962 results on '"I. Higuchi"'
Search Results
2. Transscleral Iontophoresis for Noninvasive Ocular Drug Delivery of Macromolecules
- Author
-
Sarah A. Molokhia, Charlotte Butler, Kongnara Papangkorn, John W. Higuchi, William I. Higuchi, S. Kevin Li, Balbir Brar, and Balamurali K. Ambati
- Subjects
genetic structures ,Macromolecular Substances ,Angiogenesis Inhibitors ,Pharmacology ,Permeability ,Drug Delivery Systems ,In vivo ,medicine ,Animals ,Pharmacology (medical) ,Iontophoresis ,Chemistry ,Biological Transport ,Original Articles ,Magnetic Resonance Imaging ,eye diseases ,Choroidal Neovascularization ,Bevacizumab ,Ophthalmology ,Choroidal neovascularization ,Immunoglobulin G ,Drug delivery ,Intravitreal Injections ,Models, Animal ,sense organs ,Rabbits ,medicine.symptom ,Electroosmosis ,Conjunctiva ,Sclera ,Macromolecule - Abstract
Purpose: The objectives were to investigate the effect of transscleral iontophoresis of macromolecules in vitro and in vivo, to study the importance of electroosmosis on macromolecules of low charge to mass ratio, and to evaluate transscleral iontophoresis efficacy in a choroidal neovascularization (CNV) animal model. Methods: Through in vitro transport experiments, the permeability coefficients of macromolecules [eg, immunoglobulin G (IgG), dextran 70 kDa] were determined under different conditions. The effect of ionic strength formulations and iontophoretic conditions was studied on the distribution of IgG and bevacizumab into the eye in vivo. Magnetic resonance imaging (MRI) was utilized to evaluate in vivo real time distribution of gadolinium-labeled albumin (Galbumin) following iontophoresis. The efficacy between no treatment, intravitreal injection (IVT), and iontophoresis of bevacizumab on a CNV model of subretinal injection of adeno-associated virus encoding human VEGF-165 was investigated. Results: The permeability data suggested a significant effect of ionic strength on the iontophoretic transport of macromolecules. Transscleral iontophoresis of IgG at 4 mA with a low ionic strength formulation was about 600 times greater than passive diffusion and 14-fold over a conventional formulation in vitro. Approximately 0.6 mg of bevacizumab can be delivered into the rabbit eye in vivo with a 20-min treatment of iontophoresis. MRI showed that Galbumin was in the posterior tissues after iontophoresis. In the CNV model, the iontophoresis and IVT methods of bevacizumab delayed retinal neovascularization by 4 and 8 weeks, respectively. Conclusions: Transscleral iontophoresis is capable of delivering macromolecule drugs through the conjunctiva and sclera, eventually exposing the retina/choroid to the drugs.
- Published
- 2020
3. Optimized arylomycins are a new class of Gram-negative antibiotics
- Author
-
Yuan Chen, Matthew R. Durk, Lionel Rouge, Peter A. S. Smith, Man-Wah Tan, John S. Wai, Jacob Schwarz, Tucker C. Roberts, Jing Kang, Donghong Yan, Hany S. Girgis, Summer Park, John G. Quinn, Min Xu, Prasuna Paraselli, Christopher E. Heise, Jeremy Murray, Wilson Phung, Yongsheng Chen, James J. Crawford, Robert I. Higuchi, Zhiyong Yu, Michael F. T. Koehler, Elizabeth Skippington, and Hua Zhang
- Subjects
0301 basic medicine ,medicine.drug_class ,Antibiotics ,Porins ,Microbial Sensitivity Tests ,Drug resistance ,Biology ,Peptides, Cyclic ,01 natural sciences ,Substrate Specificity ,Microbiology ,03 medical and health sciences ,Antibiotic resistance ,Protein Domains ,In vivo ,Drug Resistance, Multiple, Bacterial ,Gram-Negative Bacteria ,Escherichia coli ,medicine ,Biological Products ,Signal peptidase ,Multidisciplinary ,010405 organic chemistry ,Lysine ,Serine Endopeptidases ,Membrane Proteins ,biology.organism_classification ,Anti-Bacterial Agents ,0104 chemical sciences ,Klebsiella pneumoniae ,030104 developmental biology ,Type I signal peptidase ,Biocatalysis ,Molecular mechanism ,Gram-Negative Bacterial Infections ,Bacteria ,Protein Binding - Abstract
Multidrug-resistant bacteria are spreading at alarming rates, and despite extensive efforts no new class of antibiotic with activity against Gram-negative bacteria has been approved in over fifty years. Natural products and their derivatives have a key role in combating Gram-negative pathogens. Here we report chemical optimization of the arylomycins-a class of natural products with weak activity and limited spectrum-to obtain G0775, a molecule with potent, broad-spectrum activity against Gram-negative bacteria. G0775 inhibits the essential bacterial type I signal peptidase, a new antibiotic target, through an unprecedented molecular mechanism. It circumvents existing antibiotic resistance mechanisms and retains activity against contemporary multidrug-resistant Gram-negative clinical isolates in vitro and in several in vivo infection models. These findings demonstrate that optimized arylomycin analogues such as G0775 could translate into new therapies to address the growing threat of multidrug-resistant Gram-negative infections.
- Published
- 2018
4. Ocular Drug Distribution and Safety of a Noninvasive Ocular Drug Delivery System of Dexamethasone Sodium Phosphate in Rabbit
- Author
-
Kongnara Papangkorn, Balbir Brar, John W. Higuchi, and William I. Higuchi
- Subjects
medicine.medical_specialty ,Conjunctiva ,Eye Diseases ,genetic structures ,030226 pharmacology & pharmacy ,Dexamethasone ,Mass Spectrometry ,03 medical and health sciences ,Drug Delivery Systems ,0302 clinical medicine ,Dexamethasone Sodium Phosphate ,stomatognathic system ,Ophthalmology ,Cornea ,medicine ,Animals ,Toxicokinetics ,Tissue Distribution ,Pharmacology (medical) ,Pharmacology ,business.industry ,Original Articles ,eye diseases ,Sclera ,medicine.anatomical_structure ,Tolerability ,Drug delivery ,030221 ophthalmology & optometry ,Rabbits ,sense organs ,Ophthalmic Solutions ,business ,Chromatography, Liquid ,medicine.drug - Abstract
Purpose: To determine the ocular toxicity, systemic exposure, and amounts of dexamethasone sodium phosphate (DSP) in ocular tissues after administration of DSP with the Visulex system (DSP-Visulex). Methods: DSP-Visulex was applied onto healthy rabbit eyes. DSP concentrations (4%, 8%, 15%, and 25%) and treatment durations (5, 10, and 20 min) were evaluated for the amounts of DSP in the ocular tissues and in plasma after single administrations of DSP-Visulex. The drug in eye tissues and plasma was analyzed by high-performance liquid chromatography-UV/VIS and by liquid chromatography–mass spectrometry, respectively. The safety and tolerability were ascertained based on clinical observations and histopathological examinations from repeat weekly DSP-Visulex treatments (4%, 8%, 15%, and 25% for 20 min) for 12 weeks. Results: Significant amounts of DSP (ie, higher than 1 μg/g) were found in the anterior chamber, retina-choroid, cornea, vitreous, conjunctiva, and sclera after single applications of DSP-Visulex. The DSP concentrations in the ocular tissues and in plasma increased with increased DSP concentrations in the Visulex applicator and with increased application times. Systemic DSP was rapidly detected. The plasma half-life was 2–3 h. C(max) was 148 and 1,844 ng/mL, and the area under the plasma drug concentration versus time curve (AUC) was 418 and 3,779 ng · h/mL for the low dose (4% DSP-Visulex for 5 min) and the high dose (15% DSP-Visulex for 20 min), respectively. Ocular findings over 12 weeks were mostly conjunctival injection and eye discharge. These were transient and mild. Histopathological examinations indicated the eyes to be normal. Conclusions: DSP can be administered safely and effectively into the rabbit eye with the Visulex system. Treatment duration and DSP concentration are important factors in achieving therapeutic levels. Repeat applications of DSP-Visulex are safe and well tolerated for weekly administrations over 4–12 weeks. DSP-Visulex has clinical potential for the noninvasive treatment of ocular diseases.
- Published
- 2018
5. A Novel Ocular Drug Delivery System of Dexamethasone Sodium Phosphate for Noninfectious Uveitis Treatment
- Author
-
Kongnara Papangkorn, John W. Higuchi, William I. Higuchi, and Balbir Brar
- Subjects
0303 health sciences ,03 medical and health sciences ,Infectious uveitis ,0302 clinical medicine ,Dexamethasone Sodium Phosphate ,business.industry ,Drug delivery ,030221 ophthalmology & optometry ,Medicine ,Pharmacology ,business ,030304 developmental biology - Published
- 2019
6. A Novel Ocular Drug Delivery System of Dexamethasone Sodium Phosphate for Noninfectious Uveitis Treatment
- Author
-
Kongnara, Papangkorn, W., Higuchi, John, Balbir, Brar, and I., Higuchi, William
- Subjects
InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) - Published
- 2019
7. Novel Dexamethasone Sodium Phosphate Treatment (DSP-Visulex) for Noninfectious Anterior Uveitis: A Randomized Phase I/II Clinical Trial
- Author
-
Chirag Jhaveri, Alyssa Montieth, C. Stephen Foster, Albert T. Vitale, Balbir Brar, David K. Scales, William I. Higuchi, Kim R. Truett, John W. Higuchi, and Kongnara Papangkorn
- Subjects
Adult ,Male ,Anterior Chamber ,medicine.medical_treatment ,Sodium ,Administration, Topical ,Visual Acuity ,chemistry.chemical_element ,Cell Count ,Slit Lamp Microscopy ,Dexamethasone ,Steroid ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Young Adult ,0302 clinical medicine ,Dexamethasone Sodium Phosphate ,stomatognathic system ,Double-Blind Method ,medicine ,Humans ,Glucocorticoids ,Intraocular Pressure ,Aged ,Retrospective Studies ,Dose-Response Relationship, Drug ,business.industry ,Middle Aged ,medicine.disease ,Uveitis, Anterior ,Sensory Systems ,Clinical trial ,Ophthalmology ,Phase i ii ,Treatment Outcome ,chemistry ,Anesthesia ,030221 ophthalmology & optometry ,Female ,Anterior uveitis ,Ophthalmic Solutions ,business ,030217 neurology & neurosurgery ,Uveitis ,medicine.drug ,Follow-Up Studies - Abstract
Frequent steroid drops represent a challenge in patient compliance. This study evaluated the safety and efficacy of 5 minute topical dexamethasone sodium phosphate-Visulex (DSP-Visulex) treatment regimen (two applications on the first week then weekly after) compared to daily prednisolone acetate 1% (PA) for noninfectious anterior uveitis.Forty-four patients were randomized to 8% DSP-Visulex with placebo eye drops (8% group, n = 14), 15% DSP-Visulex with placebo eye drops (15% group, n = 15), or Vehicle-Visulex with PA eye drops (PA group, n = 15). Patients received daily eye drops and Visulex treatments on days 1, 3, 8, and 15 with an optional treatment on day 22. Efficacy measures were change in anterior chamber cell (ACC) count from baseline and proportion of patients with zero ACC count at days 8, 15, and 29. Safety measures were adverse events (AEs), visual acuity, ocular symptoms, and intraocular pressure (IOP).ACC resolution over time was similar among the three groups. The percentage of patients with clear ACC was 18%, 22%, and 15% on day 8; 27%, 56%, and 54% on day 15; and 90%, 88%, and 77% on day 29 for the 8%, 15%, and PA groups, respectively. The numbers of reported AEs were 10, 36, and 12 for the 8%, 15%, and PA groups, respectively. Ten patients among all groups experienced treatment-related AEs, which included headache, eye pain, corneal abrasion, conjunctival/corneal staining, conjunctivitis, visual acuity reduction, and keratitis all of which were resolved during the timeframe of patients' participation in the study. IOP elevation was noted in the PA group throughout the study, whereas IOP elevation in the DSP-Visulex groups was observed at day 3 but not thereafter.The efficacy of the DSP-Visulex applications was comparable to the daily PA drops in the treatment of noninfectious anterior uveitis. Both 8% and 15% DSP-Visulex treatments were safe and well tolerated.
- Published
- 2018
8. Effect of Particle Size of Metastable Calcium Phosphates on Crushing Strength of Self-Setting Bioactive Calcium Phosphate Cement
- Author
-
Yoshiko Suwa, Makoto Otsuka, Yoshihisa Matsuda, I. I. Higuchi, and Jeffrey L. Fox
- Subjects
Chemical engineering ,Chemistry ,Metastability ,chemistry.chemical_element ,Particle size ,Calcium ,Calcium phosphate cement - Published
- 2017
9. Noninvasive Ocular Drug Delivery System of Dexamethasone Sodium Phosphate in the Treatment of Experimental Uveitis Rabbit
- Author
-
Kongnara Papangkorn, William I. Higuchi, Balbir Brar, John W. Higuchi, and Eri Prendergast
- Subjects
0301 basic medicine ,Pathology ,medicine.medical_specialty ,Topical treatment ,Pharmacology ,Dexamethasone ,Autoimmune Diseases ,03 medical and health sciences ,0302 clinical medicine ,Dexamethasone Sodium Phosphate ,Drug Delivery Systems ,stomatognathic system ,Panuveitis ,medicine ,Animals ,Pharmacology (medical) ,Glucocorticoids ,business.industry ,Rabbit (nuclear engineering) ,Original Articles ,medicine.disease ,Ophthalmology ,Disease Models, Animal ,030104 developmental biology ,Drug delivery ,030221 ophthalmology & optometry ,Rabbits ,business ,Uveitis ,medicine.drug - Abstract
To investigate the efficacy and safety of dexamethasone sodium phosphate administered through Visulex system (DSP-Visulex) in treating experimental uveitis.Uveitis was induced in rabbits by subcutaneous injections of complete Freund's adjuvant and an intravitreal injection of H37RA antigen. After induction, the animals of the control group received no treatment and the others received various treatment regimens of DSP-Visulex. Each regimen was different in DSP strength (4%, 8%, and 15%), application time, or treatment frequency. Efficacy and safety of DSP-Visulex were evaluated by ophthalmic observations and histopathological examinations for ocular inflammations and pathology.The control group exhibited panuveitis with significant inflammation in the vitreous, choroid, and retina, but less in the conjunctiva, cornea, and anterior chamber. The uveitis occurred within 24 h after induction and persisted throughout the study in the control group. All treatments showed some reduction in inflammation in the vitreous, choroid, and retina. The higher dose regimens generally showed more rapid and higher degree of resolution than the lower dose regimens. The posterior eye tissues of the 15% and 8% DSP-Visulex appeared normal with minimal or no inflammation, whereas the untreated eye and the 4% DSP-Visulex eyes showed minimal response.All DSP-Visulex regimens suppressed the signs of inflammation and were well tolerated over the course of a 29-day study. The 8% and 15% DSP-Visulex treatment regimens were safe and efficacious for anterior, intermediate, and posterior uveitis. On the other hand, the 4% DSP-Visulex regimen may only be considered for anterior and intermediate uveitis.
