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1

PosPush: A Highly Accurate Location-based Information Delivery System Zhao Junhui, Wang Yongcai  

E-print Network

PosPush: A Highly Accurate Location-based Information Delivery System Zhao Junhui, Wang Yongcai NECPush, a highly accurate location-based information delivery system, which utilizes the high-resolution 3D based Information Delivery (LIDS), most of them are based on very coarse location data to provide

Wang, Yongcai

2

Exploring targeted pulmonary delivery for treatment of lung cancer  

PubMed Central

Lung cancer is the most malignant cancer today. The treatment of lung cancer continues to be a challenge for oncologists. The direct delivery of chemotherapeutic agents to the lungs could represent a novel therapeutic approach for patients with pulmonary metastases. The large alveolar surface area, the low thickness of the epithelial barrier, and an extensive vascularization make the pulmonary route an ideal route for administration of oncolytics. This paper reviews the research performed over the last and current decades on the delivery of various oncolytics for pulmonary delivery for the treatment of lung cancer. Inhaled drug delivery devices in cancer therapy are also discussed in the present manuscript. PMID:23799201

Goel, Amit; Baboota, Sanjula; Sahni, Jasjeet K; Ali, Javed

2013-01-01

3

Polymeric Gene Delivery for Diabetic Treatment  

PubMed Central

Several polymers were used to delivery genes to diabetic animals. Polyaminobutyl glycolic acid was utilized to deliver IL-10 plasmid DNA to prevent autoimmune insulitis of non-obese diabetic (NOD) mouse. Polyethylene glycol grafted polylysine was combined with antisense glutamic acid decarboxylase (GAD) MRNA to represent GAD autoantigene expression. GLP1 and TSTA (SP-EX4) were delivered by bioreducible polymer to stop diabetic progression. Fas siRNA delivery was carried out to treat diabetic NOD mice animal. PMID:21977450

2011-01-01

4

Quality Control of High-Dose-Rate Brachytherapy: Treatment Delivery Analysis Using Statistical Process Control  

SciTech Connect

Purpose: Statistical process control (SPC) is a quality control method used to ensure that a process is well controlled and operates with little variation. This study determined whether SPC was a viable technique for evaluating the proper operation of a high-dose-rate (HDR) brachytherapy treatment delivery system. Methods and Materials: A surrogate prostate patient was developed using Vyse ordnance gelatin. A total of 10 metal oxide semiconductor field-effect transistors (MOSFETs) were placed from prostate base to apex. Computed tomography guidance was used to accurately position the first detector in each train at the base. The plan consisted of 12 needles with 129 dwell positions delivering a prescribed peripheral dose of 200 cGy. Sixteen accurate treatment trials were delivered as planned. Subsequently, a number of treatments were delivered with errors introduced, including wrong patient, wrong source calibration, wrong connection sequence, single needle displaced inferiorly 5 mm, and entire implant displaced 2 mm and 4 mm inferiorly. Two process behavior charts (PBC), an individual and a moving range chart, were developed for each dosimeter location. Results: There were 4 false positives resulting from 160 measurements from 16 accurately delivered treatments. For the inaccurately delivered treatments, the PBC indicated that measurements made at the periphery and apex (regions of high-dose gradient) were much more sensitive to treatment delivery errors. All errors introduced were correctly identified by either the individual or the moving range PBC in the apex region. Measurements at the urethra and base were less sensitive to errors. Conclusions: SPC is a viable method for assessing the quality of HDR treatment delivery. Further development is necessary to determine the most effective dose sampling, to ensure reproducible evaluation of treatment delivery accuracy.

Able, Charles M., E-mail: cable@wfubmc.edu [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Bright, Megan; Frizzell, Bart [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)] [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)

2013-03-01

5

Carrier-Based Drug Delivery System for Treatment of Acne  

PubMed Central

Approximately 95% of the population suffers at some point in their lifetime from acne vulgaris. Acne is a multifactorial disease of the pilosebaceous unit. This inflammatory skin disorder is most common in adolescents but also affects neonates, prepubescent children, and adults. Topical conventional systems are associated with various side effects. Novel drug delivery systems have been used to reduce the side effect of drugs commonly used in the topical treatment of acne. Topical treatment of acne with active pharmaceutical ingredients (API) makes direct contact with the target site before entering the systemic circulation which reduces the systemic side effect of the parenteral or oral administration of drug. The objective of the present review is to discuss the conventional delivery systems available for acne, their drawbacks, and limitations. The advantages, disadvantages, and outcome of using various carrier-based delivery systems like liposomes, niosomes, solid lipid nanoparticles, and so forth, are explained. This paper emphasizes approaches to overcome the drawbacks and limitations associated with the conventional system and the advances and application that are poised to further enhance the efficacy of topical acne formulations, offering the possibility of simplified dosing regimen that may improve treatment outcomes using novel delivery system. PMID:24688376

Vyas, Amber; Kumar Sonker, Avinesh

2014-01-01

6

Wind-tunnel tests and modeling indicate that aerial dispersant delivery operations are highly accurate  

Technology Transfer Automated Retrieval System (TEKTRAN)

The United States Department of Agriculture’s high-speed wind tunnel facility in College Station, Texas, USA was used to determine droplet size distributions generated by dispersant delivery nozzles at wind speeds comparable to those used in aerial dispersant application. A laser particle size anal...

7

Hollow waveguide delivery system for the ophthalmology treatment  

NASA Astrophysics Data System (ADS)

For the purpose of the ophthalmology treatments a special hollow waveguide based delivery instrument was developed. It consists of a 2 m long cyclic olefin polymer coated silver hollow glass waveguide (inner diameter 700 ?m) and the special cap allowing the contact of the waveguide with the wet eye tissues. The transmission characteristics for a delivery of a mid-infrared Er:YAG radiation (2.94 ?m) was measured. Then the pre-clinical interaction experiments of the Er:YAG laser radiation with the eye tissue (cornea, lens, and sclera) were performed with this delivery instrument. A comparison of two types of interactions results - the action of Er:YAG free running - 40 ?s long pulses and giant 450 ns long pulses were made. The human eye tissues (in vitro) were cut and samples (cornea, lens, and sclera) were gradually irradiated by the mid-infrared radiation with the energy of 7 mJ (the corresponding spot size diameter was equal ~ 700 ?m). The laser energy density used in this experiment was 1.8 J/cm2. From results it can be concluded that the giant pulses are more efficient in the ablation of the cornea, they are comparable with the free-running long pulses in the case of lens grinding, and they are less functioning for the sclera perforation. As concern the hollow waveguide delivery system, it has been proved that the energy delivered by this system was sufficient and suitable in both cases for delivery of long - free-running pulses, and short - giant pulses as well.

Jelinkova, Helena; Nemec, Michal; Sulc, Jan; Cech, Miroslav; Miyagi, Mitsunobu; Iwai, Katsumasa; Shi, Yi-Wei; Matsuura, Yuji; Pasta, Jiri

2003-07-01

8

Treatment delivery platform for conformal catheter-based ultrasound hyperthermia  

NASA Astrophysics Data System (ADS)

A clinical treatment delivery platform has been developed for providing 3D controlled hyperthermia with catheter-based ultrasound applicators in conjunction with high dose rate (HDR) brachytherapy. This integrated system consists of hardware and software components required for thermal therapy delivery, treatment monitoring and control, and realtime and post-treatment analysis; and interstitial and endocavity ultrasound heating applicators. Hardware includes a 32-channel RF amplifier with independent power (0-25 W) and frequency (5-10 MHz) control for ultrasound power delivery and a 48-channel thermometry system compatible with 0.4 mm OD multi-sensor thermocouple probes. Software graphical user interfaces (GUI) are used to monitor and control both the amplifier and the thermometry system. The amplifier GUI controls, monitors, and records individual channel frequency and power values in real-time; the thermometry GUI monitors and records temperature and thermal dose values in real-time, as well as displaying and allowing dynamic control for temperature and thermal dose target thresholds. The thermometry GUI also incorporates registration of thermocouple positions relative to target anatomy and applicator transducers based on HDR planning tools (CT/MRI/US overlays) for improved treatment control and documentation. The interstitial (2.4 mm) and endocavity (6 mm) ultrasound hyperthermia applicators are composed of linear arrays of 1-4 tubular piezoceramic transducers - sectored at 90°, 180°, 270°, and 360° for single or dual directional heating patterns - that are compatible with plastic implant catheters. QA techniques specific to these catheter-based ultrasound applicators have been devised and implemented, and include rotational beam plots and dynamic force balance efficiency measurements, which are critical to establish applicator performance. A quality assurance test matrix has been devised and used to evaluate and characterize all components of this system prior to clinical implementation.

Juang, Titania; Wootton, Jeffery; Hsu, I.-Chow; Diederich, Chris

2009-02-01

9

Mathematical model accurately predicts protein release from an affinity-based delivery system.  

PubMed

Affinity-based controlled release modulates the delivery of protein or small molecule therapeutics through transient dissociation/association. To understand which parameters can be used to tune release, we used a mathematical model based on simple binding kinetics. A comprehensive asymptotic analysis revealed three characteristic regimes for therapeutic release from affinity-based systems. These regimes can be controlled by diffusion or unbinding kinetics, and can exhibit release over either a single stage or two stages. This analysis fundamentally changes the way we think of controlling release from affinity-based systems and thereby explains some of the discrepancies in the literature on which parameters influence affinity-based release. The rate of protein release from affinity-based systems is determined by the balance of diffusion of the therapeutic agent through the hydrogel and the dissociation kinetics of the affinity pair. Equations for tuning protein release rate by altering the strength (KD) of the affinity interaction, the concentration of binding ligand in the system, the rate of dissociation (koff) of the complex, and the hydrogel size and geometry, are provided. We validated our model by collapsing the model simulations and the experimental data from a recently described affinity release system, to a single master curve. Importantly, this mathematical analysis can be applied to any single species affinity-based system to determine the parameters required for a desired release profile. PMID:25449806

Vulic, Katarina; Pakulska, Malgosia M; Sonthalia, Rohit; Ramachandran, Arun; Shoichet, Molly S

2015-01-10

10

Logic Regression for Provider Effects on Kidney Cancer Treatment Delivery  

PubMed Central

In the delivery of medical and surgical care, often times complex interactions between patient, physician, and hospital factors influence practice patterns. This paper presents a novel application of logic regression in the context of kidney cancer treatment delivery. Using linked data from the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) program and Medicare we identified patients diagnosed with kidney cancer from 1995 to 2005. The primary endpoints in the study were use of innovative treatment modalities, namely, partial nephrectomy and laparoscopy. Logic regression allowed us to uncover the interplay between patient, provider, and practice environment variables, which would not be possible using standard regression approaches. We found that surgeons who graduated in or prior to 1980 despite having some academic affiliation, low volume surgeons in a non-NCI hospital, or surgeons in rural environment were significantly less likely to use laparoscopy. Surgeons with major academic affiliation and practising in HMO, hospital, or medical school based setting were significantly more likely to use partial nephrectomy. Results from our study can show efforts towards dismantling the barriers to adoption of innovative treatment modalities, ultimately improving the quality of care provided to patients with kidney cancer. PMID:24795774

Banerjee, Mousumi; Filson, Christopher; Xia, Rong; Miller, David C.

2014-01-01

11

A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment  

SciTech Connect

Purpose: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient.Methods: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance.Results: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ?1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s).Conclusions: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.

Fuangrod, Todsaporn [Faculty of Engineering and Built Environment, School of Electrical Engineering and Computer Science, the University of Newcastle, NSW 2308 (Australia)] [Faculty of Engineering and Built Environment, School of Electrical Engineering and Computer Science, the University of Newcastle, NSW 2308 (Australia); Woodruff, Henry C.; O’Connor, Daryl J. [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308 (Australia)] [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308 (Australia); Uytven, Eric van; McCurdy, Boyd M. C. [Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada) [Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Radiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Kuncic, Zdenka [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)] [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Greer, Peter B. [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Locked Bag 7, Hunter region Mail Centre, Newcastle, NSW 2310 (Australia)] [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Locked Bag 7, Hunter region Mail Centre, Newcastle, NSW 2310 (Australia)

2013-09-15

12

Plasmonic laser treatment for Morpholino oligomer delivery in antisense applications.  

PubMed

Several cell transfection techniques have been developed in the last decades for specific applications and for various types of molecules. In this context, laser based approaches are of great interest due to their minimal invasiveness and spatial selectivity. In particular, laser induced plasmon based delivery of exogenous molecules into cells can have great impact on future applications. This approach allows high-throughput laser transfection by excitation of plasmon resonances at gold nanoparticles non-specifically attached to the cell membrane. In this study, we demonstrate specific gene-knockdown by transfection of Morpholino oligos using this technique with optimized particle size. Furthermore, we evaluated the cytotoxicity of plasmonic laser treatment by various assays, including LDH activity and ROS formation. In summary, this study gives important insights into this new approach and clearly demonstrates its relevance for possible biological applications. PMID:23740874

Kalies, Stefan; Heinemann, Dag; Schomaker, Markus; Murua Escobar, Hugo; Heisterkamp, Alexander; Ripken, Tammo; Meyer, Heiko

2014-10-01

13

Respiration-correlated treatment delivery using feedback-guided breath hold: A technical study  

SciTech Connect

Respiratory motion causes movement of internal structures in the thorax and abdomen, making accurate delivery of radiation therapy to tumors in those areas a challenge. To reduce the uncertainties caused by this motion, we have developed feedback-guided breath hold (FGBH), a novel delivery technique in which radiation is delivered only during a voluntary breath hold that is sustained for as long as the patient feels comfortable. Here we present the technical aspects of FGBH, which involve (1) fabricating the hardware so the respiratory trace can be displayed to the patient, (2) assembling a delay box to be used as a breath-hold detector, and (3) performing quality control tests to ensure that FGBH can be delivered accurately and safely. A commercial respiratory tracking system that uses an external fiducial to monitor abdominal wall motion generates and displays the breathing trace and specific positions in the breathing cycle where a breath hold needs to occur. Hardware was developed to present this display to the patient in the treatment position. Patients view the presentation either on a liquid crystal display or through a pair of virtual reality goggles. Using the respiratory trace as a visual aid, the patient performs a breath hold so that the position representing the location of a fiducial is held within a specified gating window. A delay box was fabricated to differentiate between gating signals received during free breathing and those received during breath hold, allowing radiation delivery only when the fiducial was within the breath-hold gating window. A quality control analysis of the gating delay box and the integrated system was performed to ensure that all of the hardware and components were ready for clinical use.

Nelson, Christopher; Starkschall, George; Balter, Peter; Fitzpatrick, Mathew J.; Antolak, John A.; Tolani, Naresh; Prado, Karl [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States)

2005-01-01

14

The use of a realistic VMAT delivery emulator to optimize dynamic machine parameters for improved treatment efficiency.  

PubMed

The delivery of volumetric modulated arc therapy (VMAT) requires the simultaneous movement of the linear accelerator gantry, multi-leaf collimators and jaws while the dose rate is varied. In this study, a VMAT delivery emulator was developed to accurately predict the characteristics of a given treatment plan, incorporating realistic parameters for gantry inertia and the variation in leaf speed with respect to gravity. The emulator was used to assess the impact of dynamic machine parameters on the delivery efficiency, using a set of prostate and head and neck VMAT plans. Initially, assuming a VMAT system with fixed dose rate bins, the allowable leaf and jaw speeds were increased and a significant improvement in treatment time and average dose rate was observed. The software was then adapted to simulate a VMAT system with continuously varying dose rate, and the increase in delivery efficiency was quantified, along with the impact of an increased leaf and jaw speed. Finally, a set of optimal dynamic machine parameters was derived assuming an idealized scenario in which the treatment is delivered in a single arc at constant maximum gantry speed. PMID:21693790

Boylan, C J; Rowbottom, C G; Mackay, R I

2011-07-01

15

Passive flow regulators for drug delivery and hydrocephalus treatment  

NASA Astrophysics Data System (ADS)

Passive flow regulators are usually intended to deliver or drain a fluid at a constant rate independently from pressure variations. New designs of passive flow regulators made of a stack of a silicon membrane anodically bonded to a Pyrex substrate are proposed. A first design has been built for the derivation of cerebrospinal fluid (CSF) towards peritoneum for hydrocephalus treatment. The device allows draining CSF at the patient production rate independently from postural changes. The flow rate is regulated at 20 ml/h in the range 10 to 40 mbar. Specific features to adjust in vivo the nominal flow rate are shown. A second design including high pressure shut-off feature has been made. The intended use is drug delivery with pressurized reservoir of typically 100 to 300 mbar. In both cases, the membrane comprises several holes facing pillars in the Pyrex substrate. These pillars are machined in a cavity which ensures a gap between the membrane and the pillars at rest. The fluid in the pressurized reservoir is directly in contact with the top surface of the membrane, inducing its deflection towards Pyrex substrate and closing progressively the fluidic pathway through each hole of the membrane. Since the membrane deflection is highly non-linear, FEM simulations have been performed to determine both radial position and diameter of the membrane holes that ensure a constant flow rate for a given range of pressure.

Chappel, E.; Dumont-Fillon, D.; Mefti, S.

2014-03-01

16

Progesterone use after successful treatment of threatened pre-term delivery.  

PubMed

Pre-term delivery is the leading cause of neonatal morbidity, mortality and long-term sequels. This is an open label randomised controlled trial with women with confirmed threatened pre-term labour (TPTL) after efficient tocolytic therapy with atosiban. The main outcome measure of this study was the latency period until delivery and secondary outcomes were the number of recurrent episodes of TPTL and fetal and maternal morbidity. Patients were assigned to treatment or control groups using a computer generated randomisation table. The treatment group received 200 mg vaginal progesterone daily until delivery and the control group received no therapy or placebo. The study cohort comprised 52 pregnant women, 26 in each arm, showing similar characteristics; the treatment group had a longer latency period until delivery and this was statistically significant (55 vs 38 days, p = 0.024). This study points to the benefits of the vaginal administration of progesterone, especially in prolonging latency period until delivery. PMID:24127952

Areia, A; Fonseca, E; Moura, P

2013-10-01

17

Cervical cancer treatment with a locally insertable controlled release delivery system  

Microsoft Academic Search

Local delivery of cancer chemotherapeutics enables sustained drug levels at the site of action thereby reducing systemic side effects. A novel insertable polymeric drug delivery system for cervical cancer treatment is presented. Cisplatin, the first line of therapy employed for cervical cancers, was incorporated in a poly(ethylene-co-vinyl acetate) (EVAc) device that is similar to those currently used for vaginal contraceptive

Vandana Keskar; Prem S. Mohanty; Ernest J. Gemeinhart; Richard A. Gemeinhart

2006-01-01

18

Microcapsule drug delivery device for treatment of glioblastoma multiforme  

E-print Network

Controlled-release drug delivery systems are capable of treating debilitating diseases, including cancer. Brain cancer, in particular glioblastoma multiforme (GBM), is an extremely invasive cancer with a dismal prognosis. ...

Scott, Alexander Wesley

2010-01-01

19

Energy Delivery Systems for Treatment of Benign Prostatic Hyperplasia  

PubMed Central

Executive Summary Objective The Ontario Health Technology Advisory Committee asked the Medical Advisory Secretariat (MAS) to conduct a health technology assessment on energy delivery systems for the treatment of benign prostatic hyperplasia (BPH). Clinical Need: Target Population and Condition BPH is a noncancerous enlargement of the prostate gland and the most common benign tumour in aging men. (1) It is the most common cause of lower urinary tract symptoms (LUTS) and bladder outlet obstruction (BOO) and is an important cause of diminished quality of life among aging men. (2) The primary goal in the management of BPH for most patients is a subjective improvement in urinary symptoms and quality of life. Until the 1930s, open prostatectomy, though invasive, was the most effective form of surgical treatment for BPH. Today, the benchmark surgical treatment for BPH is transurethral resection of the prostate (TURP), which produces significant changes of all subjective and objective outcome parameters. Complications after TURP include hemorrhage during or after the procedure, which often necessitates blood transfusion; transurethral resection (TUR) syndrome; urinary incontinence; bladder neck stricture; and sexual dysfunction. A retrospective review of 4,031 TURP procedures performed by one surgeon between 1979 and 2003 showed that the incidence of complications was 2.4% for blood transfusion, 0.3% for TUR syndrome, 1.5% for hemostatic procedures, 2.8% for bladder neck contracture, and 1% for urinary stricture. However, the incidence of blood transfusion and TUR syndrome decreased as the surgeon’s skills improved. During the 1990s, a variety of endoscopic techniques using a range of energy sources have been developed as alternative treatments for BPH. These techniques include the use of light amplification by stimulated emission of radiation (laser), radiofrequency, microwave, and ultrasound, to heat prostate tissue and cause coagulation or vaporization. In addition, new electrosurgical techniques that use higher amounts of energy to cut, coagulate, and vaporize prostatic tissue have entered the market as competitors to TURP. The driving force behind these new treatment modalities is the potential of producing good hemostasis, thereby reducing catheterization time and length of hospital stay. Some have the potential to be used in an office environment and performed under local anesthesia. Therefore, these new procedures have the potential to rival TURP if their effectiveness is proven over the long term. The Technology Being Reviewed The following energy-based techniques were considered for assessment: transurethral electrovaporization of the prostate (TUVP) transurethral electrovapor resection of the prostate (TUVRP) transurethral electrovaporization of the prostate using bipolar energy (plasmakinetic vaporization of the prostate [PKVP]) visual laser ablation of the prostate (VLAP) transurethral ultrasound guided laser incision prostatectomy (TULIP) contact laser vaporization of the prostate (CLV) interstitial laser coagulation (ILC) holmium laser resection of the prostate (HoLRP) holmium laser enucleation of the prostate (HoLEP) holmium laser ablation of the prostate (HoLAP) potassium titanyl phosphate (KTP) laser transurethral microwave thermotherapy (TUMT) transurethral needle ablation (TUNA) Review Strategy A search of electronic databases (OVID MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library, and the International Agency for Health Technology Assessment [INAHTA] database) was undertaken to identify evidence published from January 1, 2000 to June 21, 2006. The search was limited to English-language articles and human studies. The literature search identified 284 citations, of which 38 randomized controlled trials (RCTs) met the inclusion criteria. Since the application of high-power (80 W) KTP laser (photoselective vaporization of the prostate [PVP]) has been supported in the United States and has resulted in a rapid diffusion of this technology in the absence of any RCTs, th

2006-01-01

20

A Monte Carlo tool for evaluating VMAT and DIMRT treatment deliveries including planar detectors  

NASA Astrophysics Data System (ADS)

The aim of this work is to describe and validate a new general research tool that performs Monte Carlo (MC) simulations for volumetric modulated arc therapy (VMAT) and dynamic intensity modulated radiation therapy (DIMRT), simultaneously tracking dose deposition in both the patient CT geometry and an arbitrary planar detector system. The tool is generalized to handle either entrance or exit detectors and provides the simulated dose for the individual control-points of the time-dependent VMAT and DIMRT deliveries. The MC simulation tool was developed with the EGSnrc radiation transport. For the individual control point simulation, we rotate the patient/phantom volume only (i.e. independent of the gantry and planar detector geometries) using the gantry angle in the treatment planning system (TPS) DICOM RP file such that each control point has its own unique phantom file. After MC simulation, we obtained the total dose to the phantom by summing dose contributions for all control points. Scored dose to the sensitive layer of the planar detector is available for each control point. To validate the tool, three clinical treatment plans were used including VMAT plans for a prostate case and a head-and-neck case, and a DIMRT plan for a head-and-neck case. An electronic portal imaging device operated in ‘movie’ mode was used with the VMAT plans delivered to cylindrical and anthropomorphic phantoms to validate the code using an exit detector. The DIMRT plan was delivered to a novel transmission detector, to validate the code using an entrance detector. The total MC 3D absolute doses in patient/phantom were compared with the TPS doses, while 2D MC doses were compared with planar detector doses for all individual control points, using the gamma evaluation test with 3%/3 mm criteria. The MC 3D absolute doses demonstrated excellent agreement with the TPS doses for all the tested plans, with about 95% of voxels having ? <1 for the plans. For planar dosimetry image comparisons, we defined an acceptable pass rate of >90% of percentage pixels with ? <1. We found that over 90% of control points in the plans passed this criterion. In general, our results indicate that the simulation tool is suitable for accurately calculating both patient/phantom doses and planar doses for VMAT dose delivery. The tool will be valuable to check performance and advance the development of in vivo planar detectors for use in measurement-based VMAT dose verification. In addition, the tool can be useful as an independent research tool for VMAT commissioning of the TPS and delivery system.

Asuni, G.; van Beek, T. A.; Venkataraman, S.; Popescu, I. A.; McCurdy, B. M. C.

2013-06-01

21

A Monte Carlo tool for evaluating VMAT and DIMRT treatment deliveries including planar detectors.  

PubMed

The aim of this work is to describe and validate a new general research tool that performs Monte Carlo (MC) simulations for volumetric modulated arc therapy (VMAT) and dynamic intensity modulated radiation therapy (DIMRT), simultaneously tracking dose deposition in both the patient CT geometry and an arbitrary planar detector system. The tool is generalized to handle either entrance or exit detectors and provides the simulated dose for the individual control-points of the time-dependent VMAT and DIMRT deliveries. The MC simulation tool was developed with the EGSnrc radiation transport. For the individual control point simulation, we rotate the patient/phantom volume only (i.e. independent of the gantry and planar detector geometries) using the gantry angle in the treatment planning system (TPS) DICOM RP file such that each control point has its own unique phantom file. After MC simulation, we obtained the total dose to the phantom by summing dose contributions for all control points. Scored dose to the sensitive layer of the planar detector is available for each control point. To validate the tool, three clinical treatment plans were used including VMAT plans for a prostate case and a head-and-neck case, and a DIMRT plan for a head-and-neck case. An electronic portal imaging device operated in 'movie' mode was used with the VMAT plans delivered to cylindrical and anthropomorphic phantoms to validate the code using an exit detector. The DIMRT plan was delivered to a novel transmission detector, to validate the code using an entrance detector. The total MC 3D absolute doses in patient/phantom were compared with the TPS doses, while 2D MC doses were compared with planar detector doses for all individual control points, using the gamma evaluation test with 3%/3 mm criteria. The MC 3D absolute doses demonstrated excellent agreement with the TPS doses for all the tested plans, with about 95% of voxels having ? <1 for the plans. For planar dosimetry image comparisons, we defined an acceptable pass rate of >90% of percentage pixels with ? <1. We found that over 90% of control points in the plans passed this criterion. In general, our results indicate that the simulation tool is suitable for accurately calculating both patient/phantom doses and planar doses for VMAT dose delivery. The tool will be valuable to check performance and advance the development of in vivo planar detectors for use in measurement-based VMAT dose verification. In addition, the tool can be useful as an independent research tool for VMAT commissioning of the TPS and delivery system. PMID:23640066

Asuni, G; van Beek, T A; Venkataraman, S; Popescu, I A; McCurdy, B M C

2013-06-01

22

A Review of the Effects of Medication Delivery Systems on Treatment Adherence in Children with Asthma  

PubMed Central

Background: A patient's adherence to an appropriate treatment regimen is necessary to minimize morbidity and mortality associated with childhood asthma. Many factors influence the success of treatment adherence. Objective: The goal of this article was to examine the effect of the mode of medication delivery on the success of treatment adherence in children with asthma. Methods: Relevant clinical studies were identified through a MEDLINE search of articles published from 1966 to 2002, using the search terms adherence, aerosol, asthma, children, compliance, dry powder inhaler, metered-dose inhaler, nebulizer, and pediatric. Results: A relationship seems to exist between treatment adherence and the type of medication delivery system used in childhood asthma. The highest rates of adherence appear to be associated with oral medications. Conclusions: Clinicians should consider the mode of medication delivery as 1 factor that can influence the success of treatment adherence. PMID:24944355

Cohn, Robert C

2003-01-01

23

Airways delivery of rifampicin microparticles for the treatment of tuberculosis  

Microsoft Academic Search

A Mycobacterium tuberculosis (H37Rv)-infected guinea pig model was used to screen for targeted delivery to the lungs by insufflation (with lactose excipient) or nebulization, of either rifampicin alone, rifampicin within poly(lactide-co-glycolide) microspheres (R-PLGA) or polymer microparticles alone (PLGA). Animals treated with single and double doses of R-PLGA microspheres exhibited significantly reduced numbers of viable bacteria, inflamma- tion and lung damage

Sandra Suarez; Patrick O'Hara; Masha Kazantseva; Christian E. Newcomer; Roy Hopfer; David N. McMurray; Anthony J. Hickey

2001-01-01

24

The Impact of Advanced Technologies on Treatment Deviations in Radiation Treatment Delivery  

SciTech Connect

Purpose: To assess the impact of new technologies on deviation rates in radiation therapy (RT). Methods and Materials: Treatment delivery deviations in RT were prospectively monitored during a time of technology upgrade. In January 2003, our department had three accelerators, none with 'modern' technologies (e.g., without multileaf collimators [MLC]). In 2003 to 2004, we upgraded to five new accelerators, four with MLC, and associated advanced capabilities. The deviation rates among patients treated on 'high-technology' versus 'low-technology' machines (defined as those with vs. without MLC) were compared over time using the two-tailed Fisher's exact test. Results: In 2003, there was no significant difference between the deviation rate in the 'high-technology' versus 'low-technology' groups (0.16% vs. 0.11%, p = 0.45). In 2005 to 2006, the deviation rate for the 'high-technology' groups was lower than the 'low-technology' (0.083% vs. 0.21%, p = 0.009). This difference was caused by a decline in deviations on the 'high-technology' machines over time (p = 0.053), as well as an unexpected trend toward an increase in deviations over time on the 'low-technology' machines (p = 0.15). Conclusions: Advances in RT delivery systems appear to reduce the rate of treatment deviations. Deviation rates on 'high-technology' machines with MLC decline over time, suggesting a learning curve after the introduction of new technologies. Associated with the adoption of 'high-technology' was an unexpected increase in the deviation rate with 'low-technology' approaches, which may reflect an over-reliance on tools inherent to 'high-technology' machines. With the introduction of new technologies, continued diligence is needed to ensure that staff remain proficient with 'low-technology' approaches.

Marks, Lawrence B. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)], E-mail: lawrence.marks@duke.edu; Light, Kim L.; Hubbs, Jessica L.; Georgas, Debra L.; Jones, Ellen L. [Department of Radiation Oncology, Duke University Medical Center, Durham, C (United States); Wright, Melanie C. [Department of Anesthesiology, Duke University Medical Center, Durham, NC (United States); Willett, Christopher G.; Yin Fangfang [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

2007-12-01

25

Polymeric nanoparticles-based topical delivery systems for the treatment of dermatological diseases  

PubMed Central

Human skin not only functions as a permeation barrier (mainly due to the stratum corneum layer), but also provides a unique delivery pathway for therapeutic and other active agents. These compounds penetrate via intercellular, intracellular and transappendageal routes, resulting in topical delivery (into skin strata) and transdermal delivery (to subcutaneous tissues and into the systemic circulation). Passive and active permeation enhancement methods have been widely applied to increase the cutaneous penetration. The pathology, pathogenesis and topical treatment approaches of dermatological diseases, such as psoriasis, contact dermatitis, and skin cancer, are then discussed. Recent literature has demonstrated that nanoparticles-based topical delivery systems can be successful in treating these skin conditions. The studies are reviewed starting with the nanoparticles based on natural polymers specially chitosan, followed by those made of synthetic, degradable (aliphatic polyesters) and non-degradable (polyarylates) polymers; emphasis is given to nanospheres made of polymers derived from naturally occurring metabolites, the tyrosine-derived nanospheres (TyroSpheres™). In summary, the nanoparticles-based topical delivery systems combine the advantages of both the nano-sized drug carriers and the topical approach, and are promising for the treatment of skin diseases. For the perspectives, the penetration of ultra-small nanoparticles (size smaller than 40 nm) into skin strata, the targeted delivery of the encapsulated drugs to hair follicle stem cells, and the combination of nanoparticles and microneedle array technologies for special applications such as vaccine delivery are discussed. PMID:23386536

Zhang, Zheng; Tsai, Pei-Chin; Ramezanli, Tannaz; Michniak-Kohn, Bozena B.

2013-01-01

26

Drug Delivery for Treatment of Inner Ear Disease: Current State of Knowledge  

PubMed Central

Delivery of medications to the inner ear has been an area of considerable growth in both the research and clinical realms over the past several decades. Systemic delivery of medication destined for treatment of the inner ear is the foundation upon which newer delivery techniques have been developed. Due to systemic side effects, investigators and clinicians have begun developing and utilizing techniques to deliver therapeutic agents locally. Alongside the now commonplace use of intratympanic gentamicin for Meniere's disease and the emerging use of intratympanic steroids for sudden sensorineural hearing loss, novel technologies, such as hydrogels and nanoparticles, are being explored. At the horizon of inner ear drug delivery techniques, intracochlear devices that leverage recent advances in microsystems technology are being developed to apply medications directly into the inner ear. Potential uses for such devices include neurotrophic factor and steroid delivery with cochlear implantation, RNA interference technologies, and stem cell therapy. The historical, current, and future delivery techniques and uses of drug delivery for treatment of inner ear disease serve as the basis for this review. PMID:19952751

McCall, Andrew A.; Leary Swan, Erin E.; Borenstein, Jeffrey T.; Sewell, William F.; Kujawa, Sharon G.; McKenna, Michael J.

2009-01-01

27

Warning for unprincipled colorectal endoscopic submucosal dissection: Accurate diagnosis and reasonable treatment strategy  

PubMed Central

Piecemeal endoscopic mucosal resection (EMR) is generally indicated for laterally spreading tumors (LST) >2 cm in diameter. However, the segmentation of adenomatous parts does not affect the histopathological diagnosis and completeness of cure. Thus, possible indications for piecemeal EMR are both adenomatous homogenous-type granular-type LST (LST-G) and LST-G as carcinoma in adenoma without segmentalizing the carcinomatous part. Diagnosis of the pit pattern using magnifying endoscopy is essential for determining the correct treatment and setting segmentation borders. In contrast, endoscopic submucosal dissection (ESD) is indicated for lesions requiring endoscopic en bloc excision, as it is difficult to use the snare technique for en bloc excisions such as in non-granular-type LST (LST-NG), especially for the pseudodepressed type, tumors with a type VI pit pattern, shallow invasive submucosal carcinoma, largedepressed tumors and large elevated lesions, which are often malignant (e.g. nodular mixed-type LST-G). Other lesions, such as intramucosal tumor accompanied by submucosal fibrosis, induced by biopsy or peristalsis of the lesion; sporadic localized tumors that occur due to chronic inflammation, including ulcerative colitis; and local residual early carcinoma after endoscopic treatment, are also indications for ESD. In clinical practice, an efficient endoscopic treatment with segregation of ESD from piecemeal EMR should be carried out after a comprehensive evaluation of the completeness of cure, safety, clinical simplicity, and cost–benefit, based on an accurate preoperative diagnosis. PMID:23368854

Tanaka, Shinji; Terasaki, Motomi; Hayashi, Nana; Oka, Shiro; Chayama, Kazuaki

2013-01-01

28

Aerosol delivery devices in the treatment of asthma.  

PubMed

Nebulizers convert solutions or suspensions into aerosols with a particle size that can be inhaled into the lower respiratory tract. There are pneumatic jet nebulizers, ultrasonic nebulizers, and mesh nebulizers. Newer nebulizer designs are breath-enhanced, breath-actuated, or have aerosol-storage bags to minimize aerosol loss during exhalation. Nebulizers can be used with helium-oxygen mixture and can be used for continuous aerosol delivery. Increased attention has recently been paid to issues related to the use of a facemask with a nebulizer. The pressurized metered-dose inhaler (pMDI) is a very commonly used device for aerosol delivery. There are press-and-breathe and breath-actuated pMDI designs. Issues related to pMDIs that have received increasing attention are the conversion to hydrofluoroalkane propellant and the use of dose counters. Many patients have poor pMDI technique. Valved holding chambers and spacers are used to improve pMDI technique and to decrease aerosol deposition in the upper airway. In recent years increasing attention has been paid to the issues of electrostatic charge and facemasks related to valved holding chambers. Many newer formulations for inhalation have been released in dry-powder inhalers, which are either unit-dose or multi-dose inhalers. Systematic reviews and meta-analyses have suggested that each of these aerosol delivery devices can work equally well in patients who can use them correctly. However, many patients use these devices incorrectly, so proper patient education in their use is critical. PMID:18501026

Hess, Dean R

2008-06-01

29

Treatment planning for SBRT using automated field delivery: A case study.  

PubMed

Stereotactic body radiation therapy (SBRT) treatment planning and delivery can be accomplished using a variety of techniques that achieve highly conformal dose distributions. Herein, we describe a template-based automated treatment field approach that enables rapid delivery of more than 20 coplanar fields. A case study is presented to demonstrate how modest adaptations to traditional SBRT planning can be implemented to take clinical advantage of this technology. Treatment was planned for a left-sided lung lesion adjacent to the chest wall using 25 coplanar treatment fields spaced at 11° intervals. The plan spares the contralateral lung and is in compliance with the conformality standards set forth in Radiation Therapy and Oncology Group protocol 0915, and the dose tolerances found in the report of the American Association of Physicists in Medicine Task Group 101. Using a standard template, treatment planning was accomplished in less than 20 minutes, and each 10Gy fraction was delivered in approximately 5.4 minutes. For those centers equipped with linear accelerators capable of automated treatment field delivery, the use of more than 20 coplanar fields is a viable SBRT planning approach and yields excellent conformality and quality combined with rapid planning and treatment delivery. Although the case study discusses a laterally located lung lesion, this technique can be applied to centrally located tumors with similar results. PMID:25241356

Ritter, Timothy A; Owen, Dawn; Brooks, Cassandra M; Stenmark, Matthew H

2015-01-01

30

Health Literacy in HIV Treatment: Accurate Understanding of Key Biological Treatment Principles is Not Required for Good ART Adherence.  

PubMed

Findings on the relationship between health literacy and outcomes in HIV have been inconsistent. Health literacy has previously been operationalized as general functional literacy, but has not included content knowledge about HIV disease and treatment. Semi-structured interviews with people living with HIV in 2 U.S. cities, including questions about the etiology, pathophysiology and treatment of HIV. We compared responses to biomedical conceptions. The 32 respondents were demographically diverse. Although most understood that HIV degrades the immune system, none could explain the nature of a virus, or the mechanism of antiretroviral (ARV) drug action. Fewer than half accurately reported that it is desirable to have a high CD4+ cell count and low viral load. A minority understood the concept of drug resistance. While most believed that strict adherence to ARV regimens was important to maintain health, three believed that periodic treatment interruption was beneficial, and three believed they should not take ARVs when they used alcohol or illicit drugs. Respondents generally had very limited, and often inaccurate biomedical understanding of HIV disease. Most reported good regimen adherence but did not have any mechanistic rationale for it. The failure to find a consistent relationship between health literacy and ARV adherence may be largely because most people simply follow their doctors' instructions, without the need for deep understanding. PMID:25354736

Laws, M Barton; Danielewicz, Michael; Rana, Aadia; Kogelman, Laura; Wilson, Ira B

2014-10-30

31

Quantitative analysis of beam delivery parameters and treatment process time for proton beam therapy  

SciTech Connect

Purpose: To evaluate patient census, equipment clinical availability, maximum daily treatment capacity, use factor for major beam delivery parameters, and treatment process time for actual treatments delivered by proton therapy systems. Methods: The authors have been recording all beam delivery parameters, including delivered dose, energy, range, spread-out Bragg peak widths, gantry angles, and couch angles for every treatment field in an electronic medical record system. We analyzed delivery system downtimes that had been recorded for every equipment failure and associated incidents. These data were used to evaluate the use factor of beam delivery parameters, the size of the patient census, and the equipment clinical availability of the facility. The duration of each treatment session from patient walk-in and to patient walk-out of the treatment room was measured for 82 patients with cancers at various sites. Results: The yearly average equipment clinical availability in the last 3 yrs (June 2007-August 2010) was 97%, which exceeded the target of 95%. Approximately 2200 patients had been treated as of August 2010. The major disease sites were genitourinary (49%), thoracic (25%), central nervous system (22%), and gastrointestinal (2%). Beams have been delivered in approximately 8300 treatment fields. The use factor for six beam delivery parameters was also evaluated. Analysis of the treatment process times indicated that approximately 80% of this time was spent for patient and equipment setup. The other 20% was spent waiting for beam delivery and beam on. The total treatment process time can be expressed by a quadratic polynomial of the number of fields per session. The maximum daily treatment capacity of our facility using the current treatment processes was estimated to be 133 {+-} 35 patients. Conclusions: This analysis shows that the facility has operated at a high performance level and has treated a large number of patients with a variety of diseases. The use factor of beam delivery parameters varies by disease site. Further improvements in efficiency may be realized in the equipment- and patient-related processes of treatment.

Suzuki, Kazumichi; Gillin, Michael T.; Sahoo, Narayan; Zhu, X. Ronald; Lee, Andrew K.; Lippy, Denise [Departments of Radiation Physics and Radiation Oncology, University of Texas, MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); The Proton Therapy Center Houston, Ltd., L.L.P., 1840 Old Spanish Trail, Houston, Texas 77054 (United States)

2011-07-15

32

Recent Advances in Delivery of Drug-Nucleic Acid Combinations for Cancer Treatment  

PubMed Central

Cancer treatment that uses a combination of approaches with the ability to affect multiple disease pathways has been proven highly effective in the treatment of many cancers. Combination therapy can include multiple chemotherapeutics or combinations of chemotherapeutics with other treatment modalities like surgery or radiation. However, despite the widespread clinical use of combination therapies, relatively little attention has been given to the potential of modern nanocarrier delivery methods, like liposomes, micelles, and nanoparticles, to enhance the efficacy of combination treatments. This lack of knowledge is particularly notable in the limited success of vectors for the delivery of combinations of nucleic acids with traditional small molecule drugs. The delivery of drug-nucleic acid combinations is particularly challenging due to differences in the physicochemical properties of the two types of agents. This review discusses recent advances in the development of delivery methods using combinations of small molecule drugs and nucleic acid therapeutics to treat cancer. This review primarily focuses on the rationale used for selecting appropriate drug-nucleic acid combinations as well as progress in the development of nanocarriers suitable for simultaneous delivery of drug-nucleic acid combinations. PMID:23624358

Li, Jing; Wang, Yan; Zhu, Yu; Oupický, David

2013-01-01

33

Delivery  

PubMed Central

Enthusiasm greeted the development of synthetic organic insecticides in the mid-twentieth century, only to see this give way to dismay and eventually scepticism and outright opposition by some. Regardless of how anyone feels about this issue, insecticides and other pesticides have become indispensable, which creates something of a dilemma. Possibly as a result of the shift in public attitude towards insecticides, genetic engineering of microbes was first met with scepticism and caution among scientists. Later, the development of genetically modified crop plants was met with an attitude that hardened into both acceptance and hard-core resistance. Transgenic insects, which came along at the dawn of the twenty-first century, encountered an entrenched opposition. Those of us responsible for studying the protection of crops have been affected more or less by these protagonist and antagonistic positions, and the experiences have often left one thoughtfully mystified as decisions are made by non-participants. Most of the issues boil down to concerns over delivery mechanisms. © 2013 Society of Chemical Industry PMID:23852646

Miller, Thomas A

2013-01-01

34

CPR methodology with new steady-state criterion and more accurate statistical treatment of channel bow  

SciTech Connect

An overview is given of existing CPR design criteria and the methods used in BWR reload analysis to evaluate the impact of channel bow on CPR margins. Potential weaknesses in today's methodologies are discussed. Westinghouse in collaboration with KKL and Axpo - operator and owner of the Leibstadt NPP - has developed an optimized CPR methodology based on a new criterion to protect against dryout during normal operation and with a more rigorous treatment of channel bow. The new steady-state criterion is expressed in terms of an upper limit of 0.01 for the dryout failure probability per year. This is considered a meaningful and appropriate criterion that can be directly related to the probabilistic criteria set-up for the analyses of Anticipated Operation Occurrences (AOOs) and accidents. In the Monte Carlo approach a statistical modeling of channel bow and an accurate evaluation of CPR response functions allow the associated CPR penalties to be included directly in the plant SLMCPR and OLMCPR in a best-estimate manner. In this way, the treatment of channel bow is equivalent to all other uncertainties affecting CPR. Emphasis is put on quantifying the statistical distribution of channel bow throughout the core using measurement data. The optimized CPR methodology has been implemented in the Westinghouse Monte Carlo code, McSLAP. The methodology improves the quality of dryout safety assessments by supplying more valuable information and better control of conservatisms in establishing operational limits for CPR. The methodology is demonstrated with application examples from the introduction at KKL. (authors)

Baumgartner, S. [Axpo AG, Parkstrasse 23, CH-5401 Baden (Switzerland); Bieli, R. [Kernkraftwerk Leibstadt AG, CH-5325 Leibstadt (Switzerland); Bergmann, U. C. [Westinghouse Electric Sweden AB, SE-721 63 Vaesteraas (Sweden)

2012-07-01

35

A New Method for Accurate Treatment of Flow Equations in Cylindrical Coordinates Using Series Expansions  

NASA Technical Reports Server (NTRS)

The motivation of this work is the ongoing effort at the Center for Turbulence Research (CTR) to use large eddy simulation (LES) techniques to calculate the noise radiated by jet engines. The focus on engine exhaust noise reduction is motivated by the fact that a significant reduction has been achieved over the last decade on the other main sources of acoustic emissions of jet engines, such as the fan and turbomachinery noise, which gives increased priority to jet noise. To be able to propose methods to reduce the jet noise based on results of numerical simulations, one first has to be able to accurately predict the spatio-temporal distribution of the noise sources in the jet. Though a great deal of understanding of the fundamental turbulence mechanisms in high-speed jets was obtained from direct numerical simulations (DNS) at low Reynolds numbers, LES seems to be the only realistic available tool to obtain the necessary near-field information that is required to estimate the acoustic radiation of the turbulent compressible engine exhaust jets. The quality of jet-noise predictions is determined by the accuracy of the numerical method that has to capture the wide range of pressure fluctuations associated with the turbulence in the jet and with the resulting radiated noise, and by the boundary condition treatment and the quality of the mesh. Higher Reynolds numbers and coarser grids put in turn a higher burden on the robustness and accuracy of the numerical method used in this kind of jet LES simulations. As these calculations are often done in cylindrical coordinates, one of the most important requirements for the numerical method is to provide a flow solution that is not contaminated by numerical artifacts. The coordinate singularity is known to be a source of such artifacts. In the present work we use 6th order Pade schemes in the non-periodic directions to discretize the full compressible flow equations. It turns out that the quality of jet-noise predictions using these schemes is especially sensitive to the type of equation treatment at the singularity axis. The objective of this work is to develop a generally applicable numerical method for treating the singularities present at the polar axis, which is particularly suitable for highly accurate finite-differences schemes (e.g., Pade schemes) on non-staggered grids. The main idea is to reinterpret the regularity conditions developed in the context of pseudo-spectral methods. A set of exact equations at the singularity axis is derived using the appropriate series expansions for the variables in the original set of equations. The present treatment of the equations preserves the same level of accuracy as for the interior scheme. We also want to point out the wider utility of the method, proposed here in the context of compressible flow equations, as its extension for incompressible flows or for any other set of equations that are solved on a non-staggered mesh in cylindrical coordinates with finite-differences schemes of various level of accuracy is straightforward. The robustness and accuracy of the proposed technique is assessed by comparing results from simulations of laminar forced-jets and turbulent compressible jets using LES with similar calculations in which the equations are solved in Cartesian coordinates at the polar axis, or in which the singularity is removed by employing a staggered mesh in the radial direction without a mesh point at r = 0.

Constantinescu, G.S.; Lele, S. K.

2000-01-01

36

Ondansetron for treatment of intrathecal morphine-induced pruritus after cesarean delivery  

Microsoft Academic Search

Background and Objectives: Pruritus induced by intrathecal morphine is a concern in many obstetric patients after cesarean delivery and may detract from the benefit of postoperative pain relief. This study was performed to investigate the efficacy of ondansetron (5-HT3 receptor antagonist) in treatment of pruritus following intrathecal morphine. Methods: Eighty parturients developing moderate to severe pruritus following intrathecal morphine were

S. Charuluxananan; W. Somboonviboon; O. Kyokong; K. Nimcharoendee

2000-01-01

37

Combinatorial delivery of Crizotinib-Palbociclib-Sildenafil using TPGS-PLA micelles for improved cancer treatment.  

PubMed

The co-delivery of multiple chemotherapeutics by micellar delivery systems is a valuable approach to improve cancer treatment since various disease hallmarks can be targeted simultaneously. However, the delivery of multiple drugs requires a nanocarrier structure that can encapsulate various bioactive molecules. In this study, we evaluate the simultaneous encapsulation of a novel triple drug combination in D-?-tocopheryl polyethylene glycol 1000 succinate-poly(lactic acid) (TPGS-PLA) amphiphilic micelles for cancer therapy. The drug mixture involves two anti-tumoral drugs, Crizotinib and Palbociclib combined with Sildenafil, a compound that is capable of increasing drug accumulation in the intracellular compartment. Such combination aims to achieve an enhanced cytotoxic effect in cancer cells. Our results demonstrated that TPGS-PLA copolymers self-assembled into stable nanosized micelles (158.3nm) capable of co-encapsulating the three drugs with high loading efficiency. Triple drug loaded TPGS-PLA micelles were internalized in A549 non-small lung cancer cells and exhibited an improved cytotoxic effect in comparison with single (Crizotinib) or dual (Crizotinib-Palbociclib) drug loaded micelles, indicating the therapeutic potential of the triple co-delivery strategy. These findings demonstrate that TPGS-PLA micelles are suitable carriers for multiple drug delivery and also that this particular drug combination may have potential to improve cancer treatment. PMID:25308930

de Melo-Diogo, Duarte; Gaspar, Vítor M; Costa, Elisabete C; Moreira, André F; Oppolzer, David; Gallardo, Eugénia; Correia, Ilídio J

2014-11-01

38

Skin Delivery of Kojic Acid-Loaded Nanotechnology-Based Drug Delivery Systems for the Treatment of Skin Aging  

PubMed Central

The aging process causes a number of changes in the skin, including oxidative stress and dyschromia. The kojic acid (KA) is iron chelator employed in treatment of skin aging, and inhibits tyrosinase, promotes depigmentation. Nanotechnology-based drug delivery systems, such as liquid crystalline systems (LCSs), can modulate drug permeation through the skin and improve the drug activity. This study is aimed at structurally developing and characterizing a kojic acid-loaded LCS, consists of water (W), cetostearyl isononanoate (oil—O) and PPG-5-CETETH-20 (surfactant-S) and evaluating its in vitro skin permeation and retention. Three regions of the diagram were selected for characterization: A (35% O, 50% S, 15% W), B (30% O, 50% S, 20% W) and C (20% O, 50% S, 30% W), to which 2% KA was added. The formulations were subjected to polarized light microscopy, which indicated the presence of a hexagonal mesophase. Texture and bioadhesion assay showed that formulation B is suitable for topical application. According to the results from the in vitro permeation and retention of KA, the formulations developed can modulate the permeation of KA in the skin. The in vitro cytotoxic assays showed that KA-unloaded LCS and KA-loaded LCS didn't present cytotoxicity. PPG-5-CETETH-20-based systems may be a promising platform for KA skin delivery. PMID:24369010

Gonçalez, M. L.; Corrêa, M. A.; Chorilli, M.

2013-01-01

39

Volumetric-modulated arc therapy with RapidArc®: An evaluation of treatment delivery efficiency  

PubMed Central

Aim/background To evaluate how the use of volumetric-modulated arc therapy (VMAT) with RapidArc® can improve treatment delivery efficiency based on the analysis of the beam-on times and monitor units (MU) needed to deliver therapy for multiple clinical applications in a large patient population. Materials and methods A total of 898 treatment courses were delivered in 745 patients treated from October 2008 to March 2013 using RapidArc® treatment plans generated in Eclipse™ TPS. All patients were treated with curative or palliative intent using different techniques including conventional fractionation (83%) and radiosurgery or SBRT (17%), depending on the clinical indications. Treatment delivery was evaluated based on measured beam-on time and recorded MU values delivered on a Varian Trilogy™ linear accelerator. Results For conventional fractionation treatments using RapidArc®, the delivery times ranged from 38 s to 4 min and 40 s (average 2 min and 6 s). For radiosurgical treatments the delivery times ranged from 1 min and 42 s to 9 min and 22 s (average 4 min and 4 s). The average number of MU per Gy was 301 for the entire group, with 285 for the conventional group and 317 for the radiosurgical group. Conclusions In this study with a large heterogeneous population, treatments using RapidArc® were delivered with substantially less beam-on time and fewer MUs than conventional fractionation. This was highly advantageous, increasing flexibility of the scheduling allowing treatment of radiosurgery patients during the regular daily work schedule. Additionally, reduction of leakage radiation dose was achieved. PMID:24416583

Amendola, Beatriz E.; Amendola, Marco; Perez, Naipy; Iglesias, Alejandro; Wu, Xiaodong

2013-01-01

40

Simultaneous double clipping delivery guide strategy for treatment of severe coaptation failure in functional mitral regurgitation.  

PubMed

We report on a novel treatment strategy using two clip delivery systems (CDS) simultaneously, after double transseptal puncture, for treatment of severe functional mitral regurgitation. Both CDS were used to titrate for an optimal result in a patient with a severe coaptation gap of both mitral leaflets. The patient was successfully treated with two MitraClips. Thus, even a contraindication for MitraClip can be overcome with a more complex double guide intervention. PMID:25308769

Schaefer, Ulrich; Frerker, Christian; Kreidel, Felix

2015-01-01

41

Social Workers and Delivery of Evidence-Based Psychosocial Treatments for Substance Use Disorders  

PubMed Central

Social workers encounter individuals with substance use disorders (SUDs) in a variety of settings. With changes in health care policy and a movement toward integration of health and behavioral health services, social workers will play an increased role vis-a-vis SUD. As direct service providers, administrators, care managers and policy makers, they will select, deliver, or advocate for delivery of evidence-based SUD treatment practices. This paper provides an overview of effective psychosocial SUD treatment approaches. In addition to describing the treatments, the article discusses empirical support, populations for whom the treatments are known to be efficacious, and implementation issues. PMID:23731420

WELLS, ELIZABETH A.; KRISTMAN-VALENTE, ALLISON N.; PEAVY, K. MICHELLE; JACKSON, T. RON

2013-01-01

42

Treatment of intermediate stage hepatocellular carcinoma: a review of intrahepatic doxorubicin drug-delivery systems.  

PubMed

The biopharmaceutical properties of doxorubicin delivered via two drug-delivery systems (DDSs) for the palliative treatment of unresectable hepatocellular carcinoma were reviewed with relation to the associated liver and tumor (patho)physiology. These two DDSs, doxorubicin emulsified with Lipiodol(®) and doxorubicin loaded into DC Bead(®) are different regarding tumor delivery, release rate, local bioavailability, if and how they can be given repeatedly, biodegradability, length of embolization and safety profile. There have been few direct head-to-head comparisons of these DDSs, and in-depth investigations into their in vitro and in vivo performance is warranted. PMID:24856170

Dubbelboer, Ilse R; Lilienberg, Elsa; Ahnfelt, Emelie; Sjögren, Erik; Axén, Niklas; Lennernäs, Hans

2014-04-01

43

Improved delivery of magnetic nanoparticles with chemotherapy cancer treatment  

NASA Astrophysics Data System (ADS)

Most nanoparticle-based cancer therapeutic strategies seek to develop an effective individual cancer cell or metastatic tumor treatment. Critical to the success of these therapies is to direct as much of the agent as possible to the targeted tissue while avoiding unacceptable normal tissue complications. In this light, three different cisplatinum/magnetic nanoparticle (mNP) administration regimens were investigated. The most important finding suggests that clinically relevant doses of cisplatinum result in a significant increase in the tumor uptake of systemically delivered mNP. This enhancement of mNP tumor uptake creates the potential for an even greater therapeutic ratio through the addition of mNP based, intracellular hyperthermia.

Petryk, Alicia A.; Giustini, Andrew J.; Gottesman, Rachel E.; Hoopes, P. Jack

2013-02-01

44

Predisposing factors for bacterial vaginosis, treatment efficacy and pregnancy outcome among term deliveries; results from a preterm delivery study  

PubMed Central

Background Bacterial vaginosis (BV) during pregnancy is associated with an increased risk of preterm delivery but little is known about factors that could predict BV. We have analyzed if it is possible to identify a category of pregnant women that should be screened for BV, and if BV would alter the pregnancy outcome at term; we have also studied the treatment efficacy of clindamycin. Methods Prospective BV screening and treatment study of 9025 women in a geographically defined region in southeast Sweden. BV was defined as a modified Nugent score of 6 and above. Data was collected from the Swedish Medical Birth Register. Women allocated to treatment were supplied with vaginal clindamycin cream. The main outcome goals were to identify factors that could predict BV. Results Vaginal smears were consistent with BV criteria in 9.3%. Logistic regression indicates a significant correlation between smoking and BV (p < 0.001) and a greater prevalence of BV in the lower age groups (p < 0.001). We found no correlation between BV and history of preterm deliveries, previous miscarriages, extra-uterine pregnancies, infertility problems or reported history of urinary tract infections–factors that earlier have been associated with BV. Treatment with clindamycin cream showed a cure rate of 77%. Less than 1% of women with a normal vaginal smear in early pregnancy will develop BV during the pregnancy. There was no association between BV and the obstetric outcome among women who delivered at term. Women with BV, both treated patients and nontreated, had the same obstetric outcome at term as women with normal vaginal flora. Conclusion BV is more than twice as common among smokers, and there is a higher prevalence in the younger age group. However these two markers for BV do not suffice as a tool for screening, and considering the lack of other risk factors associated with BV, screening of all pregnant women might be a strategy to follow in a program intended to reduce the number of preterm births. PMID:17953762

Larsson, P-G; Fåhraeus, Lars; Carlsson, Bodil; Jakobsson, Tell; Forsum, Urban

2007-01-01

45

Large-scale extraction of accurate drug-disease treatment pairs from biomedical literature for drug repurposing  

PubMed Central

Background A large-scale, highly accurate, machine-understandable drug-disease treatment relationship knowledge base is important for computational approaches to drug repurposing. The large body of published biomedical research articles and clinical case reports available on MEDLINE is a rich source of FDA-approved drug-disease indication as well as drug-repurposing knowledge that is crucial for applying FDA-approved drugs for new diseases. However, much of this information is buried in free text and not captured in any existing databases. The goal of this study is to extract a large number of accurate drug-disease treatment pairs from published literature. Results In this study, we developed a simple but highly accurate pattern-learning approach to extract treatment-specific drug-disease pairs from 20 million biomedical abstracts available on MEDLINE. We extracted a total of 34,305 unique drug-disease treatment pairs, the majority of which are not included in existing structured databases. Our algorithm achieved a precision of 0.904 and a recall of 0.131 in extracting all pairs, and a precision of 0.904 and a recall of 0.842 in extracting frequent pairs. In addition, we have shown that the extracted pairs strongly correlate with both drug target genes and therapeutic classes, therefore may have high potential in drug discovery. Conclusions We demonstrated that our simple pattern-learning relationship extraction algorithm is able to accurately extract many drug-disease pairs from the free text of biomedical literature that are not captured in structured databases. The large-scale, accurate, machine-understandable drug-disease treatment knowledge base that is resultant of our study, in combination with pairs from structured databases, will have high potential in computational drug repurposing tasks. PMID:23742147

2013-01-01

46

A computational model of drug delivery through microcirculation to compare different tumor treatments.  

PubMed

Starting from the fundamental laws of filtration and transport in biological tissues, we develop a computational model to capture the interplay between blood perfusion, fluid exchange with the interstitial volume, mass transport in the capillary bed, through the capillary walls and into the surrounding tissue. These phenomena are accounted at the microscale level, where capillaries and interstitial volume are viewed as two separate regions. The capillaries are described as a network of vessels carrying blood flow. We apply the model to study drug delivery to tumors. The model can be adapted to compare various treatment options. In particular, we consider delivery using drug bolus injection and nanoparticle injection into the blood stream. The computational approach is suitable for a systematic quantification of the treatment performance, enabling the analysis of interstitial drug concentration levels, metabolization rates and cell surviving fractions. Our study suggests that for the treatment based on bolus injection, the drug dose is not optimally delivered to the tumor interstitial volume. Using nanoparticles as intermediate drug carriers overrides the shortcomings of the previous delivery approach. This work shows that the proposed theoretical and computational framework represents a promising tool to compare the efficacy of different cancer treatments. PMID:25044965

Cattaneo, L; Zunino, P

2014-11-01

47

Current treatment options and drug delivery systems as potential therapeutic agents for ovarian cancer: a review.  

