionized oncology. More recently optical techniques, that have access to unique molecular reporting strategies and functional contrasts, show promise for oncologic imaging This dissertation focuses on the development and optimization of a fiber-based, video-rate fluorescence molecular tomography: FMT) instrument. Concurrent acquisition of fluorescence and reference signals allowed the efficient generation of ratio-metric data for 3D image reconstruction. Accurate depth localization and high sensitivity to fluorescent targets were established to depths of \u3e10 mm. In vivo accumulation of indocyanine green dye was imaged in the region of the sentinel lymph node: SLN) following intradermal injection into the forepaw of rats. These results suggest that video-rate FMT has potential as a clinical tool for noninvasive mapping of SLN. Spatial and temporal co-registration of nuclear and optical images can enable the fusion of the information from these complementary molecular imaging modalities. A critical challenge is in integrating the optical and nuclear imaging hardware. Flexible fiber-based FMT systems provide a viable solution. The various imaging bore sizes of small animal nuclear imaging systems can potentially accommodate the FMT fiber imaging arrays. In addition FMT imaging facilitates co-registering the nuclear and optical contrasts in time. In this dissertation, the feasibility of integrating the fiber-based, video-rate FMT system with a commercial preclinical NanoSPECT/CT platform was established. Feasibility of in vivo imaging is demonstrated by tracking a monomolecular multimodal-imaging agent: MOMIA) during transport from the forepaw to the axillary lymph nodes region of a rat. These co-registered FMT/SPECT/CT imaging results with MOMIAs may facilitate the development of the next generation preclinical and clinical multimodal optical-nuclear platforms for a broad array of imaging applications, and help elucidate the underlying biological processes relevant to cancer diagnosis and therapy monitoring. Finally, I demonstrated that video-rate FMT is sufficiently fast to enable imaging of cardiac, respiratory and pharmacokinetic induced dynamic fluorescent signals. From these measurements, the image-derived input function and the real-time uptake of injected agents can be deduced for pharmacokinetic analysis of fluorescing agents. In a study comparing normal mice against mice liver disease, we developed anatomically guided dynamic FMT in conjunction with tracer kinetic modeling to quantify uptake rates of fluorescing agents. This work establishes fiber-based, video-rate FMT system as a practical and powerful tool that is well suited to a broad array of potential imaging applications, ranging from early disease detection, quantifying physiology and monitoring progression of disease and therapies

Preclinical Development of a Novel Antileishmanial Agent OJT007: Bioanalytical Assay, in Vitro Studies and Pharmacokinetics

Current treatments for cutaneous leishmaniasis suffer from toxic side effects, high cost, parenteral administration, and drug resistance. Thus, there is a critical need to develop oral drugs for the treatment of leishmaniasis. OJT007 is a novel class of drug with potent antiproliferative effects against Leishmania Major. The purpose of this project is to conduct preclinical drug development studies for OJT007 including bioanalytical assay development, pre-formulation studies, in vitro hepatic drug metabolism and in vivo pharmacokinetics. A sensitive, specific, and reproducible ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated. The separation was achieved on a UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm) using a mobile phase consisting of 0.1% formic acid in acetonitrile and 0.1% formic acid in water as gradient elution at a flow rate of 0.4 mL/min. The mass analysis was performed with a 4000 QTRAP® mass spectrometer using multiple-ion reaction monitoring (MRM) in the positive mode, with the transition of m/z 325 → m/z 205 for OJT007 and m/z 350 → m/z 101 for voriconazole (as internal standard). Rat plasma and urine were extracted for OJT007 by protein precipitation in acetonitrile for quantification. Plasma protein binding of OJT007 was determined using the ultrafiltration method. In vitro phase I and II hepatic metabolism of OJT007 was evaluated in rat liver microsomes using standard reaction protocols. OJT007 metabolites were identified by LC-MS/MS using Q1MI, product ion, precursor ion and neutral loss scan and by β-glucuronidase hydrolysis. The OJT007 glucuronidation rates were determined by quantifying OJT007 glucuronide using UPLC, and the kinetic parameters of OJT007 were determined by measuring the initial glucuronidation rates. . Oral bioavailability of OJT007 was evaluated using a crossover study design. Serial plasma samples were collected at predetermined time points. Total urine samples were also collected from each rat for 24 hours after each dose. The pharmacokinetic parameters were calculated using Phoenix WinNonlin® 8.3 software. The intra- and inter-day precision and accuracy were within the acceptable limit of ≤20% for LLOQ and ≤15% for high, medium and low QC. The extraction recovery in rat plasma and urine samples were 95.1% and 83%, respectively. OJT007 exhibited a matrix factor in plasma and urine of 7.96% and 12.4%, respectively. The fraction of OJT007 bound to plasma protein had a mean value of 99.1%, suggesting the drug is highly bound to plasma proteins. OJT007 is glucuronidated rapidly in rat liver microsomes to form a mono-glucuronide, which was confirmed by LC-MS/MS and β-glucuronidase hydrolysis. The kinetic parameters of glucuronidation Vmax and Km were 1.125 nmol/min/mg and 10.73 μM., respectively. After intravenous administration, OJT007 displayed a bi-exponential disposition with a rapid distribution followed by a slower elimination. The mean AUC, volume of distribution, and clearance were 2.06 h.mg/L, 6.90 L/Kg and 2.30 L/hr/Kg, respectively. Following oral administration, OJT007 was rapidly absorbed with a tmax of 1.4 hours. After oral dosing the mean AUC, volume of distribution, and clearance were 0.45 h.mg/L, 78.6 L/Kg and 23.19 L/hr/Kg, respectively. Mean oral bioavailability of OJT007 in the co-solvent formulation was 10.9%. The mean percentage of OJT007 dose excreted unchanged in urine after 24 hours following intravenous and oral administration was less than 1%, suggesting OJT007 was extensively metabolized in vivo. A sensitive, specific and reproducible LC-MS/MS method was developed and validated to quantify OJT007 in rat plasma and urine. The method was successfully used for pharmacokinetic studies. This is the first time that oral bioavailability of OJT007 after oral administration in rat is determined. These results may prove valuable for further preclinical and clinical evaluation of OJT00

Therapeutic alternatives for the treatment of ocular inflammatory diseases

In the present thesis, different formulations of tacrolimus for topical-ophthalmic administration have been proposed, supported by extensive preclinical studies in order to achieve a consistent basis for the treatment of ocular inflammatory diseases. On the other hand, a pharmacokinetic and distribution study of an anti-TNFα monoclonal antibody (adalimumab) injected intravitreally was also carried out, allowing to know its behavior in the eye and thus develop new administration systems