- Published
- 2017
10. Mechanistic Studies of Permeation Enhancers
- Author
-
S. Kevin Li and William I. Higuchi
- Subjects
chemistry.chemical_classification ,Animal model ,medicine.anatomical_structure ,integumentary system ,Double bond ,chemistry ,Biophysics ,Stratum corneum ,medicine ,Permeation ,Enhancer ,Alkyl ,Transdermal - Abstract
Effective methodologies are required for the mechanistic studies of chemical permeation enhancers in topical and transdermal drug delivery. Our previous studies have employed a systematic approach (a symmetric and equilibrium configuration) to study the mechanisms of action of chemical permeation enhancers for permeation across the lipoidal pathway of the stratum corneum. With this approach, the permeability coefficients determined for the permeants can be used directly to evaluate the effectiveness of an enhancer, and new insights into the factors affecting the effectiveness of permeation enhancers have been obtained. These factors include the effects of substitution of a carbon–carbon single bond on the hydrocarbon chain of the enhancer with a carbon–carbon double bond, alkyl chain branching of the enhancer, and enhancer aqueous and stratum corneum lipid concentrations upon the apparent and intrinsic potencies of the enhancers. This chapter summarizes the findings in our studies employing this experimental approach and reviews the mechanistic insights obtained for the enhancers.
- Published
- 2017
11. Transport of a Lipophilic Ionizable Permeant (Capric Acid) Across a Lipophilic Membrane (Silicone Polymer Membrane) from Aqueous Buffered Solutions in the Presence of Hydroxypropyl-β-Cyclodextrin
- Author
-
Richard V. Hymas, Norman F.H. Ho, and William I. Higuchi
- Subjects
chemistry.chemical_classification ,Antifungal Agents ,Aqueous solution ,Membrane permeability ,Cyclodextrin ,Chemistry ,beta-Cyclodextrins ,Inorganic chemistry ,Silicones ,Aqueous two-phase system ,Pharmaceutical Science ,Membranes, Artificial ,Membrane transport ,Permeability ,2-Hydroxypropyl-beta-cyclodextrin ,Diffusion ,Membrane ,Models, Chemical ,Capric Acid ,Organic chemistry ,Pharmaceutical Vehicles ,Solubility ,Decanoic Acids - Abstract
The present study describes a physical model approach applicable to understanding the transport of highly lipophilic, ionizable drugs across a lipophilic membrane between two aqueous compartments in the presence of a cyclodextrin in the aqueous phase. Model predictions were compared with experimental results of capric acid (HA) transport across a silicone polymer membrane in the presence and in the absence of 2-hydroxypropyl-β-cyclodextrin (HPB) in the aqueous phase over wide ranges of conditions. Key parameters entering into the physical model calculations were the HA–HPB and the A − –HPB binding constants, the unionized and ionized free and the complexed HA species diffusion coefficients, the HA p K a, the HA intrinsic silicone polymer membrane permeability coefficient, and the aqueous boundary layer thickness. All of these key parameters were determined from independent or essentially independent experiments. The agreement between the model predictions and the experiments were generally quite good over the entire ranges of the studied independent variables. The results of this study provide an approach that is useful in the mechanistic understanding of how cyclodextrins may enhance the passive absorption of highly lipophilic, low solubility drug molecules in the intestinal tract.
- Published
- 2012
12. Chemometric evaluation of physicochemical properties of carbonated-apatitic preparations by Fourier transform infrared spectroscopy
- Author
-
Arif Ali Baig, William I. Higuchi, Makoto Otsuka, and Kongnara Papangkorn
- Subjects
Materials science ,Chemical Phenomena ,Biomedical Engineering ,Analytical chemistry ,Apatite ,Biomaterials ,Chemometrics ,Adsorption ,X-Ray Diffraction ,Apatites ,Specific surface area ,Spectroscopy, Fourier Transform Infrared ,Least-Squares Analysis ,Particle Size ,Solubility ,Fourier transform infrared spectroscopy ,Metals and Alloys ,Reproducibility of Results ,Chemistry, Inorganic ,Hildebrand solubility parameter ,visual_art ,Calibration ,Ceramics and Composites ,visual_art.visual_art_medium ,Crystallization ,Powder diffraction - Abstract
The purpose of this study was to develop a simple and quick method of evaluating the physicochemical properties of carbonated apatite preparations (CAP) as an index of the bioaffinity of implantable materials based on Fourier-transformed-infrared (IR) spectra by chemometrics. The wet-synthesized CAPs contained various levels of carbonate content (CO3), and were analyzed microstrain parameter (MS), crystallite size parameter (CP), specific surface area (Sw), CO3, and solubility parameter (pKHAP) using by X-ray powder diffraction, nitrogen gas adsorption, IR, and UV absorption. The IR spectral results of CAPs suggested that the peak intensities of CAP reflected the physicochemical properties of the samples. The IR data sets were calculated to obtain calibration models evaluating the physicochemical properties of CAPs by a partial least squares regression analysis (PLS). As validation of the calibration model, physicochemical properties of CAP could be evaluated based on validation IR data sets of independent samples, and those values had sufficient accuracy. The regression vector of each calibration model suggested that the physicochemical properties of CAP, such as CO3, Sw, MS, CP, and pKHAP, were affected by phosphate, hydroxyl, and carbonate groups. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
- Published
- 2012
13. Transport Behavior of Hairless Mouse Skin During Constant Current DC Iontophoresis, Part 2: Iontophoresis of Nonionic Molecules with Cotransport of Polystyrene Sulfonate Oligomers
- Author
-
William I. Higuchi, Mark R. Liddell, and S. Kevin Li
- Subjects
Skin Absorption ,Diffusion ,Analytical chemistry ,Pharmaceutical Science ,In Vitro Techniques ,Administration, Cutaneous ,Models, Biological ,Permeability ,Polystyrene sulfonate ,Mice ,chemistry.chemical_compound ,Raffinose ,Animals ,Urea ,Mannitol ,Skin ,Mice, Hairless ,Iontophoresis ,Viscosity ,Electric Conductivity ,Conductance ,Biological Transport ,Anode ,Membrane ,chemistry ,Permeability (electromagnetism) ,Biophysics ,Polystyrenes ,Female ,Electroosmosis ,Cotransporter ,Porosity - Abstract
The purpose of this study was to characterize changes that occur in the iontophoretic transport of nonionic probe permeants in hairless mouse skin epidermal membrane from the anode to cathode when polystyrene sulfonate (PSS) oligomers are cotransported from the cathode to anode. The experiments were conducted with trace levels of the nonionic probe permeants: urea, mannitol, and raffinose. In order to systematically assess changes that occur as a result of having PSS in the cathodal chamber, the steady-state transport parameters of the membrane and the experimental permeability coefficients of the probe permeants were determined and compared with results obtained from earlier baseline experiments where both the cathodal and anodal chamber media were phosphate buffered saline. In addition, the physicochemical properties of the PSS solutions were determined including the solution viscosity and conductance as well as the mobilities of individual PSS oligomers. The effective pore radii of the transport pathways were calculated using a theoretical expression based on simultaneous diffusion and electroosmosis. Compared with the baseline results, the calculated radii were found to have increased up to around twofold and the iontophoretic fluxes of the probe permeants increased by as much sixfold.
- Published
- 2011
14. Discovery of orally available tetrahydroquinoline-based glucocorticoid receptor agonists
- Author
-
Angela Vassar, Jeffrey N. Miner, Andrew R. Hudson, Mark E. Adams, Steven L. Roach, Dale E. Mais, Zhi Lin, Peter M. Syka, Keith B. Marschke, and Robert I. Higuchi
- Subjects
Clinical Biochemistry ,Administration, Oral ,Pharmaceutical Science ,Enzyme-Linked Immunosorbent Assay ,Pharmacology ,Biochemistry ,Rats, Sprague-Dawley ,Structure-Activity Relationship ,Receptors, Glucocorticoid ,Glucocorticoid receptor ,In vivo ,Oral administration ,Drug Discovery ,medicine ,Animals ,Humans ,Structure–activity relationship ,Receptor ,Molecular Biology ,Drug discovery ,Chemistry ,Organic Chemistry ,Rats ,Quinolines ,Prednisolone ,Molecular Medicine ,Glucocorticoid ,medicine.drug - Abstract
A series of tetrahydroquinoline derivatives were synthesized and profiled for their ability to act as glucocorticoid receptor selective modulators. Structure-activity relationships of the tetrahydroquinoline B-ring lead to the discovery of orally available GR-selective agonists with high in vivo activity.
- Published
- 2011
15. Editorials
- Author
-
Edward G. Feldmann and William I. Higuchi
- Subjects
Pharmaceutical Science - Published
- 2011
16. A Monomer-Micelle Model for the Formation of Simple Taurocholate Micelles
- Author
-
Huey-Jenn Chiang, William I. Higuchi, Chen-Lun Liu, and June-Wen Yang
- Subjects
chemistry.chemical_compound ,SIMPLE (dark matter experiment) ,Aggregation number ,Monomer ,Chromatography ,chemistry ,Dimer ,Critical micelle concentration ,Thermodynamics of micellization ,Analytical chemistry ,General Chemistry ,Dialysis technique ,Micelle - Abstract
A kinetic dialysis technique was used to validate a relationship between monomer taurocholate (TC) concentration and total TC concentration in TC solutions containing 0.15 M NaCl and 0.01 M buffer (pH = 7.4). Based on the experimental data and Mukerjee's equations, the number average degree and the weight average degree of TC aggregates were estimated to be nearly the same (∼5), indicating that simple TC micelles were the only aggregates. Furthermore, the TC dimer concentration was quantified to be negligible. According to the validated relationship, aggregation number of 5 for simple TC micelles, and the definition of critical micelle concentration (CMC), a modified monomer-micelle model was used for describing simple TC micelle formation. Moreover, the CMC value was estimated to be ∼6.3 mM, which is consistent with the reported value of ∼6.0 mM.
- Published
- 2010
17. Effect of geometrical structure on drug release rate of a three-dimensionally perforated porous apatite/collagen composite cement
- Author
-
Atsuo Ito, Hidenori Nakagawa, Makoto Otsuka, and William I. Higuchi
- Subjects
Cement ,Materials science ,Chemical Phenomena ,Biocompatibility ,Simulated body fluid ,Anti-Inflammatory Agents, Non-Steroidal ,Composite number ,Bone Cements ,Pharmaceutical Science ,Biocompatible Materials ,Porosimetry ,Apatite ,Drug Delivery Systems ,Solubility ,X-Ray Diffraction ,visual_art ,Materials Testing ,Spectroscopy, Fourier Transform Infrared ,visual_art.visual_art_medium ,Collagen ,Hydroxyapatites ,Composite material ,Drug carrier ,Porosity - Abstract
To improve the biocompatibility, inter-connective pore structure, and drug delivery ability of self-setting apatite/collagen composite cement (ACC), a three-dimensionally perforated porous apatite/collagen composite cement (TPPACC) containing 3% indomethacin (IMC) was obtained in an arranged multi-cross with 20, 40, and 60 stainless steel needlelike male dies, and stored and hardened at 37°C and 100% relative humidity for 24 h. The mean radius of micro-pores of the TPPACC was evaluated to be 0.125 µm by mercury porosimetry. X-ray powder diffraction and FT-IR spectroscopy suggested that TPPACC consisted of carbonated apatite and had a structure similar to that of natural rat bone. The IMC release rates from a TPPACC block containing the drug were measured in simulated body fluid. The rate of release increased with the number of macro-pores that from planar surface matrix systems followed the Higuchi equation. The relationship between the Higuchi constant and surface area of TPPACC showed a straight line with K = 0.2123 and R2 = 0.9892. These results indicated that the rate of drug release from TPPACC could be controlled by the number of macro-pores for bone cells. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:286–292, 2010
- Published
- 2010
18. Effects of Oxygen-Containing Terpenes as Skin Permeation Enhancers on the Lipoidal Pathways of Human Epidermal Membrane
- Author
-
Doungdaw Chantasart, William I. Higuchi, Thaned Pongjanyakul, and S. Kevin Li
- Subjects
Adult ,inorganic chemicals ,Chromatography, Gas ,Skin Absorption ,Pharmaceutical Science ,In Vitro Techniques ,Permeability ,Heptanes ,Excipients ,Terpene ,chemistry.chemical_compound ,Electric Impedance ,Oils, Volatile ,polycyclic compounds ,Stratum corneum ,medicine ,Humans ,Organic chemistry ,Carvacrol ,Thymol ,Chromatography, High Pressure Liquid ,Aged ,integumentary system ,Terpenes ,Middle Aged ,Permeation ,Lipids ,Menthone ,Terpenoid ,Oxygen ,medicine.anatomical_structure ,Solubility ,chemistry ,Biophysics ,Female ,Epidermis ,Menthol - Abstract
The present study investigated the effects of oxygen-containing terpenes as skin permeation enhancers on the lipoidal pathways of human epidermal membrane (HEM). The enhancement (E(HEM)) effects of menthol, thymol, carvacrol, menthone, and cineole on the transport of a probe permeant, corticosterone, across HEM were determined. It was found that the enhancer potencies of menthol, thymol, carvacrol, and menthone were essentially the same and higher than that of cineole based on their aqueous concentration in the diffusion cell chamber at E(HEM) = 4. Thymol and carvacrol also had the same E(HEM) = 10 concentration further supporting that they had the same enhancer potency based on the aqueous concentration. The uptake amounts of terpene into the HEM stratum corneum (SC) intercellular lipid under the same conditions indicate that the intrinsic potencies of the studied terpenes are the same based on their concentration in the SC and similar to those of n-alkanol and n-alkylphenyl alcohol. Moreover, they are all better enhancers compared to branched-chain alkanol. The approximately same uptake enhancement of beta-estradiol induced by the studied terpenes and alcohols at E(HEM) conditions into the SC intercellular lipids suggests that the mechanism of enhancement action for the terpenes and those of alcohols are essentially the same.