PubMed

Ovarian cancer is one of the most common and deadliest gynecologic cancer with about 75% of the patients presenting in advanced stages. The introduction of intraperitoneal chemotherapy in 2006 had led to a 16 month improvement in the overall survival. However, catheter-related complication and the complexity of the procedure had deterred intraperitoneal route as the preferred route of treatment. Other alternative treatments had been developed by incorporating other FDA-approved agents or procedures such as pegylated liposomal doxorubicin (PLD), hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) and the administration of bevacizumab. Various clinical trials were conducted on these alternatives as both the first-line treatment and second- or third-line therapy for the recurrent disease. The outcome of these studies were summarized and discussed. A prospective improvement in the treatment of ovarian cancer could be done through the use of a drug delivery system. Selected promising recent developments in ovarian cancer drug delivery systems using different delivery vehicles, surface modifications, materials and drugs were also reviewed. PMID:25491871

Ye, Hongye; Karim, Anis Abdul; Loh, Xian Jun

2014-12-01

48

Anti-vascular endothelial growth factor treatment normalizes tuberculosis granuloma vasculature and improves small molecule delivery  

PubMed Central

Tuberculosis (TB) causes almost 2 million deaths annually, and an increasing number of patients are resistant to existing therapies. Patients who have TB require lengthy chemotherapy, possibly because of poor penetration of antibiotics into granulomas where the bacilli reside. Granulomas are morphologically similar to solid cancerous tumors in that they contain hypoxic microenvironments and can be highly fibrotic. Here, we show that TB-infected rabbits have impaired small molecule distribution into these disease sites due to a functionally abnormal vasculature, with a low-molecular-weight tracer accumulating only in peripheral regions of granulomatous lesions. Granuloma-associated vessels are morphologically and spatially heterogeneous, with poor vessel pericyte coverage in both human and experimental rabbit TB granulomas. Moreover, we found enhanced VEGF expression in both species. In tumors, antiangiogenic, specifically anti-VEGF, treatments can “normalize” their vasculature, reducing hypoxia and creating a window of opportunity for concurrent chemotherapy; thus, we investigated vessel normalization in rabbit TB granulomas. Treatment of TB-infected rabbits with the anti-VEGF antibody bevacizumab significantly decreased the total number of vessels while normalizing those vessels that remained. As a result, hypoxic fractions of these granulomas were reduced and small molecule tracer delivery was increased. These findings demonstrate that bevacizumab treatment promotes vascular normalization, improves small molecule delivery, and decreases hypoxia in TB granulomas, thereby providing a potential avenue to improve delivery and efficacy of current treatment regimens. PMID:25624495

Datta, Meenal; Via, Laura E.; Kamoun, Walid S.; Liu, Chong; Chen, Wei; Seano, Giorgio; Weiner, Danielle M.; Schimel, Daniel; England, Kathleen; Gao, Xing; Xu, Lei; Barry, Clifton E.; Jain, Rakesh K.

2015-01-01

49

Treatment planning, optimization, and beam delivery technqiues for intensity modulated proton therapy  

NASA Astrophysics Data System (ADS)

Physical properties of proton interactions in matter give them a theoretical advantage over photons in radiation therapy for cancer treatment, but they are seldom used relative to photons. The primary barriers to wider acceptance of proton therapy are the technical feasibility, size, and price of proton therapy systems. Several aspects of the proton therapy landscape are investigated, and new techniques for treatment planning, optimization, and beam delivery are presented. The results of these investigations suggest a means by which proton therapy can be delivered more efficiently, effectively, and to a much larger proportion of eligible patients. An analysis of the existing proton therapy market was performed. Personal interviews with over 30 radiation oncology leaders were conducted with regard to the current and future use of proton therapy. In addition, global proton therapy market projections are presented. The results of these investigations serve as motivation and guidance for the subsequent development of treatment system designs and treatment planning, optimization, and beam delivery methods. A major factor impacting the size and cost of proton treatment systems is the maximum energy of the accelerator. Historically, 250 MeV has been the accepted value, but there is minimal quantitative evidence in the literature that supports this standard. A retrospective study of 100 patients is presented that quantifies the maximum proton kinetic energy requirements for cancer treatment, and the impact of those results with regard to treatment system size, cost, and neutron production is discussed. This study is subsequently expanded to include 100 cranial stereotactic radiosurgery (SRS) patients, and the results are discussed in the context of a proposed dedicated proton SRS treatment system. Finally, novel proton therapy optimization and delivery techniques are presented. Algorithms are developed that optimize treatment plans over beam angle, spot size, spot spacing, beamlet weight, the number of delivered beamlets, and the number of delivery angles. These methods are evaluated via treatment planning studies including left-sided whole breast irradiation, lung stereotactic body radiotherapy, nasopharyngeal carcinoma, and whole brain radiotherapy with hippocampal avoidance. Improvements in efficiency and efficacy relative to traditional proton therapy and intensity modulated photon radiation therapy are discussed.

Sengbusch, Evan R.

50

Nanotechnology-based drug delivery systems for treatment of oral cancer: a review  

PubMed Central

Oral cancer (oral cavity and oropharynx) is a common and aggressive cancer that invades local tissue, can cause metastasis, and has a high mortality rate. Conventional treatment strategies, such as surgery and chemoradiotherapy, have improved over the past few decades; however, they remain far from optimal. Currently, cancer research is focused on improving cancer diagnosis and treatment methods (oral cavity and oropharynx) nanotechnology, which involves the design, characterization, production, and application of nanoscale drug delivery systems. In medicine, nanotechnologies, such as polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, gold nanoparticles, hydrogels, cyclodextrin complexes, and liquid crystals, are promising tools for diagnostic probes and therapeutic devices. The objective of this study is to present a systematic review of nanotechnology-based drug delivery systems for oral cancers. PMID:25143724

Calixto, Giovana; Bernegossi, Jéssica; Fonseca-Santos, Bruno; Chorilli, Marlus

2014-01-01

51

Chitosan and glyceryl monooleate nanostructures containing gemcitabine: potential delivery system for pancreatic cancer treatment.  

PubMed

The objectives of this study are to enhance cellular accumulation of gemcitabine with chitosan/glyceryl monooleate (GMO) nanostructures, and to provide significant increase in cell death of human pancreatic cancer cells in vitro. The delivery system was prepared by a multiple emulsion solvent evaporation method. The nanostructure topography, size, and surface charge were determined by atomic force microscopy (AFM), and a zetameter. The cellular accumulation, cellular internalization and cytotoxicity of the nanostructures were evaluated by HPLC, confocal microscopy, or MTT assay in Mia PaCa-2 and BxPC-3 cells. The average particle diameter for 2% and 4% (w/w) drug loaded delivery system were 382.3 +/- 28.6 nm, and 385.2 +/- 16.1 nm, respectively with a surface charge of +21.94 +/- 4.37 and +21.23 +/- 1.46 mV. The MTT cytotoxicity dose-response studies revealed the placebo at/or below 1 mg/ml has no effect on MIA PaCa-2 or BxPC-3 cells. The delivery system demonstrated a significant decrease in the IC50 (3 to 4 log unit shift) in cell survival for gemcitabine nanostructures at 72 and 96 h post-treatment when compared with a solution of gemcitabine alone. The nanostructure reported here can be resuspended in an aqueous medium that demonstrate increased effective treatment compared with gemcitabine treatment alone in an in vitro model of human pancreatic cancer. The drug delivery system demonstrates capability to entrap both hydrophilic and hydrophobic compounds to potentially provide an effective treatment option in human pancreatic cancer. PMID:20238190

Trickler, William J; Khurana, Jatin; Nagvekar, Ankita A; Dash, Alekha K

2010-03-01

52

PR_b-targeted delivery of tumor necrosis factor-a by polymersomes for the treatment of prostate cancer  

E-print Network

PR_b-targeted delivery of tumor necrosis factor-a by polymersomes for the treatment of prostate. In this study we design and assess peptide functionalized polymer vesicles, or polymersomes, self assembled from of these PR_b-targeted polymersomes show great promise for the targeted delivery of therapeutics. Introduction

Kokkoli, Efie

53

A Bayesian approach to real-time 3D tumor localization via monoscopic x-ray imaging during treatment delivery  

SciTech Connect

Purpose: Monoscopic x-ray imaging with on-board kV devices is an attractive approach for real-time image guidance in modern radiation therapy such as VMAT or IMRT, but it falls short in providing reliable information along the direction of imaging x-ray. By effectively taking consideration of projection data at prior times and/or angles through a Bayesian formalism, the authors develop an algorithm for real-time and full 3D tumor localization with a single x-ray imager during treatment delivery. Methods: First, a prior probability density function is constructed using the 2D tumor locations on the projection images acquired during patient setup. Whenever an x-ray image is acquired during the treatment delivery, the corresponding 2D tumor location on the imager is used to update the likelihood function. The unresolved third dimension is obtained by maximizing the posterior probability distribution. The algorithm can also be used in a retrospective fashion when all the projection images during the treatment delivery are used for 3D localization purposes. The algorithm does not involve complex optimization of any model parameter and therefore can be used in a ''plug-and-play'' fashion. The authors validated the algorithm using (1) simulated 3D linear and elliptic motion and (2) 3D tumor motion trajectories of a lung and a pancreas patient reproduced by a physical phantom. Continuous kV images were acquired over a full gantry rotation with the Varian TrueBeam on-board imaging system. Three scenarios were considered: fluoroscopic setup, cone beam CT setup, and retrospective analysis. Results: For the simulation study, the RMS 3D localization error is 1.2 and 2.4 mm for the linear and elliptic motions, respectively. For the phantom experiments, the 3D localization error is < 1 mm on average and < 1.5 mm at 95th percentile in the lung and pancreas cases for all three scenarios. The difference in 3D localization error for different scenarios is small and is not statistically significant. Conclusions: The proposed algorithm eliminates the need for any population based model parameters in monoscopic image guided radiotherapy and allows accurate and real-time 3D tumor localization on current standard LINACs with a single x-ray imager.

Li, Ruijiang; Fahimian, Benjamin P.; Xing, Lei [Department of Radiation Oncology, Stanford University School of Medicine, 875 Blake Wilbur Drive, Stanford, California 94305-5847 (United States)

2011-07-15

54

Investigating end-to-end accuracy of image guided radiation treatment delivery using a micro-irradiator  

NASA Astrophysics Data System (ADS)

There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumour control and normal tissue damage. For these studies it is vital that image guidance systems and target positioning are accurately aligned (IGRT), in order to deliver dose precisely and accurately according to the treatment plan. In this work we investigate the IGRT targeting accuracy of the X-RAD 225 Cx system from Precision X-Ray using high-resolution 3D dosimetry techniques. Small cylindrical PRESAGE® dosimeters were used with optical-CT readout (DMOS) to verify the accuracy of 2.5, 1.0, and 5.0 mm X-RAD cone attachments. The dosimeters were equipped with four target points, visible on both CBCT and optical-CT, at which a 7-field coplanar treatment plan was delivered with the respective cone. Targeting accuracy (distance to agreement between the target point and delivery isocenter) and cone alignment (isocenter precision under gantry rotation) were measured using the optical-CT images. Optical-CT readout of the first 2.5 mm cone dosimeter revealed a significant targeting error of 2.1 ± 0.6 mm and a cone misalignment of 1.3 ± 0.1 mm. After the IGRT hardware and software had been recalibrated, these errors were reduced to 0.5 ± 0.1 and 0.18 ± 0.04 mm respectively, within the manufacturer specified 0.5 mm. Results from the 1.0 mm cone were 0.5 ± 0.3 mm targeting accuracy and 0.4 ± 0.1 mm cone misalignment, within the 0.5 mm specification. The results from the 5.0 mm cone were 1.0 ± 0.2 mm targeting accuracy and 0.18 ± 0.06 mm cone misalignment, outside of accuracy specifications. Quality assurance of small field IGRT targeting and delivery accuracy is a challenging task. The use of a 3D dosimetry technique, where targets are visible on both CBCT and optical-CT, enabled identification and quantification of a targeting error in 3D. After correction, the targeting accuracy of the irradiator was verified to be within 0.5 mm (or 1.0 mm for the 5.0 mm cone) and the cone alignment was verified to be within 0.2 mm (or 0.4 mm for the 1.0 mm cone). The PRESAGE®/DMOS system proved valuable for end-to-end verification of small field IGRT capabilities.

Rankine, L. J.; Newton, J.; Bache, S. T.; Das, S. K.; Adamovics, J.; Kirsch, D. G.; Oldham, M.

2013-11-01

55

Investigating end-to-end accuracy of image guided radiation treatment delivery using a micro-irradiator  

PubMed Central

Purpose There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumour control and normal tissue damage. For these studies it is vital that image guidance systems and target positioning are accurately aligned (IGRT), in order to deliver dose precisely and accurately according to the treatment plan. In this work we investigate the IGRT targeting accuracy of the X-RAD 225 Cx system from Precision X-Ray using high resolution 3D dosimetry techniques. Method Small cylindrical PRESAGE™ dosimeters were used with optical-CT readout (DMOS) to verify the accuracy of 2.5, 1.0, and 5.0 mm X-RAD cone attachments. The dosimeters were equipped with four target points, visible on both CBCT and optical-CT, at which a 7-field coplanar treatment plan was delivered with the respective cone. Targeting accuracy (distance to agreement between imaging positioning and therapeutic delivery) and cone alignment (isocenter precision under gantry rotation) were measured using the optical-CT images. Results Optical-CT readout of the first 2.5 mm cone dosimeter revealed a significant targeting error of 2.1±0.6 mm and a cone misalignment of 1.3±0.1 mm. After the IGRT hardware and software had been recalibrated, these errors were reduced to 0.5±0.1 mm and 0.18±0.04 mm respectively, within the manufacturer specified 0.5 mm. Results from the 1.0 mm cone were 0.5±0.3 mm targeting accuracy and 0.4±0.1 mm cone misalignment, within the 0.5 mm specification. The results from the 5.0 mm cone were 1.0±0.2 mm targeting accuracy and 0.18±0.06 mm cone misalignment, outside of accuracy specifications. Conclusion Quality assurance of small field IGRT targeting and delivery accuracy is a challenging task. The use of a 3D dosimetry technique, where targets are visible on both CBCT and optical-CT, enabled identification and quantification of a targeting error in 3D. After correction, the targeting accuracy of the irradiator was verified to be within 0.5 mm (or 1.0 mm for the 5.0 mm cone) and the cone alignment was verified to be within 0.2 mm (or 0.4 mm for the 1.0 mm cone). The PRESAGE™/DMOS system proved valuable for end-to-end verification of small field IGRT capabilities. PMID:24140983

Rankine, L J; Newton, J; Bache, S T; Das, S K; Adamovics, J; Kirsch, D G; Oldham, M

2013-01-01

56

Current nanotechnological strategies for an effective delivery of drugs in treatment of periodontal disease.  

PubMed

Periodontal disease is a localized inflammatory disorder, with tissue destruction resulting from the host response to bacterial antigens and irritants. Several other risk factors, such as smoking, hormonal changes, diabetes, drugs, disease, and genetic factors, play an important role in the progression of periodontal disease. This disease results in the formation of periodontal pockets or deepened crevices between the gingival and tooth root that produce occasional pain and discomfort, impaired mastication, and irreversible tooth loss. The primary rationale for controlled, sustained, and targeted drug delivery is necessary to achieve better therapeutic outcomes or patient compliance against periodontal disease and its various stages. Both systemic (liposomes, microspheres, nanoparticles, hydrogels) and local (fibers, patches, films, gels) antibiotic/antimicrobial approaches have their important place in periodontal therapy. The overall goal of this article is to provide the clinician with information related to the pathogenesis, risk, polymer used for drug delivery, and current nanotechnological systems for an effective treatment of periodontal disease. PMID:24940625

Goyal, Gagan; Garg, Tarun; Rath, Goutam; Goyal, Amit Kumar

2014-01-01

57

Transdermal delivery of naltrexol and skin permeability lifetime after microneedle treatment in hairless guinea pigs  

PubMed Central

Controlled-release delivery of 6-?-naltrexol (NTXOL), the major active metabolite of naltrexone, via a transdermal patch is desirable for treatment of alcoholism. Unfortunately, NTXOL does not diffuse across skin at a therapeutic rate. Therefore, the focus of this study was to evaluate microneedle (MN) skin permeation enhancement of NTXOL's hydrochloride salt in hairless guinea pigs. Specifically, these studies were designed to determine the lifetime of MN-created aqueous pore pathways. Microneedle pore lifetime was estimated by pharmacokinetic evaluation, transepidermal water loss (TEWL) and visualization of MN-treated skin pore diameters using light microscopy. A 3.6 fold enhancement in steady state plasma concentration was observed in vivo with MN treated skin with NTXOL·HCl, as compared to NTXOL base. TEWL measurements and microscopic evaluation of stained MN-treated guinea pig skin indicated the presence of pores, suggesting a feasible non-lipid bilayer pathway for enhanced transdermal delivery. Overall, MN-assisted transdermal delivery appears viable for at least 48 h after MN-application. PMID:20166200

Banks, Stan L.; Pinninti, Raghotham R.; Gill, Harvinder S.; Paudel, Kalpana S.; Crooks, Peter A.; Brogden, Nicole K.; Prausnitz, Mark R.; Stinchcomb, Audra L.

2010-01-01

58

Investigation of pulsed IMRT and VMAT for re-irradiation treatments: dosimetric and delivery feasibilities.  

PubMed

Many tumor cells demonstrate hyperradiosensitivity at doses below ~50 cGy. Together with the increased normal tissue repair under low dose rate, the pulsed low dose rate radiotherapy (PLDR), which separates a daily fractional dose of 200 cGy into 10 pulses with 3 min interval between pulses (~20 cGy/pulse and effective dose rate 6.7 cGy min?1), potentially reduces late normal tissue toxicity while still providing significant tumor control for re-irradiation treatments. This work investigates the dosimetric and technical feasibilities of intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT)-based PLDR treatments using Varian Linacs. Twenty one cases (12 real re-irradiation cases) including treatment sites of pancreas, prostate, pelvis, lung, head-and-neck, and breast were recruited for this study. The lowest machine operation dose rate (100 MU min?1) was employed in the plan delivery. Ten-field step-and-shoot IMRT and dual-arc VMAT plans were generated using the Eclipse TPS with routine planning strategies. The dual-arc plans were delivered five times to achieve a 200 cGy daily dose (~20 cGy arc?1). The resulting plan quality was evaluated according to the heterogeneity and conformity indexes (HI and CI) of the planning target volume (PTV). The dosimetric feasibility of retaining the hyperradiosensitivity for PLDR was assessed based on the minimum and maximum dose in the target volume from each pulse. The delivery accuracy of VMAT and IMRT at the 100 MU min?1 machine operation dose rate was verified using a 2D diode array and ion chamber measurements. The delivery reproducibility was further investigated by analyzing the Dynalog files of repeated deliveries. A comparable plan quality was achieved by the IMRT (CI 1.10–1.38; HI 1.04–1.10) and the VMAT (CI 1.08–1.26; HI 1.05–1.10) techniques. The minimum/maximum PTV dose per pulse is 7.9 ± 5.1 cGy/33.7 ± 6.9 cGy for the IMRT and 12.3 ± 4.1 cGy/29.2 ± 4.7 cGy for the VMAT. Six out of the 186 IMRT pulses (fields) were found to exceed 50 cGy maximum PTV dose per pulse while the maximum PTV dose per pulse was within 40 cGy for all the VMAT pulses (arcs). However, for VMAT plans, the dosimetric quality of the entire treatment plan was less superior for the breast cases and large irregular targets. The gamma passing rates for both techniques at the 100 MU min?1 dose rate were at least 94.1% (3%/3 mm) and the point dose measurements agreed with the planned values to within 2.2%. The average root mean square error of the leaf position was 0.93 ± 0.83 mm for IMRT and 0.53 ± 0.48 mm for VMAT based on the Dynalog file analysis. The RMS error of the leaf position was nearly identical for the repeated deliveries of the same plans. In general, both techniques are feasible for PLDR treatments. VMAT was more advantageous for PLDR with more uniform target dose per pulse, especially for centrally located tumors. However, for large, irregular and/or peripheral tumors, IMRT could produce more favorable PLDR plans. By taking the biological benefit of PLDR delivery and the dosimetric benefit of IMRT and VMAT, the proposed methods have a great potential for those previously-irradiated recurrent patients. PMID:24200917

Lin, Mu-Han; Price, Robert A; Li, Jinsheng; Kang, Shengwei; Li, Jie; Ma, C-M

2013-11-21

59

Investigation of pulsed IMRT and VMAT for re-irradiation treatments: dosimetric and delivery feasibilities  

NASA Astrophysics Data System (ADS)

Many tumor cells demonstrate hyperradiosensitivity at doses below ˜50 cGy. Together with the increased normal tissue repair under low dose rate, the pulsed low dose rate radiotherapy (PLDR), which separates a daily fractional dose of 200 cGy into 10 pulses with 3 min interval between pulses (˜20 cGy/pulse and effective dose rate 6.7 cGy min-1), potentially reduces late normal tissue toxicity while still providing significant tumor control for re-irradiation treatments. This work investigates the dosimetric and technical feasibilities of intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT)-based PLDR treatments using Varian Linacs. Twenty one cases (12 real re-irradiation cases) including treatment sites of pancreas, prostate, pelvis, lung, head-and-neck, and breast were recruited for this study. The lowest machine operation dose rate (100 MU min-1) was employed in the plan delivery. Ten-field step-and-shoot IMRT and dual-arc VMAT plans were generated using the Eclipse TPS with routine planning strategies. The dual-arc plans were delivered five times to achieve a 200 cGy daily dose (˜20 cGy arc-1). The resulting plan quality was evaluated according to the heterogeneity and conformity indexes (HI and CI) of the planning target volume (PTV). The dosimetric feasibility of retaining the hyperradiosensitivity for PLDR was assessed based on the minimum and maximum dose in the target volume from each pulse. The delivery accuracy of VMAT and IMRT at the 100 MU min-1 machine operation dose rate was verified using a 2D diode array and ion chamber measurements. The delivery reproducibility was further investigated by analyzing the Dynalog files of repeated deliveries. A comparable plan quality was achieved by the IMRT (CI 1.10-1.38 HI 1.04-1.10) and the VMAT (CI 1.08-1.26 HI 1.05-1.10) techniques. The minimum/maximum PTV dose per pulse is 7.9 ± 5.1 cGy/33.7 ± 6.9 cGy for the IMRT and 12.3 ± 4.1 cGy/29.2 ± 4.7 cGy for the VMAT. Six out of the 186 IMRT pulses (fields) were found to exceed 50 cGy maximum PTV dose per pulse while the maximum PTV dose per pulse was within 40 cGy for all the VMAT pulses (arcs). However, for VMAT plans, the dosimetric quality of the entire treatment plan was less superior for the breast cases and large irregular targets. The gamma passing rates for both techniques at the 100 MU min-1 dose rate were at least 94.1% (3%/3 mm) and the point dose measurements agreed with the planned values to within 2.2%. The average root mean square error of the leaf position was 0.93 ± 0.83 mm for IMRT and 0.53 ± 0.48 mm for VMAT based on the Dynalog file analysis. The RMS error of the leaf position was nearly identical for the repeated deliveries of the same plans. In general, both techniques are feasible for PLDR treatments. VMAT was more advantageous for PLDR with more uniform target dose per pulse, especially for centrally located tumors. However, for large, irregular and/or peripheral tumors, IMRT could produce more favorable PLDR plans. By taking the biological benefit of PLDR delivery and the dosimetric benefit of IMRT and VMAT, the proposed methods have a great potential for those previously-irradiated recurrent patients.

Lin, Mu-Han; Price, Robert A., Jr.; Li, Jinsheng; Kang, Shengwei; Li, Jie; Ma, C.-M.

2013-11-01

60

Transrectal high-intensity focused ultrasound ablation of prostate cancer: effective treatment requiring accurate imaging.  

PubMed

Transrectal HIFU ablation has become a reasonable option for the treatment of localized prostate cancer in non-surgical patients, with 5-year disease-free survival similar to that of radiation therapy. It is also a promising salvage therapy of local recurrence after radiation therapy. These favourable results are partly due to recent improvements in prostate cancer imaging. However, further improvements are needed in patient selection, pre-operative localization of the tumor foci, assessment of the volume treated and early detection of recurrence. A better knowledge of the factors influencing the HIFU-induced tissue destruction and a better pre-operative assessment of them by imaging techniques should improve treatment outcome. Whereas prostate HIFU ablation is currently performed under transrectal ultrasound guidance, MR guidance with real-time operative monitoring of temperature will be available in the near future. If this technique will give better targeting and more uniform tissue destruction, its cost-effectiveness will have to be carefully evaluated. Finally, a recently reported synergistic effect between HIFU ablation and chemotherapy opens possibilities for treatment in high-risk or clinically advanced tumors. PMID:17689218

Rouvière, Olivier; Souchon, Rémi; Salomir, Rarès; Gelet, Albert; Chapelon, Jean-Yves; Lyonnet, Denis

2007-09-01

61

Cell mediated therapeutics for cancer treatment: Tumor homing cells as therapeutic delivery vehicles  

NASA Astrophysics Data System (ADS)

Many cell types were known to have migratory properties towards tumors and different research groups have shown reliable results regarding cells as delivery vehicles of therapeutics for targeted cancer treatment. Present report discusses proof of concept for 1. Cell mediated delivery of Magnetic nanoparticles (MNPs) and targeted Magnetic hyperthermia (MHT) as a cancer treatment by using in vivo mouse cancer models, 2. Cells surface engineering with chimeric proteins for targeted cancer treatment by using in vitro models. 1. Tumor homing cells can carry MNPs specifically to the tumor site and tumor burden will decrease after alternating magnetic field (AMF) exposure. To test this hypothesis, first we loaded Fe/Fe3O4 bi-magnetic NPs into neural progenitor cells (NPCs), which were previously shown to migrate towards melanoma tumors. We observed that NPCs loaded with MNPs travel to subcutaneous melanoma tumors. After alternating magnetic field (AMF) exposure, the targeted delivery of MNPs by the NPCs resulted in a mild decrease in tumor size (Chapter-2). Monocytes/macrophages (Mo/Ma) are known to infiltrate tumor sites, and also have phagocytic activity which can increase their uptake of MNPs. To test Mo/Ma-mediated MHT we transplanted Mo/Ma loaded with MNPs into a mouse model of pancreatic peritoneal carcinomatosis. We observed that MNP-loaded Mo/Ma infiltrated pancreatic tumors and, after AMF treatment, significantly prolonged the lives of mice bearing disseminated intraperitoneal pancreatic tumors (Chapter-3). 2. Targeted cancer treatment could be achieved by engineering tumor homing cell surfaces with tumor proteases cleavable, cancer cell specific recombinant therapeutic proteins. To test this, Urokinase and Calpain (tumor specific proteases) cleavable; prostate cancer cell (CaP) specific (CaP1 targeting peptide); apoptosis inducible (Caspase3 V266ED3)- rCasp3V266ED3 chimeric protein was designed in silico. Hypothesized membrane anchored chimeric protein (rCasp3V266ED3, rMcherry red) plasmids were constructed. Membrane anchoring and activity of designed proteins were analyzed in RAW264.7 Mo/Ma and HEK293 cells in vitro. Further, Urokinase (uPA) mediated cleavage and release of rCasp3V266ED3 from engineered cells was tested (Chapter-4). Animal models for cancer therapy are invaluable for preclinical testing of potential cancer treatments. Final chapter of present report shows evidence for immune-deficient line of pigs as a model for human cancers (Chapter-5)

Balivada, Sivasai

62

Treatment delivery software for a new clinical grade ultrasound system for thermoradiotherapy.  

PubMed

A detailed description of a clinical grade Scanning Ultrasound Reflector Linear Array System (SURLAS) applicator was given in a previous paper [Med. Phys. 32, 230-240 (2005)]. In this paper we concentrate on the design, development, and testing of the personal computer (PC) based treatment delivery software that runs the therapy system. The SURLAS requires the coordinated interaction between the therapy applicator and several peripheral devices for its proper and safe operation. One of the most important tasks was the coordination of the input power sequences for the elements of two parallel opposed ultrasound arrays (eight 1.5 cm x 2 cm elements/array, array 1 and 2 operate at 1.9 and 4.9 MHz, respectively) in coordination with the position of a dual-face scanning acoustic reflector. To achieve this, the treatment delivery software can divide the applicator's treatment window in up to 64 sectors (minimum size of 2 cm x 2 cm), and control the power to each sector independently by adjusting the power output levels from the channels of a 16-channel radio-frequency generator. The software coordinates the generator outputs with the position of the reflector as it scans back and forth between the arrays. Individual sector control and dual frequency operation allows the SURLAS to adjust power deposition in three dimensions to superficial targets coupled to its treatment window. The treatment delivery software also monitors and logs several parameters such as temperatures acquired using a 16-channel thermocouple thermometry unit. Safety (in particular to patients) was the paramount concern and design criterion. Failure mode and effects analysis (FMEA) was applied to the applicator as well as to the entire therapy system in order to identify safety issues and rank their relative importance. This analysis led to the implementation of several safety mechanisms and a software structure where each device communicates with the controlling PC independently of the others. In case of a malfunction in any part of the system or a violation of a user-defined safety criterion based on temperature readings, the software terminates treatment immediately and the user is notified. The software development process consisting of problem analysis, design, implementation, and testing is presented in this paper. Once the software was finished and integrated with the hardware, the therapy system was extensively tested. Results demonstrated that the software operates the SURLAS as intended with minimum risk to future patients. PMID:16372408

Novák, Petr; Moros, Eduardo G; Straube, William L; Myerson, Robert J

2005-11-01

63

Experimental verification of IMPT treatment plans in an anthropomorphic phantom in the presence of delivery uncertainties.  

PubMed

Clinically relevant intensity modulated proton therapy (IMPT) treatment plans were measured in a newly developed anthropomorphic phantom (i) to assess plan accuracy in the presence of high heterogeneity and (ii) to measure plan robustness in the case of treatment uncertainties (range and spatial). The new phantom consists of five different tissue substitute materials simulating different tissue types and was cut into sagittal planes so as to facilitate the verification of co-planar proton fields. GafChromic films were positioned in the different planes of the phantom, and 3D-IMPT and distal edge tracking (DET) plans were delivered to a volume simulating a skull base chordoma. In addition, treatments planned on CTs of the phantom with HU units modified were delivered to simulate systematic range uncertainties (range-error treatments). Finally, plans were delivered with the phantom rotated to simulate spatial errors. Results show excellent agreement between the calculated and the measured dose distribution: >99% and 98% of points with a gamma value <1 (3%/3 mm) for the 3D-IMPT and the DET plan, respectively. For both range and spatial errors, the 3D-IMPT plan was more robust than the DET plan. Both plans were more robust to range than to the spatial uncertainties. Finally, for range error treatments, measured distributions were compared to a model for predicting delivery errors in the treatment planning system. Good agreement has been found between the model and the measurements for both types of IMPT plan. PMID:21709345

Albertini, F; Casiraghi, M; Lorentini, S; Rombi, B; Lomax, A J

2011-07-21

64

Experimental verification of IMPT treatment plans in an anthropomorphic phantom in the presence of delivery uncertainties  

NASA Astrophysics Data System (ADS)

Clinically relevant intensity modulated proton therapy (IMPT) treatment plans were measured in a newly developed anthropomorphic phantom (i) to assess plan accuracy in the presence of high heterogeneity and (ii) to measure plan robustness in the case of treatment uncertainties (range and spatial). The new phantom consists of five different tissue substitute materials simulating different tissue types and was cut into sagittal planes so as to facilitate the verification of co-planar proton fields. GafChromic films were positioned in the different planes of the phantom, and 3D-IMPT and distal edge tracking (DET) plans were delivered to a volume simulating a skull base chordoma. In addition, treatments planned on CTs of the phantom with HU units modified were delivered to simulate systematic range uncertainties (range-error treatments). Finally, plans were delivered with the phantom rotated to simulate spatial errors. Results show excellent agreement between the calculated and the measured dose distribution: >99% and 98% of points with a gamma value <1 (3%/3 mm) for the 3D-IMPT and the DET plan, respectively. For both range and spatial errors, the 3D-IMPT plan was more robust than the DET plan. Both plans were more robust to range than to the spatial uncertainties. Finally, for range error treatments, measured distributions were compared to a model for predicting delivery errors in the treatment planning system. Good agreement has been found between the model and the measurements for both types of IMPT plan.

Albertini, F.; Casiraghi, M.; Lorentini, S.; Rombi, B.; Lomax, A. J.

2011-07-01

65

QA Issues for Computer-Controlled Treatment Delivery: This Is Not Your Old R/V System Any More{exclamation_point}  

SciTech Connect

State-of-the-art radiotherapy treatment delivery has changed dramatically during the past decade, moving from manual individual field setup and treatment to automated computer-controlled delivery of complex treatments, including intensity-modulated radiotherapy and other similarly complex delivery strategies. However, the quality assurance methods typically used to ensure treatment is performed precisely and correctly have not evolved in a similarly dramatic way. This paper reviews the old manual treatment process and use of record-and-verify systems, and describes differences with modern computer-controlled treatment delivery. The process and technology used for computer-controlled treatment delivery are analyzed in terms of potential (and actual) problems, as well as relevant published guidance on quality assurance. The potential for improved quality assurance for computer-controlled delivery is discussed.

Fraass, Benedick A. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI (United States)], E-mail: bfraass@umich.edu

2008-05-01

66

Treatment Planning to Improve Delivery Accuracy and Patient Throughput in Helical Tomotherapy  

SciTech Connect

Purpose: To investigate delivery quality assurance (DQA) discrepancies observed for a subset of helical tomotherapy patients. Methods and Materials: Six tomotherapy patient plans were selected for analysis. Three had passing DQA ion chamber (IC) measurements, whereas 3 had measurements deviating from the expected dose by more than 3.0%. All plans used similar parameters, including: 2.5 cm field-width, 15-s gantry period, and pitch values ranging from 0.143 to 0.215. Preliminary analysis suggested discrepancies were associated with plans having predominantly small leaf open times (LOTs). To test this, patients with failing DQA measurements were replanned using an increased pitch of 0.287. New DQA plans were generated and IC measurements performed. Exit fluence data were also collected during DQA delivery for dose reconstruction purposes. Results: Sinogram analysis showed increases in mean LOTs ranging from 29.8% to 83.1% for the increased pitch replans. IC measurements for these plans showed a reduction in dose discrepancies, bringing all measurements within {+-}3.0%. The replans were also more efficient to deliver, resulting in reduced treatment times. Dose reconstruction results were in excellent agreement with IC measurements, illustrating the impact of leaf-timing inaccuracies on plans having predominantly small LOTs. Conclusions: The impact of leaf-timing inaccuracies on plans with small mean LOTs can be considerable. These inaccuracies result from deviations in multileaf collimator latency from the linear approximation used by the treatment planning system and can be important for plans having a 15-s gantry period. The ability to reduce this effect while improving delivery efficiency by increasing the pitch is demonstrated.

Westerly, David C. [Department of Medical Physics, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States)], E-mail: westerly@wisc.edu; Soisson, Emilie [Department of Human Oncology, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States); Chen Quan [Department of TomoTherapy, Inc., Madison, WI (United States); Woch, Katherine [Department of Human Oncology, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States); Schubert, Leah [Department of Medical Physics, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States); Olivera, Gustavo [Department of Medical Physics, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States); Department of TomoTherapy, Inc., Madison, WI (United States); Mackie, Thomas R. [Department of Medical Physics, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States); Department of Human Oncology, University of Wisconsin, School of Medicine and Public Health, Madison, WI (United States); Department of TomoTherapy, Inc., Madison, WI (United States)

2009-07-15

67

Liposomal delivery and polyethylene glycol-liposomal oxaliplatin for the treatment of colorectal cancer (Review)  

PubMed Central

Oxaliplatin is effective for the treatment of advanced colorectal cancer; however, its application is restricted due to its dose-limiting toxicity. Liposomes are sphere-shaped vesicles consisting of one or more phospholipid bilayers. Liposomes as drug carriers are characterized by delayed release, lesion targeting and may be used as a drug-delivery system to decrease the side effects of cytotoxic drugs. Active targeting modification of liposomes may change the biological distribution of the anticancer agents, reduce or reverse multidrug resistance of tumor cells and enhance the effects of anticancer therapy. Based on the characteristics mentioned above, the aim of the present review was to demonstrate that polyethylene glycol-liposomes containing oxaliplatin may offer advantages for the treatment of colorectal cancer in clinical practice. PMID:24748970

YANG, CHUANG; FU, ZHONG-XUE

2014-01-01

68

Down syndrome and dementia: Is depression a confounder for accurate diagnosis and treatment?  

PubMed

The past century has seen a dramatic improvement in the life expectancy of people with Down syndrome. However, research has shown that individuals with Down syndrome now have an increased likelihood of early onset dementia. They are more likely than their mainstream peers to experience other significant co-morbidities including mental health issues such as depression. This case study reports a phenomenon in which three individuals with Down syndrome and dementia are described as experiencing a rebound in their functioning after a clear and sustained period of decline. It is hypothesized that this phenomenon is not actually a reversal of the expected dementia trajectory but is an undiagnosed depression exaggerating the true level of functional decline associated with the dementia. The proactive identification and treatment of depressive symptoms may therefore increase the quality of life of some people with Down syndrome and dementia. PMID:25249377

Wark, Stuart; Hussain, Rafat; Parmenter, Trevor

2014-12-01

69

Accurate Diagnosis as a Prognostic Factor in Intrauterine Insemination Treatment of Infertile Saudi Patients  

PubMed Central

Background The study meant to define the prognostic factors that help in prescribing intrauterine insemination (IUI) for infertility treatment which remains an area of continuous improvements. Methods The diagnostic indications of a cohort of IUI-treated patients and their corresponding pregnancy rates (PRs) were randomly and prospectively studied among Saudi cohort of 303 patients for a period of 20 months. The indications of IUI cases were statistically analyzed for those eligible patients over a period of twenty months (January 2010 till August 2011), and the PR that corresponded to each group was investigated as well. P-value less than 0.05 was considered significant. Results The highest PR, 18.87%, of the polycystic ovarian syndrome (PCOS)-only diagnosed patients, was significantly higher than the average PR of all other indications combined, 7.22%, (p = 0.011, compared to all other groups combined). The second highest PR, 14.0%, of the tubal factor (TF)-only indication, was double the PR average of all other indications combined, though it did not reach significance. However, PCOS and TF accompanied by other indications caused the PR to drop to 5.88% and 5.56%, respectively. However, a group of some hormonal-imbalance based indications had the least PR (0.0% to 2.70%). Those indications were elevated serum FSH, hyperprolactinemia, hypogonadotrophy, hypothyroidism and endometriosis. The rest of the indications had an average PR (8.33% to 11.11%). Conclusion There is a reasonable chance of conception after IUI treatment for female factor infertility except in cases with sever hormonal imbalance. The PCOS cases having the best success chances. PMID:25473626

Isa, Ahmed Mostafa; Abu-Rafea, Basim; Alasiri, Saleh Ahmed; Al-Mutawa, Johara; Binsaleh, Saleh; Al-Saif, Sameera; Al-Saqer, Aisha

2014-01-01

70

An Efficient and Accurate Formalism for the Treatment of Large Amplitude Intramolecular Motion  

PubMed Central

We propose a general approach to describe large amplitude motions (LAM) with multiple degrees of freedom (DOF) in molecules or reaction intermediates, which is useful for the computation of thermochemical or kinetic data. The kinetic part of the LAM Lagrangian is derived using a Z-matrix internal coordinate representation within a new numerical procedure. This derivation is exact for a classical system, and the uncertainties on the prediction of observable quantities largely arise from uncertainties on the LAM potential energy surface (PES) itself. In order to rigorously account for these uncertainties, we present an approach based on Bayesian theory to infer a parametrized physical model of the PES using ab initio calculations. This framework allows for quantification of uncertainties associated with a PES model as well as the forward propagation of these uncertainties to the quantity of interest. A selection and generalization of some treatments accounting for the coupling of the LAM with other internal or external DOF are also presented. Finally, we discuss and validate the approach with two applications: the calculation of the partition function of 1,3-butadiene and the calculation of the high-pressure reaction rate of the CH3 + H ? CH4 recombination. PMID:22904694

2012-01-01

71

An Overview on Dry Eye Treatment: Approaches for Cyclosporin A Delivery  

PubMed Central

Dry eye syndrome (DES, Keratoconjunctivitis sicca) is a common disorder of the tear film caused by decreased tear production or increased evaporation. Changes in tear composition also promote inflammation on the ocular surface by various mechanisms. Artificial tear drops, tear retention treatment, stimulation of tear secretion, or anti-inflammatory drugs may be used for dry eye treatment according to the severity of the disease. For untreated patients, the risk of ocular infection increases at considerable level and clinical course of the disease may proceed up to infection, corneal ulcer, and blindness. Artificial tears and/or punctual occlusions are used for tear replacement or preservation. New treatment approaches are designed to modify the underlying disease process. For the treatment of severe dry eye disease, cyclosporin A (CsA), the first one of the new generation immunomodulatory drugs, which has an anti-inflammatory effect, is frequently used. CsA has immunosuppressive effects following systemic application. Following local administration of CsA, it is expected to obtain effective drug concentration at the target area and to avoid the various side effects associated with systemic delivery. Microspheres, implants, and liposomes have been developed for administration of CsA subconjunctivally in order to enhance its efficiency. PMID:22619624

Yavuz, Burçin; Bozda? Pehlivan, Sibel; Ünlü, Nur?en

2012-01-01

72

Treatment planning and dosimetric comparison study on two different volumetric modulated arc therapy delivery techniques  

PubMed Central

Aim To compare and evaluate the performance of two different volumetric modulated arc therapy delivery techniques. Background Volumetric modulated arc therapy is a novel technique that has recently been made available for clinical use. Planning and dosimetric comparison study was done for Elekta VMAT and Varian RapidArc for different treatment sites. Materials and methods Ten patients were selected for the planning comparison study. This includes 2 head and neck, 2 oesophagus, 1 bladder, 3 cervix and 2 rectum cases. Total dose of 50 Gy was given for all the plans. All plans were done for RapidArc using Eclipse and for Elekta VMAT with Monaco treatment planning system. All plans were generated with 6 MV X-rays for both RapidArc and Elekta VMAT. Plans were evaluated based on the ability to meet the dose volume histogram, dose homogeneity index, radiation conformity index, estimated radiation delivery time, integral dose and monitor units needed to deliver the prescribed dose. Results RapidArc plans achieved the best conformity (CI95% = 1.08 ± 0.07) while Elekta VMAT plans were slightly inferior (CI95% = 1.10 ± 0.05). The in-homogeneity in the PTV was highest with Elekta VMAT with HI equal to 0.12 ± 0.02 Gy when compared to RapidArc with 0.08 ± 0.03. Significant changes were observed between the RapidArc and Elekta VMAT plans in terms of the healthy tissue mean dose and integral dose. Elekta VMAT plans show a reduction in the healthy tissue mean dose (6.92 ± 2.90) Gy when compared to RapidArc (7.83 ± 3.31) Gy. The integral dose is found to be inferior with Elekta VMAT (11.50 ± 6.49) × 104 Gy cm3 when compared to RapidArc (13.11 ± 7.52) × 104 Gy cm3. Both Varian RapidArc and Elekta VMAT respected the planning objective for all organs at risk. Gamma analysis result for the pre-treatment quality assurance shows good agreement between the planned and delivered fluence for 3 mm DTA, 3% DD for all the evaluated points inside the PTV, for both VMAT and RapidArc techniques. Conclusion The study concludes that a variable gantry speed with variable dose rate is important for efficient arc therapy delivery. RapidArc presents a slight improvement in the OAR sparing with better target coverage when compared to Elekta VMAT. Trivial differences were noted in all the plans for organ at risk but the two techniques provided satisfactory conformal avoidance and conformation. PMID:24416535

Kumar, S.A. Syam; Holla, Raghavendra; Sukumar, Prabakar; Padmanaban, Sriram; Vivekanandan, Nagarajan

2012-01-01

73

Advances in the psychosocial treatment of addiction: the role of technology in the delivery of evidence-based psychosocial treatment.  

PubMed

The clinical community has a growing array of psychosocial interventions with a strong evidence base available for the treatment of SUDs. Considerable opportunity exists for leveraging technology in the delivery of evidence-based interventions to promote widespread reach and impact of evidence-based care. Data from this line of research to date are promising, and underscore the potential public health impact of technology-based therapeutic tools. To fully realize the potential of technology-delivered interventions, several areas of inquiry remain important. First, scientifically sound strategies should be explored to ensure technology-based interventions are optimally designed to produce maximal behavior change. Second, efficient and effective methods should be identified to integrate technology-based interventions into systems of care in a manner that is most responsive to the needs of individual users. Third, payment, privacy, and regulatory systems should be refined and extended to go beyond electronic medical records and telehealth/distance care models, and support the deployment of technology-based systems to enhance the quality, efficiency and cost-effectiveness of care. Fourth, the mechanisms underlying behavior change derived from technology-based treatments should be explicated, including new mechanisms that may be tapped via novel, technology-based tools. Such work will be critical in isolating mechanisms that are useful in predicting treatment response, and in ensuring that key ingredients are present in technology-based interventions as they are made widely available. PMID:22640767

Marsch, Lisa A; Dallery, Jesse

2012-06-01

74

The role of Cobalt-60 source in Intensity Modulated Radiation Therapy: From modeling finite sources to treatment planning and conformal dose delivery  

NASA Astrophysics Data System (ADS)

Cobalt-60 (Co-60) units played an integral role in radiation therapy from the mid-1950s to the 1970s. Although they continue to be used to treat cancer in some parts of the world, their role has been significantly reduced due to the invention of medical linear accelerators. A number of groups have indicated a strong potential for Co-60 units in modern radiation therapy. The Medical Physics group at the Cancer Center of the Southeastern Ontario and Queen's University has shown the feasibility of Intensity Modulated Radiation Therapy (IMRT) via simple conformal treatment planning and dose delivery using a Co-60 unit. In this thesis, initial Co-60 tomotherapy planning investigations on simple uniform phantoms are extended to actual clinical cases based on patient CT data. The planning is based on radiation dose data from a clinical Co-60 unit fitted with a multileaf collimator (MLC) and modeled in the EGSnrc Monte Carlo system. An in house treatment planning program is used to calculate IMRT dose distributions. Conformal delivery in a single slice on a uniform phantom based on sequentially delivered pencil beams is verified by Gafchromic film. Volumetric dose distributions for Co-60 serial tomotherapy are then generated for typical clinical sites that had been treated at our clinic by conventional 6MV IMRT using Varian Eclipse treatment plans. The Co-60 treatment plans are compared with the clinical IMRT plans using conventional matrices such as dose volume histograms (DVH). Dose delivery based on simultaneously opened MLC leaves is also explored and a novel MLC segmentation method is proposed. In order to increase efficiency of dose calculations, a novel convolution based fluence model for treatment planning is also proposed. The ion chamber measurements showed that the Monte Carlo modeling of the beam data under the MIMiC MLC is accurate. The film measurements from the uniform phantom irradiations confirm that IMRT plans from our in-house treatment planning system are deliverable. Comparing the Co-60 dose distributions and DVHs to the IMRT plans from the clinic indicates that Co-60 is able to provide similar dose conformality to targets and dose sparing to critical organs. The results of the novel MLC segmentation algorithm and the photon fluence model proposed in this work compared well with the Monte Carlo calculations. In summary, the investigations presented in this thesis confirm that Co-60 tomotherapy is indeed capable of providing state-of-the-art conformal dose delivery. We have shown that the perceived beam limitations often identified with Co-60 (e.g., lower penetration, source size artifacts under small field collimation, and larger penumbra) are negligible when using intensity modulated techniques.

Dhanesar, Sandeep Kaur

75

Pulmonary delivery of cisplatin-hyaluronan conjugates via endotracheal instillation for the treatment of lung cancer  

PubMed Central

Cisplatin (CDDP) intravenous treatments suffer several dose-limiting toxicity issues. Hyaluronan (HA), a naturally occurring biopolymer in the interstitium, is primarily cleared by the lymphatic system. An alteration in input rate and administration route through pulmonary delivery of hyaluronan-cisplatin conjugate (HA-Pt) may increase local lung CDDP concentrations and decrease systemic toxicity. Sprague-Dawley rats were split into four groups: i.v. CDDP (3.5 mg/kg), i.v. HA-Pt conjugate (3.5 mg/kg equivalent CDDP), lung instillation CDDP and lung instillation HA-Pt conjugate. Total platinum level in the lungs of the HA-Pt lung instillation group was 5.7-fold and 1.2-fold higher than the CDDP intravenous group at 24 h and 96 h, respectively. A 1.1-fold increase of Pt accumulation in lung draining nodes for the HA-Pt lung instillation group was achieved at 24 h relative to the CDDP i.v. group. In the brain and kidneys, the CDDP i.v. group had higher tissue/plasma ratios compared to the HA-Pt lung instillation group. Augmented tissue distribution from CDDP i.v. could translate into enhanced tissue toxicity compared to the altered input rate and distribution of the intrapulmonary nanoformulation. In conclusion, a local pulmonary CDDP delivery system was developed with increased platinum concentration in the lungs and draining nodes compared to i.v. therapy. PMID:20363303

Xie, Yumei; Aillon, Kristin L.; Cai, Shuang; Christian, Jason M.; Davies, Neal M.; Berkland, Cory J.; Forrest, M. Laird

2010-01-01

76

Combinational Spinal GAD65 Gene Delivery and Systemic GABA-Mimetic Treatment for Modulation of Spasticity  

PubMed Central

Background Loss of GABA-mediated pre-synaptic inhibition after spinal injury plays a key role in the progressive increase in spinal reflexes and the appearance of spasticity. Clinical studies show that the use of baclofen (GABAB receptor agonist), while effective in modulating spasticity is associated with major side effects such as general sedation and progressive tolerance development. The goal of the present study was to assess if a combined therapy composed of spinal segment-specific upregulation of GAD65 (glutamate decarboxylase) gene once combined with systemic treatment with tiagabine (GABA uptake inhibitor) will lead to an antispasticity effect and whether such an effect will only be present in GAD65 gene over-expressing spinal segments. Methods/Principal Findings Adult Sprague-Dawley (SD) rats were exposed to transient spinal ischemia (10 min) to induce muscle spasticity. Animals then received lumbar injection of HIV1-CMV-GAD65 lentivirus (LVs) targeting ventral ?-motoneuronal pools. At 2–3 weeks after lentivirus delivery animals were treated systemically with tiagabine (4, 10, 20 or 40 mg/kg or vehicle) and the degree of spasticity response measured. In a separate experiment the expression of GAD65 gene after spinal parenchymal delivery of GAD65-lentivirus in naive minipigs was studied. Spastic SD rats receiving spinal injections of the GAD65 gene and treated with systemic tiagabine showed potent and tiagabine-dose-dependent alleviation of spasticity. Neither treatment alone (i.e., GAD65-LVs injection only or tiagabine treatment only) had any significant antispasticity effect nor had any detectable side effect. Measured antispasticity effect correlated with increase in spinal parenchymal GABA synthesis and was restricted to spinal segments overexpressing GAD65 gene. Conclusions/Significance These data show that treatment with orally bioavailable GABA-mimetic drugs if combined with spinal-segment-specific GAD65 gene overexpression can represent a novel and highly effective anti-spasticity treatment which is associated with minimal side effects and is restricted to GAD65-gene over-expressing spinal segments. PMID:22291989

Kakinohana, Osamu; Hefferan, Michael P.; Miyanohara, Atsushi; Nejime, Tetsuya; Marsala, Silvia; Juhas, Stefan; Juhasova, Jana; Motlik, Jan; Kucharova, Karolina; Strnadel, Jan; Platoshyn, Oleksandr; Lazar, Peter; Galik, Jan; Vinay, Laurent; Marsala, Martin

2012-01-01

77

[Immunoglobulin treatment for neonatal hemochromatosis: a case report in a context of immunoglobulin delivery quotas].  

PubMed

Neonatal hemochromatosis is a rare disease characterized by iron deposits in several organs. The natural course leads to lethal liver failure. A preventive treatment was recently introduced: high-dose intravenous immunoglobulins during pregnancy to prevent fetomaternal allo-immunization. Nevertheless, the prescription of massive quantities of immunoglobulins can lead to a drug shortage which the hospital pharmacist must deal with. We report the case of a pregnant woman with high risk of transmitting neonatal hemochromatosis. We discuss the pharmaceutical difficulties encountered when managing patients with a high risk of neonatal hemochromatosis in the context of immunoglobulin shortage with the delivery quotas established by the French National Health Authority. In this context, a national stock would be useful to deal with rare diseases and thus to support hospitals. PMID:19695366

Lecointre, R; Lima, S; Varlet, M-N; Combe, C

2009-09-01

78

pH-responsive mesoporous silica nanoparticles employed in controlled drug delivery systems for cancer treatment  

PubMed Central

In the fight against cancer, controlled drug delivery systems have emerged to enhance the therapeutic efficacy and safety of anti-cancer drugs. Among these systems, mesoporous silica nanoparticles (MSNs) with a functional surface possess obvious advantages and were thus rapidly developed for cancer treatment. Many stimuli-responsive materials, such as nanoparticles, polymers, and inorganic materials, have been applied as caps and gatekeepers to control drug release from MSNs. This review presents an overview of the recent progress in the production of pH-responsive MSNs based on the pH gradient between normal tissues and the tumor microenvironment. Four main categories of gatekeepers can respond to acidic conditions. These categories will be described in detail. PMID:24738037

Yang, Ke-Ni; Zhang, Chun-Qiu; Wang, Wei; Wang, Paul C.; Zhou, Jian-Ping; Liang, Xing-Jie

2014-01-01

79

Bone grafts as carriers for local antibiotic delivery for the treatment and prevention of bone infections.  

PubMed

Osteomyelitis is a bone infection accompanied by inflammatory process, which can lead to destruction and bone necrosis. It is difficult to manage, and there are no commonly accepted guidelines. While most acute bone infections are usually successfully treated with intravenous antibiotics, chronic infections and infections in the presence of foreign materials usually require operative treatment with debridement, removal of metals, intravenous antibiotics, and very often local antibiotics. The aim of this study was to perform a systematic review of the existing literature concerning the use of bone grafts as carriers for local antibiotic delivery for the treatment and prevention of bone infections. According to the literature, antibiotic-loaded autologous bone grafts for the treatment of infected tibial nonunion is a good option (Grade-B recommendations). Although there are several studies concerning the use of antibiotic-loaded allogenic bone grafts in infected joint arthroplasty revisions, there is a lack of comparative studies (Grade-C recommendations). Studies concerning spinal fusion and spondylodiscitis are limited (Grade-I recommendations). PMID:25433347

Lalidou, Fani; Kolios, George; Tavridou, Anna; Drosos, Georgios I

2014-11-01

80

Innovative Technology for the Assisted Delivery of Intensive Voice Treatment (LSVT[R]LOUD) for Parkinson Disease  

ERIC Educational Resources Information Center

Purpose: To assess the feasibility and effectiveness of a newly developed assistive technology system, Lee Silverman Voice Treatment Companion (LSVT[R] Companion[TM], hereafter referred to as "Companion"), to support the delivery of LSVT[R]LOUD, an efficacious speech intervention for individuals with Parkinson disease (PD). Method: Sixteen…

Halpern, Angela E.; Ramig, Lorraine O.; Matos, Carlos E. C.; Petska-Cable, Jill A.; Spielman, Jennifer L.; Pogoda, Janice M.; Gilley, Phillip M.; Sapir, Shimon; Bennett, John K.; McFarland, David H.

2012-01-01

81

Telomerase inhibitors for the treatment of brain tumors and the potential of intranasal delivery.  

PubMed

A fundamental limitation in the treatment of brain tumors is that < 1% of most therapeutic agents administered systemically are able to cross the blood-brain barrier (BBB). The development of new strategies that circumvent the BBB should increase the likelihood of tumor response to selected therapeutic agents. Intranasal delivery (IND) is a practical, noninvasive method of bypassing the BBB to deliver therapeutic agents to the brain. This technique has demonstrated promising results in the treatment of neurological disorders. Telomerase is a reverse transcriptase that is expressed in the vast majority of malignant gliomas, although not in the healthy brain. Telomerase inhibition can therefore be used as a therapeutic strategy for selectively targeting malignant gliomas. The first successful IND of a telomerase inhibitor as a therapy for brain tumors was GRN-163, an oligonucleotide N3'-->5' thiophosphoramidate telomerase inhibitor, which was successfully administered into intracerebral tumors in rats with no apparent toxicity. GRN-163 exhibited favorable tumor uptake and inhibited tumor growth, leading to prolonged lifespan in treated animals. The IND of telomerase inhibitors represents a new therapeutic approach that appears to selectively kill tumor cells, without inducing toxic effects in the surrounding healthy brain tissue. PMID:20373260

Hashizume, Rintaro; Gupta, Nalin

2010-04-01

82

Developments on drug delivery systems for the treatment of mycobacterial infections.  

PubMed

The clinical management of tuberculosis and other mycobacterial diseases with antimycobacterial chemotherapy remains a difficult task. The classical treatment protocols are long-lasting; the drugs reach mycobacteria-infected macrophages in low amounts and/or do not persist long enough to develop the desired antimycobacterial effect; and the available agents induce severe toxic effects. Nanotechnology has provided a huge improvement to pharmacology through the designing of drug delivery systems able to target phagocytic cells infected by intracellular pathogens, such as mycobacteria. Liposomes and nanoparticles of polymeric nature represent two of the most efficient drug carrier systems that after in vivo administration are endocytosed by phagocytic cells and then release the carried agents into these cells. This article reviews the relevant publications describing the effectiveness of the association of antimycobacterial agents with liposomes or nanoparticles for the treatment of mycobacterioses, particularly for Mycobacterium tuberculosis and M. avium infections. The increased therapeutic index of antimycobacterial drugs; the reduction of dosing frequency; and the improvement of solubility of hydrophobic agents, allowing the administration of higher doses, have been demonstrated in experimental infections. These advantages may lead to new therapeutic protocols that will improve patient compliance and, consequently, lead to a more successful control of mycobacterial infections. The potential therapeutic advantages resulting from the use of non-invasive administration routes for nanoparticulate systems are also discussed. PMID:18473884

Gaspar, M M; Cruz, A; Fraga, A G; Castro, A G; Cruz, M E M; Pedrosa, J

2008-01-01

83

Comparing different short-term service delivery methods of visual-motor treatment for first grade students in mainstream schools.  

PubMed

To compare the efficacy of three different short-term service delivery methods on first grade children with soft neurological signs who suffer from visual-motor difficulties. One hundred and forty seven first grade students who scored below the 21st percentile on the Visual-Motor Integration Test (VMI) were recruited from schools and randomly divided into three intervention groups and an additional control group. One group received Direct Treatment Model (DT), the second group received Collaborative-Consultation Treatment Model (CC) and the third group received a Combined Treatment Model (CT). The CC included treatment administered by teachers, after Collaborative-Consultation with an occupational therapist (OT). The CT included the two models (DT, CC), administered simultaneously. Pre- and post-intervention tests were administered to both groups. Students in all three intervention groups made significant gains in comparison to the control group suggesting that all three service delivery methods had the same effect on children's visual-motor skills. Therapists in school settings who are obliged to be more efficient are encouraged to use the CC or the CT service delivery methods which would enable them to treat more children during the same time-frame, with full confidence that the treatment goals will be achieved as if using the DT. PMID:19394194

Ratzon, Navah Z; Lahav, Orit; Cohen-Hamsi, Shifra; Metzger, Yehiela; Efraim, Daniela; Bart, Orit

2009-01-01

84

Types of Nasal Delivery Drugs and Medications in Iranian Traditional Medicine to Treatment of Headache  

PubMed Central

Context: Headache is a common symptom throughout the world. The main purpose of patient-centered approaches is the utilization of useful and simple treatment. Nowadays, there is a rising propensity toward herbal remedies. Nasal route is one of the ancient and topical prescriptions used in headache. In Iranian traditional medicine, physicians such as Avicenna were prescribing herbal drugs through the nose to treat a variety of central nervous system diseases like headache. In this review paper, authors have attempted to introduce different types of nasal administrations which were used in Iranian traditional medicine for the treatment of headaches. Evidence Acquisition: Initially, we studied two different types of Canon and separated all herbs used in the treatment of headache. Next, all plants were classified according to the method of prescription. Then, we pick out all the plants which were nasally utilized in the treatment of headache and divided them based on the method of administration. In order to find scientific names of herbs, we used two different botany references. Moreover, we conducted various researches in scientific databases with the aim of finding results concerning the analgesic and antinociceptive effects of herbs. Throughout the research, key terms were “analgesic” and “antinociceptive “with the scientific names of all herbs separately. The databases searched included PubMed, Scopus, Cochrane library and SID. Results: 35 plants were prescribed for the treatment of headaches, which were all nasally used. These plants took either the form of powder, liquid or gas (steam). They were divided in to six categories according to the method of prescription. The Percentage of usage for each method was as follows: 62% Saoot (nasal drop), 25% Shamoom (smell), 17% Inkabab (vapor), 11% Nafookh (snuff), 11% Nashooq (inhaling) and 2% Bokhoor (smoke). Conclusions: Medications that are used via nasal delivery have greater effect than oral medications. Iranian physicians were fully aware of systemic effects of topical medications, including prescription drugs through the nose. The study of ancient medical texts helps us in identification of herbal medicine and the investigation of new way for the preparation of drugs. PMID:25068043

Ghorbanifar, Zahra; Delavar Kasmaei, Hosein; Minaei, Bagher; Rezaeizadeh, Hossein; Zayeri, Farid

2014-01-01

85

SimMom is an advanced full body birthing simulator with accurate anatomy and functionality to facilitate multi professional obstetric training of delivery management.  

E-print Network

SIMMOM SimMom is an advanced full body birthing simulator with accurate anatomy with BP Pulse palpation is detected and logged Cardiac: Extensive ECG library Heart sounds heart rate (not at the same time) Interchangeable pupils (normal, blown and constricted) Patient

Zhou, Pei

86

Biopolymer-Based Transdermal Films of Donepezil as an Alternative Delivery Approach in Alzheimer's Disease Treatment.  

PubMed

Matrix type transdermal films of donepezil (DNP) as an alternative delivery approach was designed to improve patient compliance to Alzheimer disease treatment. Sodium alginate, a natural polysaccharide, was used as matrix-forming agent in the optimization of transdermal films. Propylene glycol and dl-limonene was added into films as a plasticizer and permeation enhancer, respectively. As well as mechanical strength and bioadhesiveness of optimized transdermal films of DNP, the impact of dl-limonene concentration in films on DNP in vitro permeation across pig skin was assessed. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) measurements were carried out to examine the effects of enhancer on in vitro conformational order of the stratum corneum intercellular lipids following permeation study. Results showed that transdermal formulations of DNP were suitable due to both mechanical and bioadhesive features of the films. In vitro skin permeation study indicated that dl-limonene at a concentration of 3% was optimum with high drug flux. ATR-FTIR results confirmed a more fluidized stratum corneum lipid state in the presence of dl-limonene, indicating its permeation enhancement effect. Regarding to achieve therapeutic levels of DNP, it seems to be feasible deliver DNP with transdermal films for the management of Alzheimer disease. PMID:25273029

Galipo?lu, Maviye; Erdal, Meryem Sedef; Güngör, Sevgi

2014-10-01

87

Nanoparticulate delivery of LHRH analogue for the treatment of prostate cancer.  

PubMed

Goserelin acetate (Gos) is a luteinizing hormone-releasing hormone agonist, used in treatment of prostate cancer in which desired concentration of Gos in blood is maintained for longer duration. The aim of this study is to improve the efficacy of Gos targeted at the site of action and eliminate the need for frequent administration. Gos-encapsulated nanoparticles were fabricated by double emulsification process. The physicochemical traits of the nanoparticles including morphology, particle size, zeta-potential, entrapment efficiency, and in-vitro release profile were studied. The in-vitro cytotoxicity of the blank nanoparticles and Gos-loaded nanoparticles were also evaluated on LNCaP cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Blank methoxy PEG-poly(?-caprolactone) (mPEG-PCL) nanoparticles exhibited low cytotoxicity, which increased with increase in concentration of Gos-loaded nanoparticles. Serum Gos and testosterone levels were analyzed after subcutaneous administration in Wistar rats. In-vivo study showed that a sustained serum level of Gos successfully suppressed the plasma testosterone concentration to castration level. So, it can be concluded that mPEG-PCL nanoparticles might prove to be useful for site specific and sustain protein delivery. PMID:22380019

Tomar, Priti; Jain, Neeti; Dixit, Vinod Kumar

2013-01-01

88

A new era of cancer treatment: carbon nanotubes as drug delivery tools  

PubMed Central

Cancer is a generic term that encompasses a group of diseases characterized by an uncontrolled proliferation of cells. There are over 200 different types of cancer, each of which gains its nomenclature according to the type of tissue the cell originates in. Many patients who succumb to cancer do not die as a result of the primary tumor, but because of the systemic effects of metastases on other regions away from the original site. One of the aims of cancer therapy is to prevent the metastatic process as early as possible. There are currently many therapies in clinical use, and recent advances in biotechnology lend credence to the potential of nanotechnology in the fight against cancer. Nanomaterials such as carbon nanotubes (CNTs), quantum dots, and dendrimers have unique properties that can be exploited for diagnostic purposes, thermal ablation, and drug delivery in cancer. CNTs are tubular materials with nanometer-sized diameters and axial symmetry, giving them unique properties that can be exploited in the diagnosis and treatment of cancer. In addition, CNTs have the potential to deliver drugs directly to targeted cells and tissues. Alongside the rapid advances in the development of nanotechnology-based materials, elucidating the toxicity of nanoparticles is also imperative. Hence, in this review, we seek to explore the biomedical applications of CNTs, with particular emphasis on their use as therapeutic platforms in oncology. PMID:22162655

Madani, Seyed Yazdan; Naderi, Naghmeh; Dissanayake, Oshani; Tan, Aaron; Seifalian, Alexander M

2011-01-01

89

Herpes simplex virus vector-mediated gene delivery for the treatment of lower urinary tract pain  

PubMed Central

Interstitial cystitis (IC)/painful bladder syndrome (PBS) is a painful debilitating chronic visceral pain disorder of unknown etiology that affects an estimated 1 million people in the, United States alone. It is characterized by inflammation of the bladder that results in chronic pelvic pain associated with bladder symptoms of urinary frequency and urgency. Regardless of the etiology, IC/PBS involves either increased and/or abnormal activity in afferent nociceptive sensory neurons. Pain-related symptoms in patients with IC/PBS are often very difficult to treat. Both medical and surgical therapies have had limited clinical utility in this debilitating disease and numerous drug treatments, such as heparin, dimethylsulfoxide and amitriptyline, have proven to be palliative at best, and in some IC/PBS patients provide no relief whatsoever. Although opiate narcotics have been employed to help alleviate IC/PBS pain, this strategy is fraught with problems as systemic narcotic administration causes multiple unwanted side effects including mental status change and constipation. Moreover, chronic systemic narcotic use leads to dependency and need for dose escalation due to tolerance: therefore, new therapies are desperately needed to treat refractory IC/PBS. This has led our group to develop a gene therapy strategy that could potentially alleviate chronic pelvic pain using the herpes simplex virus-directed delivery of analgesic proteins to the bladder. PMID:19242523

Goins, WF; Goss, JR; Chancellor, MB; de Groat, WC; Glorioso, JC; Yoshimura, N

2009-01-01

90

Validation of Pinnacle treatment planning system for use with Novalis delivery unit.  

PubMed

For an institution that already owns the licenses, it is economically advantageous and technically feasible to use Pinnacle TPS (Philips Radiation Oncology Systems, Fitchburg, WI) with the BrainLab Novalis delivery system (BrainLAB A.G., Heimstetten, Germany). This takes advantage of the improved accuracy of the convolution algorithm in the presence of heterogeneities compared with the pencil beam calculation, which is particularly significant for lung SBRT treatments. The reference patient positioning DRRs still have to be generated by the BrainLab software from the CT images and isocenter coordinates transferred from Pinnacle. We validated this process with the end-to-end hidden target test, which showed an isocenter positioning error within one standard deviation from the previously established mean value. The Novalis treatment table attenuation is substantial (up to 6.2% for a beam directed straight up and up to 8.4% for oblique incidence) and has to be accounted for in calculations. A simple single-contour treatment table model was developed, resulting in mean differences between the measured and calculated attenuation factors of 0.0%-0.2%, depending on the field size. The maximum difference for a single incidence angle is 1.1%. The BrainLab micro-MLC (mMLC) leaf tip, although not geometrically round, can be represented in Pinnacle by an arch with satisfactory dosimetric accuracy. Subsequently, step-and-shoot (direct machine parameter optimization) IMRT dosimetric agreement is excellent. VMAT (called "SmartArc" in Pinnacle) treatments with constant gantry speed and dose rate are feasible without any modifications to the accelerator. Due to the 3 mm-wide mMLC leaves, the use of a 2 mm calculation grid is recommended. When dual arcs are used for the more complex cases, the overall dosimetric agreement for the SmartArc plans compares favorably with the previously reported results for other implementations of VMAT: gamma(3%,3mm) for absolute dose obtained with the biplanar diode array passing rates above 97% with the mean of 98.6%. However, a larger than expected dose error with the single-arc plans, confined predominantly to the isocenter region, requires further investigation. PMID:20717094

Faygelman, Vladimir; Hunt, Dylan; Walker, Luke; Mueller, Richard; Demarco, Mary Lou; Dilling, Thomas; Stevens, Craig; Zhang, Geoffrey

2010-01-01

91

PR_b-targeted delivery of tumor necrosis factor-? by polymersomes for the treatment of prostate cancer  

Microsoft Academic Search

Targeted delivery of therapeutics is an active area of research with cancer being an important target because of the necessity for new and better cancer therapies. In this study we design and assess peptide functionalized polymer vesicles, or polymersomes, self assembled from poly(ethylene oxide)-b- poly(butadiene) (PEO-PBD) diblock copolymers for the treatment of prostate cancer. PR_b, a highly effective a5b1 targeting

Döne Demirgöz; Todd O. Pangburn; Kevin P. Davis; Sangwoo Lee; Frank S. Bates; Efrosini Kokkoli

2009-01-01

92

Three Dimensional Transient Multifield Analysis of a Piezoelectric Micropump for Drug Delivery System for Treatment of Hemodynamic Dysfunctions  

Microsoft Academic Search

In this paper, we present design of a transdermal drug delivery system for treatment of cardiovascular or hemodynamic disorders\\u000a such as hypertension. The system comprises of integrated control electronics and microelectromechanical system devices such\\u000a as micropump, micro blood pressure sensor and microneedle array. The objective is to overcome the limitations of oral therapy\\u000a such as variable absorption profile and the

Asim Nisar; Nitin Afzulpurkar; Adisorn Tuantranont; Banchong Mahaisavariya

2008-01-01

93

Catheter displacement prior to the delivery of high-dose-rate brachytherapy in the treatment of prostate cancer patients  

PubMed Central

Purpose The purpose of this work was to report measured catheter displacement prior to the delivery of high-dose-rate brachytherapy (HDR) in the treatment of prostate cancer. Material and methods Data from 30 prostate cancer patients treated with HDR brachytherapy were analyzed retrospectively. Eighteen transperineal hollow catheters were inserted under transrectal ultrasound guidance. Gold marker seeds were also placed transperineally into the base and apex of the prostate gland. Five treatment fractions of 7.5 Gy each were administered over 3 days. The patient underwent CT scanning prior to each treatment fraction. Catheter displacement was measured from the pre-treatment CT dataset reconstructed at 1.25 mm slice thickness. Results Most of catheters were displaced in the caudal direction. Variations of 18 catheters for each patient were small (standard deviations < 1 mm for all but one patient). Mean displacements relative to the apex marker were 6 ± 4 mm, 12 ± 6 mm, 12 ± 6 mm, 12 ± 6 mm, and 12 ± 6 mm from plan to 1st, 2nd, 3rd, 4th, and 5th fractions, respectively. Conclusions Our results indicate that catheter positions must be confirmed and if required, adjusted, prior to every treatment fraction for the precise treatment delivery of HDR brachytherapy, and to potentially reduce over-dosage to the bulbo-membranous urethra. PMID:25097556

Kawakami, Shogo; Terazaki, Tsuyoshi; Soda, Itaru; Satoh, Takefumi; Kitano, Masashi; Kurosaka, Shinji; Sekiguchi, Akane; Komori, Shouko; Iwamura, Masatsugu; Hayakawa, Kazushige

2014-01-01

94

Spin-dependent localized Hartree-Fock density-functional approach for the accurate treatment of inner-shell excitation of closed-shell atoms  

E-print Network

-shell excited states of closed-shell atoms by means of a spin- dependent localized Hartree-Fock SLHF densitySpin-dependent localized Hartree-Fock density-functional approach for the accurate treatment of inner-shell excitation of closed-shell atoms Zhongyuan Zhou1,2 and Shih-I Chu1 1 Department of Chemistry

Chu, Shih-I

95

In Vitro and In Vivo Evaluation of a Hydrogel Reservoir as a Continuous Drug Delivery System for Inner Ear Treatment  

PubMed Central

Fibrous tissue growth and loss of residual hearing after cochlear implantation can be reduced by application of the glucocorticoid dexamethasone-21-phosphate-disodium-salt (DEX). To date, sustained delivery of this agent to the cochlea using a number of pharmaceutical technologies has not been entirely successful. In this study we examine a novel way of continuous local drug application into the inner ear using a refillable hydrogel functionalized silicone reservoir. A PEG-based hydrogel made of reactive NCO-sP(EO-stat-PO) prepolymers was evaluated as a drug conveying and delivery system in vitro and in vivo. Encapsulating the free form hydrogel into a silicone tube with a small opening for the drug diffusion resulted in delayed drug release but unaffected diffusion of DEX through the gel compared to the free form hydrogel. Additionally, controlled DEX release over several weeks could be demonstrated using the hydrogel filled reservoir. Using a guinea-pig cochlear trauma model the reservoir delivery of DEX significantly protected residual hearing and reduced fibrosis. As well as being used as a device in its own right or in combination with cochlear implants, the hydrogel-filled reservoir represents a new drug delivery system that feasibly could be replenished with therapeutic agents to provide sustained treatment of the inner ear. PMID:25105670

Hessler, Roland; Stöver, Timo; Esser, Karl-Heinz; Möller, Martin; Lenarz, Thomas; Jolly, Claude; Groll, Jürgen; Scheper, Verena

2014-01-01

96

Preparation and characterization of novel carbopol based bigels for topical delivery of metronidazole for the treatment of bacterial vaginosis.  

PubMed

The current study reports the development of bigels using sorbitan monostearate-sesame oil organogel and carbopol 934 hydrogel. The microstructures and physicochemical properties were investigated by microscopy, viscosity measurement, mechanical analysis and differential scanning calorimetry analysis. Fluorescence microscopy confirmed the formation of oil-in-water type of emulsion gel. There was an increase in the strength of the bigels as the proportion of the organogel was increased in the bigels. The developed bigels showed shear-thinning flow behavior. The stress relaxation study suggested viscoelastic nature of the bigels. The developed bigels were biocompatible. Metronidazole, drug of choice for the treatment of bacterial vaginosis, loaded bigels showed diffusion-mediated drug release. The drug loaded gels showed good antimicrobial efficiency against Escherichia coli. In gist, the developed bigels may be used as delivery vehicles for the vaginal delivery of the drugs. PMID:25280691

Singh, Vinay K; Anis, Arfat; Banerjee, Indranil; Pramanik, Krishna; Bhattacharya, Mrinal K; Pal, Kunal

2014-11-01

97

The nasal approach to delivering treatment for brain diseases: an anatomic, physiologic, and delivery technology overview.  

PubMed

The intricate pathophysiology of brain disorders, difficult access to the brain, and the complexity and high risks and costs of drug development represent major hurdles for improving therapies. Nose-to-brain drug transport offers an attractive alternative or addition to formulation-only strategies attempting to enhance drug penetration into the CNS. Although still a matter of controversy, many studies in animals claim direct nose-to-brain transport along the olfactory and trigeminal nerves, circumventing the traditional barriers to CNS entry. Some clinical trials in man also suggest nose-to-brain drug delivery, although definitive proof in man is lacking. This review focuses on new nasal delivery technologies designed to overcome inherent anatomical and physiological challenges and facilitate more efficient and targeted drug delivery for CNS disorders. PMID:25090283

Djupesland, Per G; Messina, John C; Mahmoud, Ramy A

2014-06-01

98

Feasibility study on the verification of actual beam delivery in a treatment room using EPID transit dosimetry.  

PubMed

PurposeThe aim of this study is to evaluate the ability of transit dosimetry using commercial treatment planning system (TPS) and an electronic portal imaging device (EPID) with simple calibration method to verify the beam delivery based on detection of large errors in treatment room.Methods and materialsTwenty four fields of intensity modulated radiotherapy (IMRT) plans were selected from four lung cancer patients and used in the irradiation of an anthropomorphic phantom. The proposed method was evaluated by comparing the calculated dose map from TPS and EPID measurement on the same plane using a gamma index method with a 3% dose and 3 mm distance-to-dose agreement tolerance limit.ResultsIn a simulation using a homogeneous plastic water phantom, performed to verify the effectiveness of the proposed method, the average passing rate of the transit dose based on gamma index was high enough, averaging 94.2% when there was no error during beam delivery. The passing rate of the transit dose for 24 IMRT fields was lower with the anthropomorphic phantom, averaging 86.8%¿±¿3.8%, a reduction partially due to the inaccuracy of TPS calculations for inhomogeneity. Compared with the TPS, the absolute value of the transit dose at the beam center differed by ¿0.38%¿±¿2.1%. The simulation study indicated that the passing rate of the gamma index was significantly reduced, to less than 40%, when a wrong field was erroneously irradiated to patient in the treatment room.ConclusionsThis feasibility study suggested that transit dosimetry based on the calculation with commercial TPS and EPID measurement with simple calibration can provide information about large errors for treatment beam delivery. PMID:25472838

Baek, Tae; Chung, Eun; Son, Jaeman; Yoon, Myonggeun

2014-12-01

99

Efficient siRNA delivery system using carboxilated single-wall carbon nanotubes in cancer treatment.  

PubMed

Several functionalized carbon nanotubes have been designed and tested for the purpose of nucleic acid delivery. In this study, the capacity of SWNTC-COOH for siRNA deliverey were investigated delivery in parallel with an efficient commercial system. Hep2G cells were reverse-transfected with 50 nM siRNA (p53 siRNA, TNF-alphasiRNA, VEGFsiRNA) using the siPORT NeoFX (Ambion) transfection agent in paralel with SWNTC-COOH, functionalised with siRNA. The highest level of gene inhibition was observed in the cases treated with p53 siRNA gene; in the case of transfection with siPort, the NeoFX value was 33.8%, while in the case of SWNTC-COOH as delivery system for p53 siRNA was 37.5%. The gene silencing capacity for VEGF was 53.7%, respectively for TNF-alpha 56.7% for siPORT NeoFX delivery systems versus 47.7% (VEGF) and 46.5% (TNF-alpha) for SWNTC-COOH delivery system. SWNTC-COOH we have been showed to have to be an efficient carrier system. The results from the inhibition of gene expresion for both transfection systems were confirmed at protein level. Overall, the lowest mRNA expression was confirmed at protein level, especially in the case of p53 siRNA and TNF-alpha siRNA transfection. Less efficient reduction protein expressions were observed in the case of VEGF siRNA, for both transfection systems at 24 h; only at 48 h, there was a statistically significant reduction of VEGF protein expression. SWCNT-COOH determined an efficient delivery of siRNA. SWNTC-COOH, combined with suitable tumor markers like p53 siRNA, TNFalpha siRNA or VEGF siRNA can be used for the efficient delivery of siRNA. PMID:22852466

Neagoe, Ioana Berindan; Braicu, Cornelia; Matea, Cristian; Bele, Constantin; Florin, Graur; Gabriel, Katona; Veronica, Chedea; Irimie, Alexandru

2012-08-01

100

Investigation of Pitch and Jaw Width to Decrease Delivery Time of Helical Tomotherapy Treatments for Head and Neck Cancer  

SciTech Connect

Helical tomotherapy plans using a combination of pitch and jaw width settings were developed for 3 patients previously treated for head and neck cancer. Three jaw widths (5, 2.5, and 1 cm) and 4 pitches (0.86, 0.43, 0.287, and 0.215) were used with a (maximum) modulation factor setting of 4. Twelve plans were generated for each patient using an identical optimization procedure (e.g., number of iterations, objective weights, and penalties, etc.), based on recommendations from TomoTherapy (Madison, WI). The plans were compared using isodose plots, dose volume histograms, dose homogeneity indexes, conformity indexes, radiobiological models, and treatment times. Smaller pitches and jaw widths showed better target dose homogeneity and sparing of normal tissue, as expected. However, the treatment time increased inversely proportional to the jaw width, resulting in delivery times of 24 {+-} 1.9 min for the 1-cm jaw width. Although treatment plans produced with the 2.5-cm jaw were dosimetrically superior to plans produced with the 5-cm jaw, subsequent calculations of tumor control probabilities and normal tissue complication probabilities suggest that these differences may not be radiobiologically meaningful. Because treatment plans produced with the 5-cm jaw can be delivered in approximately half the time of plans produced with the 2.5-cm jaw (5.1 {+-} 0.6 min vs. 9.5 {+-} 1.1 min), use of the 5-cm jaw in routine treatment planning may be a viable approach to decreasing treatment delivery times from helical tomotherapy units.

Moldovan, Monica [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Fontenot, Jonas D., E-mail: jfontenot@marybird.com [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Gibbons, John P. [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA (United States); Lee, Tae Kyu [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Rosen, Isaac I. [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA (United States); Fields, Robert S. [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Hogstrom, Kenneth R. [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA (United States)

2011-01-01

101

Multifunctional Nanocarriers for diagnostics, drug delivery and targeted treatment across blood-brain barrier: perspectives on tracking and neuroimaging  

PubMed Central

Nanotechnology has brought a variety of new possibilities into biological discovery and clinical practice. In particular, nano-scaled carriers have revolutionalized drug delivery, allowing for therapeutic agents to be selectively targeted on an organ, tissue and cell specific level, also minimizing exposure of healthy tissue to drugs. In this review we discuss and analyze three issues, which are considered to be at the core of nano-scaled drug delivery systems, namely functionalization of nanocarriers, delivery to target organs and in vivo imaging. The latest developments on highly specific conjugation strategies that are used to attach biomolecules to the surface of nanoparticles (NP) are first reviewed. Besides drug carrying capabilities, the functionalization of nanocarriers also facilitate their transport to primary target organs. We highlight the leading advantage of nanocarriers, i.e. their ability to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells surrounding the brain that prevents high-molecular weight molecules from entering the brain. The BBB has several transport molecules such as growth factors, insulin and transferrin that can potentially increase the efficiency and kinetics of brain-targeting nanocarriers. Potential treatments for common neurological disorders, such as stroke, tumours and Alzheimer's, are therefore a much sought-after application of nanomedicine. Likewise any other drug delivery system, a number of parameters need to be registered once functionalized NPs are administered, for instance their efficiency in organ-selective targeting, bioaccumulation and excretion. Finally, direct in vivo imaging of nanomaterials is an exciting recent field that can provide real-time tracking of those nanocarriers. We review a range of systems suitable for in vivo imaging and monitoring of drug delivery, with an emphasis on most recently introduced molecular imaging modalities based on optical and hybrid contrast, such as fluorescent protein tomography and multispectral optoacoustic tomography. Overall, great potential is foreseen for nanocarriers in medical diagnostics, therapeutics and molecular targeting. A proposed roadmap for ongoing and future research directions is therefore discussed in detail with emphasis on the development of novel approaches for functionalization, targeting and imaging of nano-based drug delivery systems, a cutting-edge technology poised to change the ways medicine is administered. PMID:20199661

2010-01-01

102

Nanoplatforms for constructing new approaches to cancer treatment, imaging, and drug delivery: What should be the policy?  

PubMed Central

Nanotechnology is the design and assembly of submicroscopic devices called nanoparticles, which are 1–100 nm in diameter. Nanomedicine is the application of nanotechnology for the diagnosis and treatment of human disease. Disease-specific receptors on the surface of cells provide useful targets for nanoparticles. Because nanoparticles can be engineered from components that (1) recognize disease at the cellular level, (2) are visible on imaging studies, and (3) deliver therapeutic compounds, nanotechnology is well suited for the diagnosis and treatment of a variety of diseases. Nanotechnology will enable earlier detection and treatment of diseases that are best treated in their initial stages, such as cancer. Advances in nanotechnology will also spur the discovery of new methods for delivery of therapeutic compounds, including genes and proteins, to diseased tissue. A myriad of nanostructured drugs with effective site-targeting can be developed by combining a diverse selection of targeting, diagnostic, and therapeutic components. Incorporating immune target specificity with nanostructures introduces a new type of treatment modality, nano-immunochemotherapy, for patients with cancer. In this review, we will discuss the development and potential applications of nanoscale platforms in medical diagnosis and treatment. To impact the care of patients with neurological diseases, advances in nanotechnology will require accelerated translation to the fields of brain mapping, CNS imaging, and nanoneurosurgery. Advances in nanoplatform, nano-imaging, and nano-drug delivery will drive the future development of nanomedicine, personalized medicine, and targeted therapy. We believe that the formation of a science, technology, medicine law–healthcare policy (STML) hub/center, which encourages collaboration among universities, medical centers, US government, industry, patient advocacy groups, charitable foundations, and philanthropists, could significantly facilitate such advancements and contribute to the translation of nanotechnology across medical disciplines. PMID:20149882

Kateb, Babak; Chiu, Katherine; Black, Keith L.; Yamamoto, Vicky; Khalsa, Bhavraj; Ljubimova, Julia Y.; Ding, Hui; Patil, Rameshwar; Portilla-Arias, Jose Antonio; Modo, Mike; Moore, David F.; Farahani, Keyvan; Okun, Michael S.; Prakash, Neal; Neman, Josh; Ahdoot, Daniel; Grundfest, Warren; Nikzad, Shouleh; Heiss, John D.

2012-01-01

103

Targeted Delivery of siRNA to Macrophages for Anti-inflammatory Treatment  

Microsoft Academic Search

Inflammation mediated by tumor necrosis factor-? (TNF-?) and the associated neuronal apoptosis characterizes a number of neurologic disorders. Macrophages and microglial cells are believed to be the major source of TNF-? in the central nervous system (CNS). Here, we show that suppression of TNF-? by targeted delivery of small interfering RNA (siRNA) to macrophage\\/microglial cells dramatically reduces lipopolysaccharide (LPS)-induced neuroinflammation

Sang-Soo Kim; Chunting Ye; Priti Kumar; Isaac Chiu; Sandesh Subramanya; Haoquan Wu; Premlata Shankar; N Manjunath

2010-01-01

104

Localized striatal delivery of GDNF as a treatment for Parkinson disease  

Microsoft Academic Search

Te n years ago, a glial cell line-derived neurotrophic factor (GDNF) that has prominent actions on nigral dopaminergic neurons, both in vitro and in animal models of Parkinson disease (PD), was discov- ered. A recently published open-label clinical trial now reports that long-term intracerebral delivery of GDNF may also markedly improve symptoms in patients with PD. Here we review the

Biljana Georgievska; Anders Björklund; Deniz Kirik

2004-01-01

105

Focused ultrasound induced blood-brain barrier disruption to enhance chemotherapeutic drugs (BCNU) delivery for glioblastoma treatment  

NASA Astrophysics Data System (ADS)

Focused ultrasound has been recently found to capable of temporally and reversibly disrupt local blood-brain barrier (BBB) and opens new frontier in delivering varies type of drugs into brain for central nerve system (CNS) disorder treatment. In this study, we aim to investigate the feasibility of delivering 1, 3-bits (2-chloroethyl) -1-nitrosourea (BCNU) to treat glioblastoma in animal models and evaluate whether this approach would gain treatment efficacy. Under the presence of microbubbles administration, a 400-kHz focused ultrasound was employed to deliver burst-tone ultrasonic energy stimulation to disrupt BBB in animal brains transcranially, and in-vivo monitored by magnetic-resonance imaging (MRI). C6-glioma cells were cultured and implanted into Sprague-Dawley rats as the brain-tumor model. BCNU deposited in brain was quantified by using high-performance liquid chromatography (HPLC), and brain tissues were examined histologically. MRI was employed to longitudinal evaluate the brain tumor treatment including the analysis of tumor progression and animal survival. We confirmed that the focused ultrasound, under the secure ultrasonic energy level, can significantly enhance the BCNU penetration through BBB over 300% than control without cause hemorrhage. Apparent improvement of treatment efficacy achieved by combining focused ultrasound with BCNU delivery, including significant suppression of tumor growth and a prolonged animal survival. This study highly support that this treatment strategy could be clinically-relevant and may help to provide another potential strategy in increasing local chemotherapeutic drugs for brain-tumor treatment.

Liu, Hao-Li; Hua, Mu-Yi; Chen, Pin-Yuan; Huang, Chiung-Yin; Wang, Jiun-Jie; Wei, Kuo-Chen

2010-03-01

106

Pulmonary Delivery of an Ultra-Fine Oxytocin Dry Powder Formulation: Potential for Treatment of Postpartum Haemorrhage in Developing Countries  

PubMed Central

Oxytocin is recommended by the World Health Organisation as the most effective uterotonic for the prevention and treatment of postpartum haemorrhage. The requirement for parenteral administration by trained healthcare providers and the need for the drug solution to be maintained under cold-chain storage limit the use of oxytocin in the developing world. In this study, a spray-dried ultrafine formulation of oxytocin was developed with an optimal particle size diameter (1-5 µm) to facilitate aerosolised delivery via the lungs. A powder formulation of oxytocin, using mannitol, glycine and leucine as carriers, was prepared with a volume-based median particle diameter of 1.9 µm. Oxytocin content in the formulation was assayed using high-performance liquid chromatography-mass spectroscopy and was found to be unchanged after spray-drying. Ex vivo contractility studies utilising human and ovine uterine tissue indicated no difference in the bioactivity of oxytocin before and after spray-drying. Uterine electromyographic (EMG) activity in postpartum ewes following pulmonary (in vivo) administration of oxytocin closely mimicked that observed immediately postpartum (0-12 h following normal vaginal delivery of the lamb). In comparison to the intramuscular injection, pulmonary administration of an oxytocin dry powder formulation to postpartum ewes resulted in generally similar EMG responses, however a more rapid onset of uterine EMG activity was observed following pulmonary administration (129 ± 18 s) than intramuscular injection (275 ± 22 s). This is the first study to demonstrate the potential for oxytocin to elicit uterine activity after systemic absorption as an aerosolised powder from the lungs. Aerosolised oxytocin has the potential to provide a stable and easy to administer delivery system for effective prevention and treatment of postpartum haemorrhage in resource-poor settings in the developing world. PMID:24376618

Ibrahim, Jibriil P.; Bischof, Robert J.; Nassta, Gemma C.; Olerile, Livesey D.; Russell, Adrian S.; Meiser, Felix; Parkington, Helena C.; Coleman, Harold A.; Morton, David A. V.; McIntosh, Michelle P.

2013-01-01

107

Multi-breath dry powder inhaler for delivery of cohesive powders in the treatment of bronchiectasis.  

PubMed

Abstract A series of co-engineered macrolide-mannitol particles were successfully prepared using azithromycin (AZ) as a model drug. The formulation was designed to target local inflammation and bacterial colonization, via the macrolide component, while the mannitol acted as mucolytic and taste-masking agent. The engineered particles were evaluated in terms of their physico-chemical properties and aerosol performance when delivered via a novel high-payload dry powder Orbital(™) inhaler device that operates via multiple inhalation manoeuvres. All formulations prepared were of suitable size for inhalation drug delivery and contained a mixture of amorphous AZ with crystalline mannitol. A co-spray dried formulation containing 200?mg of 50:50?w/w AZ: mannitol had 57.6%?±?7.6% delivery efficiency with a fine particle fraction (?6.8?µm) of the emitted aerosol cloud being 80.4%?±?1.1%, with minimal throat deposition (5.3?±?0.9%). Subsequently, it can be concluded that the use of this device in combination with the co-engineered macrolide-mannitol therapy may provide a means of treating bronchiectasis. PMID:24811055

Young, Paul M; Salama, Rania O; Zhu, Bing; Phillips, Gary; Crapper, John; Chan, Hak-Kim; Traini, Daniela

2014-05-01

108

Capsaicin delivery into the skin with lipidic nanoparticles for the treatment of psoriasis.  

PubMed

Abstract The study aims to explore the potential of solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) in improving the topical delivery of capsaicin (CAP) by in vitro and in vivo studies. The lipidic nanoparticles were prepared by solvent diffusion method and were characterized for average particle size, zeta potential and entrapment efficiency. TEM photomicrographs revealed that the particles were nanometric in size. Higher amount of CAP can be encapsulated in the NLCs (87.4 ± 3.28) as compared with SLNs (79.7 ± 2.93%). The cumulative amounts of CAP permeated through the skin and retained in the SC were higher in the case of NLCs as compared with plain drug solution and SLNs. SLNs and NLCs exhibited minimum to no irritation. All the results concluded that NLCs and SLNs have shown a good ability to increase drug accumulation in the various skin layers but NLCs may be a more potential carrier for topical delivery of CAP for an effective therapy of psoriasis. PMID:24040836

Agrawal, Udita; Gupta, Madhu; Vyas, S P

2015-02-01

109

Helical tomotherapy-based STAT stereotactic body radiation therapy: Dosimetric evaluation for a real-time SBRT treatment planning and delivery program.  

PubMed

Stereotactic body radiation therapy (SBRT) treatments have high-dose gradients and even slight patient misalignment from the simulation to treatment could lead to target underdosing or organ at risk (OAR) overdosing. Daily real-time SBRT treatment planning could minimize the risk of geographic miss. As an initial step toward determining the clinical feasibility of developing real-time SBRT treatment planning, we determined the calculation time of helical TomoTherapy-based STAT radiation therapy (RT) treatment plans for simple liver, lung, and spine SBRT treatments to assess whether the planning process was fast enough for practical clinical implementation. Representative SBRT planning target volumes for hypothetical liver, peripheral lung, and thoracic spine lesions and adjacent OARs were contoured onto a planning computed tomography scan (CT) of an anthropomorphic phantom. Treatment plans were generated using both STAT RT "full scatter" and conventional helical TomoTherapy "beamlet" algorithms. Optimized plans were compared with respect to conformality index (CI), heterogeneity index (HI), and maximum dose to regional OARs to determine clinical equivalence and the number of required STAT RT optimization iterations and calculation times were determined. The liver and lung dosimetry for the STAT RT and standard planning algorithms were clinically and statistically equivalent. For the liver lesions, "full scatter" and "beamlet" algorithms showed a CI of 1.04 and 1.04 and HI of 1.03 and 1.03, respectively. For the lung lesions, "full scatter" and "beamlet" algorithms showed a CI of 1.05 and 1.03 and HI of 1.05and 1.05, respectively. For spine lesions, "full scatter" and "beamlet" algorithms showed a CI of 1.15 and 1.14 and HI of 1.22 and 1.14, respectively. There was no difference between treatment algorithms with respect to maximum doses to the OARs. The STAT RT iteration time with current treatment planning systems is 45 sec, and the treatment planning required 3 iterations or 135 sec for STAT RT liver and lung SBRT plans and 7 iterations or 315 sec for STAT RT spine SBRT plans. Helical TomoTherapy-based STAT RT treatment planning with the "full scatter" algorithm provides levels of dosimetric conformality, heterogeneity, and OAR avoidance for SBRT treatments that are clinically equivalent to those generated with the Helical TomoTherapy "beamlet" algorithm. STAT RT calculation times for simple SBRT treatments are fast enough to warrant further investigation into their potential incorporation into an SBRT program with daily real-time planning. Development of methods for accurate target and OAR determination on megavoltage computed tomography scans incorporating high-resolution diagnostic image co-registration software and CT detector-based exit dose measurement for quality assurance are necessary to build a real-time SBRT planning and delivery program. PMID:21055611

Dunlap, Neal; McIntosh, Alyson; Sheng, Ke; Yang, Wensha; Turner, Benton; Shoushtari, Asal; Sheehan, Jason; Jones, David R; Lu, Weigo; Ruchala, Keneth; Olivera, Gustavo; Parnell, Donald; Larner, James L; Benedict, Stanley H; Read, Paul W

2010-01-01

110

Breast conserving treatment for breast cancer: dosimetric comparison of different non-invasive techniques for additional boost delivery  

PubMed Central

Background Today it is unclear which technique for delivery of an additional boost after whole breast radiotherapy for breast conserved patients should be state of the art. We present a dosimetric comparison of different non-invasive treatment techniques for additional boost delivery. Methods For 10 different tumor bed localizations, 7 different non-invasive treatment plans were made. Dosimetric comparison of PTV-coverage and dose to organs at risk was performed. Results The Vero system achieved an excellent PTV-coverage and at the same time could minimize the dose to the organs at risk with an average near-maximum-dose (D2) to the heart of 0.9 Gy and the average volume of ipsilateral lung receiving 5 Gy (V5) of 1.5%. The TomoTherapy modalities delivered an average D2 to the heart of 0.9 Gy for the rotational and of 2.3 Gy for the static modality and an average V5 to the ipsilateral lung of 7.3% and 2.9% respectively. A rotational technique offers an adequate conformity at the cost of more low dose spread and a larger build-up area. In most cases a 2-field technique showed acceptable PTV-coverage, but a bad conformity. Electrons often delivered a worse PTV-coverage than photons, with the planning requirements achieved only in 2 patients and with an average D2 to the heart of 2.8 Gy and an average V5 to the ipsilateral lung of 5.8%. Conclusions We present advices which can be used as guidelines for the selection of the best individualized treatment. PMID:24467916

2014-01-01

111

Delivery of glutamine synthetase gene by baculovirus vectors: a proof of concept for the treatment of acute hyperammonemia.  

PubMed

Hyperammonemia, a condition present in patients with urea cycle disorders (UCDs) or liver diseases, can cause neuropsychiatric complications, which in the worst cases result in brain damage, coma or death. Diverse treatments exist for the treatment of hyperammonemia, but they have limited efficacy, adverse effects and elevated cost. Gene therapy is a promising alternative that is explored here. A baculovirus, termed Bac-GS, containing the glutamine synthetase (GS) gene was constructed for the in vitro and in vivo treatment of hyperammonemia. Transduction of MA104 epithelial or L6 myoblast/myotubes cells with Bac-GS resulted in a high expression of the GS gene, an increase in GS concentration, and a reduction of almost half of exogenously added ammonia. When Bac-GS was tested in an acute hyperammonemia rat model by intramuscularly injecting the rear legs, the concentration of ammonia in blood decreased 351??M, in comparison with controls. A high GS concentration was detected in gastrocnemius muscles from the rats transduced with Bac-GS. These results show that gene delivery for overexpressing GS in muscle tissue is a promising alternative for the treatment of hyperammonemia in patients with acute or chronic liver diseases and hepatic encephalopathy or UCD. PMID:25338921

Torres-Vega, M A; Vargas-Jerónimo, R Y; Montiel-Martínez, A G; Muñoz-Fuentes, R M; Zamorano-Carrillo, A; Pastor, A R; Palomares, L A

2015-01-01

112

Effects of Verbal and Written Performance Feedback on Treatment Adherence: Practical Application of Two Delivery Formats  

ERIC Educational Resources Information Center

Verbal and written performance feedback for improving preschool and kindergarten teachers' treatment integrity of behavior plans was compared using a combined multiple-baseline and multiple-treatment design across teacher-student dyads with order counterbalanced as within-series conditions. Supplemental generalized least square regression…

Kaufman, Dahlia; Codding, Robin S.; Markus, Keith A.; Tryon, Georgiana Shick; Kyse, Eden Nagler

2013-01-01

113

Design, fabrication and analysis of silicon hollow microneedles for transdermal drug delivery system for treatment of hemodynamic dysfunctions.  

PubMed

In this paper, we present design, fabrication and coupled multifield analysis of hollow out-of-plane silicon microneedles with piezoelectrically actuated microfluidic device for transdermal drug delivery (TDD) system for treatment of cardiovascular or hemodynamic disorders such as hypertension. The mask layout design and fabrication process of silicon microneedles and reservoir involving deep reactive ion etching (DRIE) is first presented. This is followed by actual fabrication of silicon hollow microneedles by a series of combined isotropic and anisotropic etching processes using inductively coupled plasma (ICP) etching technology. Then coupled multifield analysis of a MEMS based piezoelectrically actuated device with integrated silicon microneedles is presented. The coupledfield analysis of hollow silicon microneedle array integrated with piezoelectric micropump has involved structural and fluid field couplings in a sequential structural-fluid analysis on a three-dimensional model of the microfluidic device. The effect of voltage and frequency on silicon membrane deflection and flow rate through the microneedle is investigated in the coupled field analysis using multiple code coupling method. The results of the present study provide valuable benchmark and prediction data to fabricate optimized designs of the silicon hollow microneedle based microfluidic devices for transdermal drug delivery applications. PMID:20730492

Ashraf, M W; Tayyaba, S; Nisar, A; Afzulpurkar, N; Bodhale, D W; Lomas, T; Poyai, A; Tuantranont, A

2010-09-01

114

Rectal cancer delivery of radiotherapy in adequate time and with adequate dose is influenced by treatment center, treatment schedule, and gender and is prognostic parameter for local control: Results of study CAO/ARO/AIO-94  

SciTech Connect

Purpose: The impact of the delivery of radiotherapy (RT) on treatment results in rectal cancer patients is unknown. Methods and Materials: The data from 788 patients with rectal cancer treated within the German CAO/AIO/ARO-94 phase III trial were analyzed concerning the impact of the delivery of RT (adequate RT: minimal radiation RT dose delivered, 4300 cGy for neoadjuvant RT or 4700 cGy for adjuvant RT; completion of RT in <44 days for neoadjuvant RT or <49 days for adjuvant RT) in different centers on the locoregional recurrence rate (LRR) and disease-free survival (DFS) at 5 years. The LRR, DFS, and delivery of RT were analyzed as endpoints in multivariate analysis. Results: A significant difference was found between the centers and the delivery of RT. The overall delivery of RT was a prognostic factor for the LRR (no RT, 29.6% {+-} 7.8%; inadequate RT, 21.2% {+-} 5.6%; adequate RT, 6.8% {+-} 1.4%; p = 0.0001) and DFS (no RT, 55.1% {+-} 9.1%; inadequate RT, 57.4% {+-} 6.3%; adequate RT, 69.1% {+-} 2.3%; p = 0.02). Postoperatively, delivery of RT was a prognostic factor for LRR on multivariate analysis (together with pathologic stage) but not for DFS (independent parameters, pathologic stage and age). Preoperatively, on multivariate analysis, pathologic stage, but not delivery of RT, was an independent prognostic parameter for LRR and DFS (together with adequate chemotherapy). On multivariate analysis, the treatment center, treatment schedule (neoadjuvant vs. adjuvant RT), and gender were prognostic parameters for adequate RT. Conclusion: Delivery of RT should be regarded as a prognostic factor for LRR in rectal cancer and is influenced by the treatment center, treatment schedule, and patient gender.

Fietkau, Rainer [Department of Radiation Therapy, University of Rostock, Rostock (Germany)]. E-mail: rainer.fietkau@med.uni-rostock.de; Roedel, Claus [Departments of Radiation Therapy and Surgery, University of Erlangen, Erlangen (Germany); Hohenberger, Werner [Departments of Radiation Therapy and Surgery, University of Erlangen, Erlangen (Germany); Raab, Rudolf [Department of Surgery, Klinikum Oldenburg, Oldenburg (Germany); Hess, Clemens [Departments of Radiation Therapy and General Surgery, University of Goettingen, Goettingen (Germany); Liersch, Torsten [Departments of Radiation Therapy and General Surgery, University of Goettingen, Goettingen (Germany); Becker, Heinz [Departments of Radiation Therapy and General Surgery, University of Goettingen, Goettingen (Germany); Wittekind, Christian [Institute of Pathology, University of Leipzig, Leipzig (Germany); Hutter, Matthias [Department of Radiation Therapy, Krankenhaus Nordwest Frankfurt, Frankfurt (Germany); Hager, Eva [Department of Radiation Therapy, Krankenhaus Klagenfurt, Klagenfurt (Austria); Karstens, Johann [Department of Radiation Therapy, University of Hannover, Hannover (Germany); Ewald, Hermann [Department of Radiation Therapy, University of Schleswig-Holstein, Campus Kiel, Kiel (Germany); Christen, Norbert [Department of Radiation Therapy, Krankenhaus Dresden-Friedrichstadt, Dresden (Germany); Jagoditsch, Michael [Department of Surgery, Klinikum St. Veit, St. Veit (Austria); Martus, Peter [Institute of Biostatistics and Clinical Epidemiology, Charite Universitary Medicine Berlin, Berlin (Germany); Sauer, Rolf [Departments of Radiation Therapy and Surgery, University of Erlangen, Erlangen (Germany)

2007-03-15

115

[Investigation for decrease of delivery time for the prostate cancer patient by modifications of treatment planning parameters in TomoTherapy planning station].  

PubMed

The purpose of present study is to investigate the decrease of delivery time for prostate cancer patient by using the helical type accelerator, Hi-Art System. The delivery time for Hi-Art System depends on planning parameters [pitch, modulation factor (MF) and field width (FW)], which are set by the operator at the beginning of the treatment planning. If you can allow for the deterioration of the dose distribution, the delivery time is able to decrease by increasing of FW and/or by decreasing of MF. On the other hands, as the use of 5.0 cm FW tends to increase the dose for the penile bulb, enough consideration for the dose distribution is needed. In addition, pitch should be set for the gantry rotation period not to become 15 s or less to prevent the increase of delivery time. PMID:22186200

Shimizu, Hidetoshi; Tachibana, Hiroyuki; Kubota, Takashi; Imamura, Hiroshi; Matsushima, Shigeru; Yoshimoto, Manabu; Kodaira, Takeshi

2011-01-01

116

Buccal mucosal delivery of a potent peptide leads to therapeutically-relevant plasma concentrations for the treatment of autoimmune diseases.  

PubMed

Stichodactyla helianthus neurotoxin (ShK) is an immunomodulatory peptide currently under development for the treatment of autoimmune diseases, including multiple sclerosis and rheumatoid arthritis by parenteral administration. To overcome the low patient compliance of conventional self-injections, we have investigated the potential of the buccal mucosa as an alternative delivery route for ShK both in vitro and in vivo. After application of fluorescent 5-Fam-ShK to untreated porcine buccal mucosa, there was no detectable peptide in the receptor chamber using an in vitro Ussing chamber model. However, the addition of the surfactants sodium taurodeoxycholate hydrate or cetrimide, and formulation of ShK in a chitosan mucoadhesive gel, led to 0.05-0.13% and 1.1% of the applied dose, respectively, appearing in the receptor chamber over 5h. Moreover, confocal microscopic studies demonstrated significantly enhanced buccal mucosal retention of the peptide (measured by mucosal fluorescence associated with 5-Fam-ShK) when enhancement strategies were employed. Administration of 5-Fam-ShK to mice (10mg/kg in a mucoadhesive chitosan-based gel (3%, w/v) with or without cetrimide (5%, w/w)) resulted in average plasma concentrations of 2.6-16.2nM between 2 and 6h, which were substantially higher than the pM concentrations required for therapeutic activity. This study demonstrated that the buccal mucosa is a promising administration route for the systemic delivery of ShK for the treatment of autoimmune diseases. PMID:25482338

Jin, Liang; Boyd, Ben J; White, Paul J; Pennington, Michael W; Norton, Raymond S; Nicolazzo, Joseph A

2015-02-10

117

Apamin-mediated actively targeted drug delivery for treatment of spinal cord injury: more than just a concept.  

PubMed

Faced with the complex medical challenge presented by spinal cord injuries (SCI) and considering the lack of any available curative therapy, the development of a novel method of delivering existing drugs or candidate agents can be perceived to be as important as the development of new therapeutic molecules. By combining three ingredients currently in clinical use or undergoing testing, we have designed a central nervous system targeted delivery system based on apamin-modified polymeric micelles (APM). Apamin, one of the major components of honey bee venom, serves as the targeting moiety, poly(ethylene glycol) (PEG) distearoylphosphatidylethanolamine (DSPE) serves as the drug-loaded material, and curcumin is used as the therapeutic agent. Apamin was conjugated with NHS (N-hydroxysuccinimide)-PEG-DSPE in a site-specific manner, and APM were prepared by a thin-film hydration method. A formulation comprising 0.5 mol % targeting ligand with 50 nm particle size showed strong targeting efficiency in vivo and was evaluated in pharmacodynamic assays. A 7-day treatment by daily intravenous administration of low doses of APM (corresponding to 5 mg/kg of curcumin) was performed. Significantly enhanced recovery and prolonged survival was found in the SCI mouse model, as compared to sham-treated groups, with no apparent toxicity. A single dose of apamin-conjugated polymers was about 700-fold lower than the LD50 amount, suggesting that APM and apamin have potential for clinical applications as spinal cord targeting ligand for delivery of agents in treatment of diseases of the central nervous system. PMID:25098949

Wu, Jin; Jiang, Hong; Bi, Qiuyan; Luo, Qingsong; Li, Jianjun; Zhang, Yan; Chen, Zhangbao; Li, Chong

2014-09-01

118

Erythrocyte-mediated delivery of phenylalanine ammonia lyase for the treatment of phenylketonuria in BTBR-Pah(enu2) mice.  

PubMed

Phenylketonuria (PKU) is an autosomal recessive genetic disease caused by defects in the phenylalanine hydroxylase gene. Preclinical and clinical investigations suggest that phenylalanine ammonia lyase (PAL) could be an effective alternative for the treatment of PKU. The aim of this study is to investigate if erythrocytes loaded with PAL may act as a safe delivery system able to overcome bioavailability issues and to provide, in vivo, a therapeutically relevant concentration of enzyme. Murine erythrocytes were loaded with recombinant PAL from Anabaena variabilis (rAvPAL) and their ability to perform as bioreactors was assessed in vivo in adult BTBR-Pah(enu2) mice, the genetic murine model of PKU. Three groups of mice were treated with a single i.v. injection of rAvPAL-RBCs at three different doses to select the most appropriate one for assessment of efficacy. Repeated administrations at 9-10day-intervals of the selected dose for 10weeks showed that the therapeutic effect was persistent and not affected by the generation of antibodies induced by the recombinant enzyme. This therapeutic approach deserves further in vivo evaluation either as a potential option for the treatment of PKU patients or as a possible model for the substitutive enzymatic treatment of other inherited metabolic disorders. PMID:25151978

Rossi, Luigia; Pierigè, Francesca; Carducci, Claudia; Gabucci, Claudia; Pascucci, Tiziana; Canonico, Barbara; Bell, Sean M; Fitzpatrick, Paul A; Leuzzi, Vincenzo; Magnani, Mauro

2014-11-28

119

Nano carriers that enable co-delivery of chemotherapy and RNAi agents for treatment of drug-resistant cancers.  

PubMed

Tumor cells exhibit drug resistant phenotypes that decrease the efficacy of chemotherapeutic treatments. The drug resistance has a genetic basis that is caused by an abnormal gene expression. There are several types of drug resistance: efflux pumps reducing the cellular concentration of the drug, alterations in membrane lipids that reduce cellular uptake, increased or altered drug targets, metabolic alteration of the drug, inhibition of apoptosis, repair of the damaged DNA, and alteration of the cell cycle checkpoints (Gottesman et al., 2002; Holohan et al., 2013). siRNA is used to silence the drug resistant phenotype and prevent this drug resistance response. Of the listed types of drug resistance, pump-type resistance (e.g., high expression of ATP-binding cassette transporter proteins such as P-glycoproteins (Pgp; also known as multi-drug resistance protein 1 or MDR1, encoded by the ATP-Binding Cassette Sub-Family B Member 1 (ABCB1) gene)) and apoptosis inhibition (e.g., expression of anti-apoptotic proteins such as Bcl-2) are the most frequently targeted for gene silencing. The co-delivery of siRNA and chemotherapeutic drugs has a synergistic effect, but many of the current projects do not control the drug release from the nanocarrier. This means that the drug payload is released before the drug resistance proteins have degraded and the drug resistance phenotype has been silenced. Current research focuses on cross-linking the carrier's polymers to prevent premature drug release, but these carriers still rely on environmental cues to release the drug payload, and the drug may be released too early. In this review, we studied the release kinetics of siRNA and chemotherapeutic drugs from a broad range of carriers. We also give examples of carriers used to co-deliver siRNA and drugs to drug-resistant tumor cells, and we examine how modifications to the carrier affect the delivery. Lastly, we give our recommendations for the future directions of the co-delivery of siRNA and chemotherapeutic drug treatments. PMID:24924617

Tsouris, Vasilios; Joo, Min Kyung; Kim, Sun Hwa; Kwon, Ick Chan; Won, You-Yeon

2014-01-01

120

A preliminary study of painless and effective transdermal botulinum toxin A delivery by jet nebulization for treatment of primary hyperhidrosis  

PubMed Central

Background Hyperhidrosis is a chronic disease characterized by increased sweat production. Local injections of botulinum toxin A (BTX-A) have been extensively used for treatment of primary hyperhidrosis (idiopathic). The current treatment for this condition involves several intradermal injections, resulting in poor patient compliance due to injection-related pain. Therefore, new protocols, including an improved anesthetic regimen, are required. Aim We designed the present study to determine whether JetPeel™-3, a medical device used for transdermal delivery of drugs by jet nebulization, could be used to deliver lidocaine prior to the standard multiple BTX-A injections or deliver lidocaine together with BTX-A in order to determine the protocol giving better results in terms of procedure-related pain, sweating, and patient satisfaction in subjects affected by primary axillary, palmar or plantar hyperhidrosis. Materials and methods Twenty patients with a visual analog scale (VAS) sweating score ? 8 cm were randomized to receive lidocaine 2% (5 mL) delivered by JetPeel™-3 followed by multiple injections of BTX-A (100 units) or lidocaine 2% (5 mL) and BTX-A (50 units) delivered together by JetPeel™-3. Effect of treatment on sweating was measured by VAS (0= minimum sweating; 10= maximum sweating) at 3-month follow-up. Pain induced by the procedure was assessed by VAS (0= minimum pain; 10= maximum pain) immediately after the procedure. Patient satisfaction was assessed at 3-month follow-up using a 5-point scale (1= not at all satisfied; 2= not satisfied; 3= partially satisfied; 4= satisfied; 5= highly satisfied). Results Both treatment modalities reduced sweating at 3-month follow-up, if compared with baseline (all P<0.001). Delivery of lidocaine and BTX-A by JetPeel™-3 resulted in lower procedure-related pain and reduced sweating, if compared with lidocaine delivered by JetPeel™-3 followed by multiple BTX-A injections (all P<0.001). Patient satisfaction with the procedure was higher in the group receiving lidocaine and BTX-A treatment by JetPeel™-3, if compared with lidocaine delivered by JetPeel™-3 followed by multiple BTX-A injections (P<0.001). No side effects were observed in both groups. Conclusion Lidocaine and BTX-A can be safely delivered together by JetPeel™-3 to treat primary palmar, plantar and axillary hyperhidrosis, resulting in lower procedure-related pain, improved sweating and higher patient satisfaction, if compared with lidocaine delivered by JetPeel™-3 followed by standard BTX-A injection therapy. Our protocol delivering lidocaine and BTX-A together by JetPeel™-3 requires a reduced quantity of BTX-A, further supporting the use of the transdermal drug delivery by jet nebulization over standard injection therapy for treatment of primary hyperhidrosis. PMID:25075176

Iannitti, Tommaso; Palmieri, Beniamino; Aspiro, Anna; Di Cerbo, Alessandro

2014-01-01

121

Kollidon ® SR colloidal particles as vehicles for oral morphine delivery in pain treatment  

Microsoft Academic Search

Due to the great importance of new therapeutic routes for morphine in pain treatment, several investigations are under development. In this way, the design of a liquid system for the oral administration of morphine would be of great help, especially in patients with difficulties in swallowing (children and elderly people). The systems studied in this work are kollidon® SR microparticles,

José L. Arias; Amparo Gómez-Gallo; Ángel V. Delgado

2009-01-01

122

Long-Term Effects of Methylphenidate Transdermal Delivery System Treatment of ADHD on Growth  

ERIC Educational Resources Information Center

Objective: To examine the long-term effects of the methylphenidate transdermal system (MTS) on the growth of children being treated for attention-deficit/hyperactivity disorder. Method: Height, weight, and body mass index (BMI) were measured in 127 children ages 6 to 12 at longitudinal assessments for up to 36 months of treatment with MTS. These…

Faraone, Stephen V.; Giefer, Eldred E.

2007-01-01

123

Electrochemotherapy: results of cancer treatment using enhanced delivery of bleomycin by electroporation  

Microsoft Academic Search

Over the last decade a new cancer treatment modality, electrochemotherapy, has emerged. By using short, intense electric pulses that surpass the capacitance of the cell membrane, permeabilization can occur (electroporation). Thus, molecules that are otherwise non-permeant can gain direct access to the cytosol of cells in the treated area.A highly toxic molecule that does not usually pass the membrane barrier

Anita Gothelf; Lluis M Mir; Julie Gehl

2003-01-01

124

Subcutaneous delivery of sumatriptan in the treatment of migraine and primary headache  

PubMed Central

Subcutaneous sumatriptan is an effective treatment for pain from acute migraine headache, and can be used in patients with known migraine syndrome and in patients with primary headaches when secondary causes have been excluded. In limited comparative trials, subcutaneous sumatriptan performed in a manner comparable with oral eletriptan and intravenous metoclopramide, was superior to intravenous aspirin and intramuscular trimethobenzamide-diphenhydramine, and was inferior to intravenous prochlorperazine for pain relief. The most common side effects seen with subcutaneous sumatriptan are injection site reactions and triptan sensations. As with all triptans, there is a risk of rare cardiovascular events with subcutaneous sumatriptan and its use should be limited to those without known cerebrovascular disease and limited in those with known cardiovascular risk factors and unknown disease status. In studies of patient preference and tolerability, the subcutaneous formulation has a faster time of onset and high rate of efficacy when compared with the oral formulation, but the oral formulation appears to be better tolerated. It is important to consider the needs of the patient, their past medical history, and what aspects of migraine treatment are most important to the patient when considering treatment of acute migraine or primary headache. Subcutaneous sumatriptan is a good first-line agent for the treatment of pain from acute migraine headaches and primary headaches. PMID:22272067

Moore, Johanna C; Miner, James R

2012-01-01

125

Three dimensional transient multifield analysis of a piezoelectric micropump for drug delivery system for treatment of hemodynamic dysfunctions.  

PubMed

In this paper, we present design of a transdermal drug delivery system for treatment of cardiovascular or hemodynamic disorders such as hypertension. The system comprises of integrated control electronics and microelectromechanical system devices such as micropump, micro blood pressure sensor and microneedle array. The objective is to overcome the limitations of oral therapy such as variable absorption profile and the need for frequent dosing, by fabricating a safe, reliable and cost effective transdermal drug delivery system to dispense various pharmacological agents through the skin for treatment of hemodynamic dysfunction such as hypertension. Moreover, design optimization of a piezoelectrically actuated valveless micropump is presented for the drug delivery system. Because of the complexity in analysis of piezoelectric micropump, which involves structural and fluid field couplings in a complicated geometrical arrangement, finite element (FE) numerical simulation rather than an analytical system has been used. The behavior of the piezoelectric actuator with biocompatible polydimethylsiloxane membrane is first studied by conducting piezoelectric analysis. Then the performance of the valveless micropump is analyzed by building a three dimensional electric-solid-fluid model of the micropump. The effect of geometrical dimensions on micropump characteristics and efficiency of nozzle/diffuser elements of a valveless micropump is investigated in the transient analysis using multiple code coupling method. The deformation results of the membrane using multifield code coupling analysis are in good agreement with analytical as well as results of single code coupling analysis of a piezoelectric micropump. The analysis predicts that to enhance the performance of the micropump, diffuser geometrical dimensions such as diffuser length, diffuser neck width and diffuser angle need to be optimized. Micropump flow rate is not strongly affected at low excitation frequencies from 10 to 200 Hz. The excitation voltage is the more dominant factor that affects the flow rate of the micropump as compared with the excitation frequency. However, at extremely high excitation frequencies beyond 8,000 Hz, the flow rate drops as the membrane exhibits multiple bending peaks which is not desirable for fluid flow. Following the extensive numerical analysis, actual fabrication and performance characterization of the micropump is presented. The performance of the micropump is characterized in terms of piezoelectric actuator deflection and micropump flow rate at different operational parameters. The set of multifield simulations and experimental measurement of deflection and flow rate at varying voltage and excitation frequency is a significant advance in the study of the electric-solid-fluid coupled field effects as it allows transient, three dimensional piezoelectric and fluid analysis of the micropump thereby facilitating a more realistic multifield analysis. The results of the present study will also help to conduct relevant strength duration tests of integrated drug delivery device with micropump and microneedle array in future. PMID:19030990

Nisar, Asim; Afzulpurkar, Nitin; Tuantranont, Adisorn; Mahaisavariya, Banchong

2008-12-01

126

Bovine serum albumin-meloxicam nanoaggregates laden contact lenses for ophthalmic drug delivery in treatment of postcataract endophthalmitis.  