- Published
- 2009
19. Effects of alternating current frequency and permeation enhancers upon human epidermal membrane
- Author
-
Rajan Kochambilli, Qingfang Xu, Jinsong Hao, Yang Song, S. Kevin Li, and William I. Higuchi
- Subjects
Adult ,Male ,Skin Absorption ,Synthetic membrane ,Analytical chemistry ,Pharmaceutical Science ,In Vitro Techniques ,Article ,Permeability ,law.invention ,Young Adult ,Electrical resistance and conductance ,law ,Electric Impedance ,Stratum corneum ,medicine ,Humans ,Aged ,integumentary system ,Iontophoresis ,Chemistry ,Electric Conductivity ,Middle Aged ,Permeation ,Pyrrolidinones ,medicine.anatomical_structure ,Membrane ,Permeability (electromagnetism) ,Biophysics ,Female ,Epidermis ,Alternating current - Abstract
Previous studies have demonstrated the ability of AC iontophoresis to control skin resistance in different transdermal iontophoresis applications. The objectives of the present study were to (a) identify the alternating current (AC) frequency for the optimization of AC pore induction of human epidermal membrane (HEM) and (b) determine the effects of chemical permeation enhancers upon the extent of pore induction under AC conditions. Experiments with a synthetic membrane system were first conducted as the control. In these synthetic membrane experiments, the electrical resistance of the membrane remained essentially constant, suggesting constant electromobility of the background electrolyte ions under the AC conditions studied. In the HEM experiments, the electrical resistance data showed that higher applied voltages were required to induce the same extent of pore induction in HEM at AC frequency of 1 kHz compared with those at 30 Hz. Even higher voltages were needed at AC frequencies of 10 kHz and higher. AC frequency also influenced the recovery of HEM electrical resistance after AC iontophoresis application. An optimal AC frequency region for effective pore induction and least sensation was proposed. Permeation enhancers were shown to enhance pore induction in HEM during AC iontophoresis. The enhancers reversibly reduced the AC voltage required to sustain a constant state of pore induction in HEM during AC iontophoresis, consistent with the mechanism of lipid lamellae electroporation in the stratum corneum.
- Published
- 2009
20. Transscleral iontophoretic and intravitreal delivery of a macromolecule: Study of ocular distribution in vivo and postmortem with MRI
- Author
-
William I. Higuchi, S. Kevin Li, Sarah A. Molokhia, and Eun Kee Jeong
- Subjects
medicine.medical_specialty ,Conjunctiva ,genetic structures ,Macromolecular Substances ,Eye ,Article ,Cellular and Molecular Neuroscience ,Drug Delivery Systems ,In vivo ,Ophthalmology ,medicine ,Animals ,Distribution (pharmacology) ,Iontophoresis ,medicine.diagnostic_test ,Chemistry ,Magnetic resonance imaging ,Magnetic Resonance Imaging ,eye diseases ,Sensory Systems ,Sclera ,Surgery ,Vitreous Body ,medicine.anatomical_structure ,Drug delivery ,Rabbits ,sense organs ,Choroid - Abstract
The distribution and clearance of macromolecules in ocular delivery are not well understood. It has been hypothesized that iontophoresis can enhance transscleral delivery of macromolecules. The objective of this study was to investigate the ocular distribution of a macromolecule after transscleral iontophoretic delivery and intravitreal injection in vivo using nuclear magnetic resonance imaging (MRI) and to compare these results. Experiments of constant current transscleral iontophoresis of 4 mA or intravitreal injection were performed on New Zealand white rabbits in vivo. Iontophoresis experiments were also performed on rabbits postmortem. Galbumin™ (Gd-labeled albumin) was the model permeant surrogate to clinical therapeutic agents. MRI was used to monitor the distribution of the molecule in the eye after ocular iontophoresis and intravitreal injection. In addition, the conjunctiva, sclera, choroid, and retina were extracted in the transscleral iontophoresis study to determine the amounts of Galbumin™ in these tissues using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The results show that iontophoresis enhanced the ocular delivery of Galbumin™. The macromolecule was mainly delivered into the conjunctiva and sclera in microgram quantities and then diffused towards the posterior section in the upper hemisphere of the eye in vivo. Both in vivo and postmortem studies show that the iontophoretic delivery of Galbumin™ into the vitreous was below the detection limit. In the intravitreal injection study, the diffusion coefficient of Galbumin™ in the vitreous humor was estimated to be close to that of free aqueous diffusion.
- Published
- 2009
21. Ion-exchange membrane assisted transdermal iontophoretic delivery of salicylate and acyclovir
- Author
-
Sarah A. Ibrahim, William I. Higuchi, Qingfang Xu, and S. Kevin Li
- Subjects
Skin Absorption ,Sodium Salicylate ,Acyclovir ,Pharmaceutical Science ,Pharmacology ,Administration, Cutaneous ,Antiviral Agents ,Article ,chemistry.chemical_compound ,Pharmaceutical technology ,Electric Impedance ,Humans ,Mannitol ,Sodium salicylate ,Transdermal ,Drug transport ,Ion exchange ,Iontophoresis ,Chemistry ,Biological Transport ,Ion Exchange ,Membrane ,Solubility ,Drug delivery ,Biophysics ,Electroosmosis ,Epidermis - Abstract
The presence of endogenous competing counterions is a main reason for the generally low efficiency of transdermal iontophoretic drug delivery. The objective of the present study was to test the hypothesis that the incorporation of an ion-exchange membrane (Ionac) in an iontophoresis system to hinder transdermal transport of these counterions can enhance iontophoretic delivery. The properties of Ionac were characterized in passive and iontophoretic transport experiments. Iontophoretic transport across human epidermal membrane (HEM) and across HEM in series with Ionac was then studied. To assess the effect of HEM electrical resistance upon Ionac-assisted iontophoresis, HEM resistance was reduced in the iontophoresis experiments with alternating current (AC). Salicylate (SA) was the negatively charged permeant first tested in this study. Mannitol was the model permeant to examine the effects of electroosmosis. At the completion of the SA study, experiments were performed with acyclovir (ACV), an antiviral drug with limited water solubility. When Ionac was used to enhance SA transdermal fluxes, higher SA fluxes were observed with HEM of lower resistances in Ionac-assisted iontophoresis. Up to a four-fold flux enhancement was achieved when the electrical resistance of HEM was reduced using an AC iontophoresis method. For ACV, two-fold flux enhancement was observed in Ionac-assisted iontophoresis compared with the conventional iontophoresis baseline. In all experiments, the contribution of electroosmosis to drug transport was less than 10%. The present study has demonstrated the potential of a new approach using a positively charged ion-exchange membrane to enhance transdermal iontophoretic transport of negatively charged drugs.
- Published
- 2009
22. Selective androgen receptor modulators based on a series of 7H-[1,4]oxazino[3,2-g]quinolin-7-ones with improved in vivo activity
- Author
-
Esther Martinborough, Donald S. Karanewsky, Francisco J. López, Robert I. Higuchi, Min Wu, William Y. Chang, Marquis L. Cummings, Lin Zhi, Thomas Lau, Yun Oliver Long, Thomas R. Caferro, and Keith B. Marschke
- Subjects
Male ,medicine.medical_specialty ,medicine.drug_class ,Clinical Biochemistry ,Administration, Oral ,Pharmaceutical Science ,Quinolones ,Biochemistry ,Rats, Sprague-Dawley ,Structure-Activity Relationship ,Anabolic Agents ,In vivo ,Internal medicine ,Oxazines ,Drug Discovery ,Androgen Receptor Antagonists ,medicine ,Animals ,Structure–activity relationship ,Testosterone ,Receptor ,Molecular Biology ,Chemistry ,Organic Chemistry ,Prostate ,Organ Size ,Androgen ,Rats ,Androgen receptor ,Endocrinology ,Models, Chemical ,Selective androgen receptor modulator ,Receptors, Androgen ,Androgens ,Molecular Medicine ,Orchiectomy - Abstract
Modification on a lead series of [1,4]oxazino[3,2-g]quinolin-7-ones at the 2-position led to selective androgen receptor modulators with improved in vivo activity. The most potent analog (-)-33a exhibited full maintenance of levator ani muscle at 3mg/kg and reduced activity on ventral prostate weight in a 2-week orally-dosed and orchidectomized rat maintenance assay.
- Published
- 2008
23. Influence of crystallite microstrain on surface complexes governing the metastable equilibrium solubility behavior of carbonated apatites
- Author
-
Guang Yan, Kunikazu Moribe, William I. Higuchi, Kongnara Papangkorn, Dustin D. Heslop, Arif Ali Baig, and Makoto Otsuka
- Subjects
Aqueous solution ,Precipitation (chemistry) ,Fluorapatite ,Analytical chemistry ,Mineralogy ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Fluorides ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Solubility ,chemistry ,Ionic strength ,Apatites ,Phase (matter) ,Crystallite ,Crystallization ,Fluoride - Abstract
This study was on the influence of the mineral phase crystallite microstrain (CM) on the nature of the surface complex (SC) governing the metastable equilibrium solubility (MES) behavior of carbonated apatites (CAPs) in aqueous acidic media (0.10 M acetate buffers, with and without fluoride, 0.50 M ionic strength maintained with NaCl). The MES behavior of a set of four CAPs (synthesized at 85 °C by a precipitation method) of increasing CM and therefore of increasing MES (CAP4 > CAP3 > CAP2 > CAP1) was quantified. The following were the findings. For CAP1 and CAP2, the SCs deduced were Ca10(PO4)6(OH)2 and Ca10(PO4)6F2 for the nonfluoride and the fluoride cases, respectively. For CAP3 and CAP4, the SCs deduced were Ca9.5(PO4)6OH or Ca9.5(HPO4)(PO4)5(OH)2 and NaCa9.5(PO4)6F2 for the nonfluoride and the fluoride cases, respectively. These results together with that from an earlier limited study show that the Ca/P ratio of the SC decreases from 1.67 to 1.58 to 1.50 with increasing CM of the CAPs; this relationship inversely correlates with the chemistry of maturation of aqueously precipitated defective apatites. Also the SCs do not appear to exist as a continuous series and only a few SCs may account for the MES behavior over a wide range of CAP preparations.
- Published
- 2008
24. Study of TeV neutrinos with upward showering muons in Super-Kamiokande
- Author
-
C. W. Walter, R. Wendell, R. Svoboda, T. Ishizuka, S. Yamada, T. Sasaki, M. Yoshida, H. G. Berns, M. B. Smy, Y. Furuse, K. Kaneyuki, C. Saji, Masashi Yokoyama, R. Terri, A. Minamino, J. Dunmore, Takaaki Kajita, Y. Totsuka, K. Iida, M. Koshiba, Y. Oyama, B. S. Yang, Y. Choi, K. Ishihara, T. J. Haines, T. Sato, D. W. Liu, Haruki Watanabe, Masato Shiozawa, N. Tamura, H. Nishino, I. Kato, Lawrence Sulak, J. L. Raaf, J. L. Stone, S. Mine, Y. Takeuchi, Atsushi Takeda, E. Kearns, S. T. Clark, C. Ishihara, Shantanu Desai, Kunio Inoue, M. Sugihara, H. Ishii, C. K. Jung, T. Ishida, M. Swanson, K. Abe, T. Kobayashi, K. Nishikawa, T. Nakaya, T. Nakadaira, Yusuke Koshio, K. Nitta, J. Yoo, S. Yamamoto, Kate Scholberg, J. Y. Kim, C. McGrew, M. R. Vagins, C. Yanagisawa, K. Kobayashi, Y. Obayashi, K. Washburn, W. E. Keig, M. Hasegawa, Shigetaka Moriyama, S. Likhoded, G. Mitsuka, K. Ueshima, I. S. Jeong, M. Sakuda, Y. Hayato, R. Gran, T. Hasegawa, F. Dufour, I. T. Lim, H. K. Seo, A. K. Ichikawa, J. S. Jang, T. Tanaka, D. Kielczewska, Y. Kuno, K. Nishijima, S. Nakayama, M. Ishitsuka, N. Tanimoto, S. Tasaka, H. Okazawa, R. J. Wilkes, W. Wang, Masayuki Nakahata, Alec Habig, T. Koike, B. Hartfiel, Y. Takenaga, K. Okumura, Y. Fukuda, Y. Idehara, K. S. Ganezer, M. Miura, Hirokazu Ishino, M. D. Messier, C. Regis, J. Kameda, Katsuki Hiraide, S. Dazeley, J. P. Cravens, T. Ishii, H. Sato, Y. Gando, J. Hill, Yasunari Suzuki, S. Matsuno, G. Guillian, A. T. Suzuki, H. W. Sobel, Eric Thrane, M. Fechner, Y. Watanabe, W. R. Kropp, S. B. Kim, A. Clough, David William Casper, C. Mitsuda, H. Ogawa, K. K. Shiraishi, I. Higuchi, J. G. Learned, H. Maesaka, M. Goldhaber, T. Kato, Yoshitaka Itow, S. Hatakeyama, K. Nakamura, and A. Sarrat
- Subjects
Physics ,Muon ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Bremsstrahlung ,Astronomy and Astrophysics ,High Energy Physics - Experiment ,Nuclear physics ,Pair production ,WIMP ,High Energy Physics::Experiment ,Neutrino ,Astrophysics - High Energy Astrophysical Phenomena ,Super-Kamiokande ,Neutrino oscillation ,Zenith - Abstract
A subset of neutrino-induced upward through-going muons in the Super-Kamiokande detector consists of high energy muons which lose energy through radiative processes such as bremsstrahlung, e^{+} e^{-} pair production and photonuclear interactions. These ``upward showering muons'' comprise an event sample whose mean parent neutrino energy is approximately 1 TeV. We show that the zenith angle distribution of upward showering muons is consistent with negligible distortion due to neutrino oscillations, as expected of such a high-energy neutrino sample. We present astronomical searches using these high energy events, such as those from WIMP annihilations in the Sun, Earth and Galactic Center, some suspected point sources, as well as searches for diffuse flux from the interstellar medium., Comment: Submitted for publication to Astroparticle Physics. Fig 12 has slightly higher resolution in the version submitted to the journal
- Published
- 2008
25. Examination of Barriers and Barrier Alteration in Transscleral Iontophoresis
- Author
-
Eun Kee Jeong, Sarah A. Molokhia, William I. Higuchi, and S. Kevin Li
- Subjects
medicine.medical_specialty ,Postmortem studies ,genetic structures ,Iontophoresis ,Chemistry ,Pharmaceutical Science ,Biological Transport ,Magnetic Resonance Imaging ,Article ,Permeability ,eye diseases ,Sclera ,Surgery ,medicine.anatomical_structure ,Pharmaceutical technology ,In vivo ,Ophthalmology ,Drug delivery ,medicine ,Animals ,sense organs ,Rabbits ,Subconjunctival injection - Abstract
The flux enhancing mechanisms of transscleral iontophoresis are not well understood. The objective of the present study was to investigate the ocular barrier and barrier alterations in transscleral iontophoretic delivery with magnetic resonance imaging (MRI). Experiments involving constant current transscleral iontophoresis of 2 mA (current density 10 mA/cm2) and subconjunctival injection were conducted with rabbits in vivo and postmortem and with excised sclera in side-by-side diffusion cells in vitro. The postmortem and in vitro experiments were expected to be helpful in clarifying the importance of vascular clearance and other transport barriers in transscleral iontophoresis. Manganese ion (Mn2+) and manganese ethylenediaminetetraacetic acid complex (MnEDTA2−) were the model permeants. The results show that pretreatment of the eye with an electric field by iontophoresis enhanced subconjunctival delivery of the permeants to the anterior segment of the eye in vivo. This suggests that electric field-induced barrier alterations can be an important absorption enhancing mechanism of ocular iontophoresis. Penetration enhancement was magnified in the postmortem experiments with larger amounts of the permeants delivered into the eye and to the back of the eye. The different results observed in the in vivo and postmortem studies can be attributed to ocular clearance in ocular delivery. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:831–844, 2008
- Published
- 2008
26. Iontophoretic Transport Across a Multiple Membrane System
- Author
-
William I. Higuchi, Yanhui Zhang, S. Kevin Li, and Sarah A. Molokhia
- Subjects
Electrophoresis ,Osmosis ,Diffusion ,Pharmaceutical Science ,Article ,Permeability ,chemistry.chemical_compound ,Drug Delivery Systems ,Chlorides ,Urea ,Computer Simulation ,Mannitol ,Models, Statistical ,Tetraethylammonium ,Chromatography ,Iontophoresis ,Ion exchange ,Sodium ,Membranes, Artificial ,Biological membrane ,Ion Exchange ,Membrane ,chemistry ,Permeability (electromagnetism) ,Biophysics ,Indicators and Reagents - Abstract
The objective of the present study was to investigate the iontophoretic transport behavior across multiple membranes of different barrier properties. Spectra/Por(R) (SP) and Ionac membranes were the synthetic membranes and sclera was the biomembrane in this model study. The barrier properties of SP membranes were determined individually in passive and iontophoresis transport experiments with tetraethylammonium ion (TEA), chloride ion (Cl), and mannitol as the model permeants. Passive and iontophoretic transport experiments were then conducted with an assembly of SP membranes. The contribution of electroosmosis to iontophoresis was assessed using the mannitol data. Model analysis was performed to study the contribution of diffusion and electromigration to electrotransport across the multiple membrane system. The effects of membrane barrier thickness upon ion-exchange membrane-enhanced iontophoresis were examined with Ionac, SP, and sclera. The present study shows that iontophoretic transport of TEA across the membrane system was related to the thicknesses and permeability coefficients of the membranes and the electromobilities of the permeant across the individual membranes in the assembly. Model analysis suggests significant contribution of diffusion within the membranes across the membrane system, and this mechanism is relatively independent of the current density applied across the system in iontophoresis dominant transport.
- Published
- 2008
27. Systematic Studies on the Paracellular Permeation of Model Permeants and Oligonucleotides in the Rat Small Intestine with Chenodeoxycholate as Enhancer
- Author
-
Richard V. Hymas, William I. Higuchi, Gregory E. Hardee, Keiko Tsutsumi, Lloyd G. Tillman, S. Kevin Li, Norman F.H. Ho, and Ching-Leou Teng
- Subjects
Male ,Chemical Phenomena ,Oligonucleotides ,Biological Availability ,Pharmaceutical Science ,Ileum ,In Vitro Techniques ,Chenodeoxycholic Acid ,digestive system ,Tight Junctions ,Bile Acids and Salts ,Excipients ,Rats, Sprague-Dawley ,Jejunum ,Raffinose ,Intestine, Small ,medicine ,Animals ,Urea ,Mannitol ,Mesentery ,Chenodeoxycholate ,Chromatography ,Tight junction ,Chemistry, Physical ,Chemistry ,digestive, oral, and skin physiology ,Permeation ,Small intestine ,Rats ,Perfusion ,medicine.anatomical_structure ,Intestinal Absorption ,Permeability (electromagnetism) ,Paracellular transport ,Indicators and Reagents ,Porosity ,Algorithms - Abstract
The objective of this study was to mechanistically and quantitatively analyze chenodeoxycholate-enhanced paracellular transport of polar permeants and oligonucleotides in the rat jejunum and ileum. Micellar chenodeoxycholate solutions were used to perturbate the tight junctions. Supporting studies included assessment of the aqueous boundary layer (ABL) with ABL-controlled permeants, measurements of the permeability coefficients and fluxes of the bile acid in dilute and micellar concentrations, and determinations of pore sizes with paracellular probes (urea, mannitol, and raffinose). The paracellular permeability coefficients, P(para), of two model oligonucleotides (ON3 and ON6; 12- and 24-mers with 11 and 23 negative charges, respectively) were determined. The enhanced permeabilities paralleled the increased fluxes of micellar bile salt solutions into mesenteric blood and the opening of the tight junctions as compared to controls. As the pore radius increased from 0.7 nm to a maximum of 2.4 nm in the jejunum and ileum, the absorption of ON3 was enhanced up to sixfold in the jejunum and about 14-fold in the ileum with P(para) values between 0.5 x 10(-6) and 6 x 10(-6) cm/s, whereas ON6 was enhanced up to twofold in the jejunum and fivefold in the ileum with permeabilities between 0.3 x 10(-6) and 2 x 10(-6) cm/s.
- Published
- 2008
28. Potent, nonsteroidal selective androgen receptor modulators (SARMs) based on 8H-[1,4]oxazino[2,3-f]quinolin-8-ones
- Author
-
Jyun-Hung Chen, Thomas R. Caferro, Charlotte Pooley Deckhut, Lin Zhi, Christopher M. Tegley, Keith B. Marschke, Anthony W. Thompson, James P. Edwards, E. Adam Kallel, Marquis L. Cummings, Francisco J. López, William T. Schrader, Robert I. Higuchi, Mark E. Adams, and Donald S. Karanewsky
- Subjects
Male ,Models, Molecular ,medicine.medical_specialty ,medicine.drug_class ,Clinical Biochemistry ,Pharmaceutical Science ,Quinolones ,Biochemistry ,Article ,Cell Line ,Structure-Activity Relationship ,In vivo ,Internal medicine ,Oxazines ,Drug Discovery ,medicine ,Animals ,Humans ,Potency ,Structure–activity relationship ,Testosterone ,Receptor ,Molecular Biology ,Dose-Response Relationship, Drug ,Chemistry ,Organic Chemistry ,Receptors, Somatotropin ,Androgen ,Rats ,Androgen receptor ,Endocrinology ,Selective androgen receptor modulator ,Receptors, Androgen ,Molecular Medicine ,Indicators and Reagents ,Receptors, Progesterone ,Orchiectomy - Abstract
A series of androgen receptor modulators based on 8H-[1,4]oxazino[2,3-f]quinolin-8-ones was synthesized and evaluated in an androgen receptor transcriptional activation assay. The most potent analogues from the series exhibited single-digit nanomolar potency in vitro. Compound 18h demonstrated full efficacy in the maintenance of muscle weight, at 10 mg/kg, with reduced activity in prostate weight in an in vivo model of androgen action.
- Published
- 2007
29. Synthesis and Characterization of Nonsteroidal Glucocorticoid Receptor Modulators for Multiple Myeloma
- Author
-
Jeffrey N. Miner, Deepa Rungta, Lino J. Valdez, Yongkai Li, Andrew Hudson, William W. Lamph, Jean Yen, Dean P. Phillips, and Andrés Negro-Vilar, Lin Zhi, Angie Vassar, Catalina Cuervo, Reid P. Bissonnette, Keith B. Marschke, E. Adam Kallel, Mark E. Adams, Catherine J. Gharbaoui, Robert I. Higuchi, Dale E. Mais, and Steven L. Roach
- Subjects
Models, Molecular ,medicine.medical_specialty ,Antineoplastic Agents ,Pharmacology ,Binding, Competitive ,Dexamethasone ,Mice ,Structure-Activity Relationship ,Receptors, Glucocorticoid ,Mineralocorticoid receptor ,Glucocorticoid receptor ,In vivo ,Internal medicine ,Drug Discovery ,medicine ,Animals ,Humans ,Structure–activity relationship ,Benzopyrans ,Receptor ,Cytotoxicity ,Mineralocorticoid Receptor Antagonists ,Chemistry ,Stereoisomerism ,Xenograft Model Antitumor Assays ,In vitro ,Receptors, Mineralocorticoid ,Endocrinology ,Quinolines ,Molecular Medicine ,Multiple Myeloma ,medicine.drug - Abstract
Structure-activity relationship studies centered around 3'-substituted (Z)-5-(2'-(thienylmethylidene))1,2-dihydro-9-hydroxy-10-methoxy-2,2,4-trimethyl-5H-chromeno[3,4-f]quinolines are described. A series of highly potent and efficacious selective glucocorticoid receptor modulators were identified with in vitro activity comparable to dexamethasone. In vivo evaluation of these compounds utilizing a 28 day mouse tumor xenograft model demonstrated efficacy equal to dexamethasone in the reduction of tumor volume.
- Published
- 2007
30. Osteotropic Peptide That Differentiates Functional Domains of the Skeleton
- Author
-
Luda S. Shlyakhtenko, William I. Higuchi, Alexander M. Portillo, Yuri L. Lyubchenko, Xin Ming Liu, Kongnara Papangkorn, Jindřich Kopeček, Pavla Kopečková, Scott C. Miller, and Dong Wang
- Subjects
Mature Bone ,Ovariectomy ,Osteoporosis ,Biomedical Engineering ,Pharmaceutical Science ,Bioengineering ,Microscopy, Atomic Force ,Bone and Bones ,Bone resorption ,Apatite ,Drug Delivery Systems ,medicine ,Animals ,Bone Resorption ,Skeleton ,Pharmacology ,Aspartic Acid ,Binding Sites ,Alendronate ,Bone Density Conservation Agents ,Diphosphonates ,Staining and Labeling ,Chemistry ,Organic Chemistry ,Anatomy ,medicine.disease ,Rats ,Resorption ,Disease Models, Animal ,Durapatite ,visual_art ,Ovariectomized rat ,Biophysics ,visual_art.visual_art_medium ,Female ,Oligopeptides ,Fluorescein-5-isothiocyanate ,Biotechnology - Abstract
HPMA copolymer-d-aspartic acid octapeptide (D-Asp8) conjugates have been found to target the entire skeleton after systemic administration. In a recent study using the ovariectomized rat model of osteoporosis, we surprisingly discovered that D-Asp8 would favorably recognize resorption sites in skeletal tissues, while another bone-targeting moiety, alendronate (ALN), directs the delivery system to both formation and resorption sites. Atomic force microscopy (AFM) analyses reveal that ALN has a stronger binding force to hydroxyapatite (HA) than D-Asp8. In vitro HA binding studies indicate that D-Asp8 is more sensitive to change of HA crystallinity than ALN. Because the bone apatite in the newly formed bone (formation sites) usually has lower crystallinity than the resorption sites (mainly mature bone), we believe that the favorable recognition of D-Asp8 to the bone resorption sites could be attributed to its relatively weak binding to apatite, when compared to bisphosphonates, and the different levels of crystallinity of bone apatite at different functional domains of the skeleton.
- Published
- 2007
31. Discovery of an androgen receptor modulator pharmacophore based on 2-quinolinones
- Author
-
Robert I. Higuchi, Todd K. Jones, Arjan van Oeveren, Barbara Pio, Lin Zhi, Min Wu, Andres Negro-Vilar, Christopher M. Tegley, and Keith B. Marschke
- Subjects
Magnetic Resonance Spectroscopy ,Clinical Biochemistry ,Pharmaceutical Science ,Pharmacology ,Transfection ,Biochemistry ,Cell Line ,Tosyl Compounds ,Structure-Activity Relationship ,chemistry.chemical_compound ,Nitriles ,Drug Discovery ,Androgen Receptor Antagonists ,Animals ,Humans ,Anilides ,Receptor ,Molecular Biology ,chemistry.chemical_classification ,Organic Chemistry ,Quinoline ,Androgen Antagonists ,Biological activity ,In vitro ,Androgen receptor ,chemistry ,Selective androgen receptor modulator ,Receptors, Androgen ,Androgens ,Quinolines ,Molecular Medicine ,Indicators and Reagents ,Pharmacophore ,Tricyclic - Abstract
A series of alkylamino-2-quinolinone compounds (3) was discovered as androgen receptor modulators based on an early linear tricyclic quinoline pharmacophore (1). The series demonstrated selective high binding affinity to androgen receptor and potent receptor modulating activities in the cotransfection assays.