PubMed

Postcataract endophthalmitis treatment through eye drops is of low corneal bioavailability and short residence time. The dominant NSAIDs therapy also suffers from severe ocular irritancy and low patients compliance. This study dispersed bovine serum albumin (BSA) coated meloxicam (MX) nanocrystals encapsulating nanoaggregates (BSA-MX-NA) in contact lenses to reduce drug ocular irritancy and increased drug release duration. The BSA-MX-NA (?100nm) were prepared using acid-base neutralization in aqueous solutions and were dispersed in poly(hydroxylethyl methacrylate) gels, which are common contact lens materials. Drug release studies showed that the gels released the drug for about 5 days. The proposed drug transport mechanism is a diffusion process which can be described by the Ritger-Peppas model with the diffusional exponent n of 0.4768. The drug release can be affected by the gel thickness and the cross-linking degree. A 400 micro thick gels with 100?L cross-linker TEGDMA leads to an adequate meloxicam release for therapeutic application. The ocular irritation studies showed that BSA-MX-NA loaded p-HEMA gels are significantly less irritating to the ocular tissues as compared to marketed MX solutions. The developed contact lenses loaded with BSA-MX-NA could be very useful for extended delivery in postcataract endophthalmitis treatment. PMID:25158220

Zhang, Wenji; Zu, Dongni; Chen, Jianting; Peng, Junjie; Liu, Yun; Zhang, Hefeng; Li, Sanming; Pan, Weisan

2014-11-20

127

Tamoxifen-poly(ethylene glycol)-thiol gold nanoparticle conjugates: enhanced potency and selective delivery for breast cancer treatment.  

PubMed

The breast cancer treatment drug tamoxifen has been widely administered for more than three decades. This small molecule competes with 17beta-estradiol for binding to estrogen receptor, a hormone receptor upregulated in a majority of breast cancers, subsequently initiating programmed cell death. We have synthesized a thiol-PEGylated tamoxifen derivative that can be used to selectively target and deliver plasmonic gold nanoparticles to estrogen receptor positive breast cancer cells with up to 2.7-fold enhanced drug potency in vitro. Optical microscopy/spectroscopy, time-dependent dose-response data, and estrogen competition studies indicate that augmented activity is due to increased rates of intracellular tamoxifen transport by nanoparticle endocytosis, rather than by passive diffusion of the free drug. Both ligand- and receptor-dependent intracellular delivery of gold nanoparticles suggest that plasma membrane localized estrogen receptor alpha may facilitate selective uptake and retention of this and other therapeutic nanoparticle conjugates. Combined targeting selectivity and enhanced potency provides opportunities for both multimodal endocrine treatment strategies and adjunctive laser photothermal therapy. PMID:19919059

Dreaden, Erik C; Mwakwari, Sandra C; Sodji, Quaovi H; Oyelere, Adegboyega K; El-Sayed, Mostafa A

2009-12-01

128

Colon Delivery of Budesonide Using Solid Dispersion in Dextran for the Treatment and Secondary Prevention of Ulcerative Colitis in Rat  

PubMed Central

Objectives: Ulcerative colitis is characterized by local inflammation. Targeting drugs directly to the site of injury has the benefit of lower adverse effects and more effective therapy. The aim of this study was colon targeted delivery of budesonide to deliver the major part of the drug to the colon. Methods: Matrix tablets of budesonide from solid dispersion of drug with dextran were prepared using different drug to polymer ratios and three molecular weights of dextran. The physical evaluation and drug release behavior were studied. In vivo efficacy of the selected formulation against acetic acid induced colitis in rats was evaluated and compared to the control (untreated) and references (mesalazine and budesonide suspensions) groups. Results: The results showed that solid dispersion of budesonide with dextran in the ratio of 1:7 using molecular weight (MW) of 10,000 dextran (SDT710) released 25% of the drug in the first 6 hours and 100% in caecal and colonic contents. It could target the drug to colon with improvement in some of the inflammatory signs of induced ulcerative colitis in rat. Treatment with SDT710 could improve not only the percent of involvement also macroscopic damage parameters. The macroscopic parameters included weight/length ratio of the colon, ulcer area, damage score, and ulcer index reduced in comparison to the control group and conventional suspension of budesonide; however, only weight/length ratio was significant. Conclusions: In the experimental model studied, the new colonic delivery system significantly improved the efficacy of budesonide in the weight/length ratio of the colon in induced colitis in rats. PMID:21566772

Varshosaz, Jaleh; Ahmadi, Fatemeh; Emami, Jaber; Tavakoli, Naser; Minaiyan, Mohsen; Mahzouni, Parvin; Dorkoosh, Farid

2010-01-01

129

Delivery presentations  

MedlinePLUS

Delivery presentation describes the way the baby (fetus) is positioned to come down the birth canal for delivery. ... THE DELIVERY PROCESS The delivery process is described in terms of fetal station, lie, attitude, and presentation. Fetal station: ...

130

New scanner fiber optic delivery system for laser phototherapy in the treatment of neonatal jaundice  

NASA Astrophysics Data System (ADS)

The authors have introduced laser phototherapy for the treatment of neonatal jaundice. Clinical trials have demonstrated its high efficacy compared to the conventionally used fluorescent phototherapy. In this paper a new modification to laser irradiation in phototherapy can be achieved by scanning the laser output beam in the selected wavelength of irradiation (488 nm) through a fiberoptic bundle which irradiate the skin of the baby. Scanning of the laser beam provides intermittent irradiation at high frequency, which can provide the same therapeutic efficacy with almost half the power of laser irradiation.

Hamza, Mostafa; Hamza, Mohammad S. E.

1995-05-01

131

Drug delivery through the skin barrier enhanced by treatment with tissue-tolerable plasma.  

PubMed

Most treatments in dermatology and cosmetology are based on the penetration of topically applied drugs into the skin or through the skin barrier to the target structure in the living tissue. In the case of healthy skin, scarcely 1% of the applied drugs pass the skin barrier, depending on their chemical properties. Therefore, different physical and chemical methods have been developed to stimulate the penetration process. All these methods are based on the partial destruction of the barrier. In this study, an electrical tissue-tolerable plasma (TTP) was used to increase the penetration of a topically applied model drug (fluorescent dye) through the skin barrier. Using laser scanning microscopy, the distribution of the model drug in different depths of the skin was investigated. It was found that the plasma treatment of the skin is a very efficient process to deliver topically applied substances into the living tissue. In the case of the non-plasma-treated skin, it was found that the fluorescent dye could be detected exclusively on the skin surface. If the dye was applied to the TTP-treated skin, it could be observed in high concentration also in deeper parts of the skin extending down to the stratum basale and the papillary structure. PMID:21371126

Lademann, Olaf; Richter, Heike; Meinke, Martina C; Patzelt, Alexa; Kramer, Axel; Hinz, Peter; Weltmann, Klaus-Dieter; Hartmann, Bernd; Koch, Stefan

2011-06-01

132

The VACS Index Accurately Predicts Mortality and Treatment Response among Multi-Drug Resistant HIV Infected Patients Participating in the Options in Management with Antiretrovirals (OPTIMA) Study  

PubMed Central

Objectives The VACS Index is highly predictive of all-cause mortality among HIV infected individuals within the first few years of combination antiretroviral therapy (cART). However, its accuracy among highly treatment experienced individuals and its responsiveness to treatment interventions have yet to be evaluated. We compared the accuracy and responsiveness of the VACS Index with a Restricted Index of age and traditional HIV biomarkers among patients enrolled in the OPTIMA study. Methods Using data from 324/339 (96%) patients in OPTIMA, we evaluated associations between indices and mortality using Kaplan-Meier estimates, proportional hazards models, Harrel’s C-statistic and net reclassification improvement (NRI). We also determined the association between study interventions and risk scores over time, and change in score and mortality. Results Both the Restricted Index (c?=?0.70) and VACS Index (c?=?0.74) predicted mortality from baseline, but discrimination was improved with the VACS Index (NRI?=?23%). Change in score from baseline to 48 weeks was more strongly associated with survival for the VACS Index than the Restricted Index with respective hazard ratios of 0.26 (95% CI 0.14–0.49) and 0.39(95% CI 0.22–0.70) among the 25% most improved scores, and 2.08 (95% CI 1.27–3.38) and 1.51 (95%CI 0.90–2.53) for the 25% least improved scores. Conclusions The VACS Index predicts all-cause mortality more accurately among multi-drug resistant, treatment experienced individuals and is more responsive to changes in risk associated with treatment intervention than an index restricted to age and HIV biomarkers. The VACS Index holds promise as an intermediate outcome for intervention research. PMID:24667813

Brown, Sheldon T.; Tate, Janet P.; Kyriakides, Tassos C.; Kirkwood, Katherine A.; Holodniy, Mark; Goulet, Joseph L.; Angus, Brian J.; Cameron, D. William; Justice, Amy C.

2014-01-01

133

The impacts of dental filling materials on RapidArc treatment planning and dose delivery: Challenges and solution  

SciTech Connect

Purpose: The presence of high-density material in the oral cavity creates dose perturbation in both downstream and upstream directions at the surfaces of dental filling materials (DFM). In this study, the authors have investigated the effect of DFM on head and neck RapidArc treatment plans and delivery. Solutions are proposed to address (1) the issue of downstream dose perturbation, which might cause target under dosage, and (2) to reduce the upstream dose from DFM which may be the primary source of mucositis. In addition, an investigation of the clinical role of a custom-made plastic dental mold/gutter (PDM) in sparing the oral mucosa and tongue reaction is outlined.Methods: The influence of the dental filling artifacts on dose distribution was investigated using a geometrically well-defined head and neck intensity modulated radiation therapy (IMRT) verification phantom (PTW, Freiberg, Germany) with DFM inserts called amalgam, which contained 50% mercury, 25% silver, 14% tin, 8% copper, and 3% other trace metals. Three RapidArc plans were generated in the Varian Eclipse System to treat the oral cavity using the same computer tomography (CT) dataset, including (1) a raw CT image, (2) a streaking artifacts region, which was replaced with a mask of 10 HU, and (3) a 2 cm-thick 6000 HU virtual filter [a volume created in treatment planning system to compensate for beam attenuation, where the thickness of this virtual filter is based on the measured percent depth dose (PDD) data and Eclipse calculation]. The dose delivery for the three plans was verified using Gafchromic-EBT2 film measurements. The custom-made PDM technique to reduce backscatter dose was clinically tested on four head and neck cancer patients (T3, N1, M0) with DFM, two patients with PDM and the other two patients without PDM. The thickness calculation of the PDM toward the mucosa and tongue was purely based on the measured upstream dose. Patients’ with oral mucosal reaction was clinically examined initially and weekly during the course of radiotherapy.Results: For a RapidArc treatment technique, the backscatter dose from the DFM insert was measured to be 9.25 ± 2.17 in the IMRT-verification-phantom. The measured backscatter upstream dose from DFM for a single-field was 22% higher than without the DFM, whereas the downstream dose was lower by 14%. The values of homogeneity index for the plans with and without the application of mask were 0.09 and 0.14, respectively. The calculated mean treatment planning volume (PTV) dose differed from the delivered dose by 13% and was reduced to 2% when using the mask and virtual filter together. A grade 3 mucosa reaction was observed in the control group after 22–24 fractions (44–48 Gy). In contrast, no grade 3 mucositis was observed in the patients wearing the PDM after 25–26 fractions (50–52 Gy).Conclusions: The backscatter from the DFM for a single, parallel-opposed fields, and RapidArc treatment technique was found significant. The application of mask in replacing streaking artifacts can be useful in improving dose homogeneity in the PTV. The use of a virtual filter around the teeth during the planning phase reduces the target underdosage issue in the phantom. Furthermore, a reduction in mucositis is observed in the head and neck patients with the use of PDM.

Mail, Noor; Al-Ghamdi, S.; Saoudi, A. [Princess Norah Oncology Center, National Guard Health Affairs, Jeddah 21423, Saudi Arabia and King Abdullah International Medical Research Center, Jeddah 21423 (Saudi Arabia)] [Princess Norah Oncology Center, National Guard Health Affairs, Jeddah 21423, Saudi Arabia and King Abdullah International Medical Research Center, Jeddah 21423 (Saudi Arabia); Albarakati, Y.; Ahmad Khan, M.; Saeedi, F.; Safadi, N. [Princess Norah Oncology Center, National Guard Health Affairs, Jeddah 21423 (Saudi Arabia)] [Princess Norah Oncology Center, National Guard Health Affairs, Jeddah 21423 (Saudi Arabia)

2013-08-15

134

Delivery of Amphotericin B for Effective Treatment of Candida Albicans Induced Dermal Mycosis in Rats via Emulgel System: Formulation and Evaluation  

PubMed Central

Background: Amphotericin B (AmB) is among the gold standard antifungal agents used for the treatment of the wide range of fungal infections. However, the drug has various side- effects. Transdermal approach for the delivery of drug is one of the accepted and convenient modes of drug delivery. Aim: The current work was designed to formulate and to evaluate the AmB emulgel system. Materials and Methods: In the preparation of AmB emulgel, Carbopol 930 was used as a gel in this study. The formulation was evaluated for viscosity, spreadability, drug content, drug release and in vitro and in vivo antifungal testing. Results: AmB emulgel was found to penetrate skin effectively and without any irritation. Further, in vivo studies revealed effective therapeutic potential against Candida albicans induced dermal mycosis. Conclusions: The current work, for the first time, revealed effective delivery of AmB across the skin. PMID:25071257

Ganeshpurkar, Aditya; Vaishya, Pooja; Jain, Sumeet; Pandey, Vikas; Bansal, Divya; Dubey, Nazneen

2014-01-01

135

Brain-Delivery of Zinc-Ions as Potential Treatment for Neurological Diseases: Mini Review  

PubMed Central

Homeostasis of metal ions such as Zn2+ is essential for proper brain function. Moreover, the list of psychiatric and neurodegenerative disorders involving a dysregulation of brain Zn2+-levels is long and steadily growing, including Parkinson’s and Alzheimer’s disease as well as schizophrenia, attention deficit and hyperactivity disorder, depression, amyotrophic lateral sclerosis, Down's syndrome, multiple sclerosis, Wilson’s disease and Pick’s disease. Furthermore, alterations in Zn2+-levels are seen in transient forebrain ischemia, seizures, traumatic brain injury and alcoholism. Thus, the possibility of altering Zn2+-levels within the brain is emerging as a new target for the prevention and treatment of psychiatric and neurological diseases. Although the role of Zn2+ in the brain has been extensively studied over the past decades, methods for controlled regulation and manipulation of Zn2+ concentrations within the brain are still in their infancy. Since the use of dietary Zn2+ supplementation and restriction has major limitations, new methods and alternative approaches are currently under investigation, such as the use of intracranial infusion of Zn2+ chelators or nanoparticle technologies to elevate or decrease intracellular Zn2+ levels. Therefore, this review briefly summarizes the role of Zn2+ in psychiatric and neurodegenerative diseases and highlights key findings and impediments of brain Zn2+-level manipulation. Furthermore, some methods and compounds, such as metal ion chelation, redistribution and supplementation that are used to control brain Zn2+-levels in order to treat brain disorders are evaluated. PMID:22102982

Grabrucker, Andreas M.; Rowan, Magali; Garner, Craig C.

2011-01-01

136

Kollidon SR colloidal particles as vehicles for oral morphine delivery in pain treatment.  

PubMed

Due to the great importance of new therapeutic routes for morphine in pain treatment, several investigations are under development. In this way, the design of a liquid system for the oral administration of morphine would be of great help, especially in patients with difficulties in swallowing (children and elderly people). The systems studied in this work are kollidon SR microparticles, a biodegradable polymer classically used as excipient in the design of solid dosage forms, as vehicles for morphine. A detailed investigation of the capabilities of the polymer particles to load this drug at their surface is described. Electrophoretic mobility and optical absorbance determinations were used with this aim. The main factors determining the drug incorporation, after incubation of the microparticles in the morphine solutions, were the adsorption time, the type of electrolyte and its concentration, and the drug concentration. The optimum loading conditions were used to perform morphine release evaluations, finding that the release profiles were biphasic since the drug adsorbed was slowly released during 24h after an initial burst release phase. PMID:19167868

Arias, José L; Gómez-Gallo, Amparo; Delgado, Angel V; Ruiz, Ma Adolfina

2009-05-01

137

Reactor beam calculations to determine optimum delivery of epithermal neutrons for treatment of brain tumors  

SciTech Connect

Studies were performed to assess theoretical tumor control probability (TCP) for brain-tumor treatment with boron neutron capture therapy (BNCT) using epithermal neutron sources from reactors. The existing epithermal-neutron beams at the Brookhaven Medical Research Reactor Facility (BMRR), the Petten High Flux Reactor Facility (HWR) and the Finnish Research Reactor 1 (FIR1) have been analyzed and characterized using common analytical and measurement methods allowing for this inter-comparison. Each of these three facilities is unique and each offers an advantage in some aspect of BNCT, but none of these existing facilities excel in all neutron-beam attributes as related to BNCT. A comparison is therefore also shown for a near-optimum reactor beam which does not currently exist but which would be feasible with existing technology. This hypothetical beam is designated BNCT-1 and has a spectrum similar to the FIR-1, the mono-directionality of the HFR and the intensity of the BMRR. A beam very similar to the BNCT-1 could perhaps be achieved with modification of the BMRR, HFR, or FIR, and could certainly be realized in a new facility with today`s technology.

Wheeler, F.J.; Nigg, D.W. [Idaho National Engineering & Environmental Lab., Idaho Falls, ID (United States); Capala, J. [Brookhaven National Lab., Upton, NY (United States)] [and others

1997-10-01

138

Skeletal muscle in motor neuron diseases: therapeutic target and delivery route for potential treatments.  

PubMed

Lower motor neuron (LMN) degeneration occurs in several diseases that affect patients from neonates to elderly and can either be genetically transmitted or occur sporadically. Among diseases involving LMN degeneration, spinal muscular atrophy (SMA) and spinal bulbar muscular atrophy (Kennedy's disease, SBMA) are pure genetic diseases linked to loss of the SMN gene (SMA) or expansion of a polyglutamine tract in the androgen receptor gene (SBMA) while amyotrophic lateral sclerosis (ALS) can either be of genetic origin or occur sporadically. In this review, our aim is to put forward the hypothesis that muscle fiber atrophy and weakness might not be a simple collateral damage of LMN degeneration, but instead that muscle fibers may be the site of crucial pathogenic events in these diseases. In SMA, the SMN gene was shown to be required for muscle structure and strength as well as for neuromuscular junction formation, and a subset of SMA patients develop myopathic pathology. In SBMA, the occurrence of myopathic histopathology in patients and animal models, along with neuromuscular phenotype of animal models expressing the androgen receptor in muscle only has lead to the proposal that SBMA may indeed be a muscle disease. Lastly, in ALS, at least part of the phenotype might be explained by pathogenic events occuring in skeletal muscle. Apart from its potential pathogenic role, skeletal muscle pathophysiological events might be a target for treatments and/or be a preferential route for targeting motor neurons. PMID:20840067

Dupuis, Luc; Echaniz-Laguna, Andoni

2010-10-01

139

Formulation, characterization and evaluation of cyclodextrin-complexed bendamustine-encapsulated PLGA nanospheres for sustained delivery in cancer treatment.  

PubMed

Abstract PLGA nanospheres are considered to be promising drug carrier in the treatment of cancer. Inclusion complex of bendamustine (BM) with epichlorohydrin beta cyclodextrin polymer was prepared by freeze-drying method. Phase solubility study revealed formation of AL type complex with stability constant (Ks?=?645?M(-1)). This inclusion complex was encapsulated into PLGA nanospheres using solid-in-oil-in-water (S/O/W) technique. The particle size and zeta potential of PLGA nanospheres loaded with cyclodextrin-complexed BM were about 151.4?±?2.53?nm and?-?31.9?±?(-3.08)?mV. In-vitro release study represented biphasic release pattern with 20% burst effect and sustained slow release. DSC studies indicated that inclusion complex incorporated in PLGA nanospheres was not in a crystalline state but existed in an amorphous or molecular state. The cytotoxicity experiment was studied in Z-138 cells and IC50 value was found to be 4.3?±?0.11?µM. Cell viability studies revealed that the PLGA nanospheres loaded with complex exerts a more pronounced effect on the cancer cells as compared to the free drug. In conclusion, PLGA nanospheres loaded with inclusion complex of BM led to sustained drug delivery. The nanospheres were stable after 3 months of storage conditions with slight change in their particle size, zeta potential and entrapment efficiency. PMID:25391288

Gidwani, Bina; Vyas, Amber

2014-11-13

140

The effectiveness of a magnetic nanoparticle-based delivery system for BCNU in the treatment of gliomas.  

PubMed

This study describes the creation and characterization of drug carriers prepared using the polymer poly[aniline-co-N-(1-one-butyric acid) aniline] (SPAnH) coated on Fe(3)O(4) cores to form three types of magnetic nanoparticles (MNPs); these particles were used to enhance the therapeutic capacity and improve the thermal stability of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a compound used to treat brain tumors. The average hydrodynamic diameter of the MNPs was 89.2 ± 8.5 nm and all the MNPs displayed superparamagnetic properties. A maximum effective dose of 379.34 ?g BCNU could be immobilized on 1 mg of MNP-3 (bound-BCNU-3). Bound-BCNU-3 was more stable than free-BCNU when stored at 4 °C, 25 °C or 37 °C. Bound-BCNU-3 could be concentrated at targeted sites in vitro and in vivo using an externally applied magnet. When applied to brain tumors, magnetic targeting increased the concentration and retention of bound-BCNU-3. This drug delivery system promises to provide more effective tumor treatment using lower therapeutic doses and potentially reducing the side effects of chemotherapy. PMID:21030073

Hua, Mu-Yi; Liu, Hao-Li; Yang, Hung-Wei; Chen, Pin-Yuan; Tsai, Rung-Ywan; Huang, Chiung-Yin; Tseng, I-Chou; Lyu, Lee-Ang; Ma, Chih-Chun; Tang, Hsiang-Jun; Yen, Tzu-Chen; Wei, Kuo-Chen

2011-01-01

141

Co-Delivery of Antiviral and Antifungal Therapeutics for the Treatment of Sexually Transmitted Infections using a Moldable, Supramolecular Hydrogel.  

PubMed

In this investigation, a therapeutic co-delivery hydrogel system is developed to provide effective HIV prophylaxis, alongside the prevention and/or treatment of candidiasis. Two components-a HIV reverse transcriptase inhibitor, tenofovir, and a cationic macromolecular antifungal agent derived from a vitamin D-functionalized polycarbonate (VD/BnCl (1:30))-are formulated into biodegradable vitamin D-functionalized polycarbonate/PEG-based supramolecular hydrogels. The hydrogels exhibit thixotropic properties and can be easily spread across surfaces for efficient drug absorption. Sustained release of tenofovir from the hydrogel is observed, where approximately 85% tenofovir is released within 3 h. VD/BnCl (1:30) does not impede drug diffusion from the hydrogel as the drug release profiles are similar with and without the polycation. Antimicrobial efficacy studies indicate that the hydrogels kill C. albicans efficiently with a minimum bactericidal concentration (MBC) of 0.25-0.5 g L(-1) . These hydrogels also eradicate C. albicans biofilm effectively at 4× MBC. When human dermal fibroblasts (as model mammalian cells) are treated with these hydrogels, cell viability remains high at above 80%, demonstrating excellent biocompatibility. When applied topically, this dual-functional hydrogel can potentially prevent HIV transmission and eliminate microbes that cause infections in the vulvovagina region. PMID:25234003

Lee, Ashlynn L Z; Ng, Victor W L; Poon, Ghim Lee; Ke, Xiyu; Hedrick, James L; Yang, Yi Yan

2014-09-18

142

Bimatoprost-Loaded Ocular Inserts as Sustained Release Drug Delivery Systems for Glaucoma Treatment: In Vitro and In Vivo Evaluation  

PubMed Central

The purpose of the present study was to develop and assess a novel sustained-release drug delivery system of Bimatoprost (BIM). Chitosan polymeric inserts were prepared using the solvent casting method and characterized by swelling studies, infrared spectroscopy, differential scanning calorimetry, drug content, scanning electron microscopy and in vitro drug release. Biodistribution of 99mTc-BIM eye drops and 99mTc-BIM-loaded inserts, after ocular administration in Wistar rats, was accessed by ex vivo radiation counting. The inserts were evaluated for their therapeutic efficacy in glaucomatous Wistar rats. Glaucoma was induced by weekly intracameral injection of hyaluronic acid. BIM-loaded inserts (equivalent to 9.0 µg BIM) were administered once into conjunctival sac, after ocular hypertension confirmation. BIM eye drop was topically instilled in a second group of glaucomatous rats for 15 days days, while placebo inserts were administered once in a third group. An untreated glaucomatous group was used as control. Intraocular pressure (IOP) was monitored for four consecutive weeks after treatment began. At the end of the experiment, retinal ganglion cells and optic nerve head cupping were evaluated in the histological eye sections. Characterization results revealed that the drug physically interacted, but did not chemically react with the polymeric matrix. Inserts sustainedly released BIM in vitro during 8 hours. Biodistribution studies showed that the amount of 99mTc-BIM that remained in the eye was significantly lower after eye drop instillation than after chitosan insert implantation. BIM-loaded inserts lowered IOP for 4 weeks, after one application, while IOP values remained significantly high for the placebo and untreated groups. Eye drops were only effective during the daily treatment period. IOP results were reflected in RGC counting and optic nerve head cupping damage. BIM-loaded inserts provided sustained release of BIM and seem to be a promising system for glaucoma management. PMID:24788066

Franca, Juçara Ribeiro; Foureaux, Giselle; Fuscaldi, Leonardo Lima; Ribeiro, Tatiana Gomes; Rodrigues, Lívia Bomfim; Bravo, Renata; Castilho, Rachel Oliveira; Yoshida, Maria Irene; Cardoso, Valbert Nascimento; Fernandes, Simone Odília; Cronemberger, Sebastião; Ferreira, Anderson José; Faraco, André Augusto Gomes

2014-01-01

143

Hydrophobic chitosan sponges modified by aluminum monostearate and dehydrothermal treatment as sustained drug delivery system.  

PubMed

The aim of this study is to develop hydrophobic chitosan sponges by using novel simple preparation technique in which hydrophobicity of chitosan was modified by aluminum monostearate (Alst) and dehydrothermal treatment (DHT). Alst was able to dissociate and to cleave stearate ion in 2% w/v lactic acid. Composite dispersion of chitosan and Alst (CLA) could be easily prepared by simple mixing at room temperature. The pH value of the CLA dispersions and particle size of the chitosan-Alst complex in the system comprising low chitosan concentration significantly increased by mixing time. The dispersions were further fabricated into sponges by using lyophilization technique and DHT. FT-IR spectra analysis indicated amidation between amino group of chitosan and carboxyl group of stearate side chain after DHT. Contact angle measurement was applied to evaluate hydrophilic/hydrophobic properties of the prepared sponges. Swelling behavior of the sponges was investigated in three different medium namely acetate buffer (pH4.0), phosphate buffer (pH7.4) and carbonate buffer (pH10.0). Drug release study was conducted in phosphate buffer pH7.4 at 37°C by using asiaticoside as a model drug. Contact angle measurement revealed that addition of Alst and DHT enhanced the hydrophobicity of the materials. Swelling of the sponges decreased as Alst amount increased. Swelling behavior of the sponges was coincident with the release of asiaticoside in which the sponge containing higher Alst amount apparently exhibited the sustained release character. Release of asiaticoside from CLA sponges fitted well with first-order kinetic and the exponent value (n) in power law model indicated that the main release mechanism was Fickian diffusion. From this study, we found the potential of the prepared hydrophobic chitosan sponges for further application as drug-sustained-release, porous wound dressing. PMID:25063173

Yodkhum, Kotchamon; Phaechamud, Thawatchai

2014-09-01

144

Biopolymeric mucoadhesive bilayer patch of pravastatin sodium for buccal delivery and treatment of patients with atherosclerosis.  

PubMed

Mucoadhesive bilayer buccal patch has been developed to improve the bioavailability and therapeutic efficacy along with providing sustained release of pravastatin sodium. Buccal patches comprising of varying composition of Carbopol 934P and HPMC K4M were designed and characterized for surface pH, swelling index, in vitro bioadhesion, mechanical properties, in vitro drug release and in vivo pharmacokinetic and pharmacodynamics performance. All formulations exhibited satisfactory technological parameters and followed non-fickian drug release mechanism. Bilayer buccal patch containing Carbopol 934P and HPMC K4M in 4:6 ratio (PBP5) was considered optimum in terms of swelling, mucoadhesion, mechanical properties and in vitro release profile. Pharmacokinetic studies in rabbits showed significantly higher (p < 0.05) Cmax (75.63 ± 6.98 ng/mL), AUC(0-8) (311.10 ± 5.89 ng/mL/h) and AUC(0-?) (909.42 ± 5.89 ng/mL/h) than pravastatin oral tablet (Cmax - 67.40 ± 9.23 ng/mL, AUC(0-8)-130.33 ± 10.25 ng/mL/h and AUC(0-?)-417.17 ± 5.89 ng/mL/h)). While, increased tmax of buccal patch indicated its sustained release property in comparison to oral tablet. Pharmacodynamic studies in rabbits showed statistically significant difference (p < 0.005) in the reduction of TG (131.10 ± 10.23 mg/dL), VLDL (26.00 ± 2.56 mg/dL) and LDL level (8.99 ± 3.01 mg/dL) as compared to oral conventional tablet. In conclusion, bioavailability from the developed buccal patch of pravastatin was 2.38 times higher than the oral dosage form, indicating its therapeutic potential in the treatment of atherosclerosis. PMID:22630116

Yedurkar, Pramod; Dhiman, Munish Kumar; Petkar, Kailash; Sawant, Krutika

2013-05-01

145

Tat peptide-decorated gelatin-siloxane nanoparticles for delivery of CGRP transgene in treatment of cerebral vasospasm  

PubMed Central

Background Gene transfer using a nanoparticle vector is a promising new approach for the safe delivery of therapeutic genes in human disease. The Tat peptide-decorated gelatin-siloxane (Tat-GS) nanoparticle has been demonstrated to be biocompatible as a vector, and to have enhanced gene transfection efficiency compared with the commercial reagent. This study investigated whether intracisternal administration of Tat-GS nanoparticles carrying the calcitonin gene-related peptide (CGRP) gene can attenuate cerebral vasospasm and improve neurological outcomes in a rat model of subarachnoid hemorrhage. Method A series of gelatin-siloxane nanoparticles with controlled size and surface charge was synthesized by a two-step sol-gel process, and then modified with the Tat peptide. The efficiency of Tat-GS nanoparticle-mediated gene transfer of pLXSN-CGRP was investigated in vitro using brain capillary endothelial cells and in vivo using a double-hemorrhage rat model. For in vivo analysis, we delivered Tat-GS nanoparticles encapsulating pLXSN-CGRP intracisternally using a double-hemorrhage rat model. Results In vitro, Tat-GS nanoparticles encapsulating pLXSN-CGRP showed 1.71 times higher sustained CGRP expression in endothelial cells than gelatin-siloxane nanoparticles encapsulating pLXSN-CGRP, and 6.92 times higher CGRP expression than naked pLXSN-CGRP. However, there were no significant differences in pLXSN-CGRP entrapment efficiency and cellular uptake between the Tat-GS nanoparticles and gelatin-siloxane nanoparticles. On day 7 of the in vivo experiment, the data indicated better neurological outcomes and reduced vasospasm in the subarachnoid hemorrhage group that received Tat-GS nanoparticles encapsulating pLXSN-CGRP than in the group receiving Tat-GS nanoparticles encapsulating pLXSN alone because of enhanced vasodilatory CGRP expression in cerebrospinal fluid. Conclusion Overexpression of CGRP attenuated vasospasm and improved neurological outcomes in an experimental rat model of subarachnoid hemorrhage. Tat-GS nanoparticle-mediated CGRP gene delivery could be an innovative strategy for treatment of cerebral vasospasm after subarachnoid hemorrhage. PMID:23576867

Tian, Xin-Hua; Wang, Zhi-Gang; Meng, Han; Wang, Yu-Hua; Feng, Wei; Wei, Feng; Huang, Zhi-Chun; Lin, Xiao-Ning; Ren, Lei

2013-01-01

146

Co-delivery of docetaxel and endostatin by a biodegradable nanoparticle for the synergistic treatment of cervical cancer  

NASA Astrophysics Data System (ADS)

Cervical cancer remains a major problem in women's health worldwide. In this research, a novel biodegradable d-?-tocopheryl polyethylene glycol 1000 succinate- b-poly(?-caprolactone- ran-glycolide) (TPGS- b-(PCL- ran-PGA)) nanoparticle (NP) was developed as a co-delivery system of docetaxel and endostatin for the synergistic treatment of cervical cancer. Docetaxel-loaded TPGS- b-(PCL- ran-PGA) NPs were prepared and further modified by polyethyleneimine for coating plasmid pShuttle2-endostatin. All NPs were characterized in size, surface charge, morphology, and in vitro release of docetaxel and pDNA. The uptake of coumarin 6-loaded TPGS- b-(PCL- ran-PGA)/PEI-pDsRED by HeLa cells was observed via fluorescent microscopy and confocal laser scanning microscopy. Endostatin expression in HeLa cells transfected by TPGS- b-(PCL- ran-PGA)/PEI-pShuttle2-endostatin NPs was detected using Western blot analysis, and the cell viability of different NP-treated HeLa cells was determined by MTT assay. The HeLa cells from the tumor model, nude mice, were treated with various NPs including docetaxel-loaded-TPGS- b-(PCL- ran-PGA)/PEI-endostatin NPs, and their survival time, tumor volume and body weight were monitored during regimen process. The tumor tissue histopathology was analyzed using hematoxylin and eosin staining, and microvessel density in tumor tissue was evaluated immunohistochemically. The results showed that the TPGS- b-(PCL- ran-PGA)/PEI NPs can efficiently and simultaneously deliver both coumarin-6 and plasmids into HeLa cells, and the expression of endostatin was verified via Western blot analysis. Compared with control groups, the TPGS- b-(PCL- ran-PGA)/PEI-pShuttle2-endostatin NPs significantly decreased the cell viability of HeLa cells ( p < 0.01), inhibited the growth of tumors, and even eradicated the tumors. The underlying mechanism is attributed to synergistic anti-tumor effects by the combined use of docetaxel, endostatin, and TPGS released from NPs. The TPGS- b-(PCL- ran-PGA) NPs could function as multifunctional carrier for chemotherapeutic drugs and genetic material delivery, and offer considerable potential as an ideal candidate for in vivo cancer therapy.

Qiu, Bo; Ji, Minghui; Song, Xiaosong; Zhu, Yongqiang; Wang, Zhongyuan; Zhang, Xudong; Wu, Shu; Chen, Hongbo; Mei, Lin; Zheng, Yi

2012-12-01

147

Control point analysis comparison for 3 different treatment planning and delivery complexity levels using a commercial 3-dimensional diode array.  

PubMed

To investigate the use of "Control Point Analysis" (Sun Nuclear Corporation, Melbourne, FL) to analyze and compare delivered volumetric-modulated arc therapy (VMAT) plans for 3 different treatment planning complexity levels. A total of 30 patients were chosen and fully anonymized for the purpose of this study. Overall, 10 lung stereotactic body radiotherapy (SBRT), 10 head-and-neck (H&N), and 10 prostate VMAT plans were generated on Pinnacle(3) and delivered on a Varian linear accelerator (LINAC). The delivered dose was measured using ArcCHECK (Sun Nuclear Corporation, Melbourne, FL). Each plan was analyzed using "Sun Nuclear Corporation (SNC) Patient 6" and "Control Point Analysis." Gamma passing percentage was used to assess the differences between the measured and planned dose distributions and to assess the role of various control point binning combinations. Of the different sites considered, the prostate cases reported the highest gamma passing percentages calculated with "SNC Patient 6" (97.5% to 99.2% for the 3%, 3mm) and "Control Point Analysis" (95.4% to 98.3% for the 3%, 3mm). The mean percentage of passing control point sectors for the prostate cases increased from 51.8 ± 7.8% for individual control points to 70.6 ± 10.5% for 5 control points binned together to 87.8 ± 11.0% for 10 control points binned together (2%, 2-mm passing criteria). Overall, there was an increasing trend in the percentage of sectors passing gamma analysis with an increase in the number of control points binned together in a sector for both the gamma passing criteria (2%, 2mm and 3%, 3mm). Although many plans passed the clinical quality assurance criteria, plans involving the delivery of high Monitor Unit (MU)/control point (SBRT) and plans involving high degree of modulation (H&N) showed less delivery accuracy per control point compared with plans with low MU/control point and low degree of modulation (prostate). PMID:24480374

Abdellatif, Ady; Gaede, Stewart

2014-01-01

148

Iontophoretic delivery of apomorphine  

Microsoft Academic Search

Apomorphine is a mixed dopamine D1\\/D2 receptor agonist which is potentially useful in the treatment of Parkinson’s disease. The delivery of apomorphine is however complicated because it is not absorbed orally and other delivery routes with the exception of the intravenous route seem to fail. The most interesting route for controlled delivery of apomorphine is transdermal iontophoresis because this could

H. E Junginger

2002-01-01

149

301. Safe and Effective Treatment of Ovarian Cancer Models Using Targeted Adenovirus Vector Delivery and Selective Expression of Tumor Necrosis Factor  

Microsoft Academic Search

Ovarian cancer is the fourth most common cancer among women, and despite advances in therapy most patients still die as a consequence of disease that is disseminated within the peritoneal cavity. Delivery of hTNFa gene to tumors using direct intra-tumoral injection of a non-replicating adenovector is a promising strategy for treatment for a variety of diseases. The relative abundance of

Selva R. Murugesan; Masaki Akiyama; David A. Einfeld; Thomas J. Wickham; C. Richter King

2006-01-01

150

Dosimetric verification and clinical evaluation of a new commercially available Monte Carlo-based dose algorithm for application in stereotactic body radiation therapy (SBRT) treatment planning  

Microsoft Academic Search

Modern cancer treatment techniques, such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT), have greatly increased the demand for more accurate treatment planning (structure definition, dose calculation, etc) and dose delivery. The ability to use fast and accurate Monte Carlo (MC)-based dose calculations within a commercial treatment planning system (TPS) in the clinical setting is now becoming

Margarida Fragoso; Ning Wen; Sanath Kumar; Dezhi Liu; Samuel Ryu; Benjamin Movsas; Ajlouni Munther; Indrin J. Chetty

2010-01-01

151

Efficacy of a portable oxygen concentrator with pulsed delivery for treatment of hypoxemia during anesthesia of wildlife.  

PubMed

Portable battery-driven oxygen concentrators provide an alternative to the use of oxygen cylinders for treatment of hypoxemia during field anesthesia. The aim of this study was to evaluate the use of the EverGo Portable Oxygen Concentrator (Respironics, Murrysville, Pennsylvania 15668, USA) with pulse-dose delivery for improvement of arterial oxygenation during anesthesia of wildlife. This concentrator delivers oxygen in a pulsed flow with pulse volumes from 12 to 70 ml, up to a maximum capacity of 1.05 L/min. The pulse-dose setting shall be adjusted according to the respiratory rate of the animal, e.g., setting 6 for a respiratory rate < or = 15/min. The study included 16 free-ranging brown bears (Ursus arctos), 18 free-ranging bighorn sheep (Ovis canadensis), and five captive reindeer (Rangifer tarandus). Oxygen was administered via two nasal lines that were inserted through the nostrils to the level of the medial canthus of the eyes. Arterial blood samples were collected before, during, and after oxygen therapy and immediately analyzed. When providing oxygen from the portable concentrator, the arterial oxygenation markedly improved in all brown bears and some reindeer, whereas no or minor improvement was seen in the bighorn sheep. The mean +/- SD (range) PaO2 during oxygen supplementation was 134 +/- 29 (90-185) mmHg in the brown bears, 52 +/- 11 (32-67) mmHg in the bighorn sheep, and 79 +/- 19 (61-110) mmHg in the reindeer. The efficacy of the evaluated method may be influenced by ambient temperature, altitude, pulse-dose setting on the concentrator, the animal's respiratory rate, and species-specific physiology during anesthesia. Advantages of the portable oxygen concentrator included small size and low weight, ease of operate, and rechargeablity. PMID:22448511

Fahlman, Asa; Caulkett, Nigel; Arnemo, Jon M; Neuhaus, Peter; Ruckstuhl, Kathreen E

2012-03-01

152

Routes of delivery for CpG and anti-CD137 for the treatment of orthotopic kidney tumors in mice.  

PubMed

We have found previously that the tumor cell lines, Renca (a renal cancer) and MC38 (a colon tumor) which had been injected subcutaneously in mice, could be successfully treated with a combination therapy of an oligodeoxynucleotide (CpG1826) (injected intratumorally) and anti-CD137 antibody (injected intraperitoneally). Thus the combination treatment was expected to initiate a "danger" signal via TLR9 on immune cells, and the anti-CD137 was expected to further activate T cells. In the present study, we found that several other tumor types injected subcutaneously could also be successfully treated with this combination therapy. In addition, we wished to determine if the treatment could work as effectively in an orthotopic metastatic model, which is more physiologically relevant to cancer in humans. Renca was selected as we were familiar with injecting this orthotopically into the outer cortex of the kidney in mice, and it spontaneously metastasizes to lung and abdominal sites. We tested various routes of delivery of CpG combined with intraperitoneal delivery of anti-CD137. Orthotopic tumors were injected with CpG intratumorally, using ultrasound-guided delivery on multiple occasions, combined with anti-CD137 intraperitoneally. A reduction in primary tumor size was observed following intratumoral injection of CpG compared to other treatments. We found that there was a statistically significant increase in survival of mice with orthotopic Renca tumor following intratumoral injection of CpG. However, we determined that the most effective route of delivery of CpG was intravenous, which led to further significantly enhanced survival of mice when combined with anti-CD137 intraperitoneally, likely due to inhibition of metastatic disease. Our data supports future development of this combination therapy for cancer. PMID:24788789

Westwood, Jennifer A; Potdevin Hunnam, Titaina C U; Pegram, Hollie J; Hicks, Rodney J; Darcy, Phillip K; Kershaw, Michael H

2014-01-01

153

Routes of Delivery for CpG and Anti-CD137 for the Treatment of Orthotopic Kidney Tumors in Mice  

PubMed Central

We have found previously that the tumor cell lines, Renca (a renal cancer) and MC38 (a colon tumor) which had been injected subcutaneously in mice, could be successfully treated with a combination therapy of an oligodeoxynucleotide (CpG1826) (injected intratumorally) and anti-CD137 antibody (injected intraperitoneally). Thus the combination treatment was expected to initiate a “danger” signal via TLR9 on immune cells, and the anti-CD137 was expected to further activate T cells. In the present study, we found that several other tumor types injected subcutaneously could also be successfully treated with this combination therapy. In addition, we wished to determine if the treatment could work as effectively in an orthotopic metastatic model, which is more physiologically relevant to cancer in humans. Renca was selected as we were familiar with injecting this orthotopically into the outer cortex of the kidney in mice, and it spontaneously metastasizes to lung and abdominal sites. We tested various routes of delivery of CpG combined with intraperitoneal delivery of anti-CD137. Orthotopic tumors were injected with CpG intratumorally, using ultrasound-guided delivery on multiple occasions, combined with anti-CD137 intraperitoneally. A reduction in primary tumor size was observed following intratumoral injection of CpG compared to other treatments. We found that there was a statistically significant increase in survival of mice with orthotopic Renca tumor following intratumoral injection of CpG. However, we determined that the most effective route of delivery of CpG was intravenous, which led to further significantly enhanced survival of mice when combined with anti-CD137 intraperitoneally, likely due to inhibition of metastatic disease. Our data supports future development of this combination therapy for cancer. PMID:24788789

Westwood, Jennifer A.; Potdevin Hunnam, Titaina C. U.; Pegram, Hollie J.; Hicks, Rodney J.; Darcy, Phillip K.; Kershaw, Michael H.

2014-01-01

154

Slow-release drug delivery through Elvax 40W to the rat retina: implications for the treatment of chronic conditions.  

PubMed

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these diseases. Chronic retinal diseases such as retinal oedema or neovascularization usually require multiple intraocular injections to effectively treat the condition. However, the risks associated with these injections increase with repeated delivery of the drug. Therefore, alternative delivery methods need to be established in order to minimize the risks of reinjection. Several other investigations have developed methods to deliver drugs over extended time, through materials capable of releasing chemicals slowly into the eye. In this investigation, we outline the use of Elvax 40W, a copolymer resin, to act as a vehicle for drug delivery to the adult rat retina. The resin is made and loaded with the drug. The drug-resin complex is then implanted into the vitreous cavity, where it will slowly release the drug over time. This method was tested using 2-amino-4-phosphonobutyrate (APB), a glutamate analogue that blocks the light response of the retina. It was demonstrated that the APB was slowly released from the resin, and was able to block the retinal response by 7 days after implantation. This indicates that slow-release drug delivery using this copolymer resin is effective for treating the retina, and could be used therapeutically with further testing. PMID:25286223

Fiorani, Lavinia; Maccarone, Rita; Fernando, Nilisha; Colecchi, Linda; Bisti, Silvia; Valter, Krisztina

2014-01-01

155

A magnetic mesoporous silica nanoparticle-based drug delivery system for photosensitive cooperative treatment of cancer with a mesopore-capping agent and mesopore-loaded drug  

NASA Astrophysics Data System (ADS)

Lately, there has been a growing interest in anticancer therapy with a combination of different drugs that work by different mechanisms of action, which decreases the possibility that resistant cancer cells will develop. Herein we report on the development of a drug delivery system for photosensitive delivery of a known anticancer drug camptothecin along with cytotoxic cadmium sulfide nanoparticles from a magnetic drug nanocarrier. Core-shell nanoparticles consisting of magnetic iron-oxide-cores and mesoporous silica shells are synthesized with a high surface area (859 m2 g-1) and hexagonal packing of mesopores, which are 2.6 nm in diameter. The mesopores are loaded with anticancer drug camptothecin while entrances of the mesopores are blocked with 2-nitro-5-mercaptobenzyl alcohol functionalized CdS nanoparticles through a photocleavable carbamate linkage. Camptothecin release from this magnetic drug delivery system is successfully triggered upon irradiation with UV light, as measured by fluorescence spectroscopy. Photosensitive anticancer activity of the drug delivery system is monitored by viability studies on Chinese hamster ovarian cells. The treatment of cancer cells with drug loaded magnetic material leads to a decrease in viability of the cells due to the activity of capping CdS nanoparticles. Upon exposure to low power UV light (365 nm) the loaded camptothecin is released which induces additional decrease in viability of CHO cells. Hence, the capping CdS nanoparticles and loaded camptothecin exert a cooperative anticancer activity. Responsiveness to light irradiation and magnetic activity of the nanocarrier enable its potential application for selective targeted treatment of cancer.

Kneževi?, Nikola Ž.; Lin, Victor S.-Y.

2013-01-01

156

Microencapsulation: A promising technique for controlled drug delivery.  

PubMed

MICROPARTICLES OFFER VARIOUS SIGNIFICANT ADVANTAGES AS DRUG DELIVERY SYSTEMS, INCLUDING: (i) an effective protection of the encapsulated active agent against (e.g. enzymatic) degradation, (ii) the possibility to accurately control the release rate of the incorporated drug over periods of hours to months, (iii) an easy administration (compared to alternative parenteral controlled release dosage forms, such as macro-sized implants), and (iv) Desired, pre-programmed drug release profiles can be provided which match the therapeutic needs of the patient. This article gives an overview on the general aspects and recent advances in drug-loaded microparticles to improve the efficiency of various medical treatments. An appropriately designed controlled release drug delivery system can be a foot ahead towards solving problems concerning to the targeting of drug to a specific organ or tissue, and controlling the rate of drug delivery to the target site. The development of oral controlled release systems has been a challenge to formulation scientist due to their inability to restrain and localize the system at targeted areas of gastrointestinal tract. Microparticulate drug delivery systems are an interesting and promising option when developing an oral controlled release system. The objective of this paper is to take a closer look at microparticles as drug delivery devices for increasing efficiency of drug delivery, improving the release profile and drug targeting. In order to appreciate the application possibilities of microcapsules in drug delivery, some fundamental aspects are briefly reviewed. PMID:21589795

Singh, M N; Hemant, K S Y; Ram, M; Shivakumar, H G

2010-07-01

157

Comparing Different Short-Term Service Delivery Methods of Visual-Motor Treatment for First Grade Students in Mainstream Schools  

ERIC Educational Resources Information Center

To compare the efficacy of three different short-term service delivery methods on first grade children with soft neurological signs who suffer from visual-motor difficulties. One hundred and forty seven first grade students who scored below the 21st percentile on the Visual-Motor Integration Test (VMI) were recruited from schools and randomly…

Ratzon, Navah Z.; Lahav, Orit; Cohen-Hamsi, Shifra; Metzger, Yehiela; Efraim, Daniela; Bart, Orit

2009-01-01

158

Women and Heart Disease - Physiologic Regulation of Gene Delivery and Expression: Bioreducible Polymers and Ischemia-Inducible Gene Therapies for the Treatment of Ischemic Heart Disease  

PubMed Central

Ischemic heart disease (IHD) is the leading cause of death in the United States today. This year over 750,000 women will have a new or recurrent myocardial infarction. Currently, the mainstay of therapy for IHD is revascularization. Increasing evidence, however, suggests that revascularization alone is insufficient for the longer-term management of many patients with IHD. To address these issues, innovative therapies that extend beyond revascularization to protection of the myocyte and preservation of ventricular function are required. The emergence of gene therapy and proteomics offers the potential for innovative prophylactic and treatment strategies for IHD. The goal of our research is to develop therapeutic gene constructs for the treatment of myocardial ischemia that are clinically safe and effective. Toward this end, we describe the development of physiologic regulation of gene delivery and expression using bioreducible polymers and ischemia-inducible gene therapies for the potential treatment of ischemic heart disease in women. PMID:19422868

Yockman, James W.; Bull, David A.

2009-01-01

159

A Highly Accurate Technique for the Treatment of Flow Equations at the Polar Axis in Cylindrical Coordinates using Series Expansions. Appendix A  

NASA Technical Reports Server (NTRS)

Numerical methods for solving the flow equations in cylindrical or spherical coordinates should be able to capture the behavior of the exact solution near the regions where the particular form of the governing equations is singular. In this work we focus on the treatment of these numerical singularities for finite-differences methods by reinterpreting the regularity conditions developed in the context of pseudo-spectral methods. A generally applicable numerical method for treating the singularities present at the polar axis, when nonaxisymmetric flows are solved in cylindrical, coordinates using highly accurate finite differences schemes (e.g., Pade schemes) on non-staggered grids, is presented. Governing equations for the flow at the polar axis are derived using series expansions near r=0. The only information needed to calculate the coefficients in these equations are the values of the flow variables and their radial derivatives at the previous iteration (or time) level. These derivatives, which are multi-valued at the polar axis, are calculated without dropping the accuracy of the numerical method using a mapping of the flow domain from (0,R)*(0,2pi) to (-R,R)*(0,pi), where R is the radius of the computational domain. This allows the radial derivatives to be evaluated using high-order differencing schemes (e.g., compact schemes) at points located on the polar axis. The proposed technique is illustrated by results from simulations of laminar-forced jets and turbulent compressible jets using large eddy simulation (LES) methods. In term of the general robustness of the numerical method and smoothness of the solution close to the polar axis, the present results compare very favorably to similar calculations in which the equations are solved in Cartesian coordinates at the polar axis, or in which the singularity is removed by employing a staggered mesh in the radial direction without a mesh point at r=0, following the method proposed recently by Mohseni and Colonius (1). Extension of the method described here for incompressible flows or for any other set of equations that are solved on a non-staggered mesh in cylindrical or spherical coordinates with finite-differences schemes of various level of accuracy is immediate.

Constantinescu, George S.; Lele, S. K.

2001-01-01

160

A silk hydrogel-based delivery system of bone morphogenic protein for the treatment of large bone defects  

PubMed Central

The use of tissue grafting for the repair of large bone defects has numerous limitations including donor site morbidity and the risk of disease transmission. These limitations have prompted research efforts to investigate the effects of combining biomaterial scaffolds with biochemical cues to augment bone repair. The goal of this study was to use a critically-sized rat femoral segmental defect model to investigate the efficacy of a delivery system consisting of an electrospun polycaprolactone (PCL) nanofiber mesh tube with a silk fibroin hydrogel for local recombinant bone morphogenetic protein 2 (BMP-2) delivery. Bilateral 8 mm segmental femoral defects were formed in 13-week-old Sprague Dawley rats. Perforated electrospun PCL nanofiber mesh tubes were fitted into the adjacent native bone such that the lumen of the tubes contained the defect (Kolambkar et al., 2011b). Silk hydrogels with or without BMP-2 were injected into the defect. Bone regeneration was longitudinally assessed using 2D X-ray radiography and 3D microcomputed topography (µCT). Following sacrifice at 12 weeks after surgery, the extracted femurs were either subjected to biomechanical testing or assigned for histology. The results demonstrated that silk was an effective carrier for BMP-2. Compared to the delivery system without BMP-2, the delivery system that contained BMP-2 resulted in more bone formation (p < 0.05) at 4, 8, 12 weeks after surgery. Biomechanical properties were also significantly improved in the presence of BMP-2 (p < 0.05) and were comparable to age-matched intact femurs. Histological evaluation of the defect region indicated that the silk hydrogel have completely been degraded by the end of the study. Based on these results, we conclude that a BMP-2 delivery system consisting of an electrospun PCL nanofiber mesh tube with a silk hydrogel presents an effective strategy for functional repair of large bone defects. PMID:22658161

Diab, Tamim; Pritchard, Eleanor M.; Uhrig, Brent A.; Boerckel, Joel D.; Kaplan, David L.; Guldberg, Robert E.

2011-01-01

161

Commissioning of an integrated platform for time-resolved treatment delivery in scanned ion beam therapy by means of optical motion monitoring.  

PubMed

The integrated use of optical technologies for patient monitoring is addressed in the framework of time-resolved treatment delivery for scanned ion beam therapy. A software application has been designed to provide the therapy control system (TCS) with a continuous geometrical feedback by processing the external surrogates tridimensional data, detected in real-time via optical tracking. Conventional procedures for phase-based respiratory phase detection were implemented, as well as the interface to patient specific correlation models, in order to estimate internal tumor motion from surface markers. In this paper, particular attention is dedicated to the quantification of time delays resulting from system integration and its compensation by means of polynomial interpolation in the time domain. Dedicated tests to assess the separate delay contributions due to optical signal processing, digital data transfer to the TCS and passive beam energy modulation actuation have been performed. We report the system technological commissioning activities reporting dose distribution errors in a phantom study, where the treatment of a lung lesion was simulated, with both lateral and range beam position compensation. The zero-delay systems integration with a specific active scanning delivery machine was achieved by tuning the amount of time prediction applied to lateral (14.61 ± 0.98 ms) and depth (34.1 ± 6.29 ms) beam position correction signals, featuring sub-millimeter accuracy in forward estimation. Direct optical target observation and motion phase (MPh) based tumor motion discretization strategies were tested, resulting in 20.3(2.3)% and 21.2(9.3)% median (IQR) percentual relative dose difference with respect to static irradiation, respectively. Results confirm the technical feasibility of the implemented strategy towards 4D treatment delivery, with negligible percentual dose deviations with respect to static irradiation. PMID:24354750

Fattori, G; Saito, N; Seregni, M; Kaderka, R; Pella, A; Constantinescu, A; Riboldi, M; Steidl, P; Cerveri, P; Bert, C; Durante, M; Baroni, G

2014-12-01

162

Evaluation of renal nerve morphological changes and norepinephrine levels following treatment with novel bipolar radiofrequency delivery systems in a porcine model  

PubMed Central

Objective: To evaluate the safety and effectiveness of different bipolar radiofrequency system algorithms in interrupting the renal sympathetic nerves and reducing renal norepinephrine in a healthy porcine model. Methods: A porcine model (N?=?46) was used to investigate renal norepinephrine levels and changes to renal artery tissues and nerves following percutaneous renal denervation with radiofrequency bipolar electrodes mounted on a balloon catheter. Parameters of the radiofrequency system (i.e. electrode length and energy delivery algorithm), and the effects of single and longitudinal treatments along the artery were studied with a 7-day model in which swine received unilateral radiofrequency treatments. Additional sets of animals were used to examine norepinephrine and histological changes 28 days following bilateral percutaneous radiofrequency treatment or surgical denervation; untreated swine were used for comparison of renal norepinephrine levels. Results: Seven days postprocedure, norepinephrine concentrations decreased proportionally to electrode length, with 81, 60 and 38% reductions (vs. contralateral control) using 16, 4 and 2-mm electrodes, respectively. Applying a temperature-control algorithm with the 4-mm electrodes increased efficacy, with a mean 89.5% norepinephrine reduction following a 30-s treatment at 68°C. Applying this treatment along the entire artery length affected more nerves vs. a single treatment, resulting in superior norepinephrine reduction 28 days following bilateral treatment. Conclusion: Percutaneous renal artery application of bipolar radiofrequency energy demonstrated safety and resulted in a significant renal norepinephrine content reduction and renal nerve injury compared with untreated controls in porcine models. PMID:24875181

Cohen-Mazor, Meital; Mathur, Prabodh; Stanley, James R.L.; Mendelsohn, Farrell O.; Lee, Henry; Baird, Rose; Zani, Brett G.; Markham, Peter M.; Rocha-Singh, Krishna

2014-01-01

163

Exploring the potential of gastro retentive dosage form in delivery of ellagic acid and aloe vera gel powder for treatment of gastric ulcers.  

PubMed

Approach of novel drug delivery system (NDDS) overcomes the limitations of conventional dosage forms. However, this concept is still not practiced to a large extent in delivery of herbal drugs in Ayurveda. Thus, the potential of herbal drugs has not been explored to its fullest. Hence, there is a growing need to amalgamate the concept of NDDS in delivery of herbal constituents. The present investigation is designed to deliver and retain two herbal constituents in stomach for better action against Helicobacter pylori induced gastric ulcers. The objective was to develop a bilayer floating tablet of ellagic acid and Aloe vera gel powder through rational combination of excipients to give the lowest possible lag time with maximum drug release in the period of 4 h. Formulation F9 containing 100 mg of HPMC K15M, 27 mg of crospovidone, 80 mg of mannitol and effervescent agents in the ratio 1:2 gave 92% drug release and desired floating properties. In vivo studies showed that combination of ellagic acid and Aloe vera gave 75 % ulcer inhibition in comparison to 57% ulcer inhibition in the group which was administered with ellagic acid alone. This suggests the use of bilayer floating tablet in gastric ulcer treatment. PMID:24261674

Ranade, Arati N; Ranpise, Nisharani S; Ramesh, C

2014-01-01

164

The delivery of poly(lactic acid)-poly(ethylene glycol) nanoparticles loaded with non-toxic drug to overcome drug resistance for the treatment of neuroblastoma  

NASA Astrophysics Data System (ADS)

Neuroblastoma is a rare cancer of the sympathetic nervous system. A neuroblastoma tumor develops in the nerve tissue and is diagnosed in infants and children. Approximately 10.2 per million children under the age of 15 are affected in the United States and is slightly more common in boys. Neuroblastoma constitutes 6% of all childhood cancers and has a long-term survival rate of only 15%. There are approximately 700 new cases of neuroblastoma each year in the United States. With such a low rate of survival, the development of more effective treatment methods is necessary. A number of therapies are available for the treatment of these tumors; however, clinicians and their patients face the challenges of systemic side effects and drug resistance of the tumor cells. The application of nanoparticles has the potential to provide a safer and more effective method of delivery drugs to tumors. The advantage of using nanoparticles for drug delivery is the ability to specifically or passively target tumors while reducing the harmful side effects of chemotherapeutics. Drug delivery via nanoparticles can also allow for lower dosage requirements with controlled release of the drugs, which can further reduce systemic toxicity. The aim of this research was to develop a polymeric nanoparticle drug delivery system for the treatment of high-risk neuroblastoma. Nanoparticles composed of a poly(lactic acid)-poly(ethylene glycol) block copolymer were formulated to deliver a non-toxic drug in combination with Temozolomide, a commonly used chemotherapeutic drug for the treatment of neuroblastoma. The non-toxic drug acts as an inhibitor to the DNA-repair protein present in neuroblastoma cells that is responsible for inducing drug resistance in the cells, which would potentially allow for enhanced temozolomide activity. A variety of studies were completed to prove the nanoparticles' low toxicity, loading abilities, and uptake into cells. Additionally, studies were performed to determine the individual effect on cell toxicity of each drug and in combination. Finally, nanoparticles were loaded with the non-toxic drug and delivered with free temozolomide to determine the overall efficacy of the drugs in reducing neuroblastoma cell viability.