- Published
- 2007
32. Quantitative Structure–Enhancement Relationship and the Microenvironment of the Enhancer Site of Action
- Author
-
S. Kevin Li and William I. Higuchi
- Subjects
medicine.anatomical_structure ,integumentary system ,Chemistry ,Lipophilicity ,Biophysics ,Stratum corneum ,medicine ,Quantitative structure ,Permeation ,Enhancer ,Site of action ,Diffusion cell ,Transdermal - Abstract
In the last several decades, a large number of studies on chemical permeation enhancers were performed to assist the development of topical and transdermal products. The mechanisms of chemical permeation enhancers on skin transport have been investigated and quantitative structure–enhancement relationships for permeation enhancers have been examined. The understanding of the enhancer mechanisms of action would allow effective prediction of the effects of skin permeation enhancers, minimize chemical permeation enhancer screening, and improve topical and transdermal formulation development. Based on the systematic approaches in our previous studies, it was determined that enhancer-induced permeation enhancement across the skin lipoidal pathway was directly related to the concentration of the enhancers in the stratum corneum lipid domain. Relationships between skin permeation enhancer potency (based on either enhancer aqueous concentration in the diffusion cell chamber or enhancer concentration in the stratum corneum lipids) and enhancer lipophilicity (enhancer n-octanol–water partition coefficient) were established. The nature of the microenvironment of the enhancer site of action in the stratum corneum was found to be mimicked by n-octanol. The present chapter summarizes these findings and reviews the quantitative structure–enhancement relationship deduced in these systematic studies.
- Published
- 2015
33. Therapeutic Effect of Selected Biomaterials (Mg/Zn/F-CaPs, Administered by Injection) on Bone Properties of Ovariectomized Rats
- Author
-
Atsuo Ito, Makoto Otsuka, Racquel Z. LeGeros, William I. Higuchi, Ayako Oshinbe, and Kuniko Otsuka
- Subjects
Bone mineral ,medicine.medical_specialty ,Materials science ,Magnesium ,Mechanical Engineering ,Metallurgy ,Therapeutic effect ,Area under the curve ,chemistry.chemical_element ,Zinc ,Calcium ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Mechanics of Materials ,Internal medicine ,Ovariectomized rat ,medicine ,General Materials Science ,Fluoride - Abstract
The purpose of this study was to evaluate the efficacy of magnesium (Mg), zinc (Zn) and fluoride (F)-containing calcium phosphate compounds (Mg/Zn/F-CaP) in correcting the bone mineral deficiency noted in ovariectomized (OVX) rats. In order to evaluate therapeutic effect of selected Mg/Zn/F-BCP preparations (G2: 1.13%Mg/13.6%Zn/2.5%F, G3:7.76%Mg/1.89%Zn /3.01%F and G4:2.72%Mg/3.75%Zn/1.35%F), suspensions consisting of Mg/Zn/F-CaP preparations and of Zn-TCP (G1: 6.17%Zn) powder were injected in the right thigs of OVX rats for 4 weeks. Injection of Zn-TCP powder suspension in G1 and G2 groups led to the recovery of plasma Zn levels in OVX rats. The area under the curve of plasma Zn for the G2, G1 and Normal (not ovariectomized) control group (GN) groups were significantly lower than those of the group G3, G4 and OVX /untreated control (GC) groups (p
- Published
- 2006
34. Measurement of neutrino oscillation by the K2K experiment
- Author
-
S. Andringa, T. Nakadaira, R. Gran, Tadayuki Takahashi, Yoshitaka Itow, Makoto Sakuda, F. Nakata, K. Fujii, A. Rodriguez, D. Kerr, M. H. Ahn, U. Dore, S. Likhoded, S P Mikheyev, K. Martens, Y. Totsuka, Y. Takubo, Kate Scholberg, Y. Takeuchi, Yu. Kudenko, Shinya Yamada, H. I. Jang, S. C. Boyd, M. Okumura, A. Blondel, A. Ikeda, K. Tashiro, Itsuo Nakano, C. K. Jung, M. Sekiguchi, H. Yokoyama, F. Pierre, Minoru Yoshida, M. Kitamura, L. Whitehead, K. Taki, S. Nawang, N. Yershov, Shogo Nishiyama, O. V. Mineev, E. Sharkey, K. Kaneyuki, Hirokazu Ishino, D. Kielczewska, Shoei Nakayama, Taichi Morita, Y. Kurimoto, Hiroyuki Noumi, T. Otaki, R. Schroeter, L. Ludovici, E. J. Jeon, Takashi Kobayashi, J. Kameda, M. Onchi, Y. Yamanoi, C. Cavata, M. Sorel, Katsuki Hiraide, H. C. Bhang, P. F. Loverre, J. Bouchez, M. Y. Pac, G. Sitjes, S. Mine, C. O. Kim, I. Kato, E. Seo, A. Shima, T. Kutter, K. Hayashi, H. So, S. M. Oser, T. Ishida, J. Hill, J. Catala, A. K. Ichikawa, Tomoyuki Maruyama, T. Hara, K. K. Joo, Lawrence Sulak, P. Novella, Susumu Noda, S. Fukuda, K. Takenaka, Yoshitaka Kuno, T. Ishii, Masaaki Tanaka, F. Nova, John G. Learned, Y. Yamada, B. H. Kang, Y. Obayashi, M. Takasaki, A. Minamino, A. Tornero-Lopez, J.J. Gómez-Cadenas, Takanori Sasaki, M. Fechner, S. Echigo, C. Yanagisawa, J. Zalipska, C. McGrew, G. Jover, J.H. Kim, K. Nakamura, K. B. McConnel Mahn, S. B. Kim, V. A. Matveev, M. Minakawa, A. Cervera, C. W. Walter, Y. Takenaga, Y. Hayato, Yuichi Oyama, Masaya Hasegawa, M. Miura, G. Kume, M. Tada, David William Casper, Takehisa Hasegawa, C. Mitsuda, K. Sato, J. Hosaka, A. Suzuki, R. L. Helmer, Hyosun Kim, Katsuhiro Kobayashi, A. Sakai, Nobuyuki Sakurai, Yusuke Koshio, S. Ueda, Shoji Yamamoto, J. Mallet, S. Matsuno, H. Takeuchi, T. Ooyabu, Masayuki Nakahata, Y. Aoyama, R. Terri, R. Ashie, H. Ishii, Y. Suga, Masashi Yokoyama, J. S. Jang, G. Mitsuka, E. Aliu, H. Tanaka, A. Sarrat, Mark R. Vagins, K. K. Shiraishi, Takaaki Kajita, Masaki Ishitsuka, Kenichi Tanaka, Yoshihiro Suzuki, H. Park, Masaharu Ieiri, X. Espinal, Y. Moriguchi, Beom Jun Kim, Michael B. Smy, Y. Fukuda, T. Iwashita, R. J. Wilkes, I. Higuchi, I. T. Lim, Y. Kato, W. R. Kropp, Federico Sanchez, Toshio Namba, C. Mariani, H. Maesaka, Ko Okumura, E. Kearns, Shigeki Aoki, T. Toshito, Hiroshi Sato, K. Asakura, P. Kitching, C. Mauger, J. Argyriades, H. Nishino, S. H. Lim, A. Okada, M. Kohama, M. Takatsuki, F. Berghaus, Tsuyoshi Nakaya, C. Saji, J. Kubota, Jordi Burguet-Castell, H. G. Berns, W. Wang, Masataka Iinuma, E. Hirose, J. Yoo, K. Nishikawa, J. Y. Kim, Henry W. Sobel, K. Nitta, Y. Tanaka, Masato Shiozawa, Shaomin Chen, A. Konaka, Shigetaka Moriyama, K. O. Cho, R. Nambu, N. Tamura, Silvia Borghi, J. L. Stone, T. Inagaki, A. N. Khotjantsev, Y. Fujii, J. H. Choi, M. M. Khabibullin, Stephane T'Jampens, E. Fernandez, I. S. Jeong, and K. Ishihara
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Tamura, Norio ,010308 nuclear & particles physics ,Oscillation ,T2K experiment ,FOS: Physical sciences ,Física ,Elementary particle ,7. Clean energy ,01 natural sciences ,High Energy Physics - Experiment ,Nuclear physics ,Massless particle ,High Energy Physics - Experiment (hep-ex) ,K2K experiment ,0103 physical sciences ,田村, 詔生 ,Neutrino ,010306 general physics ,Neutrino oscillation ,Lepton - Abstract
We present measurements of nu_mu disappearance in K2K, the KEK to Kamioka long-baseline neutrino oscillation experiment. One hundred and twelve beam-originated neutrino events are observed in the fiducial volume of Super-Kamiokande with an expectation of 158.1^{+9.2}_{-8.6} events without oscillation. A distortion of the energy spectrum is also seen in 58 single-ring muon-like events with reconstructed energies. The probability that the observations are explained by the expectation for no neutrino oscillation is 0.0015% (4.3sigma). In a two flavor oscillation scenario, the allowed Delta m^2 region at sin^2(2theta) is between 1.9 and 3.5 x 10^{-3} eV^2 at the 90% C.L. with a best-fit value of 2.8 x 10^{-3} eV^2., Comment: 40 pages, 48 figures
- Published
- 2006
35. Influence of Asymmetric Donor–Receiver ion Concentration Upon Transscleral Iontophoretic Transport
- Author
-
Yanhui Zhang, William I. Higuchi, Henry S. White, Honggang Zhu, and S. Kevin Li
- Subjects
Osmosis ,Finite Element Analysis ,Analytical chemistry ,Pharmaceutical Science ,Electrolyte ,Administration, Cutaneous ,Permeability ,Ion ,Diffusion ,chemistry.chemical_compound ,Drug Delivery Systems ,Electrochemistry ,medicine ,Computer Simulation ,Mannitol ,Tetraethylammonium ,Iontophoresis ,Chemistry ,Sclera ,Electrophoresis ,Membrane ,medicine.anatomical_structure ,Ophthalmic Solutions ,Salicylic Acid ,Current density ,Algorithms - Abstract
Recent in vitro and in vivo studies have suggested transscleral iontophoresis as a means for non-invasive drug delivery to the eye. However, there remains a lack of information of the iontophoretic transport behavior of the sclera. The objective of the present study was to investigate the effects of permeant concentration upon transscleral iontophoretic transport. Constant current direct current (DC) iontophoresis was conducted with rabbit sclera in vitro at permeant concentration ranging from 0.015 to 1.0 M in the donor chamber without background electrolyte at 0.4–4 mA (current density: 2–20 mA/cm 2 ). PBS (0.15 M) was the receiver solution. Salicylate (SA) and tetraethylammonium (TEA) were the model ionic permeants, and mannitol was the neutral probe permeant. Conductivity experiments of SA and TEA solutions were performed to determine the effects of ion concentration upon SA and TEA electromobilities. Model simulations were carried out and compared with the experimental data. It was found that the fluxes of the ionic permeants increased linearly with the electric current but were relatively independent of their donor concentrations. Electric field-induced convective solvent flow (electroosmosis) in the sclera was observed to be from the anode to cathode, suggesting that the sclera is net negatively charge at neutral pH. For the studied permeants, electrophoresis was the main transport enhancing mechanism with electroosmosis as a secondary effect. No significant interaction between the permeants and sclera was observed that significantly altered electroosmosis in the membrane. Under the asymmetric donor and receiver conditions, the transference of the permeants could not be predicted by the concentrations of the ions in the donor and receiver chambers with the assumption of constant electric field in the membrane. The membrane ion concentrations were different from those in the chambers due to the requirement of charge neutrality in the membrane.
- Published
- 2005
36. Effects of electrophoresis and electroosmosis during alternating current iontophoresis across human epidermal membrane
- Author
-
Kendall D. Peck, William I. Higuchi, Guang Yan, S. Kevin Li, and Honggang Zhu
- Subjects
Electrophoresis ,Osmosis ,Iontophoresis ,Chemistry ,Direct current ,Analytical chemistry ,Pharmaceutical Science ,Electro-osmosis ,In Vitro Techniques ,law.invention ,Electrical resistance and conductance ,law ,Permeability (electromagnetism) ,Humans ,Epidermis ,Alternating current ,DC bias ,Voltage - Abstract
Previous studies in our laboratory have demonstrated that skin electrical resistance can be controlled by an alternating current (AC) electric field. By maintaining constant skin resistance, AC iontophoresis has been shown to reduce the iontophoretic flux variability of neutral permeants. Recently, it was found that symmetric square-wave AC could enhance iontophoretic transport of both neutral and ionic permeants by means of electrophoresis and/or electroosmosis in a synthetic membrane system, and a model was presented to describe the experimental results. The objective of the present study was to assess the effects of AC voltage and frequency and direct current (DC) offset on the flux of neutral and ionic model permeants with human epidermal membrane (HEM). Experiments were conducted under two different conditions: constant AC voltage iontophoresis and iontophoresis using constant HEM resistance with DC offset voltage. The following are the main findings in these experiments. In the constant AC voltage study, when the permeability data were compared at the same HEM electrical resistance, it was demonstrated that AC even at high frequency (approximately 1 kHz) could enhance the transport of the ionic permeant (tetraethylammonium ion) across HEM, but no enhancement was observed for the neutral permeant (arabinose). For the ionic permeant flux enhancement, the higher the applied AC voltage, the greater the flux enhancement. There was little or no AC frequency dependence of the flux enhancement in the frequency range of 50-1000 Hz. In the constant HEM resistance study of AC with DC offset, approximately linear relationships were observed between flux enhancement and the DC offset voltage for both the neutral and ionic permeants, and these results were found to be consistent with predictions of the modified Nernst-Planck model for conventional constant voltage DC iontophoresis. When the DC offset voltage was increased, the AC component of the flux enhancement for the ionic permeant decreased, eventually appearing to contribute negligibly to the total flux enhancement at high DC offset voltages.
- Published
- 2005
37. Quantitative study of electrophoretic and electroosmotic enhancement during alternating current iontophoresis across synthetic membranes
- Author
-
Guang Yan, Honggang Zhu, William I. Higuchi, Kendall D. Peck, and S. Kevin Li
- Subjects
Electrophoresis ,Osmosis ,Iontophoresis ,Chemistry ,Direct current ,Electric Conductivity ,Synthetic membrane ,Analytical chemistry ,Pharmaceutical Science ,Membranes, Artificial ,Models, Theoretical ,law.invention ,Membrane ,law ,Biophysics ,Current (fluid) ,Transport phenomena ,Alternating current ,Transdermal - Abstract
One of the primary safety and tolerability limitations of direct current iontophoresis is the potential for electrochemical burns associated with the necessary current densities and/or application times required for effective treatment. Alternating current (AC) transdermal iontophoresis has the potential to eliminate electrochemical burns that are frequently observed during direct current transdermal iontophoresis. Although it has been demonstrated that the intrinsic permeability of skin can be increased by applying low-to-moderate AC voltages, transdermal transport phenomena and enhancement under AC conditions have not been systematically studied and are not well understood. The aim of the present work was to study the fundamental transport mechanisms of square-wave AC iontophoresis using a synthetic membrane system. The model synthetic membrane used was a composite Nuclepore membrane. AC frequencies ranging from 20 to 1000 Hz and AC fields ranging from 0.25 to 0.5 V/membrane were investigated. A charged permeant, tetraethyl ammonium, and a neutral permeant, arabinose, were used. The transport studies showed that flux was enhanced by increasing the AC voltage and decreasing AC frequency. Two theoretical transport models were developed: one is a homogeneous membrane model; the other is a heterogeneous membrane model. Experimental transport data were compared with computer simulations based on these models. Excellent agreement between model predictions and experimental data was observed when the data were compared with the simulations from the heterogeneous membrane model.