Dhulekar, Jhilmil

165

Development and testing of gold nanoparticles for drug delivery and treatment of heart failure: a theranostic potential for PPP cardiology  

PubMed Central

Introduction Nanoscale gold particles (AuNPs) have wide perspectives for biomedical applications because of their unique biological properties, as antioxidative activity and potentials for drug delivery. Aims and objectives The aim was to test effects of AuNPs using suggested heart failure rat model to compare with proved medication Simdax, to test gold nanoparticle for drug delivery, and to test sonoporation effect to increase nanoparticles delivery into myocardial cells. Material and methods We performed biosafety and biocompatibility tests for AuNPs and conjugate with Simdax. For in vivo tests, we included Wistar rats weighing 180–200 g (n = 54), received doxorubicin in cumulative dose of 12.0 mg/kg to model advance heart failure, registered by ultrasonography. We formed six groups: the first three groups of animals received, respectively, 0.06 ml Simdax, AuNPs, and conjugate (AuNPs-Simdax), intrapleurally, and the second three received them intravenously. The seventh group was control (saline). We performed dynamic assessment of heart failure regression in vivo measuring hydrothorax. Sonoporation of gold nanoparticles to cardiomyocytes was tested. Results We designed and constructed colloidal, spherical gold nanoparticles, AuNPs-Simdax conjugate, both founded biosafety (in cytotoxicity, genotoxicity, and immunoreactivity). In all animals of the six groups after the third day post-medication injection, no ascites and liver enlargement were registered (P < 0.001 vs controls). Conjugate injection showed significantly higher hydrothorax reduction than Simdax injection only (P < 0.01); gold nanoparticle injection showed significantly higher results than Simdax injection (P < 0.05). AuNPs and conjugate showed no significant difference for rat recovery. Difference in rat life continuity was significant between Simdax vs AuNPs (P < 0.05) and Simdax vs conjugate (P < 0.05). Sonoporation enhances AuNP transfer into the cell and mitochondria that were highly localized, superior to controls (P < 0.01 for both). Conclusions Gold nanoparticles of 30 nm and its AuNPs-Simdax conjugate gave positive results in biosafety and biocompatibility in vitro and in vivo. AuNPs-Simdax and AuNPs have similar significant cardioprotective effects in rats with doxorubicin-induced heart failure, higher than that of Simdax. Intrapleural (local) delivery is preferred over intravenous (systemic) delivery according to all tested parameters. Sonoporation is able to enhance gold nanoparticle delivery to myocardial cells in vivo. PMID:23889805

2013-01-01

166

Delivery of ofloxacin to the lung and alveolar macrophages via hyaluronan microspheres for the treatment of tuberculosis  

Microsoft Academic Search

Microspheres containing ofloxacin (HMO) with a mean diameter of 2–5 ?m were prepared by the co-spray drying of ofloxacin and the sodium salt of hyaluronic acid (hyaluronan). Recovery of lactose blends of HMO from stage II of the twin-stage impinger (TSI) reached 43%, indicating favorable delivery of the drug to the lung via inhalation. The area under the ofloxacin concentration curve

S. M. Hwang; D. D. Kim; S. J. Chung; C. K. Shim

2008-01-01

167

Developing an effective therapeutic by delivery of synthetic microRNA-520e in lung cancer treatment.  

PubMed

MicroRNAs (miRNAs) can function as tumor suppressors and might provide an efficient strategy for annihilating cancer. Specific miRNAs can be reintroduced into tumor cells to complement the loss of tumor suppression activities. The "miRNA replacement therapy" is based on the concept that the reintroduction of miRNAs depleted in cancer cells reactivates cellular pathways that lead to therapeutic responses. Here, we report the development of miRNA delivery formulation using synthesized miR-520e. This formulation proved to be effective either locally or systematically. MiR-520e accumulation becomes evident in tumor cells and then exerts anti-proliferative function. Meanwhile, intravenous delivery of formulated miR-520e does not induce any deregulation in cytokine levels and liver enzymes. Taken together, our results shed new lights on the concept that systematic delivery of synthetic mimics for tumor suppressor miR-520e and provide potential implications for miRNA therapy in clinic. PMID:25661366

Ma, Dedong; Lu, Hongxiu; Qu, Yiqing; Fu, Weijiang; Ma, Zhe

2015-02-01

168

Observations on prostate intrafraction motion and the effect of reduced treatment time using volumetric modulated arc therapy  

Microsoft Academic Search

PurposeIntensity modulated radiation therapy (IMRT) has allowed accurate delivery of prostate radiotherapy; Volumetric modulated arc therapy (VMAT) offers an advancement of this technique with possible dosimetric advantages and delivery in a shorter time than standard IMRT. We hypothesize that treatment duration is a controllable factor associated with intrafraction target motion.

Jay Shelton; Peter J. Rossi; Hao Chen; Yuan Liu; Viraj A. Master; Ashesh B. Jani

2011-01-01

169

Co-delivery of doxorubicin and paclitaxel by PEG-polypeptide nanovehicle for the treatment of non-small cell lung cancer.  

PubMed

Despite progress, combination therapy of different functional drugs to increase the efficiency of anticancer treatment still remains challenges. An amphiphilic methoxy poly(ethylene glycol)-b-poly(l-glutamic acid)-b-poly(l-lysine) triblock copolymer decorated with deoxycholate (mPEsG-b-PLG-b-PLL/DOCA) was synthesized and developed as a nanovehicle for the co-delivery of anticancer drugs: doxorubicin (DOX) and paclitaxel (PTX). The amphiphilic copolymer spontaneously self-assembled into micellar-type nanoparticles in aqueous solutions and the blank nanoparticles possessed excellent stability. Three different domains of the copolymer performed distinct functions: PEG outer corona provided prolonged circulation, middle biodegradable and hydrophilic PLG shell was designed for DOX loading through electrostatic interactions, and hydrophobic deoxycholate modified PLL served as the container for PTX. In vitro cytotoxicity assays against A549 human lung adenocarcinoma cell line demonstrated that the DOX + PTX co-delivered nanoparticles (Co-NPs) exhibited synergistic effect in inducing cancer cell apoptosis. Ex vivo DOX fluorescence imaging revealed that Co-NPs had highly efficient targeting and accumulation at the implanted site of A549 xenograft tumor in vivo. Co-NPs exhibited significantly higher antitumor efficiency in reducing tumor size compared to free drug combination or single drug-loaded nanoparticles, while no obvious side effects were observed during the treatment, indicating this co-delivery system with different functional antitumor drugs provides the clinical potential in cancer therapy. PMID:24794923

Lv, Shixian; Tang, Zhaohui; Li, Mingqiang; Lin, Jian; Song, Wantong; Liu, Huaiyu; Huang, Yubin; Zhang, Yuanyuan; Chen, Xuesi

2014-07-01

170

Fractional carbon dioxide laser-assisted drug delivery of topical timolol solution for the treatment of deep infantile hemangioma: a pilot study.  

PubMed

Infantile hemangiomas (IHs) are benign vascular tumors of infancy. Topical timolol has recently been reported to be an effective treatment for superficial IHs, although it failed to have an effect on deep IHs. This prospective study was aimed at evaluating the feasibility of ablative fractional laser-assisted drug delivery for enhancing topical timolol permeation into deep IHs. Nine patients ages 1 to 6 months with deep IHs were enrolled. A fractional carbon dioxide (CO2 ) laser system was applied to the skin surface of deep IHs using the DeepFx mode (25-30 mJ/pulse, 5% density, single pulse) at 1-week intervals. Topical timolol maleate 0.5% ophthalmic solution was applied under occlusion for 30 minutes four to five times per day for an average treatment duration of 14.2 weeks. Clinical improvement was evaluated according to a global score and the Hemangioma Activity Score (HAS). Four patients (44.4%) demonstrated excellent regression, four (44.4%) showed good response, and one (11.1%) experienced moderate regression. The HAS declined from 4.1 ± 0.7 at baseline to 1.7 ± 0.7 at 1 week (p < 0.001) and 1.4 ± 0.7 at 3 months (p = 0.03) after the last treatment procedure. Plasma timolol concentration was not detected in any of the patients after the first administration of topical timolol. No systemic complication or skin side effects were observed in any of the patients. Ablative fractional laser-assisted transdermal delivery of topical timolol is a safe and effective method for the treatment of deep IHs. PMID:24602019

Ma, Gang; Wu, Pinru; Lin, Xiaoxi; Chen, Hui; Hu, Xiaojie; Jin, Yunbo; Qiu, Yajing

2014-01-01

171

An effective absorption behavior of insulin for diabetic treatment following intranasal delivery using porous spherical calcium carbonate in monkeys and healthy human volunteers.  

PubMed

Porous spherical calcium carbonate (PS-CaCO(3)), in contrast to regular calcium carbonate (CaCO(3)), which has a cuboidal particle shape, has a characteristic spherical particle shape with a large number of porous, sliver crystals. The effect of PS-CaCO(3) as a drug carrier on intranasal insulin absorption was investigated in cynomolgus monkeys and healthy human volunteers. Each insulin formulation (powder) containing PS-CaCO(3) or regular CaCO(3) was administered intranasally. Serum insulin and glucose levels after administration were evaluated. The insulin absorption after intranasal administration with each CaCO(3) was found to be much more rapid than that after subcutaneous administration. The serum insulin level after intranasal insulin delivery (16 U per monkey) with PS-CaCO(3) showed a higher C(max) (403.5 microU/mL) and shorter T(max) (0.167 h) when compared with regular CaCO(3). The serum glucose level reduction rate after intranasal delivery using PS-CaCO(3) was faster than that of regular CaCO(3), reflecting the difference in absorption rates. Following repeated intranasal administrations for 4 weeks in monkeys, no toxicity was observed even with a maximum insulin dose level of 25 U. Furthermore, the intranasal insulin absorption rate with PS-CaCO(3) in healthy humans was also observed to be considerably faster than that with regular CaCO(3). Effects of PS-CaCO(3) on a more effective absorption behavior of insulin were considered to be the result of a greater affinity between the nasal mucosa layer and PS-CaCO(3), which is closely related to its structural characteristics. Thus, intranasal insulin delivery using PS-CaCO(3) is thought to be a safe and highly available system enabling more effective insulin absorption behavior with the appearance of endogenous postprandial insulin secretion in healthy humans. We believe that our intranasal insulin delivery system enabling a rapid and short-acting pharmacological effect against postprandial hyperglycemia will be more beneficial than pulmonary insulin delivery systems in the treatment of diabetes. PMID:12725701

Haruta, Shunji; Hanafusa, Takashi; Fukase, Hiroyuki; Miyajima, Hiroaki; Oki, Toshikazu

2003-01-01

172

Novel treatment of coronary artery fistulae concealing severe coronary artery lesion: using thrombus aspiration catheter as a delivery guide.  

PubMed

In this case report, we present the occlusion of multiple coronary artery fistulae originating from proximal left anterior descending (LAD) and right sinus valsavla and empting to the pulmonary artery at the same place. We occluded LAD fistulae by using thrombus aspiration catheter as a delivery guide. To the best of our knowlege, this is the first case of occlusion of coronary fistulae with the help of thrombus aspiration catheter. Our experience may suggest that thrombus aspiration catheters can be used in treating coronary artery fistulae with difficult anotomy. PMID:24748888

Korkmaz, Levent; Acar, Zeydin; Dursun, Ihsan; Akyüz, Ali R?za; Korkmaz, Ayca Ata

2014-03-01

173

Community-directed delivery of doxycycline for the treatment of onchocerciasis in areas of co-endemicity with loiasis in Cameroon  

PubMed Central

Background Severe side effects following ivermectin treatment of onchocerciasis in areas of co-endemicity with loaisis have been an impediment for the work of the African Programme for Onchocerciasis Control (APOC) in forested regions of several countries. Doxycycline has been shown to be effective in the treatment of onchocerciasis and has the added advantages of killing adult Onchocerca volvulus but neither adult Loa loa nor their microfilariae. This drug therefore offers great potential for the treatment of onchocerciasis in areas of co-endemicity with loiasis. The limitation of use of this drug is the duration of treatment that may pose a potential problem with therapeutic coverage and compliance with treatment. To benefit from the advantages that doxycycline offers in the treatment of onchocerciasis, it will be necessary to establish an effective distribution system that can access remote communities. This study assessed the feasibility of a large-scale distribution of doxycycline for the treatment of onchocerciasis in areas of co-endemicity with loiasis using a community-directed approach. Methods The study was carried out in 5 health areas co-endemic for Onchocerca volvulus and Loa loa which had no prior experience of the Community Directed Treatment with Ivermectin (CDTI). The community-directed delivery process was introduced using a cascade mechanism from the central health system that passed through the regional health delegation, health district and the health areas. Community health implementers (CHIs) were trained to deliver doxycycline to community members and, under the supervision of the health system, to monitor and document drug intake and side effects. Results The community members adhered massively to the process. Of the 21355 individuals counted, 17519 were eligible for treatment and 12936 were treated with doxycycline; giving a therapeutic coverage of eligible population of 73.8%. Of the 12936 who started the treatment, 97.5% complied by the end of six weeks. No serious side effect was registered during the six week treatment. Conclusion This study indicates that when empowered the community health implementers can successfully deliver doxycycline for six weeks for the treatment of onchocerciasis in areas of co-endemicity with loiasis. The therapeutic coverage and the compliance treatment rate achieved in this study coupled to the known efficacy of doxycycline on O. volvulus, are indicators that the strategy involving the mass administration of doxycycline can be used to control onchocerciasis in those areas of co-endemicity with loiasis where ivermectin may be contraindicated. PMID:19712455

Wanji, Samuel; Tendongfor, Nicholas; Nji, Theolbald; Esum, Mathias; Che, Julious N; Nkwescheu, Armand; Alassa, Fifen; Kamnang, Geremy; Enyong, Peter A; Taylor, Mark J; Hoerauf, Achim; Taylor, David W

2009-01-01

174

Delivery of berberine using chitosan/fucoidan-taurine conjugate nanoparticles for treatment of defective intestinal epithelial tight junction barrier.  

PubMed

Bacterial-derived lipopolysaccharides (LPS) can cause defective intestinal barrier function and play an important role in the development of inflammatory bowel disease. In this study, a nanocarrier based on chitosan and fucoidan was developed for oral delivery of berberine (Ber). A sulfonated fucoidan, fucoidan-taurine (FD-Tau) conjugate, was synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy. The FD-Tau conjugate was self-assembled with berberine and chitosan (CS) to form Ber-loaded CS/FD-Tau complex nanoparticles with high drug loading efficiency. Berberine release from the nanoparticles had fast release in simulated intestinal fluid (SIF, pH 7.4), while the release was slow in simulated gastric fluid (SGF, pH 2.0). The effect of the berberine-loaded nanoparticles in protecting intestinal tight-junction barrier function against nitric oxide and inflammatory cytokines released from LPS-stimulated macrophage was evaluated by determining the transepithelial electrical resistance (TEER) and paracellular permeability of a model macromolecule fluorescein isothiocyanate-dextran (FITC-dextran) in a Caco-2 cells/RAW264.7 cells co-culture system. Inhibition of redistribution of tight junction ZO-1 protein by the nanoparticles was visualized using confocal laser scanning microscopy (CLSM). The results suggest that the nanoparticles may be useful for local delivery of berberine to ameliorate LPS-induced intestinal epithelia tight junction disruption, and that the released berberine can restore barrier function in inflammatory and injured intestinal epithelial. PMID:25421323

Wu, Shao-Jung; Don, Trong-Ming; Lin, Cheng-Wei; Mi, Fwu-Long

2014-01-01

175

Applying technology to the treatment of cannabis use disorder: comparing telephone versus Internet delivery using data from two completed trials.  

PubMed

Technology-based interventions such as those delivered by telephone or online may assist in removing significant barriers to treatment seeking for cannabis use disorder. Little research, however, has addressed differing technology-based treatments regarding their comparative effectiveness, and how user profiles may affect compliance and treatment satisfaction. This study addressed this issue by examining these factors in online (N=225) versus telephone (N=160) delivered interventions for cannabis use, using data obtained from two previously published randomized controlled trials conducted by the current authors. Several differences emerged including stronger treatment effects (medium to large effect sizes in the telephone study versus small effect sizes in the Web study) and lower dropout in the telephone intervention (38% vs. 46%). Additionally, around half of the telephone study participants sought concurrent treatment, compared with 2% of participants in the Web study. Demographics and predictors of treatment engagement, retention and satisfaction also varied between the studies. Findings indicate that both telephone and Web-based treatments can be effective in assisting cannabis users to quit or reduce their use; however, participant characteristics may have important implications for treatment preference and outcome, with those who elect telephone-based treatment experiencing stronger outcomes. Thus, participant preference may shape study populations, adherence, and outcome. PMID:24051076

Rooke, Sally E; Gates, Peter J; Norberg, Melissa M; Copeland, Jan

2014-01-01

176

An analysis of breast motion using high-frequency, dense surface points captured by an optical sensor during radiotherapy treatment delivery  

NASA Astrophysics Data System (ADS)

Patient motion is an important factor affecting the quality of external beam radiotherapy in breast patients. We analyse the motion of a dense set of surface points on breast patients throughout their treatment schedule to assess the magnitude and stability of motion, in particular, with respect to breast volume. We use an optical sensor to measure the surface motion of 13 breast cancer patients. Patients were divided into two cohorts dependent upon breast volume. Measurements were made during radiotherapy treatment beam delivery for an average of 12 fractions per patient (total 158 datasets). The motion of each surface point is parameterized in terms of its period, amplitude and relative phase. Inter-comparison of the motion parameters across treatment schedules and between patients is made through the creation of corresponding regions on the breast surfaces. The motion period is spatially uniform and is similar in both patient groups (mean 4 s), with the small volume cohort exhibiting greater inter-fraction period variability. The mean motion amplitude is also similar in both groups with a range between 2 mm and 4 mm and an inter-fraction variability generally less than 1 mm. There is a phase lag of up to 0.4 s across the breast, led by the sternum. Breast patient motion is reasonably stable between and during treatment fractions, with the large volume cohort exhibiting greater repeatability than the small volume one.

Price, G. J.; Sharrock, P. J.; Marchant, T. E.; Parkhurst, J. M.; Burton, D.; Jain, P.; Price, P.; Moore, C. J.

2009-11-01

177

Promising practices for delivery of court-supervised substance abuse treatment: Perspectives from six high-performing California counties operating Proposition 36  

PubMed Central

Operative for nearly a decade, California's voter-initiated Proposition 36 program offers many offenders community-based substance abuse treatment in lieu of likely incarceration. Research has documented program successes and plans for replication have proliferated, yet very little is known about how the Proposition 36 program works or practices for achieving optimal program outcomes. In this article, we identify policies and practices that key stakeholders perceive to be most responsible for the successful delivery of court-supervised substance abuse treatment to offenders under Proposition 36. Data was collected via focus groups conducted with 59 county stakeholders in six high-performing counties during 2009. Discussion was informed by seven empirical indicators of program performance and outcomes and was focused on identifying and describing elements contributing to success. Program success was primarily attributed to four strategies, those that: (1) fostered program engagement, monitored participant progress, and sustained cooperation among participants; (2) cultivated buy-in among key stakeholders; (3) capitalized on the role of the court and the judge; and (4) created a setting which promoted a high-quality treatment system, utilization of existing resources, and broad financial and political support for the program. Goals and practices for implementing each strategy are discussed. Findings provide a “promising practices” resource for Proposition 36 program evaluation and improvement and inform the design and study of other similar types of collaborative justice treatment efforts. PMID:20965568

Evans, Elizabeth; Anglin, M. Douglas; Urada, Darren; Yang, Joy

2010-01-01

178

Accurate, two-state ab initio study of the ground and first-excited states of He2+, including exact treatment of all Born-Oppenheimer correction terms.  

PubMed

Born-Oppenheimer (BO) potentials for the ground and first-excited electronic states of He2+ are determined using high level ab initio techniques for internuclear separations R of 1.2-100 bohrs and accurately fit to analytical functions. In the present formulation, the BO potentials are nuclear mass independent, and the corresponding BO approximation is obtained by ignoring four terms of the full rovibronic Hamiltonian. These four Born-Oppenheimer correction (BOC) terms are as follows: (1) mass polarization, (2) electronic orbital angular momentum, (3) first derivative with respect to R, and (4) second derivative with respect to R. In order to enable an exact rovibronic calculation, each of the four BOC terms are computed as a function of R, for the two electronic states and for their coupling, without any approximation or use of empirical parameters. Each of the BOC terms is found to make a contribution to the total energy over at least some portion of the range of R investigated. Interestingly, the most significant coupling contribution arises from the electronic orbital angular momentum term, which is evidently computed for the first time in this work. Although several BOC curves exhibit a nontrivial dependence on R, all are accurately fit to analytical functions. The resulting functions, together with the BO potentials, are used to compute exact rovibronic energy levels for 3He 3He+,3He 4He+) and 4He 4He+. Comparison to available high quality experimental data indicates that the present BOC potentials provide the most accurate representation currently available of both the low- and high-lying levels of the ground electronic state and the bound levels of the excited state. PMID:15918707

Xie, Junkai; Poirier, Bill; Gellene, Gregory I

2005-05-01

179

Systematic measurements of whole-body dose distributions for various treatment machines and delivery techniques in radiation therapy  

SciTech Connect

Purpose: Contemporary radiotherapy treatment techniques, such as intensity-modulated radiation therapy and volumetric modulated arc therapy, could increase the radiation-induced malignancies because of the increased beam-on time, i.e., number of monitor units needed to deliver the same dose to the target and the larger volume irradiated with low doses. In this study, whole-body dose distributions from typical radiotherapy patient plans using different treatment techniques and therapy machines were measured using the same measurement setup and irradiation intention. Methods: Individually calibrated thermoluminescent dosimeters were used to measure absorbed dose in an anthropomorphic phantom at 184 locations. The dose distributions from 6 MV beams were compared in terms of treatment technique (3D-conformal, intensity-modulated radiation therapy, volumetric modulated arc therapy, helical TomoTherapy, stereotactic radiotherapy, hard wedges, and flattening filter-free radiotherapy) and therapy machine (Elekta, Siemens and Varian linear accelerators, Accuray CyberKnife and TomoTherapy). Results: Close to the target, the doses from intensity-modulated treatments (including flattening filter-free) were below the dose from a static treatment plan, whereas the CyberKnife showed a larger dose by a factor of two. Far away from the treatment field, the dose from intensity-modulated treatments showed an increase in dose from stray radiation of about 50% compared to the 3D-conformal treatment. For the flattening filter-free photon beams, the dose from stray radiation far away from the target was slightly lower than the dose from a static treatment. The CyberKnife irradiation and the treatment using hard wedges increased the dose from stray radiation by nearly a factor of three compared to the 3D-conformal treatment. Conclusions: This study showed that the dose outside of the treated volume is influenced by several sources. Therefore, when comparing different treatment techniques, the dose ratios vary with distance to the isocenter. The effective dose outside the treated volume of intensity-modulated treatments with or without flattening filter was 10%-30% larger when compared to 3D-conformal radiotherapy. This dose increase is much lower than the monitor unit scaled effective dose from a static treatment.

Haelg, Roger A.; Besserer, Juergen; Schneider, Uwe [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Aarau 5000 (Switzerland); Vetsuisse Faculty, University of Zurich, Zurich 8057 (Switzerland) and Institute for Radiotherapy, Radiotherapie Hirslanden AG, Aarau 5000 (Switzerland)

2012-12-15

180

Development of a 5-fluorouracil-loaded PLGA microsphere delivery system by a solid-in-oil-in-hydrophilic oil (S/O/hO) novel method for the treatment of tumors.  

PubMed

Tumor treatment requires a long-term regimen of chemotherapy, and both surgical tumor resection and radiation therapy are also used. The present study aimed to develop a novel method for 5-fluorouracil (5-FU)-loaded microspheres which enhance the therapeutic effects of chemotherapy, the quality of life of patients and reduce chemotherapy systemic side-effects. The preparation of a 5-FU microsphere delivery system by a solid-in-oil-in-hydrophilic oil (S/O/hO) novel method was carried out and then in vitro and in vivo evaluation of the 5-FU-microsphere delivery system was conducted. The 5-FU microsphere delivery system prepared had sustained-release function and achieved local treatment efficacy for tumors. The encapsulation efficiency of the 5-FU microsphere delivery system was >90% [better than the fabrication method using water-in-oil-in-water (W/O/W)]. The drug release profile from the 5-FU-loaded sustained-release microsphere delivery system matched the pseudo zero-order equation for 30 days in vitro. The plasma concentration of 5-FU was higher than the water solution by subcutaneous injection. The tumor growth rate of rabbits using the 5-FU microsphere delivery system was much lower than the rate in rabbit using a subcutaneous injection of 5-FU water solution. The 5-FU-loaded sustained-release microspheres using the novel method (S/O/hO) is a potential and effective method with which to inhibit tumor growth. PMID:25231485

Lin, Qing; Cai, Yunpeng; Yuan, Minglu; Ma, Lin; Qiu, Mingfeng; Su, Jing

2014-12-01

181

Pharmaceutical approaches to colon targeted drug delivery systems  

Microsoft Academic Search

Purpose. Although oral delivery has become a widely accepted route of administration of therapeutic drugs, the gastrointestinal tract presents several formidable barriers to drug delivery. Colonic drug delivery has gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon but also for its potential for the delivery of proteins

M. K. Chourasia; S. K. Jain

182

Intra-articular drug delivery from an optimized topical patch containing teriflunomide and lornoxicam for rheumatoid arthritis treatment: does the topical patch really enhance a local treatment?  

PubMed

Patients with rheumatoid arthritis (RA) often bear joint destruction and symptomatic pain. The aim of this work is to develop a compound transdermal patch containing teriflunomide (TEF) and lornoxicam (LOX) to transport these drugs across the skin with the isochronous permeation rates for RA therapy and investigate intra-articular delivery of TEF and LOX following transdermal patches applied topically. The salts of TEF and LOX with organic amines diethylamine (DEtA), triethylamine (TEtA), diethanolamine (DEA), triethanolamine (TEA) and N-(2'-hydroxy-ethanol)-piperdine (NP) were prepared to improve the skin permeation of the parent drug. The optimized patch formulation is obtained from a 3-factor, 2-level central composite design. After topical application of the optimized compound patch to only one knee joint in rabbit, intra-articular delivery of TEF and LOX on the application site was compared with that on the non-application site. Anti-inflammatory and analgesic effects of the optimized compound patch were evaluated using the adjuvant arthritis model and the pain model induced by acetic acid, respectively. The in vitro experiment results showed that the amine salts of TEF and LOX, especially TEF-TEtA and LOX-TEtA, enhanced the skin permeation of TEF and LOX from the transdermal patch system. The optimal formulation successfully displayed isochronous permeation rates for TEF and LOX across rabbit skin, and was defined with 5% of TEF-TEtA, 10% of LOX-TEtA and 15% of azone. The in vivo study showed that TEF and LOX from transdermal patches were transferred into skin, ligament and fat pad on the application site by direct diffusion and on the non-application site by the redistribution of systemic blood supply, while local absorption of TEF and LOX in synovial fluid originated from the systemic blood supply rather than direct diffusion. In the RA rat model, the results of swelling inhibition on primary arthritis of bilateral hind paws further confirmed the above-mentioned point. The optimal formulation displayed a double response on joint inflammation and symptomatic pain. In conclusion, although transdermal administration applied topically can provide a local enhanced drug delivery for the superficial joint tissues by direct diffusion, it seemed unlikely to do that for the deeper tissue synovial fluid. PMID:23567043

Xi, Honglei; Cun, Dongmei; Xiang, Rongwu; Guan, Yanli; Zhang, Yuxiu; Li, Yuanru; Fang, Liang

2013-07-10

183

Pharmacodynamic and Therapeutic Investigation of Focused Ultrasound-Induced Blood-Brain Barrier Opening for Enhanced Temozolomide Delivery in Glioma Treatment  

PubMed Central

Focused ultrasound (FUS) exposure with the presence of microbubbles has been shown to transiently open the blood-brain barrier (BBB), and thus has potential to enhance the delivery of various kinds of therapeutic agents into brain tumors. The purpose of this study was to assess the preclinical therapeutic efficacy of FUS-BBB opening for enhanced temozolomide (TMZ) delivery in glioma treatment. FUS exposure with microbubbles was delivered to open the BBB of nude mice that were either normal or implanted with U87 human glioma cells. Different TMZ dose regimens were tested, ranging from 2.5 to 25 mg/kg. Plasma and brain samples were obtained at different time-points ranging from 0.5 to 4 hours, and the TMZ concentration within samples was quantitated via a developed LC-MS/MS procedure. Tumor progression was followed with T2-MRI, and animal survival and brain tissue histology were conducted. Results demonstrated that FUS-BBB opening caused the local TMZ accumulation in the brain to increase from 6.98 to 19 ng/mg. TMZ degradation time in the tumor core was found to increase from 1.02 to 1.56 hours. Improved tumor progression and animal survival were found at different TMZ doses (up to 15% and 30%, respectively). In conclusion, this study provides preclinical evidence that FUS-BBB opening increases the local concentration of TMZ to improve the control of tumor progression and animal survival, suggesting the potential for clinical application to improve current brain tumor treatment. PMID:25490097

Liu, Hao-Li; Huang, Chiung-Yin; Chen, Ju-Yu; Wang, Hay-Yan Jack; Chen, Pin-Yuan; Wei, Kuo-Chen

2014-01-01

184

CATIONIC SHELL CROSSLINKED NANOPARTICLES AS INTRACELLULAR DELIVERY VEHICLES FOR THE DIAGNOSIS AND TREATMENT OF ACUTE LUNG INJURY  

E-print Network

on the development of polymer nanomaterials known as shell crosslinked knedel-like (SCK) nanoparticles to serve as intracellular carriers of genetic material and specifically target injured cells in the lung for the treatment of acute lung injury (ALI). SCK...

Florez, Stephanie

2011-08-08

185

Nanoparticle Delivery of Natural Products in the Prevention and Treatment of Cancers: Current Status and Future Prospects  

PubMed Central

The advent of nanotechnology has had a revolutionary impact on many aspects of 21st century life. Nanotechnology has provided an opportunity to explore new avenues that conventional technologies have been unable to make an impact on for diagnosis, prevention, and therapy of different diseases, and of cancer in particular. Entities in nanometer sizes are excellent platforms to incorporate various drugs or active materials that can be delivered effectively to the desired action site without compromising the activity of the incorporated drug or material. In particular, nanotechnology entities can be used to deliver conventional natural products that have poor solubility or a short half life. Conventional natural products used with entities in nanometer sizes enable us to solve many of the inherent problems (stability, solubility, toxicity) associated with natural products, and also provide a platform for targeted delivery to tumor sites. We recently introduced the novel concept of using nanotechnology for enhancing the outcome of chemoprevention, which we called ‘nanochemoprevention’. This idea was subsequently exploited by several laboratories worldwide and has now become an advancing field in chemoprevention research. This review examines some of the applications of nanotechnology for cancer prevention and therapy using natural products. PMID:24213123

Bharali, Dhruba J.; Siddiqui, Imtiaz A.; Adhami, Vaqar M.; Chamcheu, Jean Christopher; Aldahmash, Abdullah M.; Mukhtar, Hasan; Mousa, Shaker A.

2011-01-01

186

Nanoparticles for urothelium penetration and delivery of the histone deacetylase inhibitor belinostat for treatment of bladder cancer  

PubMed Central

Nearly 40% of patients with non-invasive bladder cancer will progress to invasive disease despite locally-directed therapy. Overcoming the bladder permeability barrier (BPB) is a challenge for intravesical drug delivery. Using the fluorophore coumarin (C6), we synthesized C6-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs), which were surface modified with a novel cell penetrating polymer, poly(guanidinium oxanorbornene) (PGON). Addition of PGON to the NP surface improved tissue penetration by 10-fold in intravesically-treated mouse bladder and ex vivo human ureter. In addition, NP-C6-PGON significantly enhanced intracellular uptake of NPs compared to NPs without PGON. To examine biological activity, we synthesized NPs that were loaded with the histone deacetylase (HDAC) inhibitor belinostat (NP-Bel-PGON). NP-Bel-PGON exhibited a significantly lower IC50 in cultured bladder cancer cells, and sustained hyperacetylation, when compared to unencapsulated belinostat. Xenograft tumors treated with NP-Bel-PGON showed a 70% reduction in volume, and a 2.5-fold higher intratumoral acetyl-H4, when compared to tumors treated with unloaded NP-PGON. PMID:23764660

Martin, Darryl T.; Hoimes, Christopher J.; Kaimakliotis, Hristos Z.; Cheng, Christopher J.; Zhang, Ke; Liu, Jingchun; Wheeler, Marcia A.; Kelly, W. Kevin; Tew, Greg N.; Saltzman, W. Mark; Weiss, Robert M.

2013-01-01

187

Transmucosal Delivery of Linagliptin for the Treatment of Type- 2 Diabetes Mellitus by Ultra-Thin Nanofibers.  

PubMed

The objective of the present research was to cultivate an oral formulation of an anti-diabetic drug using polymeric nanofiber. A biodegradable polymer i.e. poly (vinyl alcohol) (PVA) nanofiber loaded linagliptin was prepared using electro spinning technique. The drug entrapment in the developed nanofibers was confirmed by scanning electron microscopy and X-ray diffraction. The in vivo study was performed on male Wistar rats to establish the pharmacodynamics behavior of developed formulation. The mucoadhesive strength results confirmed that the drug loaded PVA nanofiber patch had the highest mucoadhesion strength compare to PVA film and blank PVA nanofiber, due to its higher water holding capacity and surface area. The in vitro release study suggested that controlled release array of the drug from the nanofiber patch. In vivo activity validated the fact that linagliptin was delivered in its active state and showed visible results when compared to the commercial formulation. Additionally an encapsulation efficacy of 92% of the experimental formulation provides sufficient suggestion that the nanofibers serve as an ideal carrier for the delivery of linagliptin via the sublingual route. PMID:25410375

Modgill, Vedant; Garg, Tarun; Goyal, Amit K; Rath, Goutam

2014-11-17

188

What is the best treatment for fluctuating Parkinson's disease: continuous drug delivery or deep brain stimulation of the subthalamic nucleus?  

PubMed

Motor complications impair quality of life and cause severe disability in patients with advanced Parkinson's disease (PD). Since they are often refractory to medical therapy, interventional therapies have been developed, which can provide a considerable reduction of daily off-time and dopaminergic dyskinesias. Continuous dopaminergic drug delivery (CDD) is based on the steady stimulation of striatal dopamine receptors by subcutaneous apomorphine or duodenal L: -DOPA infusions via portable minipumps. Advances in the understanding of basal ganglia functioning and in neurosurgical, electrophysiological and neuroimaging techniques have led to a renaissance of neurosurgery for advanced PD. Deep brain stimulation of the subthalamic nucleus (STN-DBS) is the most invasive procedure promising great benefit and the highest level of independency for suitable patients, but is definitely associated with surgical risks and DBS-related side effects. Each of these more or less invasive therapy options has its own profile, and a thorough consideration of its advantages and drawbacks for the individual situation is mandatory. In this paper, we summarize relevant facts for this decision and provide some guidelines for a responsible counseling of eligible patients. PMID:21188435

Hilker, Rüdiger; Antonini, Angelo; Odin, Per

2011-06-01

189

A Randomized, Double-Blind, Placebo-Controlled Study of Breath Powered Nasal Delivery of Sumatriptan Powder (AVP-825) in the Treatment of Acute Migraine (The TARGET Study)  

PubMed Central

Objective To evaluate the efficacy and safety of AVP-825, a drug–device combination of low-dose sumatriptan powder (22?mg loaded dose) delivered intranasally through a targeted Breath Powered device vs an identical device containing lactose powder (placebo device) in the treatment of migraine headache. Background Early treatment of migraine headaches is associated with improved outcome, but medication absorption after oral delivery may be delayed in migraineurs because of reduced gastric motility. Sumatriptan powder administered with an innovative, closed-palate, Bi-Directional, Breath Powered intranasal delivery mechanism is efficiently absorbed across the nasal mucosa and produces fast absorption into the circulation. Results from a previously conducted placebo-controlled study of AVP-825 showed a high degree of headache relief with an early onset of action (eg, 74% AVP-825 vs 38% placebo device at 1 hour, P?treatment vs placebo device (70% vs 45%, P?treatment with AVP-825 at 1 hour (19% vs 9%; P?=?.04). There were no serious adverse events (AEs), and no systemic AEs occurred in more than one patient. Chest pain or pressure was not reported, and only one patient taking AVP-825 reported mild paresthesia. No other triptan sensations were reported. Conclusions Targeted delivery of a low-dose of sumatriptan powder via a novel, closed-palate, Breath Powered, intranasal device (AVP-825) provided fast relief of moderate or severe migraine headache in adults that reached statistical significance over placebo by 30 minutes. The treatment was well tolerated with a low incidence of systemic AEs. PMID:25355310

Cady, Roger K; McAllister, Peter J; Spierings, Egilius LH; Messina, John; Carothers, Jennifer; Djupesland, Per G; Mahmoud, Ramy A

2015-01-01

190

What’s in a name? Is accurate recognition and labelling of mental disorders by young people associated with better help-seeking and treatment preferences?  

Microsoft Academic Search

Background  The possible benefits or harms of using psychiatric labels in the community have been a focus of debate for many decades.\\u000a The aim of this study was to examine associations between the accuracy of labelling of depression or psychosis by young people\\u000a aged 12–25 and their help-seeking, treatment and self-help preferences, whilst controlling for a range of potential confounding\\u000a factors.

Annemarie Wright; Anthony F. Jorm; Meredith G. Harris; Patrick D. McGorry

2007-01-01

191

Practice Patterns for the Outpatient Treatment of Depression in a Case-Managed Delivery System: A Utilization Study  

Microsoft Academic Search

Have you ever wondered how long it takes the average outpatient provider to treat a patient with a depression-related diagnosis? This article provides baseline data by diagnostic categories for women treated for depression. As a managed behavioral health care company, ValueOptions partnered with the Virginia Academy of Clinical Psychologists to study how providers use various treatment modalities. Furthermore, this study

Karen M. Ledsky; E. Vicar Reynolds; Michael S. Weissman; J. D. Ball; Marc Rabinowitz; Cheryl Collins; James J. James; Paul Mansheim

2000-01-01

192

Practice patterns for the outpatient treatment of depression in a case-managed delivery system: A utilization study  

Microsoft Academic Search

Have you ever wondered how long it takes the average outpatient provider to treat a patient with a depression-related diagnosis? This article provides baseline data by diagnostic categories for women treated for depression. As a managed behavioral health care company, ValueOptions partnered with the Virginia Academy of Clinical Psychologists to study how providers use various treatment modalities. Furthermore, this study

Karen M. Ledsky; Michael S. Weissman; J. D. Ball; Marc Rabinowitz; Cheryl Collins; James J. James; Paul Mansheim

2000-01-01

193

Accurate GSM Indoor Localization  

Microsoft Academic Search

Accurate indoor localization has long been an objective of the ubiquitous computing research community, and numerous indoor lo- calization solutions based on 802.11, Bluetooth, ultrasound and infrared technologies have been proposed. This paper presents the first accurate GSM indoor localization system that achieves median accuracy of 5 me- ters in large multi-floor buildings. The key idea that makes accurate GSM-based

Veljo Otsason; Alex Varshavsky; Anthony Lamarca; Eyal De Lara

2005-01-01

194

Rotational IMRT delivery using a digital linear accelerator in very high dose rate 'burst mode'  

NASA Astrophysics Data System (ADS)

Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units per minute (MU min-1) high dose rate bursts of dose are facilitated by a flattening-filter-free treatment beam on a Siemens Artiste (Oncology Care Systems, Siemens Medical Solutions, Concord, CA, USA) digital linear accelerator in a non-clinical configuration. Burst mode delivery differs from continuous mode delivery, used by Elekta's VMAT (Elekta Ltd, Crawley, UK) and Varian's RapidArc (Varian Medical Systems, Palo Alto, CA, USA) implementations, in that dose is not delivered while MLC leaves are moving. Instead, dose is delivered in bursts over very short arc angles and only after an MLC segment shape has been completely formed and verified by the controller. The new system was confirmed to be capable of delivering a wide array of clinically relevant treatment plans, without machine fault or other delivery anomalies. Dosimetric accuracy of the modulated arc platform, as well as the Prowess (Prowess Inc., Concord, CA, USA) prototype treatment planning version utilized here, was quantified and confirmed, and delivery times were measured as significantly brief, even with large hypofractionated doses. The burst mode modulated arc approach evaluated here appears to represent a capable, accurate and efficient delivery approach.

Salter, Bill J.; Sarkar, Vikren; Wang, Brian; Shukla, Himanshu; Szegedi, Martin; Rassiah-Szegedi, Prema

2011-04-01

195

Microemulsion as a tool for the transdermal delivery of ondansetron for the treatment of chemotherapy induced nausea and vomiting.  

PubMed

The main objective of this study was to develop a microemulsion (ME) formulation for transdermal delivery of ondansetron for chemotherapy induced nausea and vomiting (CINV). For the formulation development oil was selected on the basis of drug solubility in it while the surfactants and co-surfactants (S(mix)) were screened on the basis of their capacity to solubilize the oil as well as their efficiency to provide the microemulsion area. The microemulsion existence ranges were defined through the construction of the pseudo-ternary phase diagram and various formulations were developed. Effect of surfactant and cosurfactant mass ratio (S(mix)) on the microemulsion formation and its permeation through excised rat skin was studied. A significant increase in permeability parameters such as steady-state flux (J(ss)), permeability coefficient (K(p)), and enhancement ratio (ER) was observed in ME. Formulation B4 which consisted of 0.5% (w/w) of ondansetron, 5% (w/w) of oleic acid, 30% (w/w) S(mix) (2:1, Tween 20 and PEG 400) and 64.5% (w/w) of distilled water showed the best permeability profile. The formulation B4 was subjected to various in vitro attributes and converted to microemulsion gel (OMG). In order to predict the efficacy, pharmacokinetic studies were performed and pharmacokinetic profile was compared with ondansetron conventional gel (OCG) and oral marketed syrup (ONDANZ). The absorption of ondansetron from OMG resulted in 6.03 fold increase in bioavailability as compared to oral conventional syrup and 9.66 times with reference to the OCG gel. The future perspective includes preclinical, toxicological and clinical studies for developing clinically viable formulation. PMID:22796784

Al Abood, Raid M; Talegaonkar, Sushama; Tariq, Mohammad; Ahmad, Farhan J

2013-01-01

196

Development of intramammary delivery systems containing lasalocid for the treatment of bovine mastitis: impact of solubility improvement on safety, efficacy, and milk distribution in dairy cattle  

PubMed Central

Background Mastitis is a major disease of dairy cattle. Given the recent emergence of methicillin-resistant Staphylococcus aureus as a cause of bovine mastitis, new intramammary (IMA) treatments are urgently required. Lasalocid, a member of the polyether ionophore class of antimicrobial agents, has not been previously administered to cows by the IMA route and has favorable characteristics for development as a mastitis treatment. This study aimed to develop an IMA drug delivery system (IMDS) of lasalocid for the treatment of bovine mastitis. Methods Minimum inhibitory concentrations (MICs) were determined applying the procedures recommended by the Clinical and Laboratory Standards Institute. Solid dispersions (SDs) of lasalocid were prepared and characterized using differential scanning calorimetry and Fourier transform infrared spectroscopy. IMDSs containing lasalocid of micronized, nano-sized, or as SD form were tested for their IMA safety in cows. Therapeutic efficacy of lasalocid IMDSs was tested in a bovine model involving experimental IMA challenge with the mastitis pathogen Streptococcus uberis. Results Lasalocid demonstrated antimicrobial activity against the major Gram-positive mastitis pathogens including S. aureus (MIC range 0.5–8 ?g/mL). The solubility test confirmed limited, ion-strength-dependent water solubility of lasalocid. A kinetic solubility study showed that SDs effectively enhanced water solubility of lasalocid (21–35-fold). Polyvinylpyrrolidone (PVP)-lasalocid SD caused minimum mammary irritation in treated cows and exhibited faster distribution in milk than either nano or microsized lasalocid. IMDSs with PVP-lasalocid SD provided effective treatment with a higher mastitis clinical and microbiological cure rate (66.7%) compared to cloxacillin (62.5%). Conclusion Lasalocid SD IMDS provided high cure rates and effectiveness in treating bovine mastitis with acceptable safety in treated cows. PMID:25653501

Wang, Wen; Song, Yunmei; Petrovski, Kiro; Eats, Patricia; Trott, Darren J; Wong, Hui San; Page, Stephen W; Perry, Jeanette; Garg, Sanjay

2015-01-01

197

Sensitivity of an Elekta iView GT a-Si EPID model to delivery errors for pre-treatment verification of IMRT fields.  

PubMed

A Monte Carlo model of an Elekta iViewGT amorphous silicon electronic portal imaging device (a-Si EPID) has been validated for pre-treatment verification of clinical IMRT treatment plans. The simulations involved the use of the BEAMnrc and DOSXYZnrc Monte Carlo codes to predict the response of the iViewGT a-Si EPID model. The predicted EPID images were compared to the measured images obtained from the experiment. The measured EPID images were obtained by delivering a photon beam from an Elekta Synergy linac to the Elekta iViewGT a-Si EPID. The a-Si EPID was used with no additional build-up material. Frame averaged EPID images were acquired and processed using in-house software. The agreement between the predicted and measured images was analyzed using the gamma analysis technique with acceptance criteria of 3 %/3 mm. The results show that the predicted EPID images for four clinical IMRT treatment plans have a good agreement with the measured EPID signal. Three prostate IMRT plans were found to have an average gamma pass rate of more than 95.0 % and a spinal IMRT plan has the average gamma pass rate of 94.3 %. During the period of performing this work a routine MLC calibration was performed and one of the IMRT treatments re-measured with the EPID. A change in the gamma pass rate for one field was observed. This was the motivation for a series of experiments to investigate the sensitivity of the method by introducing delivery errors, MLC position and dosimetric overshoot, into the simulated EPID images. The method was found to be sensitive to 1 mm leaf position errors and 10 % overshoot errors. PMID:25182667

Herwiningsih, Sri; Hanlon, Peta; Fielding, Andrew

2014-09-01

198

Nanoparticle delivery of HIF1? siRNA combined with photodynamic therapy as a potential treatment strategy for head-and-neck cancer.  

PubMed

Combination therapy has become a major strategy in cancer treatment. We used anisamide-targeted lipid-calcium-phosphate (LCP) nanoparticles to efficiently deliver HIF1? siRNA to the cytoplasm of sigma receptor-expressing SCC4 and SAS cells that were also subjected to photodynamic therapy (PDT). HIF1? siRNA nanoparticles effectively reduced HIF1? expression, increased cell death, and significantly inhibited cell growth following photosan-mediated photodynamic therapy in cultured cells. Intravenous injection of the same nanoparticles into human SCC4 or SAS xenografted mice likewise resulted in concentrated siRNA accumulation and reduced HIF1? expression in tumor tissues. When combined with photodynamic therapy, HIF1? siRNA nanoparticles enhanced the regression in tumor size resulting in a?~40% decrease in volume after 10 days. Combination therapy was found to be substantially more effective than either HIF1? siRNA or photodynamic therapy alone. Results from caspase-3, TUNEL, and CD31 marker studies support this conclusion. Our results show the potential use of LCP nanoparticles for efficient delivery of HIF1? siRNA into tumors as part of combination therapy along with PDT in the treatment of oral squamous cell carcinoma. PMID:25596376

Chen, Wei-Hua; Lecaros, Rumwald Leo G; Tseng, Yu-Cheng; Huang, Leaf; Hsu, Yih-Chih

2015-04-01

199

Signaling, Delivery and Age as Emerging Issues in the Benefit/Risk Ratio Outcome of tPA For Treatment of CNS Ischemic Disorders  

PubMed Central

Stroke is a leading cause of morbidity and mortality. While tissue-type plasminogen activator (tPA) remains the only FDA approved treatment for ischemic stroke, clinical use of tPA has been constrained to roughly 3% of eligible patients because of the danger of intracranial hemorrhage and a narrow 3h time window for safe administration. Basic science studies indicate that tPA enhances excitotoxic neuronal cell death. In this review, the beneficial and deleterious effects of tPA in ischemic brain are discussed along with emphasis on development of new approaches towards treatment of patients with acute ischemic stroke. In particular, roles of tPA induced signaling and a novel delivery system for tPA administration based on tPA coupling to carrier red blood cells will be considered as therapeutic modalities for increasing tPA benefit/risk ratio. The concept of the neurovascular unit will be discussed in the context of dynamic relationships between tPA-induced changes in cerebral hemodynamics and histopathologic outcome of CNS ischemia. Additionally, the role of age will be considered since thrombolytic therapy is being increasingly used in the pediatric population, but there are few basic science studies of CNS injury in pediatric animals. PMID:20405577

Armstead, William M; Ganguly, Kumkum; Kiessling, JW; Riley, John; Chen, Xiao-Han; Smith, Douglas H; Stein, Sherman C.; Higazi, Abd AR; Cines, Douglas B; Bdeir, Khalil; Zaitsev, Sergei; Muzykantov, Vladimir R.

2010-01-01

200

Delivery parameter variations and early clinical outcomes of volumetric modulated arc therapy for 31 prostate cancer patients: an intercomparison of three treatment planning systems.  

PubMed

We created volumetric modulated arc therapy (VMAT) plans for 31 prostate cancer patients using one of three treatment planning systems (TPSs)--ERGO++, Monaco, or Pinnacle--and then treated those patients. A dose of 74 Gy was prescribed to the planning target volume (PTV). The rectum, bladder, and femur were chosen as organs at risk (OARs) with specified dose-volume constraints. Dose volume histograms (DVHs), the mean dose rate, the beam-on time, and early treatment outcomes were evaluated and compared. The DVHs calculated for the three TPSs were comparable. The mean dose rates and beam-on times for Ergo++, Monaco, and SmartArc were, respectively, 174.3?±?17.7, 149.7?±?8.4, and 185.8?±?15.6?MU/min and 132.7?±?8.4, 217.6?±?13.1, and 127.5?±?27.1?sec. During a follow-up period of 486.2?±?289.9 days, local recurrence was not observed, but distant metastasis was observed in a single patient. Adverse events of grade 3 to grade 4 were not observed. The mean dose rate for Monaco was significantly lower than that for ERGO++ and SmartArc (P < 0.0001), and the beam-on time for Monaco was significantly longer than that for ERGO++ and SmartArc (P < 0.0001). Each TPS was successfully used for prostate VMAT planning without significant differences in early clinical outcomes despite significant TPS-specific delivery parameter variations. PMID:23401667

Tsutsumi, Shinichi; Hosono, Masako N; Tatsumi, Daisaku; Miki, Yoshitaka; Masuoka, Yutaka; Ogino, Ryo; Ishii, Kentaro; Shimatani, Yasuhiko; Miki, Yukio

2013-01-01

201

Oral administration of a curcumin-phospholipid delivery system for the treatment of central serous chorioretinopathy: a 12-month follow-up study  

PubMed Central

Background The therapeutic effects of Meriva®, a curcumin-phospholipid (lecithin) delivery system (formulated as Norflo® tablets), on visual acuity and retinal thickness in patients with acute and chronic central serous chorioretinopathy was previously investigated in a six-month open-label study. Methods In this follow-up study, visual acuity was again assessed by ophthalmologic evaluation and retinal thickness by optical coherence tomography (OCT). Norflo tablets were administered twice daily to patients with central serous chorioretinopathy. The study group consisted of 12 patients (total 18 eyes) who completed 12 months of follow-up. The primary endpoint was change in visual acuity before and after treatment with Norflo, and change in neuroretinal or retinal pigment epithelium detachment on OCT was the secondary endpoint. Results After 12 months of therapy, no eyes showed further reduction in visual acuity, 39% showed stabilization, and 61% showed statistically significant improvement (P = 0.0001 by Student’s t-test and P = 0.0005 by Wilcoxon signed rank test). Ninety-five percent of eyes showed a reduction in neuroretinal or retinal pigment epithelium detachment and 5% showed stabilization. The difference in retinal thickness after 12 months was statistically significant (P = 0.0001 by Student’s t-test and P = 0.0004 by Wilcoxon signed rank test). Conclusion These results, albeit preliminary, confirm our previous finding that this curcumin delivery system is effective in the management of central serous chorioretinopathy. When administered in a bioavailable formulation, curcumin is worth considering as a therapeutic agent for the management of inflammatory and degenerative eye conditions involving activation of retinal microglial cells. PMID:23723686

Mazzolani, Fabio; Togni, Stefano

2013-01-01

202

Development and characterization of colon specific drug delivery system bearing 5-ASA and Camylofine dihydrochloride for the treatment of ulcerative colitis.  

PubMed

The treatment of ulcerative colitis (inflammatory bowel disease, IBD) has been achieved by using colon specific drug delivery system bearing 5-ASA and Camylofine dihydrochloride. Chitosan microspheres were prepared separately for both the drugs using emulsion method followed by enteric coating with EudragitS-100. The in vitro drug release was investigated in different simulated GIT medium. The drug release in PBS (pH7.4) and simulated gastric fluid has shown almost similar pattern and rate, whereas a significant increase in drug release (70.3 +/- 1.36 and 72.5 +/- 1.33% of 5-ASA and Camylofine, respectively) was observed in medium containing 3% rat caecal matter, after 24 h. In control study, 57.1 +/- 1.13% of 5-ASA and 59.2 +/- 1.2% of Camylofine release was observed in 24 h. For enzyme induction, rats were orally administered with 1 mL of 1% w/v dispersion of chitosan for 5 days and release rate studies were conducted in SCF with 3% w/v of caecal matter. An enhanced drug release (i.e., 92.3 +/- 3.81 and 95.5 +/- 3.52% 5-ASA and Camylofine, respectively) was observed after 24 h in dissolution medium containing 3% caecal content obtained from enzyme induced animals. In vivo data showed that microspheres delivered most of its drug load (76.55 +/- 2.13%) to the colon after 9 h, which reflects its targeting potential to the colon. It is concluded that orally administered microspheres of both drugs can be used together for the specific delivery of drug to the colon and reduce symptoms of ulcerative colitis. PMID:20088681

Dubey, Rupal; Dubey, Rounak; Omrey, Pratibha; Vyas, S P; Jain, S K

2010-09-01

203

Molecular bacterial load assay, a culture-free biomarker for rapid and accurate quantification of sputum Mycobacterium tuberculosis bacillary load during treatment.  

PubMed

A molecular assay to quantify Mycobacterium tuberculosis is described. In vitro, 98% (n = 96) of sputum samples with a known number of bacilli (10(7) to 10(2) bacilli) could be enumerated within 0.5 log(10). In comparison to culture, the molecular bacterial load (MBL) assay is unaffected by other microorganisms present in the sample, results are obtained more quickly (within 24 h) and are seldom inhibited (0.7% samples), and the MBL assay critically shows the same biphasic decline as observed longitudinally during treatment. As a biomarker of treatment response, the MBL assay responds rapidly, with a mean decline in bacterial load for 111 subjects of 0.99 log(10) (95% confidence interval [95% CI], 0.81 to 1.17) after 3 days of chemotherapy. There was a significant association between the rate of bacterial decline during the same 3 days and bacilli ml(-1) sputum at day 0 (linear regression, P = 0.0003) and a 3.62 increased odds ratio of relapse for every 1 log(10) increase in pretreatment bacterial load (95% CI, 1.53 to 8.59). PMID:21900522

Honeyborne, Isobella; McHugh, Timothy D; Phillips, Patrick P J; Bannoo, Selina; Bateson, Anna; Carroll, Nora; Perrin, Felicity M; Ronacher, Katharina; Wright, Laura; van Helden, Paul D; Walzl, Gerhard; Gillespie, Stephen H

2011-11-01

204

Combined cross-linking treatments of bovine serum albumin gel beadlets for controlled-delivery of caffeine  

Microsoft Academic Search

Combined cross-linking agents (CCLA) of microbial transglutaminase (MTgase) and ribose were applied during production of bovine serum albumin gels via incubation and heating treatment, respectively. CCLA produced stronger gels with lower protein solubility in disruptive solvents (1% sodium dodecyl sulphate plus 1% ?-mercaptoethanol) as compared to BSA gels (BSA\\/Control) or gels produced using single cross-linking agents (SCLA) of MTGase or

Chee-Yuen Gan; Lai-Hoong Cheng; Eng-Tong Phuah; Pei-Ni Chin; Abbas F. M. AlKarkhi; Azhar Mat Easa

2009-01-01

205

Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy  

NASA Astrophysics Data System (ADS)

In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

Hälg, R. A.; Besserer, J.; Boschung, M.; Mayer, S.; Lomax, A. J.; Schneider, U.

2014-05-01

206

Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy.  

PubMed

In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small. PMID:24778349

Hälg, R A; Besserer, J; Boschung, M; Mayer, S; Lomax, A J; Schneider, U

2014-05-21

207

Efficacy of Intracerebral Delivery of Carboplatin in Combination With Photon Irradiation for Treatment of F98 Glioma-Bearing Rats  

SciTech Connect

Purpose: To evaluate the efficacy of prolonged intracerebral (i.c.) administration of carboplatin by means of ALZET osmotic pumps, in combination with radiotherapy for the treatment of intracranial F98 glioma in rats. Methods and Materials: Seven days after stereotactic implantation of F98 glioma cells into the brains of Fischer rats, carboplatin was administrated i.c. by means of ALZET pumps over 6 days. Rats were treated at the European Synchrotron Radiation Facility with a single 15-Gy X-ray dose, either given alone or 24 h after administration of carboplatin. Results: Untreated rats had a mean survival time (MST) {+-} SE of 23 {+-} 1 days, compared with 44 {+-} 3 days for X-irradiated animals and 69 {+-} 20 days for rats that received carboplatin alone, with 3 of 13 of these surviving >195 days. Rats that received carboplatin followed by X-irradiation had a MST of >142 {+-} 21 days and a median survival time of >195 days, with 6 of 11 rats (55%) still alive at the end of the study. The corresponding percentage increases in lifespan, based on median survival times, were 25%, 85%, and 713%, respectively, for carboplatin alone, radiotherapy alone, or the combination. Conclusions: Our data demonstrate that i.c. infusion of carboplatin by means of ALZET pumps in combination with X-irradiation is highly effective for the treatment of the F98 glioma. They provide strong support for the approach of concomitantly administering chemo- and radiotherapy for the treatment of brain tumors.

Rousseau, Julia [Institut National de la Sante et de la Recherche Medicale U836, Equipe 6, Grenoble (France); Universite Joseph Fourier, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Barth, Rolf F.; Moeschberger, Melvin L. [Department of Pathology and Division of Biostatistics, Ohio State University, Columbus, OH (United States); Elleaume, Helene [Institut National de la Sante et de la Recherche Medicale U836, Equipe 6, Grenoble (France); Universite Joseph Fourier, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Centre Hospitalier Universitaire, Grenoble (France)], E-mail: h.elleaume@esrf.fr

2009-02-01

208

After Delivery  

MedlinePLUS

... frequently following delivery to avoid either high or low blood glucose levels until you get an idea of how ... danger of napping through a snack or mealtime. Low blood glucose is a real danger. It's important for your ...

209

4D analysis of influence of patient movement and anatomy alteration on the quality of 3D U/S-based prostate HDR brachytherapy treatment delivery  

SciTech Connect

Purpose: Modern HDR brachytherapy treatment for prostate cancer based on the 3D ultrasound (U/S) plays increasingly important role. The purpose of this study is to investigate possible patient movement and anatomy alteration between the clinical image set acquisition, made after the needle implantation, and the patient irradiation and their influence on the quality of treatment. Methods: The authors used 3D U/S image sets and the corresponding treatment plans based on a 4D-treatment planning procedure: plans of 25 patients are obtained right after the needle implantation (clinical plan is based on this 3D image set) and just before and after the treatment delivery. The authors notice the slight decrease of treatment quality with increase of time gap between the clinical image set acquisition and the patient irradiation. 4D analysis of dose-volume-histograms (DVHs) for prostate: CTV1 = PTV, and urethra, rectum, and bladder as organs at risk (OARs) and conformity index (COIN) is presented, demonstrating the effect of prostate, OARs, and needles displacement. Results: The authors show that in the case that the patient body movement/anatomy alteration takes place, this results in modification of DVHs and radiobiological parameters, hence the plan quality. The observed average displacement of needles (1 mm) and of prostate (0.57 mm) is quite small as compared with the average displacement noted in several other reports [A. A. Martinez et al., Int. J. Radiat. Oncol., Biol., Phys. 49(1), 61-69 (2001); S. J. Damore et al., Int. J. Radiat. Oncol., Biol., Phys. 46(5), 1205-1211 (2000); P. J. Hoskin et al., Radiotherm. Oncol. 68(3), 285-288 (2003); E. Mullokandov et al., Int. J. Radiat. Oncol., Biol., Phys. 58(4), 1063-1071 (2004)] in the literature. Conclusions: Although the decrease of quality of dosimetric and radiobiological parameters occurs, this does not cause clinically unacceptable changes to the 3D dose distribution, according to our clinical protocol.

Milickovic, Natasa; Mavroidis, Panayiotis; Tselis, Nikolaos; Nikolova, Iliyana; Katsilieri, Zaira; Kefala, Vasiliki; Zamboglou, Nikolaos; Baltas, Dimos [Department of Medical Physics and Engineering, Offenbach Clinic, Starkenburgring 66, 63069 Offenbach am Main (Germany); Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University (Sweden); Department of Radiation Oncology, Offenbach Clinic, Starkenburgring 66, 63069 Offenbach am Main (Germany); Department of Medical Physics and Engineering, Offenbach Clinic, Starkenburgring 66, 63069 Offenbach am Main (Germany); Department of Radiation Oncology, Offenbach Clinic, Starkenburgring 66, 63069 Offenbach am Main (Germany); Department of Medical Physics and Engineering, Offenbach Clinic, Starkenburgring 66, 63069 Offenbach am Main, Germany and Nuclear and Particle Physics Section, Physics Department, University of Athens, 15771 Athens (Greece)

2011-09-15

210

Local delivery of minocycline-loaded PEG-PLA nanoparticles for the enhanced treatment of periodontitis in dogs  

PubMed Central

Background Rapid local drug clearance of antimicrobials is a major drawback for the treatment of chronic periodontitis. In the study reported here, minocycline-loaded poly(ethylene glycol)-poly(lactic acid) nanoparticles were prepared and administered locally for long drug retention and enhanced treatment of periodontitis in dogs. Methods Biodegradable poly(ethylene glycol)-poly(lactic acid) was synthesized to prepare nanoparticles using an emulsion/solvent evaporation technique. The particle size and zeta potential of the minocycline-loaded nanoparticles (MIN-NPs) were determined by dynamic light scattering and the morphology of the nanoparticles was observed by transmission electron microscopy. The in vitro release of minocycline from MIN-NPs and in vivo pharmacokinetics of minocycline in gingival crevice fluid, after local administration of MIN-NPs in the periodontal pockets of beagle dogs with periodontitis, were investigated. The anti-periodontitis effects of MIN-NPs on periodontitis-bearing dogs were finally evaluated. Results Transmission electron microscopy examination and dynamic light scattering results revealed that the MIN-NPs had a round shape, with a mean diameter around 100 nm. The in vitro release of minocycline from MIN-NPs showed a remarkably sustained releasing characteristic. After local administration of the MIN-NPs, minocycline concentration in gingival crevice fluid decreased slowly and retained an effective drug concentration for a longer time (12 days) than Periocline®. Anti-periodontitis effects demonstrated that MIN-NPs could significantly decrease symptoms of periodontitis compared with Periocline and minocycline solution. These findings suggest that MIN-NPs might have great potential in the treatment of periodontitis. PMID:25170266

Yao, Wenxin; Xu, Peicheng; Pang, Zhiqing; Zhao, Jingjing; Chai, Zhilan; Li, Xiaoxia; Li, Huan; Jiang, Menglin; Cheng, Hongbo; Zhang, Bo; Cheng, Nengneng

2014-01-01

211

Delivery systems for brachytherapy.  

PubMed

Brachytherapy is described as the short distance treatment of cancer with a radioactive isotope placed on, in, or near the lesions or tumor to be treated. The main advantage of brachytherapy compared with external beam radiation (EBR) is the improved localized delivery of dose to the target volume of interest, thus normal tissue irradiation is reduced. The precise and targeted nature of brachytherapy provides a number of key benefits for the effective treatment of cancer such as efficacy, minimized risk of side effects, short treatment times, and cost-effectiveness. Brachytherapy devices have yielded promising results in preclinical and clinical studies. However, brachytherapy can only be used in localized and relatively small tumors. Although the introduction of new delivery devices allows the treatment of more complex tumor sites, with wider range of dose rate for improving treatment efficacy and reduction of side effects, a better understanding about the safety, efficacy, and accuracy of these systems is required, and further development of new techniques is warranted. Therefore, this review focuses on the delivery devices for brachytherapy and their application in prostate, breast, brain, and other tumor sites. PMID:25008970

de la Puente, Pilar; Azab, Abdel Kareem

2014-10-28

212

Topical Application of Retinyl Palmitate-Loaded Nanotechnology-Based Drug Delivery Systems for the Treatment of Skin Aging  

PubMed Central

The objective of this study was to perform a structural characterization and evaluate the in vitro safety profile and in vitro antioxidant activity of liquid crystalline systems (LCS) with and without retinyl palmitate (RP). LCS containing polyether functional siloxane (PFS) as a surfactant, silicon glycol copolymer (SGC) as oil phase, and water in the ratios 30?:?25?:?45 and 40?:?50?:?10 with (OLSv = RP-loaded opaque liquid system and TLSv = RP-loaded transparent liquid system, respectively) and without (OLS and TLS, respectively) RP were studied. Samples were characterized using polarized light microscopy (PLM) and rheology analysis. In vitro safety profile was evaluated using red cell hemolysis and in vitro cytotoxicity assays. In vitro antioxidant activity was performed by the DPPH method. PLM analysis showed the presence of lamellar LCS just to TLS. Regardless of the presence of RP, the rheological studies showed the pseudoplastic behavior of the formulations. The results showed that the incorporation of RP in LCS improved the safety profile of the drug. In vitro antioxidant activity suggests that LCS presented a higher capacity to maintain the antioxidant activity of RP. PFS-based systems may be a promising platform for RP topical application for the treatment of skin aging. PMID:24772430

Oliveira, Marcela B.; do Prado, Alice Haddad; Bernegossi, Jéssica; Sato, Claudia S.; Lourenço Brunetti, Iguatemy; Scarpa, Maria Virgínia; Leonardi, Gislaine Ricci; Friberg, Stig E.

2014-01-01

213

Co-delivery of docetaxel and Poloxamer 235 by PLGA-TPGS nanoparticles for breast cancer treatment.  

PubMed

Multidrug resistance (MDR) is a major hurdle to the success of cancer chemotherapy. Poloxamers have been shown to reverse MDR by inhibiting the P-glycoprotein (P-gp) pump. The objective of this research is to test the feasibility of docetaxel-loaded PLGA-TPGS/Poloxamer 235 nanoparticles to overcome MDR in docetaxel-resistant human breast cancer cell line. Docetaxel-loaded nanoparticles were prepared by a modified nanoprecipitation method using PLGA-TPGS and PLGA-TPGS/Poloxamer 235 mixture, respectively. The PLGA-TPGS/Poloxamer 235 nanoparticles were of spherical shape and have a rough and porous surface. The docetaxel-loaded PLGA-TPGS/Poloxamer 235 porous nanoparticles which had an average size of around 180nm with a narrow size distribution were stable, showing almost no change in particle size and surface charge during the 3-month storage period. The in vitro drug release profile of both nanoparticle formulations showed a biphasic release pattern. There was an increased level of uptake of PLGA-TPGS/Poloxamer 235 porous nanoparticles (PPNPs) in docetaxel-resistant human breast cancer cell line, MCF-7/TXT, in comparison with PLGA-TPGS nanoparticles (PTNPs). The PLGA-TPGS/Poloxamer 235 porous nanoparticles produced significantly higher level of toxicity than both of PLGA-TPGS nanoparticle formulation and Taxotere® both in vitro and in vivo, indicating docetaxel-loaded PLGA-TPGS/Poloxamer 235 porous nanoparticles have significant potential for the treatment of breast cancer. PMID:25686959

Tang, Xiaolong; Liang, Yong; Feng, Xiaojun; Zhang, Rongbo; Jin, Xu; Sun, Leilei

2015-04-01

214

Topical application of retinyl palmitate-loaded nanotechnology-based drug delivery systems for the treatment of skin aging.  

PubMed

The objective of this study was to perform a structural characterization and evaluate the in vitro safety profile and in vitro antioxidant activity of liquid crystalline systems (LCS) with and without retinyl palmitate (RP). LCS containing polyether functional siloxane (PFS) as a surfactant, silicon glycol copolymer (SGC) as oil phase, and water in the ratios 30 : 25 : 45 and 40 : 50 : 10 with (OLS(v) = RP-loaded opaque liquid system and TLS(v) = RP-loaded transparent liquid system, respectively) and without (OLS and TLS, respectively) RP were studied. Samples were characterized using polarized light microscopy (PLM) and rheology analysis. In vitro safety profile was evaluated using red cell hemolysis and in vitro cytotoxicity assays. In vitro antioxidant activity was performed by the DPPH method. PLM analysis showed the presence of lamellar LCS just to TLS. Regardless of the presence of RP, the rheological studies showed the pseudoplastic behavior of the formulations. The results showed that the incorporation of RP in LCS improved the safety profile of the drug. In vitro antioxidant activity suggests that LCS presented a higher capacity to maintain the antioxidant activity of RP. PFS-based systems may be a promising platform for RP topical application for the treatment of skin aging. PMID:24772430

Oliveira, Marcela B; do Prado, Alice Haddad; Bernegossi, Jéssica; Sato, Claudia S; Lourenço Brunetti, Iguatemy; Scarpa, Maria Virgínia; Leonardi, Gislaine Ricci; Friberg, Stig E; Chorilli, Marlus

2014-01-01

215

Expanding Alternative Delivery Systems.  

ERIC Educational Resources Information Center

Alternative educational delivery systems that might be useful to community colleges are considered. The following categories of delivery systems are covered: broadcast delivery systems; copy delivery systems, print delivery systems, computer delivery systems, telephone delivery systems, and satellites. Among the applications for broadcast…

Baltzer, Jan A.

216

Routine delivery of artemisinin-based combination treatment at fixed health facilities reduces malaria prevalence in Tanzania: an observational study  

PubMed Central

Background Artemisinin-based combination therapy (ACT) has been promoted as a means to reduce malaria transmission due to their ability to kill both asexual blood stages of malaria parasites, which sustain infections over long periods and the immature derived sexual stages responsible for infecting mosquitoes and onward transmission. Early studies reported a temporal association between ACT introduction and reduced malaria transmission in a number of ecological settings. However, these reports have come from areas with low to moderate malaria transmission, been confounded by the presence of other interventions or environmental changes that may have reduced malaria transmission, and have not included a comparison group without ACT. This report presents results from the first large-scale observational study to assess the impact of case management with ACT on population-level measures of malaria endemicity in an area with intense transmission where the benefits of effective infection clearance might be compromised by frequent and repeated re-infection. Methods A pre-post observational study with a non-randomized comparison group was conducted at two sites in Tanzania. Both sites used sulphadoxine-pyrimethamine (SP) monotherapy as a first-line anti-malarial from mid-2001 through 2002. In 2003, the ACT, artesunate (AS) co-administered with SP (AS?+?SP), was introduced in all fixed health facilities in the intervention site, including both public and registered non-governmental facilities. Population-level prevalence of Plasmodium falciparum asexual parasitaemia and gametocytaemia were assessed using light microscopy from samples collected during representative household surveys in 2001, 2002, 2004, 2005 and 2006. Findings Among 37,309 observations included in the analysis, annual asexual parasitaemia prevalence in persons of all ages ranged from 11% to 28% and gametocytaemia prevalence ranged from <1% to 2% between the two sites and across the five survey years. A multivariable logistic regression model was fitted to adjust for age, socioeconomic status, bed net use and rainfall. In the presence of consistently high coverage and efficacy of SP monotherapy and AS?+?SP in the comparison and intervention areas, the introduction of ACT in the intervention site was associated with a modest reduction in the adjusted asexual parasitaemia prevalence of 5 percentage-points or 23% (p?treatment of uncomplicated malaria and should have substantial public health impact on morbidity and mortality, but is unlikely to reduce malaria transmission substantially in much of sub-Saharan Africa where individuals are rapidly re-infected. PMID:22545573

2012-01-01

217

The Impact of Retail-Sector Delivery of Artemether–Lumefantrine on Malaria Treatment of Children under Five in Kenya: A Cluster Randomized Controlled Trial  

PubMed Central

Background It has been proposed that artemisinin-based combination therapy (ACT) be subsidised in the private sector in order to improve affordability and access. This study in western Kenya aimed to evaluate the impact of providing subsidized artemether–lumefantrine (AL) through retail providers on the coverage of prompt, effective antimalarial treatment for febrile children aged 3–59 months. Methods and Findings We used a cluster-randomized, controlled design with nine control and nine intervention sublocations, equally distributed across three districts in western Kenya. Cross-sectional household surveys were conducted before and after the delivery of the intervention. The intervention comprised provision of subsidized packs of paediatric ACT to retail outlets, training of retail outlet staff, and community awareness activities. The primary outcome was defined as the proportion of children aged 3–59 months reporting fever in the past 2 weeks who started treatment with AL on the same day or following day of fever onset. Data were collected using structured questionnaires and analyzed based on cluster-level summaries, comparing control to intervention arms, while adjusting for other covariates. Data were collected on 2,749 children in the target age group at baseline and 2,662 at follow-up. 29% of children experienced fever within 2 weeks before the interview. At follow-up, the percentage of children receiving AL on the day of fever or the following day had risen by 14.6% points in the control arm (from 5.3% [standard deviation (SD): 3.2%] to 19.9% [SD: 10.0%]) and 40.2% points in the intervention arm (from 4.7% [SD: 3.4%] to 44.9% [SD: 11.7%]). The percentage of children receiving AL was significantly greater in the intervention arm at follow-up, with a difference between the arms of 25.0% points (95% confidence interval [CI]: 14.1%, 35.9%; unadjusted p?=?0.0002, adjusted p?=?0.0001). No significant differences were observed between arms in the proportion of caregivers who sought treatment for their child's fever by source, or in the child's adherence to AL. Conclusions Subsidizing ACT in the retail sector can significantly increase ACT coverage for reported fevers in rural areas. Further research is needed on the impact and cost-effectiveness of such subsidy programmes at a national scale. Trial Registration Current Controlled Trials ISRCTN59275137 and Kenya Pharmacy and Poisons Board Ethical Committee for Clinical Trials PPB/ECCT/08/07. Please see later in the article for the Editors' Summary PMID:21655317

Kangwana, Beth P.; Kedenge, Sarah V.; Noor, Abdisalan M.; Alegana, Victor A.; Nyandigisi, Andrew J.; Pandit, Jayesh; Fegan, Greg W.; Todd, James E.; Brooker, Simon; Snow, Robert W.; Goodman, Catherine A.

2011-01-01

218

Section 21: Drug Discovery/Delivery Pharmacokinetic Considerations of Local Drug Delivery to the Inner Ear by  

E-print Network

1 Section 21: Drug Discovery/Delivery Pharmacokinetic Considerations of Local Drug Delivery.Plontke@uni-tuebingen.de Although there is increasing interest in the local delivery of drugs to the inner ear by applying them, consequences of changes in delivery method, applied drug concentration or even small alterations in treatment

Salt, Alec N.

219

Drug delivery to the ear.  

PubMed

Drug delivery to the ear is used to treat conditions of the middle and inner ear such as acute and chronic otitis media, Ménière's disease, sensorineural hearing loss and tinnitus. Drugs used include antibiotics, antifungals, steroids, local anesthetics and neuroprotective agents. A literature review was conducted searching Medline (1966-2012), Embase (1988-2012), the Cochrane Library and Ovid (1966-2012), using search terms 'drug delivery', 'middle ear', 'inner ear' and 'transtympanic'. There are numerous methods of drug delivery to the middle ear, which can be categorized as topical, systemic (intravenous), transtympanic and via the Eustachian tube. Localized treatments to the ear have the advantages of targeted drug delivery allowing higher therapeutic doses and minimizing systemic side effects. The ideal scenario would be a carrier system that could cross the intact tympanic membrane loaded with drugs or biochemical agents for the treatment of middle and inner ear conditions. PMID:23323784

Hoskison, E; Daniel, M; Al-Zahid, S; Shakesheff, K M; Bayston, R; Birchall, J P

2013-01-01

220

Grading More Accurately  

ERIC Educational Resources Information Center

Grades matter. College grading systems, however, are often ad hoc and prone to mistakes. This essay focuses on one factor that contributes to high-quality grading systems: grading accuracy (or "efficiency"). I proceed in several steps. First, I discuss the elements of "efficient" (i.e., accurate) grading. Next, I present analytical results…

Rom, Mark Carl

2011-01-01

221

Radiation delivery system and method  

DOEpatents

A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

Sorensen, Scott A. (Overland Park, KS); Robison, Thomas W. (Los Alamos, NM); Taylor, Craig M. V. (Jemez Springs, NM)

2002-01-01

222

Accurate Unlexicalized Parsing  

Microsoft Academic Search

We demonstrate that an unlexicalized PCFG can parse much more accurately than previously shown, by making use of simple, linguistically motivated state splits, which break down false independence assumptions latent in a vanilla treebank grammar. Indeed, its performance of 86.36% (LP\\/LR F PCFG models, and surprisingly close to the current state-of-the-art. This result has potential uses beyond establishing a strong

Dan Klein; Christopher D. Manning

2003-01-01

223

Accurate Finite Difference Algorithms  

NASA Technical Reports Server (NTRS)

Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

Goodrich, John W.

1996-01-01

224

Project #15: Ravi Bellamkonda and Hongbin Han: Comparison of therapeutic efficacy of neuroprotective drugs between liposomal delivery and stereotactic simple diffusion delivery (SDD) via brain extracellular  

E-print Network

of neuroprotective drugs between liposomal delivery and stereotactic simple diffusion delivery (SDD) via brain extracellular space in the treatment of Alzheimer's disease Limited delivery of neuroprotective drugs into the central nervous system (CNS) by systemic administration has led to poor treatment efficacy. Drug delivery

Weber, Rodney

225

Modeling oxaliplatin drug delivery to circadian rhythms in drug metabolism and host tolerance  

E-print Network

Modeling oxaliplatin drug delivery to circadian rhythms in drug metabolism and host tolerance Jean period) time-scheduled regimens for cytotoxic drug delivery by intravenous infusion, a pharmacokinetic; Pharmacokinetics-pharmacodynamics; Treatment outcome; Chronotherapy; Drug-delivery optimization Contents 1

Clairambault, Jean

226

Cell-Mediated Drugs Delivery  

PubMed Central

INTRODUCTION Drug targeting to sites of tissue injury, tumor or infection with limited toxicity is the goal for successful pharmaceutics. Immunocytes (including mononuclear phagocytes (dendritic cells, monocytes and macrophages), neutrophils, and lymphocytes) are highly mobile; they can migrate across impermeable barriers and release their drug cargo at sites of infection or tissue injury. Thus immune cells can be exploited as trojan horses for drug delivery. AREAS COVERED IN THIS REVIEW This paper reviews how immunocytes laden with drugs can cross the blood brain or blood tumor barriers, to facilitate treatments for infectious diseases, injury, cancer, or inflammatory diseases. The promises and perils of cell-mediated drug delivery are reviewed, with examples of how immunocytes can be harnessed to improve therapeutic end points. EXPERT OPINION Using cells as delivery vehicles enables targeted drug transport, and prolonged circulation times, along with reductions in cell and tissue toxicities. Such systems for drug carriage and targeted release represent a novel disease combating strategy being applied to a spectrum of human disorders. The design of nanocarriers for cell-mediated drug delivery may differ from those used for conventional drug delivery systems; nevertheless, engaging different defense mechanisms into drug delivery may open new perspectives for the active delivery of drugs. PMID:21348773

Batrakova, Elena V.; Gendelman, Howard E.; Kabanov, Alexander V.

2011-01-01

227

In vitro analysis of nanoparticulate hydroxyapatite/chitosan composites as potential drug delivery platforms for the sustained release of antibiotics in the treatment of osteomyelitis.  

PubMed

Nanoparticulate composites of hydroxyapatite (HAp) and chitosan were synthesized by ultrasound-assisted sequential precipitation and characterized for their microstructure at the atomic scale, surface charge, drug release properties, and combined antibacterial and osteogenic response. Crystallinity of HAp nanoparticles was reduced because of the interference of the surface layers of chitosan with the dissolution/reprecipitation-mediated recrystallization mechanism that conditions the transition from the as-precipitated amorphous calcium phosphate phase to the most thermodynamically stable one--HAp. Embedment of 5-10 nm sized, narrowly dispersed HAp nanoparticles within the polymeric matrix mitigated the burst release of the small molecule model drug, fluorescein, bound to HAp by physisorption, and promoted sustained-release kinetics throughout the 3 weeks of release time. The addition of chitosan to the particulate drug carrier formulation, however, reduced the antibacterial efficacy against S aureus. Excellent cell spreading and proliferation of osteoblastic MC3T3-E1 cells evidenced on microscopic conglomerates of HAp nanoparticles in vitro also markedly diminished on HAp/chitosan composites. Mitochondrial dehydrogenase activity exhibited normal values only for HAp/chitosan particle concentrations of up to 2 mg/cm(2) and significantly dropped, by about 50%, at higher particle concentrations (4 and 8 mg/cm(2)). The gene expression of osteocalcin, a mineralization inductor, and the transcription factor Runx2 was downregulated in cells incubated in the presence of 3 mg/cm(2) HAp/chitosan composite particles, whereas the expression of osteopontin, a potent mineralization inhibitor, was upregulated, further demonstrating the partially unfavorable osteoblastic cell response to the given particles. The peak in the expression of osteogenic markers paralleling the osteoblastic differentiation was also delayed most for the cell population incubated with HAp/chitosan particles. Overall, the positive effect of chitosan coating on the drug elution profile of HAp nanoparticles as carriers for the controlled delivery of antibiotics in the treatment of osteomyelitis was compensated for by the lower bacteriostatic efficiency and the comparatively unviable cell response to the composite material, especially at higher dosages. PMID:24382825

Uskokovi?, Vuk; Desai, Tejal A

2014-02-01

228

In Vitro Analysis of Nanoparticulate Hydroxyapatite/Chitosan Composites as Potential Drug Delivery Platforms for the Sustained Release of Antibiotics in the Treatment of Osteomyelitis  

PubMed Central

Nanoparticulate composites of hydroxyapatite (HAp) and chitosan were synthesized by ultrasound-assisted sequential precipitation and characterized for their microstructure at the atomic scale, surface charge, drug release properties, and combined antibacterial and osteogenic response. Crystallinity of HAp nanoparticles was reduced because of the interference of the surface layers of chitosan with the dissolution/reprecipitation-mediated recrystallization mechanism that conditions the transition from the as-precipitated amorphous calcium phosphate phase to the most thermodynamically stable one—HAp. Embedment of 5–10 nm sized, narrowly dispersed HAp nanoparticles within the polymeric matrix mitigated the burst release of the small molecule model drug, fluorescein, bound to HAp by physisorption, and promoted sustained-release kinetics throughout the 3 weeks of release time. The addition of chitosan to the particulate drug carrier formulation, however, reduced the antibacterial efficacy against S aureus. Excellent cell spreading and proliferation of osteoblastic MC3T3-E1 cells evidenced on microscopic conglomerates of HAp nanoparticles in vitro also markedly diminished on HAp/chitosan composites. Mitochondrial dehydrogenase activity exhibited normal values only for HAp/chitosan particle concentrations of up to 2 mg/cm2 and significantly dropped, by about 50%, at higher particle concentrations (4 and 8 mg/cm2). The gene expression of osteocalcin, a mineralization inductor, and the transcription factor Runx2 was downregulated in cells incubated in the presence of 3 mg/cm2 HAp/chitosan composite particles, whereas the expression of osteopontin, a potent mineralization inhibitor, was upregulated, further demonstrating the partially unfavorable osteoblastic cell response to the given particles. The peak in the expression of osteogenic markers paralleling the osteoblastic differentiation was also delayed most for the cell population incubated with HAp/chitosan particles. Overall, the positive effect of chitosan coating on the drug elution profile of HAp nanoparticles as carriers for the controlled delivery of antibiotics in the treatment of osteomyelitis was compensated for by the lower bacteriostatic efficiency and the comparatively unviable cell response to the composite material, especially at higher dosages. PMID:24382825

USKOKOVI?, VUK; DESAI, TEJAL A.

2014-01-01

229

Characterization of responses of 2d array seven29 detector and its combined use with octavius phantom for the patient-specific quality assurance in rapidarc treatment delivery  

SciTech Connect

A commercial 2D array seven29 detector has been characterized and its performance has been evaluated. 2D array ionization chamber equipped with 729 ionization chambers uniformly arranged in a 27 Multiplication-Sign 27 matrix with an active area of 27 Multiplication-Sign 27 cm{sup 2} was used for the study. An octagon-shaped phantom (Octavius Phantom) with a central cavity is used to insert the 2D ion chamber array. All measurements were done with a linear accelerator. The detector dose linearity, reproducibility, output factors, dose rate, source to surface distance (SSD), and directional dependency has been studied. The performance of the 2D array, when measuring clinical dose maps, was also investigated. For pretreatment quality assurance, 10 different RapidArc plans conforming to the clinical standards were selected. The 2D array demonstrates an excellent short-term output reproducibility. The long-term reproducibility was found to be within {+-}1% over a period of 5 months. Output factor measurements for the central chamber of the array showed no considerable deviation from ion chamber measurements. We found that the 2D array exhibits directional dependency for static fields. Measurement of beam profiles and wedge-modulated fields with the 2D array matched very well with the ion chamber measurements in the water phantom. The study shows that 2D array seven29 is a reliable and accurate dosimeter and a useful tool for quality assurance. The combination of the 2D array with the Octavius phantom proved to be a fast and reliable method for pretreatment verification of rotational treatments.

Syamkumar, S.A., E-mail: skppm@rediffmail.com [Department of Medical Physics, Cancer Institute (WIA), Chennai (India); Padmanabhan, Sriram; Sukumar, Prabakar; Nagarajan, Vivekanandan [Department of Medical Physics, Cancer Institute (WIA), Chennai (India)

2012-04-01

230

Accurate quantum chemical calculations  

NASA Technical Reports Server (NTRS)

An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

1989-01-01

231

Radiotherapy delivery during motion  

NASA Astrophysics Data System (ADS)

This paper discusses the 3D dosimetric consequences of radiotherapy delivery during two kinds of motion, (i) the respiratory motion by the patient and (ii) the motion by the gantry while rotating around the patient. Respiratory motion primarily compromises treatments in the thorax and abdomen regions. Several strategies to reduce respiratory motion effects have been developed or are under development. The organ motion could for instance be measured and incorporated in the treatment planning, or adapted to by using respiratory gating and tumour-tracking delivery techniques. Gantry motion is involved in various forms of intensity-modulated arc-therapy techniques. The purpose is to increase the modulation by simultaneously varying the MLC positions, the rotation speed of the gantry, and the dose rate during the treatment. The advantage of these techniques is the increased possibility to deliver a high absorbed dose to the target volume while minimizing the dose to normal tissues. However, the dosimetric uncertainties associated with motion, small fields and steep dose gradients, has to be evaluated in detail, and this requires adequate true 3D dose-verification tools.

Ceberg, Sofie; Bäck, Sven Å. J.

2010-11-01

232

Colloidal systems for CNS drug delivery  

Microsoft Academic Search

The pharmaceutical treatment of central nervous system (CNS) disorders is the second largest area of therapy, following cardiovascular diseases. Nowadays, noninvasive drug delivery systems for CNS are actively studied. The development of these new delivery systems started with the discovery that properly surface-engineered colloidal vectors, and in particular liposomes and polymeric nanoparticles, with a diameter ?200nm, were shown to be

Luca Costantino; Giovanni Tosi; Barbara Ruozi; Lucia Bondioli; Maria Angela Vandelli; Flavio Forni

2009-01-01

233

Dendrimers as Nanovectors for Nucleic Acid Delivery  

NASA Astrophysics Data System (ADS)

Nucleic acid based gene therapy holds great promise in the treatment of various diseases. However, the success of both DNA- and siRNAbased gene therapies depends critically on safe and efficient nucleic acid delivery systems. Owing to their well-defined structure and multivalent cooperativity, dendrimers have attracted particular attention as ideal nanocarriers for nucleic acid delivery. The present chapter highlights the current status of dendrimers as non-viral nanovectors for both DNA and siRNA delivery, focusing on the different dendrimers investigated for their delivery efficiency with respect to structural alterations in the view to developing safe and efficient nanovectors for gene therapy application.

Liu, Xiaoxuan; Wang, Qi; Peng, Ling

2013-09-01

234

Clindamycin release determined by high performance liquid chromatography from a novel low-cost local drug delivery system: a new potential treatment option for chronic osteomyelitis.  

PubMed

Osteomyelitis continues to be a severe problem worldwide, causing plenty of hospital admissions and entailing vast expenses. Previously, we developed a low-cost polymethyl-methacrylate (PMMA)-sorbitol based capsule system for local long-term drug delivery. In the present study we aimed to test the in vitro release of clindamycin capsules by high performance liquid chromatography. By the end of the clinically relevant period (42 days), the capsules released 70-100% of their load. Furthermore, the release kinetics suggested that an effective antimicrobial concentration may be maintained within the target area. Our findings indicate that these newly developed capsules may be a versatile device for local clindamycin delivery by providing efficient release and reducing financial burdens. PMID:22005060

Frank, D; Montskó, G; Juricskay, I; Borsiczky, B; Cseh, G; Kocsis, B; Nagy, T; Nagy, Á K; Kovács, G L; Miseta, A

2011-10-01

235

Electroporation-mediated gene delivery.  

PubMed

Electroporation has been used extensively to transfer DNA to bacteria, yeast, and mammalian cells in culture for the past 30 years. Over this time, numerous advances have been made, from using fields to facilitate cell fusion, delivery of chemotherapeutic drugs to cells and tissues, and most importantly, gene and drug delivery in living tissues from rodents to man. Electroporation uses electrical fields to transiently destabilize the membrane allowing the entry of normally impermeable macromolecules into the cytoplasm. Surprisingly, at the appropriate field strengths, the application of these fields to tissues results in little, if any, damage or trauma. Indeed, electroporation has even been used successfully in human trials for gene delivery for the treatment of tumors and for vaccine development. Electroporation can lead to between 100 and 1000-fold increases in gene delivery and expression and can also increase both the distribution of cells taking up and expressing the DNA as well as the absolute amount of gene product per cell (likely due to increased delivery of plasmids into each cell). Effective electroporation depends on electric field parameters, electrode design, the tissues and cells being targeted, and the plasmids that are being transferred themselves. Most importantly, there is no single combination of these variables that leads to greatest efficacy in every situation; optimization is required in every new setting. Electroporation-mediated in vivo gene delivery has proven highly effective in vaccine production, transgene expression, enzyme replacement, and control of a variety of cancers. Almost any tissue can be targeted with electroporation, including muscle, skin, heart, liver, lung, and vasculature. This chapter will provide an overview of the theory of electroporation for the delivery of DNA both in individual cells and in tissues and its application for in vivo gene delivery in a number of animal models. PMID:25620008

Young, Jennifer L; Dean, David A

2015-01-01

236

Delivery of adjuvant sequential dose-dense FEC–Doc to patients with breast cancer is feasible, but dose reductions and toxicity are dependent on treatment sequence  

Microsoft Academic Search

Introduction This study prospectively investigates the impact of dose densification and altering sequence of fluorouracil, epirubicin and\\u000a cyclophosphamide [FEC100] and docetaxel [Doc] on dose delivery and tolerability of adjuvant chemotherapy in breast cancer patients. Methods 117 patients with high-risk primary operable breast cancer were randomized (1:1:2:2) to conventional (three cycles of 3-weekly\\u000a FEC100 then three cycles of 3-weekly Doc 100 mg\\/m2

H. Wildiers; L. Dirix; P. Neven; A. Prové; P. Clement; P. Squifflet; F. Amant; T. Skacel; R. Paridaens

2009-01-01

237

Drug delivery systems: An updated review  

PubMed Central

Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. For the treatment of human diseases, nasal and pulmonary routes of drug delivery are gaining increasing importance. These routes provide promising alternatives to parenteral drug delivery particularly for peptide and protein therapeutics. For this purpose, several drug delivery systems have been formulated and are being investigated for nasal and pulmonary delivery. These include liposomes, proliposomes, microspheres, gels, prodrugs, cyclodextrins, among others. Nanoparticles composed of biodegradable polymers show assurance in fulfilling the stringent requirements placed on these delivery systems, such as ability to be transferred into an aerosol, stability against forces generated during aerosolization, biocompatibility, targeting of specific sites or cell populations in the lung, release of the drug in a predetermined manner, and degradation within an acceptable period of time. PMID:23071954

Tiwari, Gaurav; Tiwari, Ruchi; Sriwastawa, Birendra; Bhati, L; Pandey, S; Pandey, P; Bannerjee, Saurabh K

2012-01-01

238

Pure Insulin Nanoparticle Agglomerates for Pulmonary Delivery  

E-print Network

for pulmonary delivery, using polyvinylpyrrolidone as the xcipient. 46 After spray freze-drying, the particles wer dispersd in saline solution, then ebulized and aministerd to mice as prohylactic treatment aginst Aspergilus flavus infection. Mice treatd...

Bailey, Mark Michael

2008-04-29

239

Fabrication of drug delivery MEMS devices  

E-print Network

There is considerable amount of interest in the immediate treatment of personnel involved in high risk situations on the battlefield. A novel approach to drug delivery on the battlefield based on MEMS technology is discussed. ...

Lei, Wang S

2007-01-01

240

Novel central nervous system drug delivery systems.  

PubMed

For decades, biomedical and pharmaceutical researchers have worked to devise new and more effective therapeutics to treat diseases affecting the central nervous system. The blood-brain barrier effectively protects the brain, but poses a profound challenge to drug delivery across this barrier. Many traditional drugs cannot cross the blood-brain barrier in appreciable concentrations, with less than 1% of most drugs reaching the central nervous system, leading to a lack of available treatments for many central nervous system diseases, such as stroke, neurodegenerative disorders, and brain tumors. Due to the ineffective nature of most treatments for central nervous system disorders, the development of novel drug delivery systems is an area of great interest and active research. Multiple novel strategies show promise for effective central nervous system drug delivery, giving potential for more effective and safer therapies in the future. This review outlines several novel drug delivery techniques, including intranasal drug delivery, nanoparticles, drug modifications, convection-enhanced infusion, and ultrasound-mediated drug delivery. It also assesses possible clinical applications, limitations, and examples of current clinical and preclinical research for each of these drug delivery approaches. Improved central nervous system drug delivery is extremely important and will allow for improved treatment of central nervous system diseases, causing improved therapies for those who are affected by central nervous system diseases. PMID:24325540

Stockwell, Jocelyn; Abdi, Nabiha; Lu, Xiaofan; Maheshwari, Oshin; Taghibiglou, Changiz

2014-05-01

241

Targeted Drug Delivery in Pancreatic Cancer  

PubMed Central

Effective drug delivery in pancreatic cancer treatment remains a major challenge. Because of the high resistance to chemo and radiation therapy, the overall survival rate for pancreatic cancer is extremely low. Recent advances in drug delivery systems hold great promise for improving cancer therapy. Using liposomes, nanoparticles, and carbon nanotubes to deliver cancer drugs and other therapeutic agents such as siRNA, suicide gene, oncolytic virus, small molecule inhibitor and antibody has been a success in recent pre-clinical trials. However, how to improve the specificity and stability of the delivered drug using ligand or antibody directed delivery represent a major problem. Therefore, developing novel, specific, tumor-targeted drug delivery systems is urgently needed for this terrible disease. This review summarizes the current progress on targeted drug delivery in pancreatic cancer, and provides important information on potential therapeutic targets for pancreatic cancer treatment. PMID:19853645

Yu, Xianjun; Zhang, Yuqing; Chen, Changyi; Yao, Qizhi; Li, Min

2009-01-01

242

Delivery plan August 2007  

E-print Network

Delivery plan 2005-2008 August 2007 #12;Science and Technology Facilities Council Delivery Plan and Effectiveness 26 1 #12;Science and Technology Facilities Council Delivery Plan 2007-2008 1. INTRODUCTION This Delivery Plan describes the Science and Technology Facilities Council's (STFC) plans and key deliverables

Crowther, Paul

243

4D imaging and 4D radiation therapy: a New Era of therapy design and delivery.  

PubMed

Recently developed 4D CT imaging technologies have shown that significant organ motion can occur within radiotherapy fields during treatment. Most often a result of respiration, this motion can cause dose delivery errors that are clinically significant when unmanaged, as demonstrated in many recent investigations. Motion during the regular breathing cycling is important, but day-to-day breathing variations, as may be caused by changes in residual tidal volume, can cause systematic shifts in tumor position. These may cause delivery misalignments because the tumor is not in the same average location at each treatment. Approaches to management of this motion may involve motion-inclusive planning, gating or tracking. 4D CT has been instrumental in most of these approaches. Given the state of treatment planning software, it is not possible to preplan whether a specific patient would benefit from one or another of these methods. Daily imaging (or use of a nonimage-based system such as Calypso) is necessary to locate the tumor, and the location must be correlated with measurements from a system that tracks breathing motion during treatment delivery. This is typically done using an independent metric that characterizes the breathing cycle (e.g. the height of the abdomen). Only then can the treatment plan be accurately implemented. There are many methods to manage tumor motion, though most are challenging to implement and remain poorly supported by vendors. When determining which system to use, an important distinction between competing approaches is whether they are amplitude- or phase-based. Some implementations may use different approaches for different parts of the treatment planning and delivery process, potentially introducing errors in the characterization of breathing motion. While many advances have been achieved and are discussed here, the development of solid, stable and robust processes to effectively manage breathing motion remains a foremost and continuing challenge in radiotherapy. PMID:21625150

Low, Daniel

2011-01-01

244

Impact of conventional fractionated RT to pelvic lymph nodes and dose-escalated hypofractionated RT to prostate gland using IMRT treatment delivery in high-risk prostate cancer  

NASA Astrophysics Data System (ADS)

Prostate cancer is the most common cancer among Canadian men. The standard treatment in high-risk category is radical radiation, with androgen suppression treatment (AST). Significant disease progression is reported despite this approach. Radiation dose escalation has been shown to improve disease-free survival; however, it results in higher toxicities. Hypofractionated radiation schedules (larger dose each fraction in shorter overall treatment time) are expected to deliver higher biological doses. A hypofractionated scheme was used in this study to escalate radiation doses with AST. Treatment was well tolerated acutely. Early results of self-administered quality of life reported by patients shows a decrease in QOL which is comparable to other treatment schedules. Significant positional variation of the prostate was observed during treatment. Therefore, we suggest daily target verification to avoid a target miss. Initial late effects are reasonable and early treatment outcomes are promising. Longer follow-up is required for full outcomes assessments.

Pervez, Nadeem

245

Advances in ophthalmic drug delivery.  

PubMed

Various strategies for ocular drug delivery are considered; from basic formulation techniques for improving availability of drugs; viscosity enhancers and mucoadhesives aid drug retention and penetration enhancers promote drug transport into the eye. The use of drug-loaded contact lenses and ocular inserts allows drugs to be better placed where they are needed for more direct delivery. Developments in ocular implants gives a means to overcome the physical barriers that traditionally prevented effective treatment. Implant technologies are under development allowing long-term drug delivery from a single procedure, these devices allow posterior chamber diseases to be effectively treated. Future developments could bring artificial corneas to eliminate the need for donor tissue and one-off implantable drug depots lasting the patient's lifetime. PMID:25531930

Morrison, Peter Wj; Khutoryanskiy, Vitaliy V

2014-12-01

246

Aptamers as drug delivery vehicles.  

PubMed

The benefits of directed and selective therapy for systemic treatment are reasons for increased interest in exploiting aptamers for cell-specific drug delivery. Nucleic acid based pharmaceuticals represent an interesting and novel tool to counter human diseases. Combining inhibitory potential and cargo transfer upon internalization, nanocarriers as well as various therapeutics including siRNAs, chemotherapeutics, photosensitizers, or proteins can be imported via these synthetic nucleic acids. However, widespread clinical application is still hampered by obstacles that must be overcome. In this review, we give an overview of applications and recent advances in aptamer-mediated drug delivery. We also introduce prominent selection methods as well as useful approaches in choice of drug and conjugation method. We discuss the challenges that need to be considered and present strategies that have been applied to achieve intracellular delivery of effectors transported by readily internalized aptamers. PMID:25130604

Kruspe, Sven; Mittelberger, Florian; Szameit, Kristina; Hahn, Ulrich

2014-09-01

247

Nanoparticles with Precise Ratiometric Co-Loading and Co-Delivery of Gemcitabine Monophosphate and Cisplatin for Treatment of Bladder Cancer.  

PubMed

Combination chemotherapy is a common practice in clinical management of malignancy. Synergistic therapeutic outcome is only achieved when tumor cells are exposed to cells in an optimal ratio. However, due to diverse physicochemical properties of drugs, no free drug cocktails or nanomaterials are capable of co-loading and co-delivering drugs at an optimal ratio. Herein, we develop a novel nano-platform with precise ratiometric co-loading and co-delivery of two hydrophilic drugs for synergistic anti-tumor effects. Based on previous work, we utilize a solvent displacement method to ratiometrically load dioleoyl phosphatidic acid (DOPA)-gemcitabine monophosphate and DOPA coated cisplatin-precipitate nanocores into the same PLGA NP. These cores are designed to have similar hydrophobic surface properties. GMP and cisplatin are engineered into PLGA NP at an optimal synergistic ratio (5:1, mol:mol) with over 70% encapsulation efficiency and were ratiometrically taken up by tumor cells in vitro and in vivo. These PLGA NP exhibit synergistic anti-cancer effects in a stroma-rich bladder tumor model. A single injection of dual drugs in PLGA NP can significantly inhibit tumor growth. This nanomaterial-system solves problems related to ratiometric co-loading and co-delivery of different hydrophilic moieties and provides possibilities for co-loading hydrophilic drugs with hydrophobic drugs for combination therapy. PMID:25395922

Miao, Lei; Guo, Shutao; Zhang, Jing; Kim, William Y; Huang, Leaf

2014-11-12

248

Targeted gene delivery by polyplex micelles with crowded PEG palisade and cRGD moiety for systemic treatment of pancreatic tumors.  

PubMed

Adequate retention in systemic circulation is the preliminary requirement for systemic gene delivery to afford high bioavailability into the targeted site. Polyplex micelle formulated through self-assembly of oppositely-charged poly(ethylene glycol) (PEG)-polycation block copolymer and plasmid DNA has gained tempting perspective upon its advantageous core-shell architecture, where outer hydrophilic PEG shell offers superior stealth behaviors. Aiming to promote these potential characters toward systemic applications, we strategically introduced hydrophobic cholesteryl moiety at the ?-terminus of block copolymer, anticipating to promote not only the stability of polyplex structure but also the tethered PEG crowdedness. Moreover, Mw of PEG in the PEGylated polyplex micelle was elongated up to 20 kDa for expecting further enhancement in PEG crowdedness. Furthermore, cyclic RGD peptide as ligand molecule to integrin receptors was installed at the distal end of PEG in order for facilitating targeted delivery to the tumor site as well as promoting cellular uptake and intracellular trafficking behaviors. Thus constructed cRGD conjugated polyplex micelle with the elevated PEG shielding was challenged to a modeled intractable pancreatic cancer in mice, achieving potent tumor growth suppression by efficient gene expression of antiangiogenic protein (sFlt-1) at the tumor site. PMID:24439417

Ge, Zhishen; Chen, Qixian; Osada, Kensuke; Liu, Xueying; Tockary, Theofilus A; Uchida, Satoshi; Dirisala, Anjaneyulu; Ishii, Takehiko; Nomoto, Takahiro; Toh, Kazuko; Matsumoto, Yu; Oba, Makoto; Kano, Mitsunobu R; Itaka, Keiji; Kataoka, Kazunori

2014-03-01

249

Ocular drug delivery systems: An overview  

PubMed Central

The major challenge faced by today’s pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration, especially for the treatment of anterior segment diseases. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal, dynamic and static ocular barriers. Also, therapeutic drug levels are not maintained for longer duration in target tissues. In the past two decades, ocular drug delivery research acceleratedly advanced towards developing a novel, safe and patient compliant formulation and drug delivery devices/techniques, which may surpass these barriers and maintain drug levels in tissues. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers. Also, it includes development of conventional topical formulations such as suspensions, emulsions and ointments. Various nanoformulations have also been introduced for anterior segment ocular drug delivery. On the other hand, for posterior ocular delivery, research has been immensely focused towards development of drug releasing devices and nanoformulations for treating chronic vitreoretinal diseases. These novel devices and/or formulations may help to surpass ocular barriers and associated side effects with conventional topical drops. Also, these novel devices and/or formulations are easy to formulate, no/negligibly irritating, possess high precorneal residence time, sustain the drug release, and enhance ocular bioavailability of therapeutics. An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments. Also, recent developments with other ocular drug delivery strategies employing in situ gels, implants, contact lens and microneedles have been discussed. PMID:25590022

Patel, Ashaben; Cholkar, Kishore; Agrahari, Vibhuti; Mitra, Ashim K

2014-01-01

250

Transdermal drug delivery  

PubMed Central

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability of iontophoresis to control delivery rates in real time provides added functionality. Third-generation delivery systems target their effects to skin’s barrier layer of stratum corneum using microneedles, thermal ablation, microdermabrasion, electroporation and cavitational ultrasound. Microneedles and thermal ablation are currently progressing through clinical trials for delivery of macromolecules and vaccines, such as insulin, parathyroid hormone and influenza vaccine. Using these novel second- and third-generation enhancement strategies, transdermal delivery is poised to significantly increase impact on medicine. PMID:18997767

Prausnitz, Mark R.; Langer, Robert

2009-01-01

251

Hollow hydroxyapatite microspheres/chitosan composite as a sustained delivery vehicle for rhBMP-2 in the treatment of bone defects.  

PubMed

Composite scaffold comprised of hollow hydroxyapatite (HA) and chitosan (designated hHA/CS) was prepared as a delivery vehicle for recombinating human bone morphogenetic protein-2 (rhBMP-2). The in vitro and in vivo biological activities of rhBMP2 released from the composite scaffold were then investigated. The rhBMP-2 was firstly loaded into the hollow HA microspheres, and then the rhBMP2-loaded HA microspheres were further incorporated into the chitosan matrix. The chitosan not only served to bind the HA microspheres together and kept them at the implant site, but also effectively modified the release behavior of rhBMP-2. The in vitro release and bioactivity analysis confirmed that the rhBMP2 could be loaded and released from the composite scaffolds in bioactive form. In addition, the composite scaffolds significantly reduced the initial burst release of rhBMP2, and thus providing prolonged period of time (as long as 60 days) compared with CS scaffolds. In vivo bone regenerative potential of the rhBMP2-loaded composite scaffolds was evaluated in a rabbit radius defect model. The results revealed that the rate of new bone formation in the rhBMP2-loaded hHA/CS group was higher than that in both negative control and rhBMP2-loaded CS group. These observations suggest that the hHA/CS composite scaffold would be effective and feasible as a delivery vehicle for growth factors in bone regeneration and repair. PMID:25578692

Yao, Ai-Hua; Li, Xu-Dong; Xiong, Long; Zeng, Jian-Hua; Xu, Jun; Wang, De-Ping

2015-01-01

252

An Implantable MEMS Drug Delivery Device for Rapid Delivery in Ambulatory Emergency Care  

E-print Network

We introduce the first implantable drug delivery system based on MEMS (Micro-Electro-Mechanical-Systems) technology specifically designed as a platform for treatment in ambulatory emergency care. The device is named ...

Elman, Noel

253

Clinical Issues in Mental Health Service Delivery to Refugees.  

ERIC Educational Resources Information Center

Serious limitations exist in the delivery of mental health services to refugees throughout the resettlement process: fragmentation, instability, language barriers, culturally inappropriate treatment methods, and severe staff shortages. Suggested improvements for refugee mental health services emphasize outreach, prevention, treatment approaches,…

Gong-Guy, Elizabeth; And Others

1991-01-01

254

FUEL DELIVERY TEMPERATURE STUDY  

E-print Network

CALIFORNIA ENERGY COMMISSION FUEL DELIVERY TEMPERATURE STUDY COMMISSIONREPORT March 2009 CEC-600 and Nicholas Janusch, 2009. Fuel Delivery Temperature Study, California Energy Commission. CEC-600-2009-002-CMF

255

Vaginal delivery - discharge  

MedlinePLUS

... return in: Four to 9 weeks after your delivery if you're not breastfeeding Three to 4 ... rest. Lovemaking can begin around 6 weeks after delivery, assuming the discharge or lochia has stopped. Check ...

256

Magnetizable implants for targeted drug delivery  

NASA Astrophysics Data System (ADS)

The capability to deliver high effective dosages to specific sites in the human body has become the holy grail of drug delivery research. Drugs with proven effectiveness under in vitro investigation often reach a major roadblock under in vivo testing due to a lack of an effective delivery strategy. In addition, many clinical scenarios require delivery of agents that are therapeutic at the desired delivery point, but otherwise systemically toxic. This project proposes a method for targeted drug delivery by applying high magnetic field gradients within the body to an injected superparamagnetic colloidal fluid carrying a drug, with the aid of modest uniform magnetic field. The design involves patterning of endovascular implants, such as coronary stents, with soft magnetic coatings capable of applying high local magnetic field gradients within the body. Examination of the feasibility of the design has been focused around the treatment of coronary restenosis following angioplasty. Drug-eluting stents, which have debuted in hospitals over the past two years, have thus far reduced restenosis rates to below 10%. Our local drug delivery system is a viable alternative or enhancement to drug-eluting stents, offering increased clinician control of dose size, the ability to treat a site repeatedly, and a wide array of applications for treatment of other pathologies. The theoretical models, parallel plate and pipe flow analysis, and cell culture models presented give insight into the use of micron and sub-micron scale magnetic particles for site-specific delivery of pharmaceuticals and magnetically labeled cells.

Forbes, Zachary Graham

257

Accurate Monitor 1.2  

NSDL National Science Digital Library

With many computer users developing their own Web sites, some of them may be interested in monitoring how search engines may be ranking their site. This latest edition of Accurate Monitor may prove useful, as it allows individuals to find the position of their Web site in search engines like Altavista and Google. Additionally, Accurate Monitor can generate advanced statistics and monitor plugins, along with providing a flexible interface system. This version of Accurate Monitor is compatible with all systems running Windows 95 and higher.

2003-01-01

258

Communications Drug Delivery  

E-print Network

Communications Drug Delivery Z. Zhao, H. Meng, N. Wang, M. J. Donovan, T. Fu, M. You, Z. Chen, X Targeting and Translocation for Drug Delivery This pHLIP is no flop: Functionalizing mesoporous silica nanoparticles (MSNs) with pHLIPss peptide provides a con- trolled-release nanoparticle drug delivery system

Tan, Weihong

259

Responsive polymeric delivery systems  

Microsoft Academic Search

This paper discusses the state of the art in a relatively new approach in the field of controlled drug delivery–responsive polymeric drug delivery systems. Such systems are capable of adjusting drug release rates in response to a physiological need. The fundamental principles of externally and self-regulated delivery systems are examined. Special attention is paid to specific clinical settings such as

Joseph Kost; Robert Langer

2001-01-01

260

Home Delivery MIT Pharmacy  

E-print Network

Home Delivery from MIT Pharmacy To make refills easier, MIT Pharmacy offers a prescription home delivery service. 1. Fill out the order blank completely. If using more than one order blank, fill out delivery person. 5. Some medications will not be mailed. These include certain controlled drugs, those

Polz, Martin

261

Temporal characterization and in vitro comparison of cell survival following the delivery of 3D-conformal, intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT).  

PubMed

A phantom was designed and implemented for the delivery of treatment plans to cells in vitro. Single beam, 3D-conformal radiotherapy (3D-CRT) plans, inverse planned five-field intensity-modulated radiation therapy (IMRT), nine-field IMRT, single-arc volumetric modulated arc therapy (VMAT) and dual-arc VMAT plans were created on a CT scan of the phantom to deliver 3 Gy to the cell layer and verified using a Farmer chamber, 2D ionization chamber array and gafchromic film. Each plan was delivered to a 2D ionization chamber array to assess the temporal characteristics of the plan including delivery time and 'cell's eye view' for the central ionization chamber. The effective fraction time, defined as the percentage of the fraction time where any dose is delivered to each point examined, was also assessed across 120 ionization chambers. Each plan was delivered to human prostate cancer DU-145 cells and normal primary AGO-1522b fibroblast cells. Uniform beams were delivered to each cell line with the delivery time varying from 0.5 to 20.54 min. Effective fraction time was found to increase with a decreasing number of beams or arcs. For a uniform beam delivery, AGO-1552b cells exhibited a statistically significant trend towards increased survival with increased delivery time. This trend was not repeated when the different modulated clinical delivery methods were used. Less sensitive DU-145 cells did not exhibit a significant trend towards increased survival with increased delivery time for either the uniform or clinical deliveries. These results confirm that dose rate effects are most prevalent in more radiosensitive cells. Cell survival data generated from uniform beam deliveries over a range of dose rates and delivery times may not always be accurate in predicting response to more complex delivery techniques, such as IMRT and VMAT. PMID:21427488

McGarry, Conor K; Butterworth, Karl T; Trainor, Colman; O'Sullivan, Joe M; Prise, Kevin M; Hounsell, Alan R

2011-04-21

262

Temporal characterization and in vitro comparison of cell survival following the delivery of 3D-conformal, intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT)  

NASA Astrophysics Data System (ADS)

A phantom was designed and implemented for the delivery of treatment plans to cells in vitro. Single beam, 3D-conformal radiotherapy (3D-CRT) plans, inverse planned five-field intensity-modulated radiation therapy (IMRT), nine-field IMRT, single-arc volumetric modulated arc therapy (VMAT) and dual-arc VMAT plans were created on a CT scan of the phantom to deliver 3 Gy to the cell layer and verified using a Farmer chamber, 2D ionization chamber array and gafchromic film. Each plan was delivered to a 2D ionization chamber array to assess the temporal characteristics of the plan including delivery time and 'cell's eye view' for the central ionization chamber. The effective fraction time, defined as the percentage of the fraction time where any dose is delivered to each point examined, was also assessed across 120 ionization chambers. Each plan was delivered to human prostate cancer DU-145 cells and normal primary AGO-1522b fibroblast cells. Uniform beams were delivered to each cell line with the delivery time varying from 0.5 to 20.54 min. Effective fraction time was found to increase with a decreasing number of beams or arcs. For a uniform beam delivery, AGO-1552b cells exhibited a statistically significant trend towards increased survival with increased delivery time. This trend was not repeated when the different modulated clinical delivery methods were used. Less sensitive DU-145 cells did not exhibit a significant trend towards increased survival with increased delivery time for either the uniform or clinical deliveries. These results confirm that dose rate effects are most prevalent in more radiosensitive cells. Cell survival data generated from uniform beam deliveries over a range of dose rates and delivery times may not always be accurate in predicting response to more complex delivery techniques, such as IMRT and VMAT.

McGarry, Conor K.; Butterworth, Karl T.; Trainor, Colman; O'Sullivan, Joe M.; Prise, Kevin M.; Hounsell, Alan R.

2011-04-01

263

Improving radiotherapy planning, delivery accuracy, and normal tissue sparing using cutting edge technologies  

PubMed Central

In the United States, more than half of all new invasive cancers diagnosed are non-small cell lung cancer, with a significant number of these cases presenting at locally advanced stages, resulting in about one-third of all cancer deaths. While the advent of stereotactic ablative radiation therapy (SABR, also known as stereotactic body radiotherapy, or SBRT) for early-staged patients has improved local tumor control to >90%, survival results for locally advanced stage lung cancer remain grim. Significant challenges exist in lung cancer radiation therapy including tumor motion, accurate dose calculation in low density media, limiting dose to nearby organs at risk, and changing anatomy over the treatment course. However, many recent technological advancements have been introduced that can meet these challenges, including four-dimensional computed tomography (4DCT) and volumetric cone-beam computed tomography (CBCT) to enable more accurate target definition and precise tumor localization during radiation, respectively. In addition, advances in dose calculation algorithms have allowed for more accurate dosimetry in heterogeneous media, and intensity modulated and arc delivery techniques can help spare organs at risk. New delivery approaches, such as tumor tracking and gating, offer additional potential for further reducing target margins. Image-guided adaptive radiation therapy (IGART) introduces the potential for individualized plan adaptation based on imaging feedback, including bulky residual disease, tumor progression, and physiological changes that occur during the treatment course. This review provides an overview of the current state of the art technology for lung cancer volume definition, treatment planning, localization, and treatment plan adaptation. PMID:24688775

Glide-Hurst, Carri K.

2014-01-01

264

Comparing Two Service Delivery Models for Homeless Individuals With Complex Behavioral Health Needs: Preliminary Data From Two SAMHSA Treatment for Homeless Studies  

Microsoft Academic Search

Assertive Community Treatment (ACT) and the Comprehensive, Continuous, Integrated System of Care (CCISC) are two models for delivering services to homeless persons with complex behavioral health needs. This quasi-experimental study presents preliminary data comparing these two programs. The first program was based out of a community mental health center and utilized the ACT model of care with supported housing (ACT-SH),

M. Scott Young; Colleen Clark; Kathleen Moore; Blake Barrett

2009-01-01

265

Nanoparticles as Smart Treatment-delivery Systems in Plants: Assessment of Different Techniques of Microscopy for their Visualization in Plant Tissues  

PubMed Central

Background and Aims The great potential of using nanodevices as delivery systems to specific targets in living organisms was first explored for medical uses. In plants, the same principles can be applied for a broad range of uses, in particular to tackle infections. Nanoparticles tagged to agrochemicals or other substances could reduce the damage to other plant tissues and the amount of chemicals released into the environment. To explore the benefits of applying nanotechnology to agriculture, the first stage is to work out the correct penetration and transport of the nanoparticles into plants. This research is aimed (a) to put forward a number of tools for the detection and analysis of core-shell magnetic nanoparticles introduced into plants and (b) to assess the use of such magnetic nanoparticles for their concentration in selected plant tissues by magnetic field gradients. Methods Cucurbita pepo plants were cultivated in vitro and treated with carbon-coated Fe nanoparticles. Different microscopy techniques were used for the detection and analysis of these magnetic nanoparticles, ranging from conventional light microscopy to confocal and electron microscopy. Key Results Penetration and translocation of magnetic nanoparticles in whole living plants and into plant cells were determined. The magnetic character allowed nanoparticles to be positioned in the desired plant tissue by applying a magnetic field gradient there; also the graphitic shell made good visualization possible using different microscopy techniques. Conclusions The results open a wide range of possibilities for using magnetic nanoparticles in general plant research and agronomy. The nanoparticles can be charged with different substances, introduced within the plants and, if necessary, concentrated into localized areas by using magnets. Also simple or more complex microscopical techniques can be used in localization studies. PMID:17998213

González-Melendi, P.; Fernández-Pacheco, R.; Coronado, M. J.; Corredor, E.; Testillano, P. S.; Risueño, M. C.; Marquina, C.; Ibarra, M. R.; Rubiales, D.; Pérez-de-Luque, A.

2008-01-01

266

MAOIs and transdermal delivery.  