- Published
- 2004
38. Mechanistic study of chemical skin permeation enhancers with different polar and lipophilic functional groups
- Author
-
Ning He, S. Kevin Li, Doungdaw Chantasart, William I. Higuchi, Kevin S. Warner, and Dalia S. Shaker
- Subjects
Octanol ,Mice, Hairless ,Aqueous solution ,Stereochemistry ,Skin Absorption ,Pharmaceutical Science ,Biological Transport ,In Vitro Techniques ,Permeation ,Lipids ,Permeability ,Partition coefficient ,Mice ,Homologous series ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Mechanism of action ,medicine ,Stratum corneum ,Animals ,medicine.symptom ,Enhancer - Abstract
In a previous study, the enhancement effects on the transport of a steroidal permeant along the hairless mouse skin (HMS) stratum corneum (SC) lipoidal pathway were investigated for two homologous series of chemical enhancers: the 1‐alkyl‐2‐pyrrolidones and the 1‐alkyl‐2‐azacycloheptanones. The objective of the present study was to extend this investigation to a broader range of enhancers in order that generalizations with regard to the mechanistic aspects of enhancer function might be established. Specific questions to be addressed included: (a) what is the nature of the microenvironment of the enhancer site of action? (b) what is the extent of the equilibrium uptake of the enhancer from its E = 10 aqueous enhancer solution (the aqueous concentration for which the enhancer induces a tenfold transport enhancement) into the HMS SC intercellular lipid “phase”? and (c) are the microenvironment of the enhancer site of action and that for the equilibrium enhancer uptake at E = 10 relatively independent of the molecular characteristics of the enhancers (as suggested by the earlier study)? Enhancers selected for this study included: a wide range of polar head group size and polarity; n ‐alkyl group chain lengths from C 4 to C 12 ; and enhancers in which a double bond is substituted for a single bond in the hydrocarbon chain (3‐alkenols) from C 5 to C 9 . In addition to the main study, an ancillary set of experiments were to be conducted on the partitioning of a surrogate permeant (estradiol) into the intercellular lipid “phase” under E = 10 isoenhancement conditions to assess the extent to which the permeant partition coefficient may contribute to the permeation enhancement. The following were the principal findings of this research. First, there was very good correlation between the E = 10 isoenhancement aqueous enhancer concentrations and K octanol/water for all the studied enhancers. Second, the partitioning of the enhancer from the E = 10 aqueous enhancer solution into the HMS SC intercellular lipid “phase” was found to be relatively independent of the molecular characteristics for all studied enhancers, and the partition coefficients also correlated well with K octanol/water . These results may have the following meanings: both the microenvironment of the enhancer site of action and the SC intercellular lipid “phase” involved in the enhancer partitioning experiments are well mimicked by liquid n ‐octanol, and the “intrinsic” potencies (as assessed by the equilibrium enhancer concentration in the microenvironment at the site of action) of the enhancers are relatively independent of the molecular characteristics of the studied enhancers. Finally, the estradiol partitioning experiments suggest the permeant partitioning into the HMS SC intercellular lipid “phase” is enhanced around five‐ to seven‐fold when permeation is enhanced ten‐fold for most of the studied enhancers; therefore, the enhancement of the permeant partition coefficient rather than the permeant diffusion coefficient seems to be more important in permeation enhancement of the SC barrier lipoidal pathway. © 2004 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1415–1430, 2004
- Published
- 2004
39. Mechanistic studies of flux variability of neutral and ionic permeants during constant current dc iontophoresis with human epidermal membrane
- Author
-
William I. Higuchi, Honggang Zhu, S. Kevin Li, and Rajan Kochambilli
- Subjects
Analytical chemistry ,Pharmaceutical Science ,Ionic bonding ,In Vitro Techniques ,Models, Biological ,Permeability ,Flux (metallurgy) ,Humans ,Urea ,Mannitol ,Transdermal ,Membranes ,Iontophoresis ,Chemistry ,Electric Conductivity ,Tetraethylammonium ,Charge density ,Biological Transport ,Galvanic Skin Response ,Electrophoresis ,Membrane ,Biophysics ,Diffusion Chambers, Culture ,Constant current ,Epidermis ,Porosity - Abstract
Although constant current iontophoresis is supposed to provide constant transdermal transport, significant flux variability and/or time-dependent flux drifts are observed during iontophoresis with human skin in vitro and human studies in vivo. The objectives of the present study were to determine (a) the causes of flux variability in constant current dc transdermal iontophoresis and (b) the relationships of flux variabilities among permeants of different physicochemical properties. Changes in the human epidermal membrane (HEM) effective pore size and/or electroosmosis during constant current dc iontophoresis were examined. Tetraethylammonium ion (TEA), urea, and mannitol were the model permeants. For the neutral permeants, the results in the present study showed a significant increase of fluxes with time in a given experiment and large HEM sample-to-sample variability. Although both effective pore size and pore charge density variations contributed to the time-dependent flux drifts observed in electroosmotic transport, the significant flux drifts observed were found to be primarily a result of the time-dependent increase in effective pore charge density. For the ionic permeant, the observed flux variability was smaller than that of the neutral permeants and was believed to be primarily due to effective pore size alteration in HEM during iontophoresis as suggested in a previous study. The different extents of flux variability observed between neutral and ionic permeants are consistent with the different iontophoretically enhanced transport mechanisms for the neutral and ionic permeants (i.e. electroosmosis and electrophoresis, respectively). The results of the present study also demonstrate that flux variability of two neutral permeants are inter-related, so the flux of one neutral permeant can be predicted if the permeability coefficient of the other neutral permeant is known.
- Published
- 2004
40. Mechanistic Studies of Branched-Chain Alkanols as Skin Permeation Enhancers
- Author
-
Doungdaw Chantasart, Ning He, Kevin S. Warner, S. Kevin Li, Sompol Prakongpan, and William I. Higuchi
- Subjects
Octanol ,chemistry.chemical_classification ,Mice, Hairless ,Aqueous solution ,Stereochemistry ,Skin Absorption ,Pharmaceutical Science ,In Vitro Techniques ,Permeation ,Branching (polymer chemistry) ,Permeability ,Partition coefficient ,Mice ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Alkanes ,Stratum corneum ,medicine ,Animals ,Female ,Fatty Alcohols ,Enhancer ,Alkyl - Abstract
As part of a long-term effort to understand the structure/function relationship between chemical permeation enhancers and skin permeation enhancement, the present study examined the influence of hydrocarbon chain branching on the effectiveness of skin permeation enhancers of the type that possesses a polar group (e.g., the hydroxyl group) attached to a hydrocarbon chain(s). The effects of x -hexanol, x -heptanol, x -octanol, and x -nonanol (where x is the position of the hydroxyl group ranging from 1 up to 5) on the transport of a probe permeant, corticosterone, across hairless mouse skin (HMS) were investigated. Isoenhancement concentrations are defined as the aqueous concentrations for which different enhancers induce the same extent of permeant transport enhancement, E , across the lipoidal pathway of stratum corneum (SC). The isoenhancement concentrations of 2-alkanol, 3-alkanol, 4-alkanol, and 5-alkanol to induce E = 10 were approximately 1.9-, 2.6-, 3.1-, and 3.9-fold higher, respectively, than those of the 1-alkanols of the same molecular formula. This suggested that the branched-chain alkanols have lower enhancer potency than the 1-alkanols of the same molecular formula; the potency decreases as the hydroxyl group moves from the end of the chain towards the center of the enhancer alkyl chain. To further investigate the mechanism(s) of action of the branched-chain alkanols as skin permeation enhancers, the equilibrium uptake of the enhancers into the hairless mouse skin stratum corneum (HMS SC) from aqueous enhancer solutions of E = 10 was determined. The data from these experiments provided a direct measure of the “intrinsic” potency of the enhancer. In the same experiments, the equilibrium partitioning (distribution) of a surrogate permeant, estradiol (E2β), into the HMS SC was also determined and compared to the partitioning from PBS (no enhancer present). The uptake amounts (micromole/mg SC) for 1-alkanols into the intercellular lipids of the SC were found to be essentially the same at their isoenhancement concentrations. However, at their isoenhancement concentrations, the uptake amounts of the branched-chain alkanols into the intercellular lipids of HMS SC were higher than those of the 1-alkanols. These results support the view that: (1) the intrinsic potencies of the 1-alkanols are essentially the same and independent of their 1-alkyl chain length at their isoenhancement concentrations, (2) the intrinsic potencies of the branched-chain alkanols are lower than those of the normal alkanols, and (3) branching of the alkyl chain reduces the ability of the enhancer to effect lipid fluidization in the SC lipid lamellae at the target site(s). The enhancement effects of the branched-chain alkanols and the 1-alkanols at their isoenhancement concentrations upon E2β partitioning into the SC intercellular lipids were found to be approximately the same and in the range of five- to eight-fold enhancement. The constancy of this enhancement for E2β partitioning suggests that the mechanism of enhancement action for the branched-chain alkanols and the 1-alkanols are the same. Additionally, a good correlation of the intercellular lipid/PBS partition coefficients of both the branched-chain alkanols and the 1-alkanols with the n -octanol/PBS partition coefficients was found. This supports the view that the chemical microenvironment of the polar head group and the alkyl group of the studied enhancers at the site of skin permeation enhancer action in the SC lipid lamellae can be represented by water-saturated n -octanol for both the branched-chain alkanols and the 1-alkanols. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association
- Published
- 2004
41. In vitro and in vivo comparisons of constant resistance AC iontophoresis and DC iontophoresis
- Author
-
David J. Miller, S. Kevin Li, William I. Higuchi, Steven E. Kern, Honggang Zhu, and Matthew S. Hastings
- Subjects
medicine.medical_specialty ,Materials science ,integumentary system ,Iontophoresis ,Skin Absorption ,Direct current ,Pharmaceutical Science ,Human skin ,Galvanic Skin Response ,law.invention ,Surgery ,Electrical resistance and conductance ,law ,In vivo ,Electric Impedance ,medicine ,Diffusion Chambers, Culture ,Humans ,Constant current ,Constant (mathematics) ,Alternating current ,Biomedical engineering - Abstract
A previous in vitro constant electrical resistance alternating current (AC) iontophoresis study with human epidermal membrane (HEM) and a model neutral permeant has shown less inter- and intra-sample variability in iontophoretic transport relative to conventional constant direct current (DC) iontophoresis. The objectives of the present study were to address the following questions. (1) Can the skin electrical resistance be maintained at a constant level by AC in humans in vivo? (2) Are the in vitro data with HEM representative of those in vivo? (3) Does constant skin resistance AC iontophoresis have less inter- and intra-sample variability than conventional constant current DC iontophoresis in vivo? (4) What are the electrical and the barrier properties of skin during iontophoresis in vivo? In the present study, in vitro HEM experiments were carried out with the constant resistance AC and the conventional constant current DC methods using mannitol and glucose as the neutral model permeants. In vivo human experiments were performed using glucose as the permeant with a constant skin resistance AC only protocol and two conventional constant current DC methods (continuous constant current DC and constant current DC with its polarity alternated every 10 min with a 3:7 on:off duty cycle). Constant current DC iontophoresis was conducted with commercial constant current DC devices, and constant resistance AC iontophoresis was carried out by reducing and maintaining the skin resistance at a constant target value with AC supplied from a function generator. This study shows that (1) skin electrical resistance can be maintained at a constant level during AC iontophoresis in vivo; (2) HEM in vitro and human skin in vivo demonstrate similar electrical and barrier properties, and these properties are consistent with our previous findings; (3) there is general qualitative and semi-quantitative agreement between the HEM data in vitro and human skin data in vivo; and (4) constant skin resistance AC iontophoresis generally provides less inter- and intra-subject variability than conventional constant current DC.