PubMed

Although not currently considered a first-line treatment for depression due to safety and tolerability concerns, MAOIs are effective antidepressants, particularly for atypical or treatment-resistant depression. FDA-approved oral MAOIs inhibit both MAO-A and MAO-B; inhibition of MAO-A in the brain is required for an antidepressant effect, but inhibition in the intestinal tract can allow excessive absorption of tyramine, which can lead to hypertensive crisis. A transdermal formulation of selegiline delivers the medication directly into the circulatory system, bypassing the first-pass metabolism of the GI system and substantially reducing the risk for tyramine-related adverse events. The skin patch allows for a lower dose of the drug to achieve an antidepressant effect, maintains a steady dose of the medication over 24 hours, and avoids the need for dietary restrictions at the minimum effective dose of 6 mg/24 hours. MAOIs are useful treatment options for patients who have not responded to first-line treatments, and understanding their mechanism of action can help clinicians to accurately and safely prescribe these medications. PMID:23059160

Vandenberg, Chad M

2012-09-01

267

Delivery of Behavioral HIV Prevention Services in New York City Outpatient Substance Abuse Treatment Clinics: Providers' Perspectives on Opportunities and Challenges.  

PubMed

Providers (e.g., counselors, physicians) of substance abuse treatment have an opportunity to address HIV. This study identified: (1) providers' HIV prevention practices, (2) barriers, and (3) promoters to offering HIV prevention in substance abuse treatment. Semistructured qualitative interviews with one director, one medical provider, and four counselors, from each of six outpatient clinics (N = 36) were transcribed and coded according to thematic content analysis. Providers' practices included: (1) recommending condoms, (2) explaining HIV transmission, (3) HIV testing, and (4) assessing risk. Barriers included: (1) believing that clients know enough about HIV, (2) believing that clients are not at risk, (3) lacking information, (4) outdated training (i.e., > 5 years ago), (5) HIV stigma, and (6) avoidance. While some providers recommended condoms and HIV testing, many avoided discussing HIV. Our results suggest a need for training to improve understanding of HIV transmission, effective counseling practices, and to build capacity for HIV testing or linkages with HIV service agencies. PMID:25646726

Spector, Anya Y; Remien, Robert H

2015-02-01

268

Bioactive borate glass scaffolds: in vitro and in vivo evaluation for use as a drug delivery system in the treatment of bone infection  

Microsoft Academic Search

The objective of this work was to evaluate borate bioactive glass scaffolds (with a composition in the system Na2O–K2O–MgO–CaO–B2O3–P2O5) as devices for the release of the drug Vancomycin in the treatment of bone infection. A solution of ammonium phosphate,\\u000a with or without dissolved Vancomycin, was used to bond borate glass particles into the shape of pellets. The in vitro degradation

Xin Liu; Zongping Xie; Changqing Zhang; Haobo Pan; Mohamed N. Rahaman; Xin Zhang; Qiang Fu; Wenhai Huang

2010-01-01

269

Whole-procedure clinical accuracy of Gamma Knife treatments of large lesions  

SciTech Connect

The mechanical accuracy of Gamma Knife radiosurgery based on single-isocenter measurement has been established to within 0.3 mm. However, the full delivery accuracy for Gamma Knife treatments of large lesions has only been estimated via the quadrature-sum analysis. In this study, the authors directly measured the whole-procedure accuracy for Gamma Knife treatments of large lesions to examine the validity of such estimation. The measurements were conducted on a head-phantom simulating the whole treatment procedure that included frame placement, computed tomography imaging, treatment planning, and treatment delivery. The results of the measurements were compared with the dose calculations from the treatment planning system. Average agreements of 0.1-1.6 mm for the isodose lines ranging from 25% to 90% of the maximum dose were found despite potentially large contributing uncertainties such as 3-mm imaging resolution, 2-mm dose grid size, 1-mm frame registration, multi-isocenter deliveries, etc. The results of our measurements were found to be significantly smaller (>50%) than the calculated value based on the quadrature-sum analysis. In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain.

Ma Lijun; Chuang, Cynthia; Descovich, Martina; Petti, Paula; Smith, Vernon; Verhey, Lynn [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143 (United States)

2008-11-15

270

Intravenous drug delivery in neonates: lessons learnt.  

PubMed

Intravenous drug administration presents a series of challenges that relate to the pathophysiology of the neonate and intravenous infusion systems in neonates. These challenges arise from slow intravenous flow rates, small drug volume, dead space volume and limitations on the flush volume in neonates. While there is a reasonable understanding of newborn pharmacokinetics, an appreciation of the substantial delay and variability in the rate of drug delivery from the intravenous line is often lacking. This can lead to difficulties in accurately determining the pharmacokinetic and pharmacodynamic relationship of drugs in the smallest patients. The physical variables that affect the passage of drugs through neonatal lines need to be further explored in order to improve our understanding of their impact on the delivery of drugs by this route in neonates. Through careful investigation, the underlying causes of delayed drug delivery may be identified and administration protocols can then be modified to ensure predictable, appropriate drug input kinetics. PMID:24482352

Sherwin, Catherine M T; Medlicott, Natalie J; Reith, David M; Broadbent, Roland S

2014-06-01

271

Nanoscale particulate systems for multidrug delivery: towards improved combination chemotherapy.  

PubMed

While combination chemotherapy has led to measurable improvements in cancer treatment outcomes, its full potential remains to be realized. Nanoscale particles such as liposomes, nanoparticles and polymer micelles have been shown to increase delivery to the tumor site while bypassing many drug resistance mechanisms that limit the effectiveness of conventional therapies. Recent efforts in drug delivery have focused on coordinated, controlled delivery of multiple anticancer agents encapsulated within a single particle system. In this review, we analyze recent progress made in multidrug delivery in three main areas of interest: co-delivery of antineoplastic agents with drug sensitizers, sequential delivery via temporal release particles and simultaneous delivery of multiple agents. Future directions of the field, in light of recent advances with molecularly targeted agents, are suggested and discussed. PMID:24483194

Liboiron, Barry D; Mayer, Lawrence D

2014-02-01

272

Intracarotid Delivery of Drugs: The Potential and the Pitfalls  

PubMed Central

The major efforts to selectively deliver drugs to the brain in the last decade have relied on smart molecular techniques to penetrate the blood brain barrier while intraarterial drug delivery has drawn relatively little attention. In the last decade there have been rapid advances in endovascular techniques. Modern endovascular procedures can permit highly targeted drug delivery by intracarotid route. Intracarotid drug delivery can be the primary route of drug delivery or it could be used to facilitate the delivery of smart-neuropharmaceuticals. There have been few attempts to systematically understand the kinetics of intracarotid drugs. Anecdotal data suggests that intracarotid drug delivery is effective in the treatment of cerebral vasospasm, thromboembolic strokes, and neoplasms. Neuroanesthesiologists are frequently involved in the care of such high-risk patients. Therefore, it is necessary to understand the applications of intracarotid drug delivery and the unusual kinetics of intracarotid drugs. PMID:18719453

Joshi, Shailendra; Meyers, Phillip M.; Ornstein, Eugene

2014-01-01

273

Polymeric micelles for multi-drug delivery in cancer.  

PubMed

Drug combinations are common in cancer treatment and are rapidly evolving, moving beyond chemotherapy combinations to combinations of signal transduction inhibitors. For the delivery of drug combinations, i.e., multi-drug delivery, major considerations are synergy, dose regimen (concurrent versus sequential), pharmacokinetics, toxicity, and safety. In this contribution, we review recent research on polymeric micelles for multi-drug delivery in cancer. In concurrent drug delivery, polymeric micelles deliver multi-poorly water-soluble anticancer agents, satisfying strict requirements in solubility, stability, and safety. In sequential drug delivery, polymeric micelles participate in pretreatment strategies that "prime" solid tumors and enhance the penetration of secondarily administered anticancer agent or nanocarrier. The improved delivery of multiple poorly water-soluble anticancer agents by polymeric micelles via concurrent or sequential regimens offers novel and interesting strategies for drug combinations in cancer treatment. PMID:25501872

Cho, Hyunah; Lai, Tsz Chung; Tomoda, Keishiro; Kwon, Glen S

2015-02-01

274

Adeno-associated Virus–mediated Delivery of a Recombinant Single-chain Antibody Against Misfolded Superoxide Dismutase for Treatment of Amyotrophic Lateral Sclerosis  

PubMed Central

There is emerging evidence that the misfolding of superoxide dismutase 1 (SOD1) may represent a common pathogenic event in both familial and sporadic amyotrophic lateral sclerosis (ALS). To reduce the burden of misfolded SOD1 species in the nervous system, we have tested a novel therapeutic approach based on adeno-associated virus (AAV)–mediated tonic expression of a DNA construct encoding a secretable single-chain fragment variable (scFv) antibody composed of the variable heavy and light chain regions of a monoclonal antibody (D3H5) binding specifically to misfolded SOD1. A single intrathecal injection of the AAV encoding the single-chain antibody in SOD1G93A mice at 45 days of age resulted in sustained expression of single-chain antibodies in the spinal cord, and it delayed disease onset and extension of life span by up to 28%, in direct correlation with scFv titers in the spinal cord. The treatment caused attenuation of neuronal stress signals and reduction in levels of misfolded SOD1 in the spinal cord of SOD1G93A mice. From these results, we propose that an immunotherapy based on intrathecal inoculation of AAV encoding a secretable scFv against misfolded SOD1 should be considered as potential treatment for ALS, especially for individuals carrying SOD1 mutations. PMID:24394188

Patel, Priyanka; Kriz, Jasna; Gravel, Mathieu; Soucy, Geneviève; Bareil, Christine; Gravel, Claude; Julien, Jean-Pierre

2014-01-01

275

The formulation and delivery of curcumin with solid lipid nanoparticles for the treatment of on non-small cell lung cancer both in vitro and in vivo.  

PubMed

Curcumin was determined to have anticancer potency on several kinds of carcinoma. However, its medical application was limited because of its poor bioavailability, unsatisfying dispersity and rapid metabolism in vivo. In this study, curcumin was delivered by solid lipid nanoparticles (SLN) for lung cancer treatment. The physiochemical characters of SLN-curcumin were detected by HPLC, TEM, Zeta potential analysis and FTIR, and the anticancer efficiency on lung cancer was determined both in vitro and in vivo. SLN-curcumin was synthesized by sol-gel method with the size ranged from 20 to 80 nm. After being loaded in SLN, the IC50 of SLN-curcumin on A549 cells was 4 ?M, only 1/20 of plain drug. The plasmid concentration of curcumin was highly increased in mice via i.p. after loaded with SLN. Furthermore, SLN-curcumin enhanced the targeting of curcumin to lung and tumor, which finally increased the inhibition efficiency of curcumin from 19.5% to 69.3%. The Flow Cytometry (FCM) analysis and immuno staining confirmed that the inhibition effect mostly came from apoptosis, but not necrosis. The tumor targeting and profound tumor inhibition effect of SLN-curcumin indicated its medical application on lung cancer treatment, and also provided a novel method for new anticancer agents' development. PMID:24094190

Wang, Ping; Zhang, Libin; Peng, Hao; Li, Yongwu; Xiong, Jian; Xu, Zheyuan

2013-12-01

276

Accurate Replication in Genetic Programming  

Microsoft Academic Search

Abstract One characteristic tendency of genetic program - ming is the production of considerably larger trees than expected It has been suggested that this is related to the ability of individuals to replicate ac - curately In this paper we present theoretical anal - ysis which shows that, for certain specific cases, the pressure for accurate replication induces an increase

Nicholas Freitag Mcphee; Justin Darwin Miller

1995-01-01

277

Development of a Microfluidics-Based Intracochlear Drug Delivery Device  

Microsoft Academic Search

Background: Direct delivery of drugs and other agents into the inner ear will be important for many emerging therapies, including the treatment of degenerative disorders and guiding regeneration. Methods: We have taken a microfluidics\\/MEMS (MicroElectroMechanical Systems) technology approach to develop a fully implantable reciprocating inner-ear drug-delivery system capable of timed and sequenced delivery of agents directly into perilymph of the

William F. Sewell; Jeffrey T. Borenstein; Zhiqiang Chen; Jason Fiering; Ophir Handzel; Maria Holmboe; Ernest S. Kim; Sharon G. Kujawa; Michael J. McKenna; Mark M. Mescher; Brian Murphy; Erin E. Leary Swan; Marcello Peppi; Sarah Tao

2009-01-01

278

Non-invasive, photonics-based diagnostic, imaging, monitoring, and light delivery techniques for the recognition, quantification and treatment of malignant and chronic inflammatory conditions  

NASA Astrophysics Data System (ADS)

We report firsthand on innovative developments in non-invasive, biophotonic techniques for a wide range of diagnostic, imaging and treatment options, including the recognition and quantification of cancerous, pre-cancerous cells and chronic inflammatory conditions. These techniques have benefited from the ability to target the affected site by both monochromatic light and broad multiple wavelength spectra. The employment of such wavelength or color-specific properties embraces the fluorescence stimulation of various photosensitizing drugs, and the instigation and detection of identified fluorescence signatures attendant upon laser induced fluorescence (LIF) phenomena as transmitted and propagated by precancerous, cancerous and normal tissue. In terms of tumor imaging and therapeutic and treatment options, we have exploited the abilities of various wavelengths to penetrate to different depths, through different types of tissues, and have explored quantifiable absorption and reflection characteristics upon which diagnostic assumptions can be reliably based and formulated. These biophotonic-based diagnostic, sensing and imaging techniques have also benefited from, and have been further enhanced by, the integrated ability to provide various power levels to be employed at various stages in the procedure. Applications are myriad, including non-invasive, non destructive diagnosis of in vivo cell characteristics and functions; light-based tissue analysis; real-time monitoring and mapping of brain function and of tumor growth; real time monitoring of the surgical completeness of tumor removal during laser-imaged/guided brain resection; diagnostic procedures based on fluorescence life-time monitoring, the monitoring of chronic inflammatory conditions (including rheumatoid arthritis), and continuous blood glucose monitoring in the control of diabetes.

Davies, N.; Davies-Shaw, D.; Shaw, J. D.

2007-02-01

279

Initial dosimetric evaluation of SmartArc - a novel VMAT treatment planning module implemented in a multi-vendor delivery chain.  

PubMed

We performed an initial dosimetric evaluation of SmartArc - a novel VMAT planning module for Philips Pinnacle treatment planning system. A test suite of structure sets and dose objectives provided by the AAPM for multi-institutional comparison of IMRT dosimetry was used. A total of fifty plans were successfully delivered. The effect of control point spacing on dosimetric accuracy was investigated. When calculated with the 4 masculine spacing, the overall mean point dose errors measured with an ion chamber were 0.5+/-1.4 and -0.3+/-1.4% for the PTV and OAR, respectively. The gamma(3%,3mm) passing rate, measured for absolute dose with a biplanar diode array, was 98.2+/-1.6% (range 94.5-99.9%). Ninety percent of the passing rate values were above 97.7%. With the 6 masculine control point spacing, the highly modulated plans exhibited large dosimetric errors, while the results were still acceptable for the simpler cases. The data show that the practical accuracy of the small-arc approximation, which is at the heart of VMAT dose calculations, depends not only on the control point spacing, but also on the size and relative position of the MLC openings corresponding to the consecutive control points. The effect of the minimum allowed separation between the opposing leaves was found to be minimal. It appears that 4 masculine control point spacing may be a good compromise between calculation speed and accuracy. However each institution is encouraged to establish its own treatment planning guidelines based on the case complexity and acceptable error level. PMID:20160702

Feygelman, Vladimir; Zhang, Geoffrey; Stevens, Craig

2010-01-01

280

Increasing the Efficiency of Parkinson's Disease Treatment Using a poly(lactic-co-glycolic acid) (PLGA) Based L-DOPA Delivery System  

PubMed Central

To compare the efficacy of L-DOPA administered intranasally in the form of nanoparticles (nano-DOPA) and in standard drug forms using a rat Parkinson's Disease (PD) model. L-DOPA-containing nanoparticles (250±50 nm) were synthesized using the double emulsion method. The efficacy of nano-DOPA therapy was studied in Wistar rats with 6-OHDA-induced PD. Drugs were administered daily, 0.35 mg/kg (by L-DOPA). Animals' motor coordination and behavior were analyzed using the forelimb placing task and several other tests. Thirty minutes after the first administration, animals treated with L-DOPA, L-DOPA+benserazide, and nano-DOPA showed equally significant (p<0.05) improvements in coordination performance in comparison to the non-treated group. After 4 weeks of treatment, coordination performance in the nano-DOPA group (89±13% of the intact control level) was twice as high as in the L-DOPA and L-DOPA+benserazide groups, which did not differ from non-treated animals. The effect of nano-DOPA was significantly higher and more long-lasting (90±13% at 24 h after administration); moreover, it was still significant one week after the treatment was discontinued. Intranasal nano-DOPA was found to provide a lasting motor function recovery in the 6-OHDA-induced rat PD model with the effect sustained for one week after discontinuation, while the same doses of standard drugs provided significant effect only after the first administration. L-DOPA administered in the form of PLGA-based nanoparticles had a higher effective half-life, bioavailability, and efficacy; it was also efficiently delivered to the brain by intranasal administration. PMID:25258572

Kondrasheva, I.G.; Severin, E.S.; Guseva, A.A.; Kamensky, A.A.

2014-01-01

281

Delivery system for molten salt oxidation of solid waste  

DOEpatents

The present invention is a delivery system for safety injecting solid waste particles, including mixed wastes, into a molten salt bath for destruction by the process of molten salt oxidation. The delivery system includes a feeder system and an injector that allow the solid waste stream to be accurately metered, evenly dispersed in the oxidant gas, and maintained at a temperature below incineration temperature while entering the molten salt reactor.

Brummond, William A. (Livermore, CA); Squire, Dwight V. (Livermore, CA); Robinson, Jeffrey A. (Manteca, CA); House, Palmer A. (Walnut Creek, CA)

2002-01-01

282

Local delivery of nitric oxide: targeted delivery of therapeutics to bone and connective tissues  

PubMed Central

Non-invasive treatment of injuries and disorders affecting bones and connective tissue is a significant challenge facing the medical community. A treatment route that has recently been proposed is nitric oxide (NO) therapy. Nitric oxide plays several roles in physiology with many conditions lacking adequate levels of NO. As NO is a radical, localized delivery via NO donors is essential to promoting biological activity. Herein, we review current literature related to therapeutic NO delivery in the treatment of bone, skin and tendon repair. PMID:22433782

Nichols, Scott P.; Storm, Wesley L.; Koh, Ahyeon; Schoenfisch, Mark H.

2012-01-01

283

Delivery of Aerosolized Liposomal Amikacin as a Novel Approach for the Treatment of Nontuberculous Mycobacteria in an Experimental Model of Pulmonary Infection  

PubMed Central

Pulmonary infections caused by nontuberculous mycobacteria (NTM) are an increasing problem in individuals with chronic lung conditions and current therapies are lacking. We investigated the activity of liposomal amikacin for inhalation (LAI) against NTM in vitro as well as in a murine model of respiratory infection. Macrophage monolayers were infected with three strains of Mycobacterium avium, two strains of Mycobacterium abscessus, and exposed to LAI or free amikacin for 4 days before enumerating bacterial survival. Respiratory infection was established in mice by intranasal inoculation with M. avium and allowing three weeks for the infection to progress. Three different regimens of inhaled LAI were compared to inhaled saline and parenterally administered free amikacin over a 28 day period. Bacteria recovered from the mice were analyzed for acquired resistance to amikacin. In vitro, liposomal amikacin for inhalation was more effective than free amikacin in eliminating both intracellular M. avium and M. abscessus. In vivo, inhaled LAI demonstrated similar effectiveness to a ?25% higher total dose of parenterally administered amikacin at reducing M. avium in the lungs when compared to inhaled saline. Additionally, there was no acquired resistance to amikacin observed after the treatment regimen. The data suggest that LAI has the potential to be an effective therapy against NTM respiratory infections in humans. PMID:25264757

Rose, Sasha J.; Neville, Mary E.; Gupta, Renu; Bermudez, Luiz E.

2014-01-01

284

Prophylaxis and treatment of Alzheimer's disease by delivery of an adeno-associated virus encoding a monoclonal antibody targeting the amyloid Beta protein.  

PubMed

We previously reported on a monoclonal antibody (mAb) that targeted amyloid beta (Aß) protein. Repeated injection of that mAb reduced the accumulation of Aß protein in the brain of human Aß transgenic mice (Tg2576). In the present study, cDNA encoding the heavy and light chains of this mAb were subcloned into an adeno-associated virus type 1 (AAV) vector with a 2A/furin adapter. A single intramuscular injection of 3.0×10(10) viral genome of these AAV vectors into C57BL/6 mice generated serum anti-Aß Ab levels up to 0.3 mg/ml. Anti-Aß Ab levels in excess of 0.1 mg/ml were maintained for up to 64 weeks. The effect of AAV administration on Aß levels in vivo was examined. A significant decrease in Aß levels in the brain of Tg2576 mice treated at 5 months (prophylactic) or 10 months (therapeutic) of age was observed. These results support the use of AAV vector encoding anti-Aß Ab for the prevention and treatment of Alzheimer's disease. PMID:23555563

Shimada, Masaru; Abe, Shinya; Takahashi, Toru; Shiozaki, Kazumasa; Okuda, Mitsue; Mizukami, Hiroaki; Klinman, Dennis M; Ozawa, Keiya; Okuda, Kenji

2013-01-01

285

Phase composition control of calcium phosphate nanoparticles for tunable drug delivery kinetics and treatment of osteomyelitis. II. Antibacterial and osteoblastic response.  

PubMed

Osteomyelitis has been traditionally treated by the combination of long-term antibiotic therapies and surgical removal of diseased tissue. The multifunctional material was developed in this study with the aim to improve this therapeutic approach by: (a) enabling locally delivered and sustained release of antibiotics at a tunable rate, so as to eliminate the need for repetitive administration of systemically distributed antibiotics; and (b) controllably dissolving itself, so as to promote natural remineralization of the portion of bone lost to disease. We report hereby on the effect of previously synthesized calcium phosphates (CAPs) with tunable solubilities and drug release timescales on bacterial and osteoblastic cell cultures. All CAP powders exhibited satisfying antibacterial performance against Staphylococcus aureus, the main causative agent of osteomyelitis. Still, owing to its highest drug adsorption efficiency, the most bacteriostatically effective phase was amorphous CAP with the minimal inhibitory concentration of less than 1 mg/mL. At the same time, the positive cell response and osteogenic effect of the antibiotic-loaded CAP particles was confirmed in vitro for all the sparsely soluble CAP phases. Adsorption of the antibiotic onto CAP particles reversed the deleterious effect that the pure antibiotic exerted on the osteogenic activity of the osteoblastic cells. The simultaneous osteogenic and antimicrobial performance of the material developed in this study, altogether with its ability to exhibit sustained drug release, may favor its consideration as a material base for alternative therapeutic approaches to prolonged antibiotic administration and surgical debridement typically prescribed in the treatment of osteomyelitis. PMID:23115128

Uskokovi?, Vuk; Desai, Tejal A

2013-05-01

286

Accurate models for EUV lithography  

Microsoft Academic Search

Accurate modeling of EUV Lithography is a mandatory step in driving the technology towards its foreseen insertion point for 22-16nm node patterning. The models are needed to correct EUV designs for imaging effects, and to understand and improve the CD fingerprint of the exposure tools. With a full-field EUV ADT from ASML now available in the IMEC cleanroom, wafer data

Eric Hendrickx; Gian F. Lorusso; Jiong Jiang; Luoqi Chen; Wei Liu; Eelco van Setten; Steve Hansen

2009-01-01

287

Prevention of preterm delivery in twin pregnancy.  

PubMed

The incidence of twin gestation has increased markedly over the past decades, mostly because of increased use of assisted reproductive technologies. Twin pregnancies are at increased risk of preterm delivery (i.e. birth before 37 weeks of gestation). Multiple gestations therefore account for 2-3% of all pregnancies but constitute at least 10% of cases of preterm delivery. Complications from preterm birth are not limited to the neonatal period, such as in retinopathy of prematurity, intraventricular haemorrhage, necrotising enterocolitis, respiratory disorder and sepsis; they can also constitute sequelae such as abnormal neurophysiological development in early childhood and underachievement in school. Several treatment modalities have been proposed in singleton high-risk pregnancies. The mechanism of initiating labour may, however, be different in singleton and twin gestations. Therefore, it is mandatory to evaluate the proposed treatments in randomised trials of multiple gestations. In this chapter, we describe the results of trials to prevent preterm delivery in twin pregnancies. PMID:24378186

Rode, Line; Tabor, Ann

2014-02-01

288

Barriers to drug delivery in solid tumors  

PubMed Central

Over the last decade, significant progress has been made in the field of drug delivery. The advent of engineered nanoparticles has allowed us to circumvent the initial limitations to drug delivery such as pharmacokinetics and solubility. However, in spite of significant advances to tumor targeting, an effective treatment strategy for malignant tumors still remains elusive. Tumors possess distinct physiological features which allow them to resist traditional treatment approaches. This combined with the complexity of the biological system presents significant hurdles to the site-specific delivery of therapeutic drugs. One of the key features of engineered nanoparticles is that these can be tailored to execute specific functions. With this review, we hope to provide the reader with a clear understanding and knowledge of biological barriers and the methods to exploit these characteristics to design multifunctional nanocarriers, effect useful dosing regimens and subsequently improve therapeutic outcomes in the clinic. PMID:25068098

Sriraman, Shravan Kumar; Aryasomayajula, Bhawani; Torchilin, Vladimir P

2014-01-01

289

Power delivery system  

Microsoft Academic Search

This patent describes a power delivery system for connecting a transmission to an output shaft of an engine, the transmission including a dog clutch for establishing a power transmission route by the engagement of the dog clutch, the power delivery system comprising; a clutch for disconnecting the engagement between an output member of the fluid coupling and the output shaft

S. Moroto; S. Sakakibara

1987-01-01

290

Formality in Rhetorical Delivery.  

ERIC Educational Resources Information Center

Formality in rhetorical delivery can be defined as a complex variable that represents the speaker's efforts to invoke sociocultural rules of audience control through the nonverbal components of the delivery. This document describes some of the aspects of formality, outlines its significance in rhetorical contexts, and evaluates the concept in…

Skopec, Eric Wm.

291

conventional delivery? (ie  

E-print Network

Is this a new programme proposal? Is the programme for conventional delivery? (ie not blended? (subject and SCQF level) Where is the programme being delivered? Is the programme for conventional delivery, it is a modification Does modification involve changes to/additions of: Modes of Study Locations of Study Language

Painter, Kevin

292

What Is the Most Effective Drug Delivery System for Cisplatin during the Treatment of Hepatic Tumors with Single-Session Transcatheter Chemotherapy? A Pilot Study  

PubMed Central

Background/Aims The aim of this study was to determine the pharmacodynamics of cisplatin following three different treatment procedures for intrahepatic arterial infusion therapy for hepatocellular carcinoma (HCC). Methods We divided 13 HCC patients into the following three groups: group A, lone injection of cisplatin (n=3); group B, combined injection of cisplatin and lipiodol, with embolization using small gelatin cubes (GCs) (n=5); and group C, injection of suspended lipiodol with cisplatin powder, with embolization using small GCs (n=5). In each group, the free cisplatin concentration in the hepatic vein was measured at 0, 5, 10, and 30 minutes. Results The mean free cisplatin concentrations were as follows. For group A, the mean was 48.58 µg/mL at 0 minute, 7.31 µg/mL at 5 minutes, 5.70 µg/mL at 10 minutes, and 7.15 µg/mL at 30 minutes. For the same time points, for group B, the concentrations were 8.66, 4.23, 3.22, and 1.65 µg/mL, respectively, and for group C, the concentrations were 4.81, 2.61, 2.52, and 1.75 µg/mL, respectively. The mean area under the curve (AUC)0-infinity for the free cisplatin concentration was 7.80 in group A, 2.48 in group B, and 2.27 in group C. The AUC0-infinity for the free cisplatin concentration gradually decreased, from group A to group C. Conclusions These results indicate that the combination of lipiodol and small GCs may be useful for delaying cisplatin drainage from the liver. PMID:24073316

Ikeda, Kenji; Fukushima, Taito; Seko, Yuya; Hara, Tasuku; Sezaki, Hitomi; Hosaka, Tetsuya; Akuta, Norio; Kobayashi, Masahiro; Saitoh, Satoshi; Suzuki, Fumitaka; Suzuki, Yoshiyuki; Arase, Yasuji; Kumada, Hiromitsu

2013-01-01

293

Total Body Irradiation, Toward Optimal Individual Delivery: Dose Evaluation With Metal Oxide Field Effect Transistors, Thermoluminescence Detectors, and a Treatment Planning System  

SciTech Connect

Purpose: To predict the three-dimensional dose distribution of our total body irradiation technique, using a commercial treatment planning system (TPS). In vivo dosimetry, using metal oxide field effect transistors (MOSFETs) and thermoluminescence detectors (TLDs), was used to verify the calculated dose distributions. Methods and Materials: A total body computed tomography scan was performed and loaded into our TPS, and a three-dimensional-dose distribution was generated. In vivo dosimetry was performed at five locations on the patient. Entrance and exit dose values were converted to midline doses using conversion factors, previously determined with phantom measurements. The TPS-predicted dose values were compared with the MOSFET and TLD in vivo dose values. Results: The MOSFET and TLD dose values agreed within 3.0% and the MOSFET and TPS data within 0.5%. The convolution algorithm of the TPS, which is routinely applied in the clinic, overestimated the dose in the lung region. Using a superposition algorithm reduced the calculated lung dose by approximately 3%. The dose inhomogeneity, as predicted by the TPS, can be reduced using a simple intensity-modulated radiotherapy technique. Conclusions: The use of a TPS to calculate the dose distributions in individual patients during total body irradiation is strongly recommended. Using a TPS gives good insight of the over- and underdosage in a patient and the influence of patient positioning on dose homogeneity. MOSFETs are suitable for in vivo dosimetry purposes during total body irradiation, when using appropriate conversion factors. The MOSFET, TLD, and TPS results agreed within acceptable margins.

Bloemen-van Gurp, Esther J. [Department of Radiation Oncology, Maastro Clinic, GROW, University Hospital Maastricht, Maastricht (Netherlands)], E-mail: esther.bloemen@maastro.nl; Mijnheer, Ben J.; Verschueren, Tom A.M.; Lambin, Philippe [Department of Radiation Oncology, Maastro Clinic, GROW, University Hospital Maastricht, Maastricht (Netherlands)

2007-11-15

294

A review of the gastrointestinal therapeutic system (GITS) formulation and its effectiveness in the delivery of antihypertensive drug treatment (focus on nifedipine GITS)  

PubMed Central

Hypertension treatment guidelines do not discriminate within drug classes and, furthermore, do not consider whether or not all of the formulations of any given drug licensed for once-daily administration can be considered to be therapeutically interchangeable. This article focuses on this issue with respect to nifedipine and the development of the gastrointestinal therapeutic system (GITS) formulation. Nifedipine GITS is regarded as the gold standard once-daily formulation of nifedipine and, as such, it is anticipated that alternative formulations will be therapeutically equivalent to nifedipine GITS. In general, this depends on demonstrating pharmacokinetic bioequivalence. This article is intended to focus attention on generic substitution and, in particular, on aspects of the scientific basis for the substitution of generic products in place of branded products. Such substitution is required for cost-saving or cost-containment reasons and is justified on the basis that the generic (substitute) drug is “therapeutically” equivalent to the branded drug. Unfortunately, there are serious shortcomings in the current methods of assessment insofar as they are typically based on statistical comparisons of average pharmacokinetic parameter values, using arbitrary comparative criteria. This article illustrates the shortcomings of the current approaches to generic substitution and concludes that, in regulatory terms, either more rigorous pharmacokinetic criteria are required or pharmacodynamic indices should be added to reinforce the regulatory criteria. Generic substitution is a balancing act but, at the moment, the cost issue is dominant. To restore the balance, equivalent efficacy must be confirmed. At present, therefore, in the absence of such regulatory rigor, the obvious course is to prefer the branded product, the therapeutic efficacy of which (including outcome benefits) has been established. PMID:23901292

Meredith, Peter A; Elliott, Henry L

2013-01-01

295

Nano and Microparticles as Controlled Drug Delivery Devices  

Microsoft Academic Search

Although, the drug delivery system (DDS) concept is not new, great progress has recently been made in the treatment of a variety of diseases. Targeting delivery of drugs to the diseased lesions is one of the most important aspects of DDS. To convey a sufficient dose of drug to the lesion, suitable carriers of drugs are needed. Nano and microparticle

Majeti N. V. Ravi

2000-01-01

296

Current status and future potential of transdermal drug delivery  

Microsoft Academic Search

The past twenty five years have seen an explosion in the creation and discovery of new medicinal agents. Related innovations in drug delivery systems have not only enabled the successful implementation of many of these novel pharmaceuticals, but have also permitted the development of new medical treatments with existing drugs. The creation of transdermal delivery systems has been one of

Mark R. Prausnitz; Samir Mitragotri; Robert Langer

2004-01-01

297

Delivery of antimicrobials into parasites  

PubMed Central

To eliminate apicomplexan parasites, inhibitory compounds must cross host cell, parasitophorous vacuole, and parasite membranes and cyst walls, making delivery challenging. Here, we show that short oligomers of arginine enter Toxoplasma gondii tachyzoites and encysted bradyzoites. Triclosan, which inhibits enoyl-ACP reductase (ENR), conjugated to arginine oligomers enters extracellular tachyzoites, host cells, tachyzoites inside parasitophorous vacuoles within host cells, extracellular bradyzoites, and bradyzoites within cysts. We identify, clone, and sequence T. gondii enr and produce and characterize enzymatically active, recombinant ENR. This enzyme has the requisite amino acids to bind triclosan. Triclosan released after conjugation to octaarginine via a readily hydrolyzable ester linkage inhibits ENR activity, tachyzoites in vitro, and tachyzoites in mice. Delivery of an inhibitor to a microorganism via conjugation to octaarginine provides an approach to transporting antimicrobials and other small molecules to sequestered parasites, a model system to characterize transport across multiple membrane barriers and structures, a widely applicable paradigm for treatment of active and encysted apicomplexan and other infections, and a generic proof of principle for a mechanism of medicine delivery. PMID:14623959

Samuel, B. U.; Hearn, B.; Mack, D.; Wender, P.; Rothbard, J.; Kirisits, M. J.; Mui, E.; Wernimont, S.; Roberts, C. W.; Muench, S. P.; Rice, D. W.; Prigge, S. T.; Law, A. B.; McLeod, R.

2003-01-01

298

Recent developments in drug delivery.  

PubMed

Some recent innovative approaches to drug delivery have demonstrated that the administration of drugs can be more rigidly controlled with respect to the rate and amount of drug delivered to sites of action than from the conventional dosage forms. One category of controlled release referred to as programmed drug delivery primarily involves the application of polymers of defined specifications to release agents from either non-bioerodible membrane-controlled systems or bioerodible and non-bioerodible matrices. Also included here are the pro-drugs, inactive derivatives of drugs which are transformed into the active form in vivo but possess improved solubility, stability and disposition properties, yielding more efficient action and fewer side effects. Thus, exploitation of several routes of administration have resulted in products which are inserted ophtalmically, rectally or vaginally, implanted subcutaneously, taken orally or applied topically to achieve transdermal delivery of drugs to the systemic circulation. In several cases, release is designed to follow zero-order kinetics to achieve control of therapeutic plasma concentrations for prolonged time periods. Targeting of drugs by carrier is another form of controlled release technology. Normally administered intravenously, carriers such as liposomes, nanoparticles, microspheres, human cells and linear macromolecules are finding application in treating disease states with drugs which previously were unavailable to treatment. PMID:10262189

Rogers, J A

1982-01-01

299

On the use of explicitly correlated treatment methods for the generation of accurate polyatomic -He/H2 interaction potential energy surfaces: The case of C3-He complex and generalization.  

PubMed

Through the study of the C3(X1?g (+)) (1)?g (+)) + He((1)S) astrophysical relevant system using standard (CCSD(T)) and explicitly correlated (CCSD(T)-F12) coupled cluster approaches, we show that the CCSD(T)-F12/aug-cc-pVTZ level represents a good compromise between accuracy and low computational cost for the generation of multi-dimensional potential energy surfaces (PESs) over both intra- and inter-monomer degrees of freedom. Indeed, the CCSD(T)-F12/aug-cc-pVTZ 2D-PES for linear C3 and the CCSD(T)-F12/aug-cc-pVTZ 4D-PES for bent C3 configurations gently approach those mapped at the CCSD(T)/aug-cc-pVXZ (X = T,Q) + bond functions level, whereas a strong reduction of computational effort is observed. After exact dynamical computations, the pattern of the rovibrational levels of the intermediate C3-He complex and the rotational and rovibrational (de-) excitation of C3 by He derived using both sets of PESs agree quite well. Since C3 shows a floppy character, the interaction PES is defined in four dimensions to obtain realistic collisional parameters. The C-C-C bending mode, which fundamental lies at 63 cm(-1) and can be excited at very low temperatures is explicitly considered as independent coordinate. Our work suggests hence that CCSD(T)-F12/aug-cc-pVTZ methodology is the key method for the generation of accurate polyatomic - He/H2 multi-dimensional PESs. PMID:25084911

Al Mogren, M M; Denis-Alpizar, O; Ben Abdallah, D; Stoecklin, T; Halvick, P; Senent, M-L; Hochlaf, M

2014-07-28

300

Elective Delivery Before 39 Weeks  

MedlinePLUS

... born through incisions made in the abdomen and uterus ). What is an “elective” delivery? An elective delivery ... which the uterus tears during labor or delivery. Uterus: A muscular organ located in the female pelvis ...

301

Impact of community-based support services on antiretroviral treatment programme delivery and outcomes in resource-limited countries: a synthetic review  

PubMed Central

Background Task-shifting to lay community health providers is increasingly suggested as a potential strategy to overcome the barriers to sustainable antiretroviral treatment (ART) scale-up in high-HIV-prevalence, resource-limited settings. The dearth of systematic scientific evidence on the contributory role and function of these forms of community mobilisation has rendered a formal evaluation of the published results of existing community support programmes a research priority. Methods We reviewed the relevant published work for the period from November 2003 to December 2011 in accordance with the guidelines for a synthetic review. ISI Web of Knowledge, Science Direct, BioMed Central, OVID Medline, PubMed, Social Services Abstracts, and Sociological Abstracts and a number of relevant websites were searched. Results The reviewed literature reported an unambiguous positive impact of community support on a wide range of aspects, including access, coverage, adherence, virological and immunological outcomes, patient retention and survival. Looking at the mechanisms through which community support can impact ART programmes, the review indicates that community support initiatives are a promising strategy to address five often cited challenges to ART scale-up, namely (1) the lack of integration of ART services into the general health system; (2) the growing need for comprehensive care, (3) patient empowerment, (4) and defaulter tracing; and (5) the crippling shortage in human resources for health. The literature indicates that by linking HIV/AIDS-care to other primary health care programmes, by providing psychosocial care in addition to the technical-medical care from nurses and doctors, by empowering patients towards self-management and by tracing defaulters, well-organised community support initiatives are a vital part of any sustainable public-sector ART programme. Conclusions The review demonstrates that community support initiatives are a potentially effective strategy to address the growing shortage of health workers, and to broaden care to accommodate the needs associated with chronic HIV/AIDS. The existing evidence suggests that community support programmes, although not necessarily cheap or easy, remain a good investment to improve coverage of communities with much needed health services, such as ART. For this reason, health policy makers, managers, and providers must acknowledge and strengthen the role of community support in the fight against HIV/AIDS. PMID:22776682

2012-01-01

302

Treatment of Peritoneal Carcinomatosis by Targeted Delivery of the Radio-Labeled Tumor Homing Peptide 213Bi-DTPA-[F3]2 into the Nucleus of Tumor Cells  

PubMed Central

Background ?-particle emitting isotopes are effective novel tools in cancer therapy, but targeted delivery into tumors is a prerequisite of their application to avoid toxic side effects. Peritoneal carcinomatosis is a widespread dissemination of tumors throughout the peritoneal cavity. As peritoneal carcinomatosis is fatal in most cases, novel therapies are needed. F3 is a tumor homing peptide which is internalized into the nucleus of tumor cells upon binding to nucleolin on the cell surface. Therefore, F3 may be an appropriate carrier for ?-particle emitting isotopes facilitating selective tumor therapies. Principal Findings A dimer of the vascular tumor homing peptide F3 was chemically coupled to the ?-emitter 213Bi (213Bi-DTPA-[F3]2). We found 213Bi-DTPA-[F3]2 to accumulate in the nucleus of tumor cells in vitro and in intraperitoneally growing tumors in vivo. To study the anti-tumor activity of 213Bi-DTPA-[F3]2 we treated mice bearing intraperitoneally growing xenograft tumors with 213Bi-DTPA-[F3]2. In a tumor prevention study between the days 4–14 after inoculation of tumor cells 6×1.85 MBq (50 µCi) of 213Bi-DTPA-[F3]2 were injected. In a tumor reduction study between the days 16–26 after inoculation of tumor cells 6×1.85 MBq of 213Bi-DTPA-[F3]2 were injected. The survival time of the animals was increased from 51 to 93.5 days in the prevention study and from 57 days to 78 days in the tumor reduction study. No toxicity of the treatment was observed. In bio-distribution studies we found 213Bi-DTPA-[F3]2 to accumulate in tumors but only low activities were found in control organs except for the kidneys, where 213Bi-DTPA-[F3]2 is found due to renal excretion. Conclusions/Significance In conclusion we report that 213Bi-DTPA-[F3]2 is a novel tool for the targeted delivery of ?-emitters into the nucleus of tumor cells that effectively controls peritoneal carcinomatosis in preclinical models and may also be useful in oncology. PMID:19479088

Miederer, Matthias; Blechert, Birgit; Vallon, Mario; Müller, Jan M.; Alke, Andrea; Seidl, Christof; Bruchertseifer, Frank; Morgenstern, Alfred; Senekowitsch-Schmidtke, Reingard; Essler, Markus

2009-01-01

303

Bioavailability of phytochemicals and its enhancement by drug delivery systems  

PubMed Central

Issues of poor oral bioavailability of cancer chemopreventives have hindered progress in cancer prevention. Novel delivery systems that modulate the pharmacokinetics of existing drugs, such as nanoparticles, cyclodextrins, niosomes, liposomes and implants, could be used to enhance the delivery of chemopreventive agents to target sites. The development of new approaches in prevention and treatment of cancer could encompass new delivery systems for approved and newly investigated compounds. In this review, we discuss some of the delivery approaches that have already made an impact by either delivering a drug to target tissue or increasing its bioavailability by many fold. PMID:23435377

Aqil, Farrukh; Munagala, Radha; Jeyabalan, Jeyaprakash; Vadhanam, Manicka V.

2013-01-01

304

Novel drug delivery systems for glaucoma  

PubMed Central

Reduction of intraocular pressure (IOP) by pharmaceutical or surgical means has long been the standard treatment for glaucoma. A number of excellent drugs are available that are effective in reducing IOP. These drugs are typically applied as eye drops. However, patient adherence can be poor, thus reducing the clinical efficacy of the drugs. Several novel delivery systems designed to address the issue of adherence and to ensure consistent reduction of IOP are currently under development. These delivery systems include contact lenses-releasing glaucoma medications, injectables such as biodegradable micro- and nanoparticles, and surgically implanted systems. These new technologies are aimed at increasing clinical efficacy by offering multiple delivery options and are capable of managing IOP for several months. There is also a desire to have complementary neuroprotective approaches for those who continue to show progression, despite IOP reduction. Many potential neuroprotective agents are not suitable for traditional oral or drop formulations. Their potential is dependent on developing suitable delivery systems that can provide the drugs in a sustained, local manner to the retina and optic nerve. Drug delivery systems have the potential to improve patient adherence, reduce side effects, increase efficacy, and ultimately, preserve sight for glaucoma patients. In this review, we discuss benefits and limitations of the current systems of delivery and application, as well as those on the horizon. PMID:21475311

Lavik, E; Kuehn, M H; Kwon, Y H

2011-01-01

305

DRUG DELIVERY INTO THE HUMAN BRAIN  

Microsoft Academic Search

Large proteins for the treatment of diseases such as Parkinson's, Alzheimer's and other disorders affecting the central nervous system (CNS) cannot easily penetrate the brain blood barrier (BBB). As an alternative to delivery through the blood stream, drugs may be inserted into the brain tissue directly using invasive release techniques. Direct injection is expected to gain importance in advanced medical

A. A. Linninger; M. B. R Somayaji; M. Xenos; S. Kondapalli

306

Delivery quality assurance with ArcCHECK.  

PubMed

Radiation therapy requires delivery quality assurance (DQA) to ensure that treatment is accurate and closely follows the plan. We report our experience with the ArcCHECK phantom and investigate its potential optimization for the DQA process. One-hundred seventy DQA plans from 84 patients were studied. Plans were classified into 2 groups: those with the target situated on the diodes of the ArcCHECK (D plans) and those with the target situated at the center (C plans). Gamma pass rates for 8 target sites were examined. The parameters used to analyze the data included 3%/3 mm with the Van Dyk percent difference criteria (VD) on, 3%/3 mm with the VD off, 2%/2 mm with the VD on, and x/3 mm with the VD on and the percentage dosimetric agreement "x" for diode plans adjusted. D plans typically displayed maximum planned dose (MPD) on the cylindrical surface containing ArcCHECK diodes than center plans, resulting in inflated gamma pass rates. When this was taken into account by adjusting the percentage dosimetric agreement, C plans outperformed D plans by an average of 3.5%. ArcCHECK can streamline the DQA process, consuming less time and resources than radiographic films. It is unnecessary to generate 2 DQA plans for each patient; a single center plan will suffice. Six of 8 target sites consistently displayed pass rates well within our acceptance criteria; the lesser performance of head and neck and spinal sites can be attributed to marginally lower doses and increased high gradient of plans. PMID:22917964

Neilson, Christopher; Klein, Michael; Barnett, Rob; Yartsev, Slav

2013-01-01

307

Intraperiodontal pocket: An ideal route for local antimicrobial drug delivery  

PubMed Central

Periodontal pockets act as a natural reservoir filled with gingival crevicular fluid for the controlled release delivery of antimicrobials directly. This article reflects the present status of nonsurgical controlled local intrapocket delivery of antimicrobials in the treatment of periodontitis. These sites have specialty in terms of anatomy, permeability, and their ability to retain a delivery system for a desired length of time. A number of antimicrobial products and the composition of the delivery systems, its use, clinical results, and their release are summarized. The goal in using an intrapocket device for the delivery of an antimicrobial agent is the achievement and maintenance of therapeutic drug concentration for the desired period of time. Novel controlled drug delivery system are capable of improving patient compliance as well as therapeutic efficacy with precise control of the rate by which a particular drug dosage is released from a delivery system without the need for frequent administration. These are considered superior drug delivery system because of low cost, greater stability, non-toxicity, biocompatibility, non-immunogenicity, and are biodegradable in nature. This review also focus on the importance and ideal features of periodontal pockets as a drug delivery platform for designing a suitable dosage form along with its potential advantage and limitations. The microbes in the periodontal pocket could destroy periodontal tissues, and a complete knowledge of these as well as an ideal treatment strategy could be helpful in treating this disease. PMID:22470888

Nair, Sreeja C.; Anoop, K. R.

2012-01-01

308

Efficient and accurate fragmentation methods.  

PubMed

Conspectus Three novel fragmentation methods that are available in the electronic structure program GAMESS (general atomic and molecular electronic structure system) are discussed in this Account. The fragment molecular orbital (FMO) method can be combined with any electronic structure method to perform accurate calculations on large molecular species with no reliance on capping atoms or empirical parameters. The FMO method is highly scalable and can take advantage of massively parallel computer systems. For example, the method has been shown to scale nearly linearly on up to 131?000 processor cores for calculations on large water clusters. There have been many applications of the FMO method to large molecular clusters, to biomolecules (e.g., proteins), and to materials that are used as heterogeneous catalysts. The effective fragment potential (EFP) method is a model potential approach that is fully derived from first principles and has no empirically fitted parameters. Consequently, an EFP can be generated for any molecule by a simple preparatory GAMESS calculation. The EFP method provides accurate descriptions of all types of intermolecular interactions, including Coulombic interactions, polarization/induction, exchange repulsion, dispersion, and charge transfer. The EFP method has been applied successfully to the study of liquid water, ?-stacking in substituted benzenes and in DNA base pairs, solvent effects on positive and negative ions, electronic spectra and dynamics, non-adiabatic phenomena in electronic excited states, and nonlinear excited state properties. The effective fragment molecular orbital (EFMO) method is a merger of the FMO and EFP methods, in which interfragment interactions are described by the EFP potential, rather than the less accurate electrostatic potential. The use of EFP in this manner facilitates the use of a smaller value for the distance cut-off (Rcut). Rcut determines the distance at which EFP interactions replace fully quantum mechanical calculations on fragment-fragment (dimer) interactions. The EFMO method is both more accurate and more computationally efficient than the most commonly used FMO implementation (FMO2), in which all dimers are explicitly included in the calculation. While the FMO2 method itself does not incorporate three-body interactions, such interactions are included in the EFMO method via the EFP self-consistent induction term. Several applications (ranging from clusters to proteins) of the three methods are discussed to demonstrate their efficacy. The EFMO method will be especially exciting once the analytic gradients have been completed, because this will allow geometry optimizations, the prediction of vibrational spectra, reaction path following, and molecular dynamics simulations using the method. PMID:24810424

Pruitt, Spencer R; Bertoni, Colleen; Brorsen, Kurt R; Gordon, Mark S

2014-09-16

309

Psychosocial, behavioural and health system barriers to delivery and uptake of intermittent preventive treatment of malaria in pregnancy in Tanzania – viewpoints of service providers in Mkuranga and Mufindi districts  

PubMed Central

Background Intermittent preventive treatment of malaria in pregnancy (IPTp) using sulphurdoxine-pyrimethamine (SP) is one of key malaria control strategies in Africa. Yet, IPTp coverage rates across Africa are still low due to several demand and supply constraints. Many countries implement the IPTp-SP strategy at antenatal care (ANC) clinics. This paper reports from a study on the knowledge and experience of health workers (HWs) at ANC clinics regarding psychosocial, behavioural and health system barriers to IPTp-SP delivery and uptake in Tanzania. Methods Data were collected through questionnaire-based interviews with 78 HWs at 28 ANC clinics supplemented with informal discussions with current and recent ANC users in Mkuranga and Mufindi districts. Qualitative data were analysed using a qualitative content analysis approach. Quantitative data derived from interviews with HWs were analysed using non-parametric statistical analysis. Results The majority of interviewed HWs were aware of the IPTp-SP strategy’s existence and of the recommended one month spacing of administration of SP doses. Some HWs were unsure of that it is not recommended to administer IPTp-SP and ferrous/folic acid concurrently. Others were administering three doses of SP per client following instruction from a non-governmental agency while believing that this was in conflict with national guidelines. About half of HWs did not find it appropriate for the government to recommend private ANC providers to provide IPTp-SP free of charge since doing so forces private providers to recover the costs elsewhere. HWs noted that pregnant women often register at clinics late and some do not comply with the regularity of appointments for revisits, hence miss IPTp and other ANC services. HWs also noted some amplified rumours among clients regarding health risks and treatment failures of SP used during pregnancy, and together with clients’ disappointment with waiting times and the sharing of cups at ANC clinics for SP, limit the uptake of IPTp-doses. Conclusion HWs still question SP’s treatment advantages and are confused about policy ambiguity on the recommended number of IPTp-SP doses and other IPTp-SP related guidelines. IPTp-SP uptake is further constrained by pregnant women’s perceived health risks of taking SP and of poor service quality. PMID:24410770

2014-01-01

310

FUNCTIONAL NANOPARTICLES FOR MOLECULAR IMAGING GUIDED GENE DELIVERY  

PubMed Central

Gene therapy has great potential to bring tremendous changes in treatment of various diseases and disorders. However, one of the impediments to successful gene therapy is the inefficient delivery of genes to target tissues and the inability to monitor delivery of genes and therapeutic responses at the targeted site. The emergence of molecular imaging strategies has been pivotal in optimizing gene therapy; since it can allow us to evaluate the effectiveness of gene delivery noninvasively and spatiotemporally. Due to the unique physiochemical properties of nanomaterials, numerous functional nanoparticles show promise in accomplishing gene delivery with the necessary feature of visualizing the delivery. In this review, recent developments of nanoparticles for molecular imaging guided gene delivery are summarized. PMID:22473061

Liu, Gang; Swierczewska, Magdalena; Lee, Seulki; Chen, Xiaoyuan

2010-01-01

311

A fully implantable intracochlear drug delivery device : development and characterization  

E-print Network

In a collaborative effort with the Massachusetts Eye and Ear Infirmary, Draper Laboratory is developing an implantable microfluidic drug delivery system for long-term treatment of inner ear disorders and prevention of ...

Swan, Erin Eileen Leary, 1976-

2009-01-01

312

Nanoparticle-based drug delivery to the vagina: a review.  

PubMed

Vaginal drug administration can improve prophylaxis and treatment of many conditions affecting the female reproductive tract, including sexually transmitted diseases, fungal and bacterial infections, and cancer. However, achieving sustained local drug concentrations in the vagina can be challenging, due to the high permeability of the vaginal epithelium and expulsion of conventional soluble drug dosage forms. Nanoparticle-based drug delivery platforms have received considerable attention for vaginal drug delivery, as nanoparticles can provide sustained release, cellular targeting, and even intrinsic antimicrobial or adjuvant properties that can improve the potency and/or efficacy of prophylactic and therapeutic modalities. Here, we review the use of polymeric nanoparticles, liposomes, dendrimers, and inorganic nanoparticles for vaginal drug delivery. Although most of the work toward nanoparticle-based drug delivery in the vagina has been focused on HIV prevention, strategies for treatment and prevention of other sexually transmitted infections, treatment for reproductive tract cancer, and treatment of fungal and bacterial infections are also highlighted. PMID:24830303

Ensign, Laura M; Cone, Richard; Hanes, Justin

2014-09-28

313

MODIFICATION AND CHARACTERIZATION OF DRY MATERIAL FEEDER FOR DELIVERY OF RED AND VIOLET DYE MIXTURES  

EPA Science Inventory

Uniform delivery of dry material for stable concentrations of aerosols in inhalation exposure chambers is essential in inhalation experiments. his paper characterizes an AccuRate dry material feeder with modifications, for different helix sizes, actuation rates, nozzle types and ...

314

Accurate shear measurement with faint sources  

NASA Astrophysics Data System (ADS)

For cosmic shear to become an accurate cosmological probe, systematic errors in the shear measurement method must be unambiguously identified and corrected for. Previous work of this series has demonstrated that cosmic shears can be measured accurately in Fourier space in the presence of background noise and finite pixel size, without assumptions on the morphologies of galaxy and PSF. The remaining major source of error is source Poisson noise, due to the finiteness of source photon number. This problem is particularly important for faint galaxies in space-based weak lensing measurements, and for ground-based images of short exposure times. In this work, we propose a simple and rigorous way of removing the shear bias from the source Poisson noise. Our noise treatment can be generalized for images made of multiple exposures through MultiDrizzle. This is demonstrated with the SDSS and COSMOS/ACS data. With a large ensemble of mock galaxy images of unrestricted morphologies, we show that our shear measurement method can achieve sub-percent level accuracy even for images of signal-to-noise ratio less than 5 in general, making it the most promising technique for cosmic shear measurement in the ongoing and upcoming large scale galaxy surveys.

Zhang, Jun; Luo, Wentao; Foucaud, Sebastien

2015-01-01

315

Tunable physiologic interactions of adhesion molecules for inflamed cell-selective drug delivery  

E-print Network

Tunable physiologic interactions of adhesion molecules for inflamed cell-selective drug delivery delivery a b s t r a c t Dysregulated inflammation contributes to the pathogenesis of various diseases-directed drug delivery systems would thus render more effective and safer treatments by increasing local dosage

Daniel, Susan

316

Design and in vitro development of resorbable urologic drug delivery device  

E-print Network

Implantable, controlled release drug delivery devices offer several advantages over systemic oral administration routes and immediate drug release treatments including direct therapy to target organ, more continuous ...

Tobias, Irene S. (Irene Sophie)

2008-01-01

317

Therapeutic gene delivery using bioreducible polymers.  

PubMed

Bioreducible polymers, which can be degraded in reducing environment due to the cleavage of internal disulfide bonds, have been developed for gene delivery systems. They show high stability in extracellular physiological condition and cytoplasm-specific release of genetic materials, as well as decreased cytotoxicity because cytoplasm is a reducing environment containing high level of reducing molecules such as glutathione. Based on these advantages, recently, many bioreducible polymers have been further investigated with therapeutic genes for the treatment of diseases and demonstrated promising results. This review will focus on the therapeutic gene delivery using bioreducible polymers and the evaluation of therapeutic efficacy for cancer, myocardial infarction, diabetes and miscellaneous diseases. PMID:24178745

Ryu, Kitae; Kim, Tae-Il

2014-01-01

318

NANOMATERIALS FOR PROTEIN MEDIATED THERAPY AND DELIVERY  

PubMed Central

There has been a significant amount of research done on liposomes and nanoparticles as drug carriers for protein drugs. Proteins and enzymes have been used both as targeting moieties and for their therapeutic potential. High specificity and rapid reaction rates make proteins and enzymes excellent candidates for therapeutic treatment, but some limitations exist. Many of these limitations can be addressed by a well studied nanotechnology based delivery system. Such a system can provide a medium for delivery, stabilization of the drugs, and enable site specific accumulation of drugs. Nanomedicines such as these have great potential to revolutionize the pharmaceutical industry and improve healthcare worldwide. PMID:25414730

Barry, John N.; Vertegel, Alexey A.

2014-01-01

319

Nanoparticles for Pulmonary Delivery  

Microsoft Academic Search

\\u000a This chapter aims to provide a rational for the use of nanoparticles in pulmonary delivery as well as an overview of strategies\\u000a and physiological implications of nanoparticle delivery to the lungs. Formulation aspects of nanoparticle systems in the form\\u000a of liquid dispersions and inhaled dry powders are also reviewed. The chapter also addresses the expanse of lung toxicology\\u000a research surrounding

Alan B. Watts; Robert O. Williams

320

Secure Multicast Software Delivery  

Microsoft Academic Search

Nowadays, purchased software is delivered via sending CD-ROMs or downloading from the Internet. These solutions are either time-consuming or not scalable when the number of end-users becomes large. In this paper, we explore the use of multicast technology as an option for software delivery. We present a global structure for multicast software delivery and look into security issues, mainly focusing

Lin Han; Nahid Shahmehri

2000-01-01

321

Protein-Based Nanomedicine Platforms for Drug Delivery  

SciTech Connect

Drug delivery systems have been developed for many years, however some limitations still hurdle the pace of going to clinical phase, for example, poor biodistribution, drug molecule cytotoxicity, tissue damage, quick clearance from the circulation system, solubility and stability of drug molecules. To overcome the limitations of drug delivery, biomaterials have to be developed and applied to drug delivery to protect the drug molecules and to enhance the drug’s efficacy. Protein-based nanomedicine platforms for drug delivery are platforms comprised of naturally self-assembled protein subunits of the same protein or a combination of proteins making up a complete system. They are ideal for drug delivery platforms due to their biocompatibility and biodegradability coupled with low toxicity. A variety of proteins have been used and characterized for drug delivery systems including the ferritin/apoferritin protein cage, plant derived viral capsids, the small Heat shock protein (sHsp) cage, albumin, soy and whey protein, collagen, and gelatin. There are many different types and shapes that have been prepared to deliver drug molecules using protein-based platforms including the various protein cages, microspheres, nanoparticles, hydrogels, films, minirods and minipellets. There are over 30 therapeutic compounds that have been investigated with protein-based drug delivery platforms for the potential treatment of various cancers, infectious diseases, chronic diseases, autoimmune diseases. In protein-based drug delivery platforms, protein cage is the most newly developed biomaterials for drug delivery and therapeutic applications. Their uniform sizes, multifunctions, and biodegradability push them to the frontier for drug delivery. In this review, the recent strategic development of drug delivery has been discussed with a special emphasis upon the polymer based, especially protein-based nanomedicine platforms for drug delivery. The advantages and disadvantages are also discussed for each type of protein based drug delivery system.