- Published
- 2003
42. Search for the Electric Dipole Moment of the τ Lepton
- Author
-
K. Inami, K. Abe, R. Abe, T. Abe, I. Adachi, H. Aihara, M. Akatsu, Y. Asano, T. Aso, V. Aulchenko, T. Aushev, A.M. Bakich, Y. Ban, E. Banas, P.K. Behera, I. Bizjak, A. Bondar, T.E. Browder, P. Chang, Y. Chao, B.G. Cheon, R. Chistov, Y. Choi, Y.K. Choi, L.Y. Dong, S. Eidelman, V. Eiges, Y. Enari, C. Fukunaga, N. Gabyshev, A. Garmash, T. Gershon, B. Golob, C. Hagner, F. Handa, T. Hara, H. Hayashii, M. Hazumi, I. Higuchi, T. Higuchi, T. Hokuue, Y. Hoshi, W.-S. Hou, H.-C. Huang, T. Igaki, T. Iijima, A. Ishikawa, H. Ishino, R. Itoh, H. Iwasaki, H.K. Jang, J.H. Kang, J.S. Kang, N. Katayama, H. Kawai, Y. Kawakami, N. Kawamura, T. Kawasaki, H. Kichimi, H.O. Kim, Hyunwoo Kim, J.H. Kim, S.K. Kim, S. Korpar, P. Krokovny, R. Kulasiri, A. Kuzmin, Y.-J. Kwon, J.S. Lange, G. Leder, S.H. Lee, J. Li, D. Liventsev, R.-S. Lu, J. MacNaughton, F. Mandl, T. Matsuishi, S. Matsumoto, T. Matsumoto, W. Mitaroff, H. Miyake, H. Miyata, T. Nagamine, Y. Nagasaka, T. Nakadaira, E. Nakano, M. Nakao, J.W. Nam, S. Nishida, T. Nozaki, S. Ogawa, T. Ohshima, T. Okabe, S. Okuno, S.L. Olsen, W. Ostrowicz, H. Ozaki, P. Pakhlov, H. Park, K.S. Park, L.S. Peak, J.-P. Perroud, L.E. Piilonen, K. Rybicki, H. Sagawa, S. Saitoh, Y. Sakai, M. Satapathy, O. Schneider, S. Semenov, K. Senyo, M.E. Sevior, H. Shibuya, B. Shwartz, V. Sidorov, J.B. Singh, N. Soni, S. Stanič, M. Starič, A. Sugi, A. Sugiyama, K. Sumisawa, T. Sumiyoshi, S. Suzuki, S.Y. Suzuki, T. Takahashi, F. Takasaki, K. Tamai, N. Tamura, J. Tanaka, M. Tanaka, G.N. Taylor, Y. Teramoto, S. Tokuda, T. Tomura, T. Tsuboyama, T. Tsukamoto, S. Uehara, Y. Unno, S. Uno, G. Varner, K.E. Varvell, C.C. Wang, Y. Watanabe, B.D. Yabsley, Y. Yamada, A. Yamaguchi, Y. Yamashita, Y. Yusa, Z.P. Zhang, V. Zhilich, and D. Žontar
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Electric dipole moment ,Form factor (quantum field theory) ,FOS: Physical sciences ,Observable ,Optimal observable ,Atomic and Molecular Physics, and Optics ,High Energy Physics - Experiment ,law.invention ,High Energy Physics - Experiment (hep-ex) ,Dipole ,CP violation ,KEKB ,law ,Tau ,Signature (topology) ,Collider ,Lepton - Abstract
We have searched for a T/CP violation signature arising from an electric dipole form factor (d_tau) of the tau lepton in the e+e- -> tau+tau- reaction. Using an optimal observable method for 29.5 fb^{-1} of data collected with the Belle detector at the KEKB collider at sqrt{s}=10.58 GeV, we obtained the preliminary result Re(d_tau) = (1.15 +- 1.70) x 10^{-17} ecm and Im(d_tau) = (-0.83 +- 0.86) x 10^{-17} ecm for the real and imaginary parts of d_tau, respectively, and set the 95% confidence level limits -2.2 < Re(d_tau) < 4.5 (10^{-17} ecm) and -2.5 < Im(d_tau) < 0.8 (10^{-17} ecm)., Invited talk at the Seventh International Workshop on Tau Lepton Physics (TAU02), Santa Cruz, Ca, USA, Sept 2002, 8 pages, LaTeX, 19 eps figures
- Published
- 2003
43. Study of →Dππ decays
- Author
-
A Satpathy, K Abe, R Abe, T Abe, I Adachi, H Aihara, M Akatsu, Y Asano, T Aso, T Aushev, A.M Bakich, Y Ban, A Bay, I Bedny, P.K Behera, A Bondar, A Bozek, M Bračko, T.E Browder, B.C.K Casey, P Chang, Y Chao, K.-F Chen, B.G Cheon, R Chistov, S.-K Choi, Y Choi, M Danilov, L.Y Dong, S Eidelman, V Eiges, C Fukunaga, N Gabyshev, A Garmash, T Gershon, B Golob, J Haba, T Hara, N.C Hastings, H Hayashii, M Hazumi, I Higuchi, L Hinz, T Hokuue, W.-S Hou, H.-C Huang, T Igaki, Y Igarashi, T Iijima, K Inami, A Ishikawa, R Itoh, H Iwasaki, Y Iwasaki, H.K Jang, J.H Kang, P Kapusta, S.U Kataoka, N Katayama, H Kawai, Y Kawakami, N Kawamura, T Kawasaki, H Kichimi, D.W Kim, H.J Kim, Hyunwoo Kim, S.K Kim, K Kinoshita, S Kobayashi, P Krokovny, R Kulasiri, S Kumar, A Kuzmin, Y.-J Kwon, S.H Lee, J Li, D Liventsev, R.-S Lu, J MacNaughton, G Majumder, F Mandl, S Matsumoto, T Matsumoto, W Mitaroff, K Miyabayashi, H Miyake, H Miyata, T Mori, T Nagamine, Y Nagasaka, T Nakadaira, E Nakano, M Nakao, H Nakazawa, J.W Nam, Z Natkaniec, S Nishida, O Nitoh, S Noguchi, S Ogawa, T Ohshima, T Okabe, S Okuno, S.L Olsen, Y Onuki, W Ostrowicz, H Ozaki, P Pakhlov, H Palka, C.W Park, K.S Park, J.-P Perroud, M Peters, L.E Piilonen, K Rybicki, H Sagawa, S Saitoh, Y Sakai, M Satapathy, O Schneider, S Schrenk, C Schwanda, S Semenov, K Senyo, R Seuster, H Shibuya, V Sidorov, J.B Singh, N Soni, S Stanič, M Starič, A Sugi, K Sumisawa, T Sumiyoshi, S Suzuki, S.Y Suzuki, S.K Swain, T Takahashi, F Takasaki, K Tamai, N Tamura, J Tanaka, M Tanaka, G.N Taylor, Y Teramoto, T Tomura, K Trabelsi, T Tsuboyama, T Tsukamoto, S Uehara, K Ueno, S Uno, G Varner, C.H Wang, J.G Wang, M.-Z Wang, E Won, B.D Yabsley, Y Yamada, A Yamaguchi, Y Yamashita, M Yamauchi, H Yanai, Y Yuan, C.C Zhang, Z.P Zhang, and V Zhilich
- Subjects
Nuclear physics ,Hadronic decay ,Physics ,Nuclear and High Energy Physics ,Particle physics ,KEKB ,Annihilation ,Branching fraction ,Pi ,Omega - Abstract
We report on a study of $\bar{B^{0}} \to D^{(*) 0} \pi^+ \pi^-$ decays using 29.1 fb$^{-1}$ of $e^{+}e^{-}$ annihilation data recorded at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB storage ring. Making no assumptions about the intermediate mechanism, the branching fractions for $\bar{B}^0 \to D^0 \pi^+ \pi^-$ and $\bar{B}^0 \to D^{* 0} \pi^+ \pi^-$ are determined to be $(8.0 \pm 0.6 \pm 1.5) \times 10^{-4} $ and $ (6.2 \pm 1.2 \pm 1.8) \times 10^{-4}$ respectively. An analysis of $\bar{B^{0}} \to D^{0} \pi^+ \pi^-$ candidates yields to the first observation of the color-suppressed hadronic decay $\bar{B}^0 \to D^0 \rho^0$ with the branching fraction $(2.9 \pm 1.0 \pm 0.4) \times 10^{-4}$. We measure the ratio of branching fractions ${\mathcal B}(\bar{B^0} \to D^0 \rho^0) / {\mathcal B}(\bar{B^0} \to D^0 \omega)$ = 1.6 $\pm$ 0.8.
- Published
- 2003
44. Metastable Equilibrium Solubility Behavior of Carbonated Apatite in the Presence of Solution Strontium
- Author
-
Y. Bi, Arif Ali Baig, William I. Higuchi, and D. D. Heslop
- Subjects
Strontium ,Surface Properties ,Precipitation (chemistry) ,Endocrinology, Diabetes and Metabolism ,Inorganic chemistry ,Carbonates ,chemistry.chemical_element ,Calcium ,Phosphate ,Apatite ,Solutions ,chemistry.chemical_compound ,Endocrinology ,Solubility ,X-Ray Diffraction ,chemistry ,Apatites ,visual_art ,visual_art.visual_art_medium ,Thermodynamics ,Orthopedics and Sports Medicine ,Dissolution ,Stoichiometry - Abstract
The purpose of this study was to use the concept of metastable equilibrium solubility (MES) to describe the anomalous solubility behavior of carbonated apatite (CAP) in the presence of solution strontium. A CAP sample (4.8 wt% CO(3), synthesized at 70 degrees C) was prepared by precipitation. Baseline MES distributions were determined in a series of 0.1 M acetate buffers containing only calcium and phosphate (no strontium) over a broad range of solution conditions. In order to assess the influence of strontium, MES profiles were then determined in a similar fashion with 20, 30, 40, 50, 60, 70, and 80% of the solution calcium being replaced on an equal molar basis by solution strontium. From the compositions of the equilibrating buffer solutions, ion activity products (IAPs) of the form Ca(10-n)Sr(n)(PO(4))(6)(OH)(2) (n = 0-10) were calculated in an attempt to determine the correct function governing the dissolution of the CAP preparation. The results demonstrate the following important findings: (a) at high solution strontium/calcium ratios (i.e., when 60% or more of the solution calcium was replaced by strontium), the MES profiles in all the experiments were found to be essentially superimposable when the solution IAPs were calculated using the stoichiometry of Ca(6)Sr(4)(PO(4))(6)(OH)(2), and (b), at low solution strontium/calcium ratios (i.e., when 40% or less of the solution calcium was replaced by strontium), the stoichiometry yielding MES data superpositioning was found to be that of hydroxyapatite. When other stoichiometries were assumed, good superpositioning of the data was not possible.
- Published
- 2003
45. Drug Release from a Three-Dimensionally Perforated Porous Apatite/Collagen Composite Cement
- Author
-
William I. Higuchi, Kuniko Otsuka, Atsuo Ito, Hidenori Nakagawa, and Makoto Otsuka
- Subjects
Cement ,Artificial bone ,Materials science ,Biocompatibility ,Simulated body fluid ,Composite number ,Nanotechnology ,General Medicine ,Apatite ,Chemical engineering ,visual_art ,Drug delivery ,visual_art.visual_art_medium ,Porosity - Abstract
Artificial bone (PC, containing 3% indomethacin) with biocompatibility, inter-connective pore structure, and drug delivery ability was obtained from self-setting apatite/collagen composite cement. X-ray powder diffrac- tion and FT-IR spectroscopy suggested that PC consisted of carbonated apatite and had a structure similar to that of natural rat bone. The IMC release rates from a PC block containing the drug were measured in simulated body fluid. The rate of release increased with the number of macro- pore, that from planar surface matrix systems followed the Higuchi equation.
- Published
- 2012
46. Measurement of CP-violating parameters in B→η′K decays
- Author
-
K.-F. Chen, K. Hara, K. Abe, T. Abe, I. Adachi, Byoung Sup Ahn, H. Aihara, M. Akatsu, Y. Asano, T. Aso, V. Aulchenko, T. Aushev, A.M. Bakich, Y. Ban, A. Bay, I. Bedny, P.K. Behera, I. Bizjak, A. Bondar, A. Bozek, M. Bračko, J. Brodzicka, T.E. Browder, B.C.K. Casey, P. Chang, Y. Chao, B.G. Cheon, R. Chistov, S.-K. Choi, Y. Choi, Y.K. Choi, M. Danilov, L.Y. Dong, J. Dragic, S. Eidelman, V. Eiges, Y. Enari, F. Fang, C. Fukunaga, N. Gabyshev, A. Garmash, T. Gershon, B. Golob, A. Gordon, R. Guo, J. Haba, K. Hanagaki, F. Handa, T. Hara, N.C. Hastings, H. Hayashii, M. Hazumi, E.M. Heenan, I. Higuchi, T. Higuchi, L. Hinz, Y. Hoshi, W.-S. Hou, Y.B. Hsiung, S.-C. Hsu, H.-C. Huang, T. Igaki, Y. Igarashi, T. Iijima, K. Inami, A. Ishikawa, R. Itoh, H. Iwasaki, Y. Iwasaki, H.K. Jang, J.H. Kang, J.S. Kang, N. Katayama, H. Kawai, Y. Kawakami, N. Kawamura, H. Kichimi, D.W. Kim, Heejong Kim, H.J. Kim, Hyunwoo Kim, T.H. Kim, K. Kinoshita, S. Korpar, P. Križan, P. Krokovny, R. Kulasiri, S. Kumar, A. Kuzmin, Y.-J. Kwon, J.S. Lange, G. Leder, S.H. Lee, J. Li, R.-S. Lu, J. MacNaughton, G. Majumder, F. Mandl, D. Marlow, T. Matsuishi, S. Matsumoto, T. Matsumoto, K. Miyabayashi, Y. Miyabayashi, H. Miyata, G.R. Moloney, T. Mori, A. Murakami, T. Nagamine, Y. Nagasaka, T. Nakadaira, E. Nakano, M. Nakao, J.W. Nam, Z. Natkaniec, S. Nishida, O. Nitoh, S. Noguchi, S. Ogawa, T. Ohshima, T. Okabe, S. Okuno, S.L. Olsen, Y. Onuki, W. Ostrowicz, H. Ozaki, H. Palka, C.W. Park, H. Park, L.S. Peak, J.-P. Perroud, M. Peters, L.E. Piilonen, N. Root, M. Rozanska, K. Rybicki, H. Sagawa, S. Saitoh, Y. Sakai, H. Sakamoto, M. Satapathy, A. Satpathy, O. Schneider, S. Schrenk, C. Schwanda, S. Semenov, K. Senyo, R. Seuster, M.E. Sevior, H. Shibuya, B. Shwartz, J.B. Singh, N. Soni, S. Stanič, M. Starič, A. Sugi, A. Sugiyama, K. Sumisawa, T. Sumiyoshi, S. Suzuki, S.Y. Suzuki, T. Takahashi, F. Takasaki, N. Tamura, J. Tanaka, M. Tanaka, G.N. Taylor, Y. Teramoto, S. Tokuda, M. Tomoto, T. Tomura, K. Trabelsi, W. Trischuk, T. Tsuboyama, T. Tsukamoto, S. Uehara, K. Ueno, Y. Unno, S. Uno, Y. Ushiroda, G. Varner, K.E. Varvell, C.C. Wang, C.H. Wang, J.G. Wang, M.-Z. Wang, Y. Watanabe, E. Won, B.D. Yabsley, Y. Yamada, A. Yamaguchi, Y. Yamashita, M. Yamauchi, H. Yanai, P. Yeh, M. Yokoyama, Y. Yuan, Y. Yusa, Z.P. Zhang, V. Zhilich, and D. Žontar
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,KEKB ,Meson ,Resonance ,High Energy Physics::Experiment ,Nuclear Experiment ,Prime (order theory) - Abstract
We present measurements of CP-violating parameters in $B^0(\bar{B}{}^0) \to \eta^\prime K_S^0$ and $B^{\pm} \to \eta' K^{\pm}$ decays based on a 41.8 fb$^{-1}$ data sample collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider. We fully reconstruct one neutral $B$ meson as a $B^0(\bar{B}{}^0) \to \eta^\prime K_S^0$ CP eigenstate and identify the flavor of the accompanying $B$ from its decay products. From the distribution of time intervals between pairs of $B$ meson decay points, we obtain the CP-violating asymmetry parameters ${\mathcal S}_{\eta^\prime K_S^0} = 0.28\pm0.55(stat)^{+0.07}_{-0.08}(syst)$, and ${\mathcal A}_{\eta^\prime K_S^0} = 0.13\pm0.32(stat)^{+0.09}_{-0.06}(syst)$. We also reconstruct charged $B^{\pm} \to \eta^\prime K^{\pm}$ decays and determine a direct-CP violating asymmetry value of ${\mathcal A}_{\eta^\prime K^\pm}=(-1.5\pm7.0(stat)\pm0.9(syst))%$.
- Published
- 2002
47. Cholesterol crystallite nucleation in supersaturated model biles from a thermodynamic standpoint
- Author
-
William I. Higuchi and Chen-Lun Liu
- Subjects
Taurocholic Acid ,Time Factors ,Cations, Divalent ,Catalytic site ,Nucleation ,Cholesterol thermodynamic activity ,Light scattering ,Catalysis ,Ion ,Taurochenodeoxycholic Acid ,Bile ,Chemical Precipitation ,Molecular Biology ,Supersaturation ,Chemistry ,Vesicle ,Models, Theoretical ,Solutions ,Cholesterol ,Phosphatidylcholines ,Physical chemistry ,Particle ,Thermodynamics ,Molecular Medicine ,Calcium ,Crystallite ,Crystallization - Abstract
A rapid, silicone polymer film uptake method was used to determine the cholesterol (Ch) thermodynamic activity (AT) in taurocholate (TC)–lecithin (L) and taurochenodeoxycholate (TCDC)–L model biles supersaturated with Ch. Also, time-dependent quasielastic light scattering (QLS) measurements and microscopic observations were made to determine the nature of particle species and the Ch nucleation times. In all cases in which Ch–L vesicles were present, a linear relationship between the logarithm of Ch nucleation times and Ch AT was found. These findings support that Ch AT is the appropriate parameter that represents the Ch nucleation tendency and that vesicles are catalytic sites in the Ch nucleation process. When Ca2+, a nucleation promoter ion, was present in the supersaturated model biles, the increased values of Ch AT quantitatively correlated with shorter Ch nucleation times. These latter findings further demonstrate that Ch AT is the dominant factor in explaining the Ch nucleation tendencies in supersaturated model biles.
- Published
- 2002
- Full Text
- View/download PDF
48. Observation of B→DKK decays
- Author
-
A. Drutskoy, K. Abe, N. Abe, R. Abe, T. Abe, I. Adachi, Byoung Sup Ahn, H. Aihara, M. Akatsu, Y. Asano, T. Aso, V. Aulchenko, T. Aushev, A.M. Bakich, Y. Ban, E. Banas, A. Bay, I. Bedny, P.K. Behera, I. Bizjak, A. Bondar, A. Bozek, T.E. Browder, B.C.K. Casey, M.-C. Chang, P. Chang, Y. Chao, K.-F. Chen, B.G. Cheon, R. Chistov, S.-K. Choi, Y. Choi, Y.K. Choi, M. Danilov, L.Y. Dong, S. Eidelman, V. Eiges, Y. Enari, C.W. Everton, F. Fang, C. Fukunaga, N. Gabyshev, A. Garmash, T. Gershon, R. Guo, J. Haba, T. Hara, Y. Harada, H. Hayashii, M. Hazumi, E.M. Heenan, I. Higuchi, T. Higuchi, L. Hinz, T. Hokuue, Y. Hoshi, W.-S. Hou, S.-C. Hsu, H.-C. Huang, T. Igaki, Y. Igarashi, T. Iijima, K. Inami, A. Ishikawa, H. Ishino, R. Itoh, H. Iwasaki, Y. Iwasaki, H.K. Jang, J.H. Kang, J.S. Kang, P. Kapusta, S.U. Kataoka, N. Katayama, H. Kawai, Y. Kawakami, T. Kawasaki, H. Kichimi, D.W. Kim, Heejong Kim, H.J. Kim, Hyunwoo Kim, T.H. Kim, K. Kinoshita, S. Korpar, P. Križan, P. Krokovny, R. Kulasiri, S. Kumar, A. Kuzmin, Y.-J. Kwon, G. Leder, S.H. Lee, J. Li, D. Liventsev, R.-S. Lu, J. MacNaughton, G. Majumder, F. Mandl, D. Marlow, T. Matsuishi, S. Matsumoto, T. Matsumoto, W. Mitaroff, Y. Miyabayashi, H. Miyake, H. Miyata, G.R. Moloney, T. Mori, T. Nagamine, Y. Nagasaka, T. Nakadaira, E. Nakano, M. Nakao, J.W. Nam, Z. Natkaniec, K. Neichi, S. Nishida, O. Nitoh, S. Noguchi, T. Nozaki, S. Ogawa, F. Ohno, T. Ohshima, T. Okabe, S. Okuno, S.L. Olsen, Y. Onuki, W. Ostrowicz, H. Ozaki, P. Pakhlov, H. Palka, C.W. Park, H. Park, L.S. Peak, J.-P. Perroud, M. Peters, L.E. Piilonen, N. Root, M. Rozanska, K. Rybicki, H. Sagawa, S. Saitoh, Y. Sakai, H. Sakamoto, M. Satapathy, A. Satpathy, O. Schneider, S. Schrenk, S. Semenov, K. Senyo, R. Seuster, M.E. Sevior, H. Shibuya, V. Sidorov, J.B. Singh, N. Soni, S. Stanič, M. Starič, A. Sugi, A. Sugiyama, K. Sumisawa, T. Sumiyoshi, S.Y. Suzuki, T. Takahashi, F. Takasaki, K. Tamai, N. Tamura, J. Tanaka, M. Tanaka, G.N. Taylor, Y. Teramoto, S. Tokuda, M. Tomoto, T. Tomura, S.N. Tovey, K. Trabelsi, T. Tsuboyama, T. Tsukamoto, S. Uehara, K. Ueno, Y. Unno, S. Uno, Y. Ushiroda, G. Varner, K.E. Varvell, C.C. Wang, C.H. Wang, J.G. Wang, M.-Z. Wang, Y. Watanabe, E. Won, B.D. Yabsley, Y. Yamada, A. Yamaguchi, Y. Yamashita, M. Yamauchi, H. Yanai, P. Yeh, Y. Yusa, J. Zhang, Z.P. Zhang, V. Zhilich, and D. Žontar
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,KEKB ,law ,Invariant mass ,Polarization (waves) ,Collider ,law.invention - Abstract
The B -> D^{(*)} K^- K^{(*)0} decays have been observed for the first time. The branching fractions of the B -> D^{(*)} K^- K^{(*)0} decay modes are measured. Significant signals are found for the B -> D^{(*)} K^- K^{*0} and B^- -> D^0 K^- K^0_S decay modes. The invariant mass and polarization distributions for the K^-K^{*0} and K^-K^0_S subsystems have been studied. For the K^-K^{*0} sybsystem these distributions agree well with those expected for two-body B -> D^{(*)} a_1^-(1260) decays, with a_1^-(1260) -> K^- K^{*0}. The analysis was done using 29.4 fb^{-1} of data collected with the Belle detector at the e^+ e^- asymmetric collider KEKB.
- Published
- 2002
49. Study of B→ρπ decays at Belle
- Author
-
A. Gordon, Y. Chao, K. Abe, N. Abe, R. Abe, T. Abe, Byoung Sup Ahn, H. Aihara, M. Akatsu, Y. Asano, T. Aso, V. Aulchenko, T. Aushev, A.M. Bakich, Y. Ban, A. Bay, I. Bedny, P.K. Behera, I. Bizjak, A. Bondar, A. Bozek, M. Bračko, T.E. Browder, B.C.K. Casey, M.-C. Chang, P. Chang, B.G. Cheon, R. Chistov, Y. Choi, Y.K. Choi, M. Danilov, L.Y. Dong, J. Dragic, A. Drutskoy, S. Eidelman, V. Eiges, Y. Enari, C.W. Everton, F. Fang, H. Fujii, C. Fukunaga, N. Gabyshev, A. Garmash, T. Gershon, B. Golob, R. Guo, J. Haba, T. Hara, Y. Harada, N.C. Hastings, H. Hayashii, M. Hazumi, E.M. Heenan, I. Higuchi, T. Higuchi, L. Hinz, T. Hokuue, Y. Hoshi, S.R. Hou, W.-S. Hou, S.-C. Hsu, H.-C. Huang, T. Igaki, Y. Igarashi, T. Iijima, K. Inami, A. Ishikawa, H. Ishino, R. Itoh, H. Iwasaki, Y. Iwasaki, H.K. Jang, J.H. Kang, J.S. Kang, N. Katayama, Y. Kawakami, N. Kawamura, T. Kawasaki, H. Kichimi, D.W. Kim, Heejong Kim, H.J. Kim, H.O. Kim, Hyunwoo Kim, S.K. Kim, T.H. Kim, K. Kinoshita, S. Korpar, P. Krokovny, R. Kulasiri, S. Kumar, A. Kuzmin, Y.-J. Kwon, J.S. Lange, G. Leder, S.H. Lee, J. Li, A. Limosani, D. Liventsev, R.-S. Lu, J. MacNaughton, G. Majumder, F. Mandl, D. Marlow, S. Matsumoto, T. Matsumoto, W. Mitaroff, K. Miyabayashi, Y. Miyabayashi, H. Miyake, H. Miyata, G.R. Moloney, T. Mori, T. Nagamine, Y. Nagasaka, T. Nakadaira, E. Nakano, M. Nakao, J.W. Nam, Z. Natkaniec, K. Neichi, S. Nishida, O. Nitoh, S. Noguchi, T. Nozaki, S. Ogawa, T. Ohshima, T. Okabe, S. Okuno, S.L. Olsen, Y. Onuki, W. Ostrowicz, H. Ozaki, P. Pakhlov, H. Palka, C.W. Park, H. Park, L.S. Peak, J.-P. Perroud, M. Peters, L.E. Piilonen, J.L. Rodriguez, F.J. Ronga, N. Root, M. Rozanska, K. Rybicki, H. Sagawa, S. Saitoh, Y. Sakai, M. Satapathy, A. Satpathy, O. Schneider, S. Schrenk, C. Schwanda, S. Semenov, K. Senyo, R. Seuster, M.E. Sevior, H. Shibuya, V. Sidorov, J.B. Singh, S. Stanič, M. Starič, A. Sugi, A. Sugiyama, K. Sumisawa, T. Sumiyoshi, K. Suzuki, S. Suzuki, S.Y. Suzuki, T. Takahashi, F. Takasaki, K. Tamai, N. Tamura, J. Tanaka, M. Tanaka, G.N. Taylor, Y. Teramoto, S. Tokuda, S.N. Tovey, T. Tsuboyama, T. Tsukamoto, S. Uehara, K. Ueno, Y. Unno, S. Uno, Y. Ushiroda, G. Varner, K.E. Varvell, C.C. Wang, C.H. Wang, J.G. Wang, M.-Z. Wang, Y. Watanabe, E. Won, B.D. Yabsley, Y. Yamada, A. Yamaguchi, Y. Yamashita, M. Yamauchi, H. Yanai, P. Yeh, Y. Yuan, Y. Yusa, J. Zhang, Z.P. Zhang, Y. Zheng, and D. Žontar
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,KEKB ,Pi ,B meson - Abstract
This paper describes a study of B meson decays to the pseudoscalar-vector final state \rho\pi using 31.9\times 10^6 B\bar{B} events collected with the Belle detector at KEKB. The branching fractions B(B^+ \to \rho^0\pi^+) = (8.0^{+2.3+0.7}_{-2.0-0.7}) \times 10^{-6} and B(B^0 -> \rho^{+-} \pi^{-+}) = (20.8^{+6.0+2.8}_{-6.3-3.1}) \times 10^{-6} are obtained. In addition, a 90% confidence level upper limit of B(B^0 \to \rho^0\pi^0) < 5.3 \times 10^{-6}is reported.
- Published
- 2002
50. Effect of Age on Rat Bone Solubility and Crystallinity
- Author
-
Arif Ali Baig, William I. Higuchi, A.B. Barry, and Scott C. Miller
- Subjects
Aging ,animal structures ,Endocrinology, Diabetes and Metabolism ,chemistry.chemical_element ,Calcium ,Rats, Sprague-Dawley ,Crystallinity ,chemistry.chemical_compound ,Endocrinology ,Animals ,Orthopedics and Sports Medicine ,Femur ,Solubility ,Dissolution ,Bone mineral ,Minerals ,Chemistry ,Phosphate ,Rats ,Crystallography ,Full width at half maximum ,Female ,Crystallization ,Powder diffraction ,Nuclear chemistry - Abstract
It has been shown that biominerals such as dental enamel and bone demonstrate a non-thermodynamic equilibrium state following initial dissolution where no further mineral dissolution or precipitation occurs; this state is termed metastable equilibrium solubility (MES). Furthermore, these minerals are composed of a distribution of domains each with their own MES. Recent studies have also demonstrated a linear relationship between crystallinity and the mean MES of these minerals, with solubility decreasing with increasing crystallinity. This study investigates the effect of age on the MES and crystallinity of rat bone mineral. The bone mineral samples were prepared by protein extraction with a series of hydrazine and alcohol solutions. The MES distributions of the bone mineral were measured by exposure to 0.1 M acetate buffers containing a range of calculated amounts of calcium (Ca) and phosphate for 48 h. The amount of mineral dissolved in each solution was determined from Ca and phosphate analyses of the undissolved residue. The full width of the half maximum (FWHM) of the 002 reflection of the X-ray powder diffraction was used as an indicator of crystallinity. The MES of mineral from bone of rats of different ages (1-25 months) were compared. Results of this study indicate that (l) there is a difference in the mean MES of bone mineral from rats of different ages, with older bone mineral being less soluble and more crystalline than bone mineral from younger rats; (2) the nature of the solubility distribution changes from a narrow to a broader distribution with age; and (3) all of the bone samples demonstrated an inverse-linear correlation between crystallinity and mean MES value consistent with previous results obtained with synthetic apatites and dental enamel.
- Published
- 2002
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.