Ma Ham, Aihui; Tang, Zhiwen; Wu, Hong; Wang, Jun; Lin, Yuehe

2009-08-03

322

Inorganic Nanoporous Membranes for Immunoisolated Cell-Based Drug Delivery  

PubMed Central

Materials advances enabled by nanotechnology have brought about promising approaches to improve the encapsulation mechanism for immunoisolated cell-based drug delivery. Cell-based drug delivery is a promising treatment for many diseases but has thus far achieved only limited clinical success. Treatment of insulin dependent diabetes mellitus (IDDM) by transplantation of pancreatic ?-cells represents the most anticipated application of cell-based drug delivery technology. This review outlines the challenges involved with maintaining transplanted cell viability and discusses how inorganic nanoporous membranes may be useful in achieving clinical success. PMID:20384222

Mendelsohn, Adam; Desai, Tejal

2014-01-01

323

Service Delivery Strategies for Multicultural  

E-print Network

Service Delivery Strategies for Multicultural Environments #12;Identifying Service Delivery: Service delivery has become an increasingly important part of managing public lands for recreation of more than one service delivery strategy. Two questions were examined: (1) Are there differences in site

Standiford, Richard B.

324

Accurate extraction of the News  

E-print Network

We propose a new scheme for extracting gravitational radiation from a characteristic numerical simulation of a spacetime. This method is similar in conception to our earlier work but analytical and numerical implementation is different. The scheme is based on direct transformation to the Bondi coordinates and the gravitational waves are extracted by calculating the Bondi news function in Bondi coordinates. The entire calculation is done in a way which will make the implementation easy when we use uniform Bondi angular grid at $\\mathcal I^+$. Using uniform Bondi grid for news calculation has added advantage that we have to solve only ordinary differential equations instead of partial differential equation. For the test problems this new scheme allows us to extract gravitational radiation much more accurately than the previous schemes.

Shrirang S. Deshingkar

2006-09-14

325

On numerically accurate finite element  

NASA Technical Reports Server (NTRS)

A general criterion for testing a mesh with topologically similar repeat units is given, and the analysis shows that only a few conventional element types and arrangements are, or can be made suitable for computations in the fully plastic range. Further, a new variational principle, which can easily and simply be incorporated into an existing finite element program, is presented. This allows accurate computations to be made even for element designs that would not normally be suitable. Numerical results are given for three plane strain problems, namely pure bending of a beam, a thick-walled tube under pressure, and a deep double edge cracked tensile specimen. The effects of various element designs and of the new variational procedure are illustrated. Elastic-plastic computation at finite strain are discussed.

Nagtegaal, J. C.; Parks, D. M.; Rice, J. R.

1974-01-01

326

Biopolymeric alginate-chitosan nanoparticles as drug delivery carriers for cancer therapy.  

PubMed

Nanoparticulate drug delivery systems enhance cancer treatment by direct entry of nanometer particles into the fenestration in the vasculature of cancer cells. Nanoparticles for encapsulation of anticancer drugs are preferably prepared using natural polymers as carriers, with polysaccharides being particularly favorable. Alginate and chitosan polysaccharides have been widely used in nanoparticulate drug delivery systems because of their biodegradable, biocompatible, non-toxic and bioadhesive properties. In this review, we present an overview of drug delivery systems for cancer treatment, describe the use of biopolymeric alginate-chitosan nanoparticles for anticancer drug delivery, and discuss the important characteristics of these nanoparticles for use in drug delivery. PMID:25158565

Bhunchu, S; Rojsitthisak, P

2014-08-01

327

Gene Expression Profiling Can Accurately Diagnose Burkitt's Lymphoma  

Cancer.gov

Gene profiling, a molecular technique that examines many genes simultaneously, can accurately distinguish between two types of immune cell tumors, Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL). Burkitt's lymphoma and DLBCL appear similar when viewed under a microscope but correct diagnosis is critical because each requires very different treatments.

328

Gene Delivery to the Spinal Cord: Comparison Between Lentiviral, Adenoviral, and Retroviral Vector Delivery Systems  

PubMed Central

Viral gene delivery for spinal cord injury (SCI) is a promising approach for enhancing axonal regeneration and neuroprotection. An understanding of spatio-temporal transgene expression in the spinal cord is essential for future studies of SCI therapies. Commonly, intracellular marker proteins (e.g., EGFP) were used as indicators of transgene levels after viral delivery, which may not accurately reflect levels of secreted transgene. This study examined transgene expression using ELISA after viral delivery of D15A, a neurotrophin with BDNF and NT-3 activities, at 1, 2, and 4 weeks after in vivo and ex vivo delivery using lentiviral, adenoviral, and retroviral vectors. Further, the inflammatory responses and viral infection patterns after in vivo delivery were examined. Lentiviral vectors had the most stable pattern of gene expression, with D15A levels of 536 ± 38 and 363 ± 47 pg/mg protein seen at 4 weeks after the in vivo and ex vivo delivery, respectively. Our results show that protein levels downregulate disproportionately to levels of EGFP after adenoviral vectors both in vivo and ex vivo. D15A dropped from initial levels of 422 ± 87 to 153 ± 18 pg/mg protein at 4 weeks after in vivo administration. Similarly, ex vivo retrovirus-mediated transgene expression exhibited rapid downregulation by 2 weeks post-grafting. Compared to adenoviral infection, macrophage activation was attenuated after lentiviral infection. These results suggest that lentiviral vectors are most suitable in situations where stable long-term transgene expression is needed. Retroviral ex vivo delivery is optional when transient expression within targeted spinal tissue is desired, with adenoviral vectors in between. PMID:16786574

Abdellatif, Ahmed A.; Pelt, Jennifer L.; Benton, Richard L.; Howard, Russell M.; Tsoulfas, Pantelis; Ping, Peipei; Xu, Xiao-Ming; Whittemore, Scott R.

2010-01-01

329

N-Acetylcarnosine sustained drug delivery eye drops to control the signs of ageless vision: Glare sensitivity, cataract amelioration and quality of vision currently available treatment for the challenging 50,000-patient population  

PubMed Central

Background: Innovative Vision Products, Inc. (IVP)’s scientists developed the lubricant eye drops (Can-C™) designed as 1% N-acetylcarnosine (NAC) prodrug of l-carnosine containing a mucoadhesive cellulose-based compound combined with corneal absorption promoters in a sustained drug delivery system. Only the natural l-isomeric form of NAC raw material was specifically synthesized at the cGMP facility and employed for the manufacturing of Can-C™ eye drops. Objective and study design: In the present clinical study the authors assessed vision before and after 9 month term of topical ocular administration of NAC lubricant eye drops or placebo in 75 symptomatic patients with age-related uncomplicated cataracts in one or both eyes, with acuity in one eye of 20/40 or worse (best-corrected distance), and no previous cataract surgery in either eye and no other ocular abnormality and 72 noncataract subjects ranged in age from 54 to 78 years. Setting: Subjects in these subsample groups have reported complaints of glare and wanted to administer eye drops to get quick eye relief and quality of vision for their daily activities including driving and computer works. Following 9 months of treatment with NAC lubricant eye drops, most patients’ glare scores were improved or returned to normal in disability glare tests with Halometer DG. Improvement in disability glare was accompanied with independent improvement in acuity. Furthermore, patients with the poorest pretreatment vision were as likely to regain certain better visual function after 9 months of treatment with N-acetylcarnosine lubricant eye drops as those with the worth pretreatment vision. Patients or other participants: The authors made a reference to electronic records of the product sales to patients who have been made the repurchase of the Can-C™ eye drops since December 2001. Intervention: Based on this analysis of recorded adjustments to inventory, various parameters were analyzed during the continued repurchase behavior program, including testimonials from buyers. With these figures, researchers judged on the patients’ compliance rate to self-administer NAC eye-drops. Main outcome measure and results: The ophthalmic drug showed potential for the non-surgical treatment of age-related cataracts for participants after controlling for age, gender and daily activities and on a combined basis of repurchases behavior reports in more than 50,000 various cohort survivors, has been demonstrated to have a high efficacy and good tolerability for prevention and treatment of visual impairment determined for the older population with relative stable pattern of causes for blindness and visual impairment. The mechanisms of prevention and reversal of cataracts with NAC ophthalmic drug are considered which include prevention by the intraocular released carnosine of free-radical-induced inactivation of proprietary lens antioxidant enzymes (superoxide dismutase); prevention of carbohydrate and metal-catalyzed autooxidation of ascorbic acid-induced cross-linking glycation reactions to the lens proteins; transglycation properties of carnosine, allowing it to compete for the glycating agent, protecting proteins (lens crystallins) against modification; universal antioxidant and scavenging activity towards lipid hydroperoxides, aldehydes and oxygen radicals; activation with l-carnosine ingredient of proteasome activity in the lens; chaperone-like disaggregating to lens crystallins activity of NAC and of its bioactivated principal carnosine. Blindness incidence increased with advancing age, such as cataract and glaucoma, which are by far the commonest causes of blindness in our sample and in all age groups, glaucomatous neurodegeneration can be treated with developed NAC autoinduction prodrug eye drops equipped with corneal absorption promoters. The common blinding affections presenting in developed countries such as, senile macular degeneration, hereditary chorioretinal dystrophies, diabetic retinopathy are poorly represented in our current summary of vital

Babizhayev, Mark A; Burke, Leslie; Micans, Philip; Richer, Stuart P

2009-01-01

330

Accurate models for EUV lithography  

NASA Astrophysics Data System (ADS)

Accurate modeling of EUV Lithography is a mandatory step in driving the technology towards its foreseen insertion point for 22-16nm node patterning. The models are needed to correct EUV designs for imaging effects, and to understand and improve the CD fingerprint of the exposure tools. With a full-field EUV ADT from ASML now available in the IMEC cleanroom, wafer data can be collected to calibrate accurate models and check if the existing modeling infrastructure can be extended to EUV lithography. As a first topic, we have measured the CD on wafer of a typical OPC dataset at different flare levels and modeled the evolution of wafer CD through flare, reticle CD, and pitch using Brion's Tachyon OPC engine. The modeling first requires the generation of a flare map using long-range kernels to model the EUV specific long-range flare. The accuracy of the flare map can be established independently from the CD measurements, by using the traditional disappearing pad test for flare determination (Kirk test). The flare map is then used as background intensity in the calibration of the traditional optical models with short-range kernels. For a structure set of 600 features and over a flare range of 4-6%, an rms fit value of 0.9nm was obtained. As a second aspect of the modeling, we have calibrated a full resist model to process window data. The full resist model is then used in a combination with experimental measurements of reticle CD, slit intensity uniformity, focal plane behavior, and EUV thick mask effects to model the evolution of wafer CD across the exposure field. The modeled evolution of CD across the exposure field was found to be a good match to the experimentally seen evolution of CD across the field, and confirms that the 4 factors mentioned above are main contributions to the CD uniformity across the field. As such the modeling work enables a better understanding of the errors contributing to CD variation across the field for EUV technology.

Hendrickx, Eric; Lorusso, Gian F.; Jiang, Jiong; Chen, Luoqi; Liu, Wei; Van Setten, Eelco; Hansen, Steve

2009-10-01

331

Clinical Applications of Biomedical Microdevices for Controlled Drug Delivery.  

PubMed

Miniaturization of devices to micrometer and nanometer scales, combined with the use of biocompatible and functional materials, has created new opportunities for the implementation of drug delivery systems. Advances in biomedical microdevices for controlled drug delivery platforms promise a new generation of capabilities for the treatment of acute conditions and chronic illnesses, which require high adherence to treatment, in which temporal control over the pharmacokinetic profiles is critical. In addition, clinical conditions that require a combination of drugs with specific pharmacodynamic profiles and local delivery will benefit from drug delivery microdevices. This review provides a summary of various clinical applications for state-of-the-art controlled drug delivery microdevices, including cancer, endocrine and ocular disorders, and acute conditions such as hemorrhagic shock. Regulatory considerations for clinical translation of drug delivery microdevices are also discussed. Drug delivery microdevices promise a remarkable gain in clinical outcomes and a substantial social impact. A review of articles covering the field of microdevices for drug delivery was performed between January 1, 1990, and January 1, 2014, using PubMed as a search engine. PMID:25484235

Gurman, Pablo; Miranda, Oscar R; Clayton, Kevin; Rosen, Yitzhak; Elman, Noel M

2014-12-01

332

Ocular Drug Delivery Using Ultrasound  

NASA Astrophysics Data System (ADS)

Our goal was to evaluate ultrasound (US) enhancement of drug delivery through the cornea, and the histological appearance of the cornea, up to 24 h after treatment. The aqueous humor concentration of topically applied sodium fluorescein was determined quantitatively in US-treated and sham rabbit eyes in vivo. Gross and light microscopic examinations were used to observe structural changes in the cornea 0-24 h after US exposure. The increase in the dye concentration in aqueous humor, after the simultaneous application of 880 kHz US and the dye solution (for 5 min), was 2.4 times at 0.19 W/cm2, 3.8 times at 0.34 W/cm2, and 10.6 times at 0.56 W/m2 (p<0.05). The dye delivery was found to increase with increasing US intensity, which corresponded with an increase in cavitation activity. After the separate application of US and the dye solution, the increase in the dye concentration was 3.8 times at 0.56 W/cm2 (p<0.01), while no increase was achieved at 0.19-0.34 W/cm2. The majority of damaged cells were present in the surface layer of the corneal epithelium. Corneal pits, observed in the US-treated epithelium, completely disappeared within 90 min. The application of 880 kHz ultrasound provided enhancement in the delivery of a hydrophilic compound through the cornea while producing minor changes in the corneal epithelium.

Zderic, Vesna; Clark, John I.; Vaezy, Shahram

2005-03-01

333

Dosimetric verification of IMAT delivery with a conventional EPID system and a commercial portal dose image prediction tool  

SciTech Connect

Purpose: The electronic portal imaging device (EPID) is a system for checking the patient setup; as a result of its integration with the linear accelerator and software customized for dosimetry, it is increasingly used for verification of the delivery of fixed-field intensity-modulated radiation therapy (IMRT). In order to extend such an approach to intensity-modulated arc therapy (IMAT), the combined use of an EPID system and a portal dose image prediction (PDIP) tool has been investigated. Methods: The dosimetric behavior of an EPID system, mechanically reinforced to maintain its positional stability during the accelerator gantry rotation, has been studied to assess its ability to measure portal dose distributions for IMAT treatment beams. In addition, the PDIP tool of a commercial treatment planning system, commonly used for static IMRT dosimetry, has been validated for simulating the PDIs of IMAT treatment fields. The method has been applied to the delivery verification of 23 treatment fields that were measured in their dual mode of IMRT and IMAT modalities. Results: The EPID system has proved to be appropriate for measuring the PDIs of IMAT fields; additionally the PDIP tool was able to simulate these accurately. The results are quite similar to those obtained for static IMRT treatment verification, although it was necessary to investigate the dependence of the EPID signal and of the accelerator monitor chamber response on variable dose rate. Conclusions: Our initial tests indicate that the EPID system, together with the PDIP tool, is a suitable device for the verification of IMAT plan delivery; however, additional tests are necessary to confirm these results.

Iori, Mauro; Cagni, Elisabetta; Paiusco, Marta; Munro, Peter; Nahum, Alan E. [Servizio di Fisica Sanitaria, Arceispedale S. Maria Nuova, Reggio Emilia 42100 (Italy); Varian Medical Systems, Palo Alto, California 94304 (United States); Department of Physics, Clatterbridge Centre for Oncology, Bebington CH63 4JY (United Kingdom)

2010-01-15

334

38 CFR 4.46 - Accurate measurement.  

Code of Federal Regulations, 2010 CFR

...46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect to landmarks, should be insisted on. The use of a goniometer in the measurement of limitation of motion...

2010-07-01

335

Progress in antiretroviral drug delivery using nanotechnology  

PubMed Central

There are currently a number of antiretroviral drugs that have been approved by the Food and Drug Administration for use in the treatment of human immunodeficiency virus (HIV). More recently, antiretrovirals are being evaluated in the clinic for prevention of HIV infection. Due to the challenging nature of treatment and prevention of this disease, the use of nanocarriers to achieve more efficient delivery of antiretroviral drugs has been studied. Various forms of nanocarriers, such as nanoparticles (polymeric, inorganic, and solid lipid), liposomes, polymeric micelles, dendrimers, cyclodextrins, and cell-based nanoformulations have been studied for delivery of drugs intended for HIV prevention or therapy. The aim of this review is to provide a summary of the application of nanocarrier systems to the delivery of anti-HIV drugs, specifically antiretrovirals. For anti-HIV drugs to be effective, adequate distribution to specific sites in the body must be achieved, and effective drug concentrations must be maintained at those sites for the required period of time. Nanocarriers provide a means to overcome cellular and anatomical barriers to drug delivery. Their application in the area of HIV prevention and therapy may lead to the development of more effective drug products for combating this pandemic disease. PMID:20957115

Mallipeddi, Rama; Rohan, Lisa Cencia

2010-01-01

336

Transungual delivery: deliberations and creeds.  

PubMed

Although considered as trifling illness, nail diseases have a reasonably high occurrence and a noteworthy impact on the patients' quality of life. Furthermore, there is a need to improve the topical treatment for nail diseases to avoid drug interactions and to reduce side effects associated with oral therapy. Topical drug delivery to the nails has established amplified consideration lately. Strategies (such as chemical enhancers, formulation strategies, physical and mechanical methods) are being investigated in order to improve drug permeability across the nail plate. The rationale of this review is to present contemporary information on the structure of human nail along with its comparison with animal hooves. Precincts of nail permeability have been briefly discussed with respect to factors like permeant's molecular size, hydrophilicity, charge and the nature of the vehicle. These factors affect drug uptake and permeation through the nail. Formulations like nail lacquers which mimic cosmetic varnish and colloidal carriers along with nail substitutes that can be utilized for transungual delivery have also been discussed. PMID:24888698

Thatai, P; Sapra, B

2014-10-01

337

Delivery of epidrugs.  

PubMed

Inhibitors of epigenetic targets have entered clinical trials with some success, in particular for combined therapies. Like many other chemotherapeutics these new classes of molecules have dose-limiting toxicities and highly active metabolism in vivo resulting in lower efficacy than expected. This review presents drug delivery strategies proposed to prolong epigenetic inhibitor effects while reducing toxicities and metabolic clearance. Inspired from the work done in cancer-targeted strategies, prodrugs and nanoparticle-based drug delivery systems are discussed in a comprehensive way, detailing the chemical and physiological principles of the selected releasing method and, when available, how epigenetic chemistry can be exploited. PMID:24680930

el Bahhaj, Fatima; Dekker, Frank J; Martinet, Nadine; Bertrand, Philippe

2014-09-01

338

Systems and Components Fuel Delivery System, Water Delivery System, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur, Huntsville, Madison County, AL

339

A Simple 2D Accurate Mini Implant Positioning Guide  

PubMed Central

One of the major issues in orthodontic treatment is anchorage planning when using a pre adjusted edgewise appliance system. The conventional methods described in the literature include banding of second molars, transpalatal arches and headgears that involve additional teeth or wire components. With the introduction of temporary anchorage devices, anchorage can be ideally planned to treat a case successfully. However, the stability and placement of these mini implants demands accurate positioning, good bone thickness without damaging the adjacent structures. Here, we illustrate a very economical and two dimensional mini implant guide for accurate and easy placement. PMID:25177667

Parimi, Sushma; M.S.V, Kishore; Shashidhar, Nagam Reddy; Dharmender, Sathu Reddy

2014-01-01

340

Nanodisks: hydrophobic drug delivery vehicles.  

PubMed

Members of the class of exchangeable apolipoproteins possess the unique capacity to transform phospholipid vesicle substrates into nanoscale disk-shaped bilayers. This reaction can proceed in the presence of exogenous hydrophobic biomolecules, resulting in the formation of novel transport vehicles termed nanodisks (NDs). The objective of this study is to describe the structural organization of NDs and evaluate the utility of these complexes as hydrophobic biomolecule transport vehicles. The topics presented focus on two distinct water insoluble drugs, amphotericin B (AMB) and all trans retinoic acid (ATRA). In vitro and in vivo studies reveal that AMB-ND display potent anti-fungal and anti-protozoal activity, while ATRA-ND show promise in the treatment of cancer. The versatility conferred by the presence of a polypeptide component provides opportunities for targeted delivery of ND to cells. PMID:18318655

Ryan, Robert O

2008-03-01

341

Educational Telecommunications Delivery Systems.  

ERIC Educational Resources Information Center

This monograph is a single volume reference manual providing an overall review of the current status and likely near future application of six major educational telecommunications delivery technologies. The introduction provides an overview to the usage and potential for these systems in the context of the major educational issues involved. Each…

Curtis, John A., Ed.; Biedenbach, Joseph M., Ed.

342

Iontophoretic drug delivery  

Microsoft Academic Search

The composition and architecture of the stratum corneum render it a formidable barrier to the topical and transdermal administration of therapeutic agents. The physicochemical constraints severely limit the number of molecules that can be considered as realistic candidates for transdermal delivery. Iontophoresis provides a mechanism to enhance the penetration of hydrophilic and charged molecules across the skin. The principal distinguishing

Yogeshvar N. Kalia; Aarti Naik; James Garrison; Richard H. Guy

2004-01-01

343

Document Delivery Update.  

ERIC Educational Resources Information Center

Presents highlights of research that used industrywide surveys, focus groups, personal interviews, and industry-published data to explore the future of electronic information delivery in libraries. Topics discussed include CD-ROMs; prices; full-text products; magnetic tape leasing; engineering and technical literature; connections between online…

Nelson, Nancy Melin

1992-01-01

344

Microprocessor controlled transdermal drug delivery.  

PubMed

Transdermal drug delivery via iontophoresis is reviewed with special focus on the delivery of lidocaine for local anesthesia and fentanyl for patient controlled acute therapy such as postoperative pain. The role of the microprocessor controller in achieving dosimetry, alternating/reverse polarity, pre-programmed, and sensor-based delivery is highlighted. Unique features such as the use of tactile signaling, telemetry control, and pulsatile waveforms in iontophoretic drug delivery are described briefly. PMID:16713690

Subramony, J Anand; Sharma, Ashutosh; Phipps, J B

2006-07-01

345

Nano to micro delivery systems: targeting angiogenesis in brain tumors  

PubMed Central

Treating brain tumors using inhibitors of angiogenesis is extensively researched and tested in clinical trials. Although anti-angiogenic treatment holds a great potential for treating primary and secondary brain tumors, no clinical treatment is currently approved for brain tumor patients. One of the main hurdles in treating brain tumors is the blood brain barrier - a protective barrier of the brain, which prevents drugs from entering the brain parenchyma. As most therapeutics are excluded from the brain there is an urgent need to develop delivery platforms which will bypass such hurdles and enable the delivery of anti-angiogenic drugs into the tumor bed. Such delivery systems should be able to control release the drug or a combination of drugs at a therapeutic level for the desired time. In this mini-review we will discuss the latest improvements in nano and micro drug delivery platforms that were designed to deliver inhibitors of angiogenesis to the brain. PMID:20932320

2010-01-01

346

STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 2009/109/109/109/10 Annual Delivery Report  

E-print Network

STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 2009/109/109/109/10 0 Annual Delivery Report 2009/10 August 2010 #12;STFC Annual Delivery Plan Report 200STFC Annual Delivery Plan Report 200STFC Annual Delivery

347

Chitosan Microspheres in Novel Drug Delivery Systems  

PubMed Central

The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

Mitra, Analava; Dey, Baishakhi

2011-01-01

348

Accurate, reproducible measurement of blood pressure.  

PubMed Central

The diagnosis of mild hypertension and the treatment of hypertension require accurate measurement of blood pressure. Blood pressure readings are altered by various factors that influence the patient, the techniques used and the accuracy of the sphygmomanometer. The variability of readings can be reduced if informed patients prepare in advance by emptying their bladder and bowel, by avoiding over-the-counter vasoactive drugs the day of measurement and by avoiding exposure to cold, caffeine consumption, smoking and physical exertion within half an hour before measurement. The use of standardized techniques to measure blood pressure will help to avoid large systematic errors. Poor technique can account for differences in readings of more than 15 mm Hg and ultimately misdiagnosis. Most of the recommended procedures are simple and, when routinely incorporated into clinical practice, require little additional time. The equipment must be appropriate and in good condition. Physicians should have a suitable selection of cuff sizes readily available; the use of the correct cuff size is essential to minimize systematic errors in blood pressure measurement. Semiannual calibration of aneroid sphygmomanometers and annual inspection of mercury sphygmomanometers and blood pressure cuffs are recommended. We review the methods recommended for measuring blood pressure and discuss the factors known to produce large differences in blood pressure readings. PMID:2192791

Campbell, N R; Chockalingam, A; Fodor, J G; McKay, D W

1990-01-01

349

Accurate adiabatic correction in the hydrogen molecule  

NASA Astrophysics Data System (ADS)

A new formalism for the accurate treatment of adiabatic effects in the hydrogen molecule is presented, in which the electronic wave function is expanded in the James-Coolidge basis functions. Systematic increase in the size of the basis set permits estimation of the accuracy. Numerical results for the adiabatic correction to the Born-Oppenheimer interaction energy reveal a relative precision of 10-12 at an arbitrary internuclear distance. Such calculations have been performed for 88 internuclear distances in the range of 0 < R ? 12 bohrs to construct the adiabatic correction potential and to solve the nuclear Schrödinger equation. Finally, the adiabatic correction to the dissociation energies of all rovibrational levels in H2, HD, HT, D2, DT, and T2 has been determined. For the ground state of H2 the estimated precision is 3 × 10-7 cm-1, which is almost three orders of magnitude higher than that of the best previous result. The achieved accuracy removes the adiabatic contribution from the overall error budget of the present day theoretical predictions for the rovibrational levels.

Pachucki, Krzysztof; Komasa, Jacek

2014-12-01

350

Improvement of different vaccine delivery systems for cancer therapy  

PubMed Central

Cancer vaccines are the promising tools in the hands of the clinical oncologist. Many tumor-associated antigens are excellent targets for immune therapy and vaccine design. Optimally designed cancer vaccines should combine the best tumor antigens with the most effective immunotherapy agents and/or delivery strategies to achieve positive clinical results. Various vaccine delivery systems such as different routes of immunization and physical/chemical delivery methods have been used in cancer therapy with the goal to induce immunity against tumor-associated antigens. Two basic delivery approaches including physical delivery to achieve higher levels of antigen production and formulation with microparticles to target antigen-presenting cells (APCs) have demonstrated to be effective in animal models. New developments in vaccine delivery systems will improve the efficiency of clinical trials in the near future. Among them, nanoparticles (NPs) such as dendrimers, polymeric NPs, metallic NPs, magnetic NPs and quantum dots have emerged as effective vaccine adjuvants for infectious diseases and cancer therapy. Furthermore, cell-penetrating peptides (CPP) have been known as attractive carrier having applications in drug delivery, gene transfer and DNA vaccination. This review will focus on the utilization of different vaccine delivery systems for prevention or treatment of cancer. We will discuss their clinical applications and the future prospects for cancer vaccine development. PMID:21211062

2011-01-01

351

to cigna Home Delivery Pharmacy  

E-print Network

Welcome to cigna Home Delivery Pharmacy 572507 q 3/12 Offered by: Connecticut General Life Insurance Company or Cigna Health and Life Insurance Company. #12;At Cigna Home Delivery PharmacySM we have at Cigna Home Delivery Pharmacy, I am honored to be part of a team that provides our customers

Nelson, Tim

352

Cyclodextrins in nasal drug delivery  

Microsoft Academic Search

Nasal drug delivery is an attractive approach for the systemic delivery of high potency drugs with a low oral bioavailability due to extensive gastrointestinal breakdown and high hepatic first-pass effect. For lipophilic drugs nasal delivery is possible if they can be dissolved in the dosage form. Peptide and protein drugs often have a low nasal bioavailability because of their large

F. W. H. M Merkus; J. C Verhoef; E Marttin; S. G Romeijn; P. H. M van der Kuy; W. A. J. J Hermens; N. G. M Schipper

1999-01-01

353

Photosensitizer delivery for photodynamic therapy of choroidal neovascularization.  

PubMed

The present review examines the importance of improving photosensitizer delivery for choroidal neovascularization (CNV) in light of the clinical impact of photodynamic therapy (PDT) for CNV. An overview of the classes of available photosensitizers is provided and the properties governing photosensitizer uptake and circulation in serum are discussed. Current delivery systems, for example liposomal formulations as well as the use of the promising strategy of antibody targeted delivery as a strategy to improve PDT selectivity and efficiency for CNV treatment are described. A summary of the work using Verteporfin, tin ethyl purpurin and Lu-Tex--photosensitizers currently in clinical trials for CNV--is given. PMID:11672876

Renno, R Z; Miller, J W

2001-10-31

354

Micromachined therapeutic delivery systems: from concept to clinic  

NASA Astrophysics Data System (ADS)

Microfabrication techniques which permit the creation of therapeutic delivery systems that possess a combination of structural, mechanical, and perhaps electronic features may surmount challenges associated with conventional delivery of therapy. In this review, delivery concepts are presented which capitalize on the strengths of microfabrication. Possible applications include micromachined silicon membranes to create implantable biocapsules for the immunoisolation of pancreatic islet cells--as a possible treatment for diabetes--and sustained release of injectable drugs needed over long time periods. Asymmetrical, drug- loaded microfabricated particles with specific ligands linked to the surface are proposed for improving oral bioavailability of peptide (and perhaps protein) drugs.

Desai, Tejal A.

2001-05-01

355

Revolutionary Impact of Nanodrug Delivery on Neuroscience  

PubMed Central

Brain research is the most expanding interdisciplinary research that is using the state of the art techniques to overcome limitations in order to conduct more accurate and effective experiments. Drug delivery to the target site in the central nervous system (CNS) is one of the most difficult steps in neuroscience researches and therapies. Taking advantage of the nanoscale structure of neural cells (both neurons and glia); nanodrug delivery (second generation of biotechnological products) has a potential revolutionary impact into the basic understanding, visualization and therapeutic applications of neuroscience. Current review article firstly provides an overview of preparation and characterization, purification and separation, loading and delivering of nanodrugs. Different types of nanoparticle bioproducts and a number of methods for their fabrication and delivery systems including (carbon) nanotubes are explained. In the second part, neuroscience and nervous system drugs are deeply investigated. Different mechanisms in which nanoparticles enhance the uptake and clearance of molecules form cerebrospinal fluid (CSF) are discussed. The focus is on nanodrugs that are being used or have potential to improve neural researches, diagnosis and therapy of neurodegenerative disorders. PMID:23730260

Khanbabaie, Reza; Jahanshahi, Mohsen

2012-01-01

356

Delivery of Cancer Therapeutics Using Nanotechnology  

PubMed Central

Nanoparticles have been investigated as drug carriers, because they provide a great opportunity due to their advantageous features: (i) various formulations using organic/inorganic materials, (ii) easy modification of targeting molecules, drugs or other molecules on them, (iii) effective delivery to target sites, resulting in high therapeutic efficacy and (iv) controlling drug release by external/internal stimuli. Because of these features, therapeutic efficacy can be improved and unwanted side effects can be reduced. Theranostic nanoparticles have been developed by incorporating imaging agents in drug carriers as all-in-one system, which makes it possible to diagnose and treat cancer by monitoring drug delivery behavior simultaneously. Recently, stimuli-responsive, activatable nanomaterials are being applied that are capable of producing chemical or physical changes by external stimuli. By using these nanoparticles, multiple tasks can be carried out simultaneously, e.g., early and accurate diagnosis, efficient cataloguing of patient groups of personalized therapy and real-time monitoring of disease progress. In this paper, we describe various types of nanoparticles for drug delivery systems, as well as theranostic systems. PMID:24300452

Lim, Eun-Kyung; Jang, Eunji; Lee, Kwangyeol; Haam, Seungjoo; Huh, Yong-Min

2013-01-01

357

Delivery systems for {sup 252}Cf used in industrial applications  

SciTech Connect

Californium-252 is used in a variety of industrial applications to deliver neutron dose. The design of the delivery system, i.e., the system that places the {sup 252}Cf source next to the item being exposed, is a crucial part of a successful irradiator system. This paper reviews different types of delivery systems and discusses the benefits and limitations of each type of system. A recently installed irradiator uses a straight-line pneumatic tube and a multiple-source carousel to rapidly and accurately deliver different radioactive sources to the same position.

Rushton, R.O.

2000-07-01

358

Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery  

SciTech Connect

Purpose: The curative potential of external beam radiation therapy is critically dependent on having the ability to accurately aim radiation beams at intended targets while avoiding surrounding healthy tissues. However, existing technologies are incapable of real-time, volumetric, soft-tissue imaging during radiation beam delivery, when accurate target tracking is most critical. The authors address this challenge in the development and evaluation of a novel, minimally interfering, telerobotic ultrasound (U.S.) imaging system that can be integrated with existing medical linear accelerators (LINACs) for therapy guidance. Methods: A customized human-safe robotic manipulator was designed and built to control the pressure and pitch of an abdominal U.S. transducer while avoiding LINAC gantry collisions. A haptic device was integrated to remotely control the robotic manipulator motion and U.S. image acquisition outside the LINAC room. The ability of the system to continuously maintain high quality prostate images was evaluated in volunteers over extended time periods. Treatment feasibility was assessed by comparing a clinically deployed prostate treatment plan to an alternative plan in which beam directions were restricted to sectors that did not interfere with the transabdominal U.S. transducer. To demonstrate imaging capability concurrent with delivery, robot performance and U.S. target tracking in a phantom were tested with a 15 MV radiation beam active. Results: Remote image acquisition and maintenance of image quality with the haptic interface was successfully demonstrated over 10 min periods in representative treatment setups of volunteers. Furthermore, the robot's ability to maintain a constant probe force and desired pitch angle was unaffected by the LINAC beam. For a representative prostate patient, the dose-volume histogram (DVH) for a plan with restricted sectors remained virtually identical to the DVH of a clinically deployed plan. With reduced margins, as would be enabled by real-time imaging, gross tumor volume coverage was identical while notable reductions of bladder and rectal volumes exposed to large doses were possible. The quality of U.S. images obtained during beam operation was not appreciably degraded by radiofrequency interference and 2D tracking of a phantom object in U.S. images obtained with the beam on/off yielded no significant differences. Conclusions: Remotely controlled robotic U.S. imaging is feasible in the radiotherapy environment and for the first time may offer real-time volumetric soft-tissue guidance concurrent with radiotherapy delivery.

Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Department of Computer Science and Department of Surgery, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

2010-12-15

359

Synthetic fluorescent probes capable of selective recognition of 3'-overhanging nucleotides for siRNA delivery imaging.  

PubMed

Peptide nucleic acid (PNA)-thiazole orange (TO) conjugates are developed as fluorescent probes capable of selective recognition of 3'-overhanging nucleotides of siRNAs for an accurate analysis of the siRNA delivery process. PMID:25483137

Sato, Takaya; Sato, Yusuke; Iwai, Kenta; Kuge, Shusuke; Nishizawa, Seiichi; Teramae, Norio

2015-01-01

360

Novel enhanced delivery taxanes: an update.  

PubMed

Taxanes are widely used for many solid tumors, including metastatic breast cancer. Enhanced-delivery taxanes (EDTs) were specifically designed to improve the efficacy and tolerability of taxanes through the utilization of biocompatible, tumor-selective, taxane delivery vehicles, removing the need for drug delivery in toxic, conventional solvents. Nab-paclitaxel is a first-generation EDT that consists of paclitaxel encapsulated in albumin-bound nanoparticles that utilize a standard, endogenous serum albumin pathway to deliver paclitaxel to tumor cells. Second-generation EDTs, including Tocosol Paclitaxel (Sonus Pharmaceuticals, Inc., Bothell, Washington) and paclitaxel poliglumex, use biocompatible drug delivery vehicles that not only eliminate the need for toxic conventional solvents but also exploit tumor pathophysiological phenomena such as enhanced permeability and retention. Emerging evidence suggests that the use of EDTs may promote a more favorable and predictable pharmacokinetic profile with increased bioavailability of taxanes at the tumor site, limiting their exposure to normal tissues and improving the therapeutic benefits associated with taxane treatment. PMID:17598283

Perez, Edith A

2007-06-01

361

Topical Drug Delivery for Chronic Rhinosinusitis  

PubMed Central

Chronic rhinosinusitis is a multifactorial disorder that may be heterogeneous in presentation and clinical course. While the introduction of endoscopic sinus surgery revolutionized surgical management and has led to significantly improved patient outcomes, medical therapy remains the foundation of long-term care of chronic rhinosinusitis, particularly in surgically recalcitrant cases. A variety of devices and pharmaceutical agents have been developed to apply topical medical therapy to the sinuses, taking advantage of the access provided by endoscopic surgery. The goal of topical therapy is to address the inflammation, infection, and mucociliary dysfunction that underlies the disease. Major factors that impact success include the patient’s sinus anatomy and the dynamics of the delivery device. Despite a growing number of topical treatment options, the evidence-based literature to support their use is limited. In this article, we comprehensively review current delivery methods and the available topical agents. We also discuss biotechnological advances that promise enhanced delivery in the future, and evolving pharmacotherapeutical compounds that may be added to rhinologist’s armamentarium. A complete understand of topical drug delivery is increasingly essential to the management of chronic rhinosinusitis when traditional forms of medical therapy and surgery have failed. PMID:23525506

Liang, Jonathan; Lane, Andrew P.

2013-01-01

362

Bioengineered Nanoparticles for siRNA delivery  

PubMed Central

Short interfering RNA (siRNA) has been an important laboratory tool in the last two decades and has allowed researchers to better understand the functions of non-protein-coding genes through RNA interference (RNAi). Although RNAi holds great promise for this purpose as well as for treatment of many diseases, efforts at using siRNA have been hampered by the difficulty of safely and effectively introducing it into cells of interest, both in vitro and in vivo. To overcome this challenge, many biomaterials and nanoparticles (NPs) have been developed and optimized for siRNA delivery, often taking cues from the DNA delivery field, although different barriers exist for these two types of molecules. In this review, we discuss general properties of biomaterials and nanoparticles that are necessary for effective nucleic acid delivery. We also discuss specific examples of bioengineered materials, including lipid-based NPs, polymeric NPs, inorganic NPs, and RNA-based NPs, which clearly illustrate the problems and successes in siRNA delivery. PMID:23821336

Kozielski, Kristen L.; Tzeng, Stephany Y.; Green, Jordan J.

2014-01-01

363

Superhydrophobic materials for drug delivery  

NASA Astrophysics Data System (ADS)

Superhydrophobicity is a property of material surfaces reflecting the ability to maintain air at the solid-liquid interface when in contact with water. These surfaces have characteristically high apparent contact angles, by definition exceeding 150°, as a result of the composite material-air surface formed under an applied water droplet. Superhydrophobic surfaces were first discovered on naturally occurring substrates, and have subsequently been fabricated in the last several decades to harness these favorable surface properties for a number of emerging applications, including their use in biomedical settings. This work describes fabrication and characterization of superhydrophobic 3D materials, as well as their use as drug delivery devices. Superhydrophobic 3D materials are distinct from 2D superhydrophobic surfaces in that air is maintained not just at the surface of the material, but also within the bulk. When the superhydrophobic 3D materials are submerged in water, water infiltrates slowly and continuously as a new water-air-material interface is formed with controlled displacement of air. Electrospinning and electrospraying are used to fabricate superhydrophobic 3D materials utilizing blends of the biocompatible polymers poly(epsilon-caprolactone) and poly(caprolactone-co-glycerol monostearate) (PGC-C18). PGC-C18 is significantly more hydrophobic than PCL (contact angle of 116° versus 83° for flat materials), and further additions of PGC-C18 into electrospun meshes and electrosprayed coatings affords increased stability of the entrapped air layer. For example, PCL meshes alone (500 mum thick) take 10 days to fully wet, and with 10% or 30% PGC-C18 addition wetting rates are dramatically slowed to 60% wetted by 77 days and 4% by 75 days, respectively. Stability of the superhydrophobic materials can be further probed with a variety of physio-chemical techniques, including pressure, surfactant containing solutions, and solvents of varying surface tension. Superhydrophobicity is shown to be enhanced with further increases in PGC-C18 content and surface roughness (a decrease in fiber size). We demonstrate the utility of superhydrophobicity as a method for drug delivery. When the camptothecin derivatives SN-38 and CPT-11 are encapsulated within electrospun meshes, changes in air layer stability (due to changes in PGC-C18 content) dictate the rate of drug release by controlling the rate in which water can permeate into the porous 3D electrospun structure. Drug release can be tuned from 2 weeks to >10 weeks from 300 mum meshes, and meshes effectively kill a variety of cancer cell lines (lung, colon, breast) when utilized in a cytotoxicity assay. After determining that air could be used to control the rate of drug release, superhydrophobic 3D materials are explored for three applications. First, meshes are considered as a potential combination reinforcement-drug delivery device for use in resectable colorectal cancer. Second, removal of the air layer in superhydrophobic meshes is used as a method to trigger drug release. The pressure generated from high-intensity focused ultrasound (0.75-4.25 MPa) can remove the air layer spatially and temporally, allowing drug release to be controlled with application of a sufficient treatment. Third, "connective" electrosprayed coatings are deposited on chemically distinct material surfaces, which are both three-dimensional and mechanically robust. In summary, superhydrophobic 3D materials are fabricated and characterized, and are utilized as drug delivery devices. Controlled air removal from these materials offers an entirely new strategy for drug delivery, and is promising for the applications considered in this work as well as many others.

Yohe, Stefan Thomas

364

Protease-mediated drug delivery  

NASA Astrophysics Data System (ADS)

Drugs used in disease treatment can cause damage to both malignant and normal tissue. This toxicity limits the maximum therapeutic dose. Drug targeting is of high interest to increase the therapeutic efficacy of the drug without increasing systemic toxicity. Certain tissue abnormalities, disease processes, cancers, and infections are characterized by high levels of activity of specific extracellular and/or intracellular proteases. Abnormally high activity levels of specific proteases are present at sites of physical or chemical trauma, blood clots, malignant tumors, rheumatoid arthritis, inflammatory bowel disease, gingival disease, glomerulonerphritis, and acute pancreatitis. Abnormal protease activity is suspected in development of liver thrombosis, pulmonary emphysema, atherosclerosis, and muscular dystrophy. Inactiviating disease-associated proteases by the administration of appropriate protease inhibitors has had limited success. Instead, one could use such proteases to target drugs to treat the condition. Protease mediated drug delivery offers such a possibility. Solubilizing groups are attached to insoluble drugs via a polypeptide chain which is specifically cleavable by certian proteases. When the solubilized drug enounters the protease, the solubilizing moieties are cleaved, and the drug precipitates at the disease location. Thus, a smaller systemic dosage could result in a therapeutic drug concentration at the treatment site with less systemic toxicity.

Dickson, Eva F.; Goyan, Rebecca L.; Kennedy, James C.; Mackay, M.; Mendes, M. A. K.; Pottier, Roy H.

2003-12-01

365

Tool to visualize and evaluate operator proficiency in laser hair-removal treatments  

PubMed Central

Background The uniform delivery of laser energy is particularly important for safe and effective laser hair removal (LHR) treatment. Although it is necessary to quantitatively assess the spatial distribution of the delivered laser, laser spots are difficult to trace owing to a lack of visual cues. This study proposes a novel preclinic tool to evaluate operator proficiency in LHR treatment and applies this tool to train novice operators and compare two different treatment techniques (sliding versus spot-by-spot). Methods A simulation bed is constructed to visualize the irradiated laser spots. Six novice operators are recruited to perform four sessions of simulation while changing the treatment techniques and the presence of feedback (sliding without feedback, sliding with feedback, spot-by-spot without feedback, and spot-by-spot with feedback). Laser distribution maps (LDMs) are reconstructed through a series of images processed from the recorded video for each simulation session. Then, an experienced dermatologist classifies the collected LDMs into three different performance groups, which are quantitatively analyzed in terms of four performance indices. Results The performance groups are characterized by using a combination of four proposed indices. The best-performing group exhibited the lowest amount of randomness in laser delivery and accurate estimation of mean spot distances. The training was only effective in the sliding treatment technique. After the training, omission errors decreased by 6.32% and better estimation of the mean spot distance of the actual size of the laser-emitting window was achieved. Gels required operators to be trained when the spot-by-spot technique was used, and imposed difficulties in maintaining regular laser delivery when the sliding technique was used. Conclusions Because the proposed system is simple and highly affordable, it is expected to benefit many operators in clinics to train and maintain skilled performance in LHR treatment, which will eventually lead to accomplishing a uniform laser delivery for safe and effective LHR treatment. PMID:24708724

2014-01-01

366

On-demand controlled release of docetaxel from a battery-less MEMS drug delivery device.  

PubMed

We report the development of a magnetically controlled MEMS device capable of on-demand release of defined quantities of an antiproliferative drug, docetaxel (DTX). Controlled release of DTX with a dosage suitable for the treatment of diabetic retinopathy has been achieved for 35 days. The device consists of a drug-loaded microreservoir (Ø6 mm ×?550 ?m), sealed by an elastic magnetic PDMS (polydimethylsiloxane) membrane (Ø6 mm × 40 ?m) with a laser-drilled aperture (?100 × 100 ?m(2)). By applying a magnetic field, the magnetic PDMS membrane deforms, causing the discharge of the drug solution from the device. Controlled DTX release at a rate of 171 ± 16.7 ng per actuation interval has been achieved for 35 days using a 255 mT magnetic field. The background leakage of drug solution through the aperture was negligible at 0.053 ± 0.014 ng min(-1). The biological activity of the released drug was investigated using a cytotoxicity assay (cell apoptosis) for two cell lines, HUVEC (human umbilical vein endothelial cells) and PC3 (prostate cancer) cells. Reproducible release rates have been achieved and DTX within the PDMS MEMS reservoir maintains full pharmacological efficacy for more than two months. This device is a proof-of-concept development for targeted delivery of hydrophobic drugs such as DTX and other taxane-based agents that require accurate delivery in nanomolar concentrations. PMID:21698338

Pirmoradi, Fatemeh Nazly; Jackson, John K; Burt, Helen M; Chiao, Mu

2011-08-21

367

Delivery verification and dose reconstruction in tomotherapy  

NASA Astrophysics Data System (ADS)

It has long been a desire in photon-beam radiation therapy to make use of the significant fraction of the beam exiting the patient to infer how much of the beam energy was actually deposited in the patient. With a linear accelerator and corresponding exit detector mounted on the same ring gantry, tomotherapy provides a unique opportunity to accomplish this. Dose reconstruction describes the process in which the full three-dimensional dose actually deposited in a patient is computed. Dose reconstruction requires two inputs: an image of the patient at the time of treatment and the actual energy fluence delivered. Dose is reconstructed by computing the dose in the CT with the verified energy fluence using any model-based algorithm such as convolution/superposition or Monte Carlo. In tomotherapy, the CT at the time of treatment is obtained by megavoltage CT, the merits of which have been studied and proven. The actual energy fluence delivered to the patient is computed in a process called delivery verification. Methods for delivery verification and dose reconstruction in tomotherapy were investigated in this work. It is shown that delivery verification can be realized by a linear model of the tornotherapy system. However, due to the measurements required with this initial approach, clinical implementation would be difficult. Therefore, a clinically viable method for delivery verification was established, the details of which are discussed. With the verified energy fluence from delivery verification, an assessment of the accuracy and usefulness of dose reconstruction is performed. The latter two topics are presented in the context of a generalized dose comparison tool developed for intensity modulated radiation therapy. Finally, the importance of having a CT from the time of treatment for reconstructing the dose is shown. This is currently a point of contention in modern clinical radiotherapy and it is proven that using the incorrect CT for dose reconstruction can lead to misleading conclusions regarding a treatment. With the correct CT, dose reconstruction may allow for adaptive radiotherapy, in which errors in previous fraction(s) are remedied in subsequent fraction(s), and improved outcomes.

Kapatoes, Jeffrey Michael

2000-11-01

368

Delivery Systems for {sup 252}Cf Used in Industrial Applications  

SciTech Connect

Californium-252 is used in a variety of industrial applications to deliver neutron dose. The design of the delivery system, i.e., the system that places the {sup 252}Cf source next to the item being exposed, is a crucial part of a successful irradiator system. This paper reviews different types of delivery systems and discusses the benefits and limitations of each type of system. Several types of delivery systems are commercially available for {sup 252}Cf irradiators. The best design depends on the application for which it is used. For calibrating instruments and exposing dosimetry badges, the new straight-line, carousel system has proven to be effective, accurate, reliable, and safe.

R. O. Rushton

2000-06-04

369

Optimization, delivery and evaluation of intensity modulated arc therapy  

NASA Astrophysics Data System (ADS)

Intensity modulated arc therapy (IMAT) is a radiation therapy technique whereby the shape of the cone beam of radiation changes as it rotates around the patient. This is in contrast to other more commonly delivered forms of advanced radiation therapy, Intensity Modulated Radiation Therapy (IMRT) or helical tomotherapy. IMRT is a radiation technique where a patient is treated with a cone beam of radiation from a number of fixed beam directions, where the shapes and weights of the radiation beams are varied and tomotherapy is treated with a fan beam of radiation that follows a helical trajectory. In this thesis two aspects of IMAT were investigated: optimization of treatment plans and delivery of plans in conjunction with and without respiratory motion management. Optimization of IMAT deliveries consisted of two studies. In the first study, an algorithm that uses dosimetric ray tracing to set multi-leaf collimator (MLC) positions then directly optimizes the MLC positions to create IMAT treatment plans with only beam shape variations was developed and tested in three phantom studies and a clinical case. The second study investigated variable angular dose rate deliveries to a concave target and assessed the optimization strategy including arc initialization strategy, angular sampling and delivery efficiency. IMAT delivery with and without respiratory gated radiation delivery was studied with dose measurement using radiographic film in a motion phantom. In addition, simulations based on delivered log files were used to confirm that motion management for IMAT is effective and within dosimetric tolerances. As a pilot test, plans from IMRT and tomotherapy for partial breast irradiation were first studied, comparing them to conventional treatments. An IMAT plan was generated for one patient, demonstrating feasibility and was compared with IMRT and tomotherapy. This thesis has introduced a new IMAT optimization algorithm with and without variable angular dose rate, applied to partial breast treatment, and verified its delivery under motion and gating conditions. Keywords. Intensity Modulated Arc Therapy, respiratory gating, accelerated partial breast irradiation.

Oliver, Michael R.

370

Microsystems Technologies for Drug Delivery to the Inner Ear  

PubMed Central

The inner ear represents one of the most technologically challenging targets for local drug delivery, but its clinical significance is rapidly increasing. The prevalence of sensorineural hearing loss and other auditory diseases, along with balance disorders and tinnitus, has spurred broad efforts to develop therapeutic compounds and regenerative approaches to treat these conditions, necessitating advances in systems capable of targeted and sustained drug delivery. The delicate nature of hearing structures combined with the relative inaccessibility of the cochlea by means of conventional delivery routes together necessitate significant advancements in both the precision and miniaturization of delivery systems, and the nature of the molecular and cellular targets for these therapies suggests that multiple compounds may need to be delivered in a time-sequenced fashion over an extended duration. Here we address the various approaches being developed for inner ear drug delivery, including micropump-based devices, reciprocating systems, and cochlear prosthesis-mediated delivery, concluding with an analysis of emerging challenges and opportunities for the first generation of technologies suitable for human clinical use. These developments represent exciting advances that have the potential to repair and regenerate hearing structures in millions of patients for whom no currently available medical treatments exist, a situation that requires them to function with electronic hearing augmentation devices or to live with severely impaired auditory function. These advances also have the potential for broader clinical applications that share similar requirements and challenges with the inner ear, such as drug delivery to the central nervous system. PMID:22386561

Leary Pararas, Erin E.; Borkholder, David A.; Borenstein, Jeffrey T.

2012-01-01

371

Development of a Microfluidics-Based Intracochlear Drug Delivery Device  

PubMed Central

Background Direct delivery of drugs and other agents into the inner ear will be important for many emerging therapies, including the treatment of degenerative disorders and guiding regeneration. Methods We have taken a microfluidics/MEMS (MicroElectroMechanical Systems) technology approach to develop a fully implantable reciprocating inner-ear drug-delivery system capable of timed and sequenced delivery of agents directly into perilymph of the cochlea. Iterations of the device were tested in guinea pigs to determine the flow characteristics required for safe and effective delivery. For these tests, we used the glutamate receptor blocker DNQX, which alters auditory nerve responses but not cochlear distortion product otoacoustic emissions. Results We have demonstrated safe and effective delivery of agents into the scala tympani. Equilibration of the drug in the basal turn occurs rapidly (within tens of minutes) and is dependent on reciprocating flow parameters. Conclusion We have described a prototype system for the direct delivery of drugs to the inner ear that has the potential to be a fully implantable means for safe and effective treatment of hearing loss and other diseases. PMID:19923811

Sewell, William F.; Borenstein, Jeffrey T.; Chen, Zhiqiang; Fiering, Jason; Handzel, Ophir; Holmboe, Maria; Kim, Ernest S.; Kujawa, Sharon G.; McKenna, Michael J.; Mescher, Mark M.; Murphy, Brian; Leary Swan, Erin E.; Peppi, Marcello; Tao, Sarah

2009-01-01

372

Drug Delivery Nanoparticles in Skin Cancers  

PubMed Central

Nanotechnology involves the engineering of functional systems at nanoscale, thus being attractive for disciplines ranging from materials science to biomedicine. One of the most active research areas of the nanotechnology is nanomedicine, which applies nanotechnology to highly specific medical interventions for prevention, diagnosis, and treatment of diseases, including cancer disease. Over the past two decades, the rapid developments in nanotechnology have allowed the incorporation of multiple therapeutic, sensing, and targeting agents into nanoparticles, for detection, prevention, and treatment of cancer diseases. Nanoparticles offer many advantages as drug carrier systems since they can improve the solubility of poorly water-soluble drugs, modify pharmacokinetics, increase drug half-life by reducing immunogenicity, improve bioavailability, and diminish drug metabolism. They can also enable a tunable release of therapeutic compounds and the simultaneous delivery of two or more drugs for combination therapy. In this review, we discuss the recent advances in the use of different types of nanoparticles for systemic and topical drug delivery in the treatment of skin cancer. In particular, the progress in the treatment with nanocarriers of basal cell carcinoma, squamous cell carcinoma, and melanoma has been reported. PMID:25101298

Dianzani, Chiara; Zara, Gian Paolo; Maina, Giovanni; Pettazzoni, Piergiorgio; Pizzimenti, Stefania; Rossi, Federica; Gigliotti, Casimiro Luca; Ciamporcero, Eric Stefano; Daga, Martina; Barrera, Giuseppina

2014-01-01

373

Light delivery schemes for uterine photodynamic therapy  

NASA Astrophysics Data System (ADS)

The use of photodynamic therapy in the removal of the endometrial layer of the uterus provides the possibility of a rapid and effective treatment of menorrhagia avoiding the difficulties and complications of conventional methods. A treatment is proposed in which topical application of 5-aminolaevulinic acid to the inner surface of the uterus is followed by illumination at 630 nm. The surface layer would in this way be rendered necrotic to slough off over subsequent days. The removal of the entire endometrium must be achieved in order to prevent the return of the original condition, which demands that a therapeutic dose of both light and photosensitizer must be achieved throughout the depth of the tissue. This work presents a method of light delivery suitable for intra-uterine PDT along with in vitro optical phantom and ex vivo tissue measurements that aid in the characterization of the light field prior to treatment. These measurements allow the prediction of a treatment time suitable for the delivery of an effective light dose.

Stringer, Mark R.; Hudson, Emma J.; Dunkley, Colin P.; Boyce, Jeanetta C.; Gannon, Michael J.; Smith, Michael A.

1994-03-01

374

DELIVERY OF THERAPEUTIC PROTEINS  

PubMed Central

The safety and efficacy of protein therapeutics are limited by three interrelated pharmaceutical issues, in vitro and in vivo instability, immunogenicity and shorter half-lives. Novel drug modifications for overcoming these issues are under investigation and include covalent attachment of poly(ethylene glycol) (PEG), polysialic acid, or glycolic acid, as well as developing new formulations containing nanoparticulate or colloidal systems (e.g. liposomes, polymeric microspheres, polymeric nanoparticles). Such strategies have the potential to develop as next generation protein therapeutics. This review includes a general discussion on these delivery approaches. PMID:20049941

Pisal, Dipak S.; Kosloski, Matthew P.; Balu-Iyer, Sathy V.

2009-01-01

375

Stimuli-responsive nanomaterials for therapeutic protein delivery.  

PubMed

Protein therapeutics have emerged as a significant role in treatment of a broad spectrum of diseases, including cancer, metabolic disorders and autoimmune diseases. The efficacy of protein therapeutics, however, is limited by their instability, immunogenicity and short half-life. In order to overcome these barriers, tremendous efforts have recently been made in developing controlled protein delivery systems. Stimuli-triggered release is an appealing and promising approach for protein delivery and has made protein delivery with both spatiotemporal- and dosage-controlled manners possible. This review surveys recent advances in controlled protein delivery of proteins or peptides using stimuli-responsive nanomaterials. Strategies utilizing both physiological and external stimuli are introduced and discussed. PMID:25151983

Lu, Yue; Sun, Wujin; Gu, Zhen

2014-11-28

376

Intracellular delivery of RNA-based therapeutics using aptamers  

PubMed Central

The clinical potential of siRNAs for silencing genes critical to disease progression is clear, but a fail-proof method for delivering siRNAs to the cytoplasm of diseased tissues or cells has yet to be identified. A variety of delivery approaches have been explored to directly or indirectly couple siRNAs to delivery vehicles. This review explores the use of synthetic single-stranded DNA and RNA aptamers as a means to deliver siRNAs, shRNAs and antisense oligonucleotides for therapeutic intervention. Topics covered include: the advantages and challenges of using aptamers as delivery tools; current aptamer-mediated siRNA delivery platforms for the treatment of cancer and HIV; and emerging methodologies for the identification of aptamers capable of internalizing into target cell types. PMID:21643487

Thiel, Kristina W; Giangrande, Paloma H

2011-01-01

377

Partial breast irradiation. Patient selection, guidelines for treatment, and current results.  

PubMed

Studies evaluating selected patients treated with partial breast irradiation (PBI) in accelerated fractionation schemes have demonstrated the equivalence of PBI with traditional whole-breast irradiation. The major advantage of PBI is the time compression of treatment down to less than 1 week compared with 6.5 weeks for whole-breast external beam treatments. Four techniques are available to deliver PBI. These include interstitial brachytherapy multicatheter systems, the Mammosite Radiation Therapy System applicator, external beam three-dimensional conformal radiation therapy and intraoperative radiation therapy. For the two brachytherapy techniques of multicatheter implantation and the Mammosite, accurate placement is achieved with image guidance via intraoperative ultrasonography, mammography, and/or CT scanning. Technologies such as image-guided cone beam CT assure accurate delivery of PBI with external beam three-dimensional conformal radiation therapy. Results of PBI show excellent control rates with mild toxicities; cosmetic outcomes are good to excellent in the vast majority of patients. PMID:17641514

Chen, Peter Y; Vicini, Frank A

2007-01-01

378

Delivery methods for LVSD systems  

NASA Astrophysics Data System (ADS)

In this paper we present formats and delivery methods of Large Volume Streaming Data (LVSD) systems. LVSD systems collect TBs of data per mission with aggregate camera sizes in the 100 Mpixel to several Gpixel range at temporal rates of 2 - 60 Hz. We present options and recommendations for the different stages of LVSD data collection and delivery, to include the raw (multi-camera) data, delivery of processed (stabilized mosaic) data, and delivery of user-defined region of interest windows. Many LVSD systems use JPEG 2000 for the compression of raw and processed data. We explore the use of the JPEG 2000 Interactive Protocol (JPIP) for interactive client/server delivery to thick-clients (desktops and laptops) and MPEG-2 and H.264 to handheld thin-clients (tablets, cell phones). We also explore the use of 3D JPEG 2000 compression, defined in ISO 15444-2, for storage and delivery as well. The delivery of raw, processed, and region of interest data requires different metadata delivery techniques and metadata content. Beyond the format and delivery of data and metadata we discuss the requirements for a client/server protocol that provides data discovery and retrieval. Finally, we look into the future as LVSD systems perform automated processing to produce "information" from the original data. This information may include tracks of moving targets, changes of the background, snap shots of targets, fusion of multiple sensors, and information about "events" that have happened.

Kasner, James H.; Brower, Bernard V.

2011-06-01

379

Remote balance weighs accurately amid high radiation  

NASA Technical Reports Server (NTRS)

Commercial beam-type balance, modified and outfitted with electronic controls and digital readout, can be remotely controlled for use in high radiation environments. This allows accurate weighing of breeder-reactor fuel pieces when they are radioactively hot.

Eggenberger, D. N.; Shuck, A. B.

1969-01-01

380