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1.
Nutrients ; 16(13)2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38999833

ABSTRACT

The outcome of total hip arthroplasty (THA) in patients with end-stage arthritis of the hip is associated with preoperative physical status. This study was performed to examine the relationship between the preoperative severity of sarcopenia and clinical outcomes after THA. This retrospective cohort study was performed among 306 consecutive patients (mean age: 63.7 ± 12.9 years, 222 women) undergoing THA at a university hospital. The severity of sarcopenia was determined based on the skeletal muscle mass index (SMI), handgrip strength, and gait speed according to the criteria of the Asian Working Group for Sarcopenia 2019. The severe sarcopenia prevalence rate was 10.6%. Severe sarcopenia was significantly associated with the risk of delayed functional recovery (adjusted odds ratio, 2.82; 95% confidence interval, 1.03-7.72; p = 0.043) compared with the non-sarcopenia group after adjusting for pre-existing risk factors, including preoperative hip function and physical activity. The addition of SMI, handgrip strength, and gait speed to the model for risk of functional recovery delay significantly increased the area under the receiver operating characteristic curve (p = 0.038). Severe sarcopenia was significantly associated with poorer hip function and patient-reported outcomes at 6 months after surgery compared with the non-sarcopenia group. Severe sarcopenia was adversely associated with postoperative clinical outcomes in patients undergoing THA.


Subject(s)
Arthroplasty, Replacement, Hip , Hand Strength , Recovery of Function , Sarcopenia , Severity of Illness Index , Humans , Sarcopenia/epidemiology , Sarcopenia/complications , Arthroplasty, Replacement, Hip/adverse effects , Female , Male , Middle Aged , Retrospective Studies , Aged , Treatment Outcome , Muscle, Skeletal/physiopathology , Preoperative Period , Risk Factors , Walking Speed
2.
Auris Nasus Larynx ; 51(2): 361-364, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37838568

ABSTRACT

Ultrasound (US) imaging effectively provides real-time anatomical information for clinical examinations. In otolaryngology, US imaging can visualize laryngeal muscles as well as cervical muscles. Here we present the case where US imaging was used while injecting botulinum toxin (BT) for the treatment of abductor spasmodic dysphonia, which provided definite results. We could visualize not only the injection pathway but also the infiltration of the BT solution into the posterior cricoarytenoid muscles. Therefore, our laryngeal US imaging is useful for both improving the success rate and avoiding injection complications of BT.


Subject(s)
Botulinum Toxins, Type A , Botulinum Toxins , Dysphonia , Voice Disorders , Humans , Dysphonia/diagnostic imaging , Dysphonia/drug therapy , Botulinum Toxins/therapeutic use , Neck , Laryngeal Muscles/diagnostic imaging , Botulinum Toxins, Type A/therapeutic use , Treatment Outcome , Voice Disorders/drug therapy
3.
Nat Commun ; 14(1): 5876, 2023 Sep 21.
Article in English | MEDLINE | ID: mdl-37735573

ABSTRACT

Two-photon polymerization lithography is promising for producing three-dimensional structures with user-defined micro- and nanoscale features. Additionally, shrinkage by thermolysis can readily shorten the lattice constant of three-dimensional photonic crystals and enhance their resolution and mechanical properties; however, this technique suffers from non-uniform shrinkage owing to substrate pinning during heating. Here, we develop a simple method using poly(vinyl alcohol)-assisted uniform shrinking of three-dimensional printed structures. Microscopic three-dimensional printed objects are picked and placed onto a receiving substrate, followed by heating to induce shrinkage. We show the successful uniform heat-shrinking of three-dimensional prints with various shapes and sizes, without sacrificial support structures, and observe that the surface properties of the receiving substrate are important factors for uniform shrinking. Moreover, we print a three-dimensional mascot model that is then uniformly shrunk, producing vivid colors from colorless woodpile photonic crystals. The proposed method has significant potential for application in mechanics, optics, and photonics.

4.
ACS Macro Lett ; 12(4): 523-529, 2023 Apr 18.
Article in English | MEDLINE | ID: mdl-37015037

ABSTRACT

Triplet-triplet annihilation photon upconversion (TTA-UC) has received significant attention in energy harvesting applications such as solar cells. The realization of high upconversion (UC) performance in the form of films is a crucial factor for the incorporation of this technology into large-area devices. Herein, we propose a porous UC film prepared by an emulsification method with a poly(vinyl alcohol) (PVA) aqueous solution and a toluene solution of chromophores (rubrene/Pd-tetraphenyltetraanthraporphyrin pair) that achieved considerable UC performance in the near-infrared (NIR) (810 nm) to visible (560 nm) range with a maximum quantum yield of 3.7% (out of 50%). Notably, the films displayed a UC emission when using an NIR light-emitting diode as a low-power-density noncoherent light source, which was confirmed by the naked eye. Excitation-power-dependent time-resolved photoluminescence measurements showed almost identical triplet lifetimes of emitter species for the films and toluene solutions; however, lower threshold intensities (Ith = 1-2 W/cm2) were observed for the films than those of the solutions (Ith = ∼10 W/cm2). An evaluation of the remaining toluene in the film and UC emission behavior in liquid nitrogen suggested that the chromophores exist as an amorphous solid in the pores, thus enabling hybrid triplet energy transfer (chromophore mobility based and exciton migration) in this unique film. The presented methodology can be generalized to other wavelengths and can enable diverse applications of the TTA-UC technology.

5.
Membranes (Basel) ; 12(3)2022 Mar 10.
Article in English | MEDLINE | ID: mdl-35323789

ABSTRACT

When using the extracorporeal capillary membrane oxygenator (sample A) for ECMO treatments of COVID-19 severely ill patients, which is dominantly used in Japan and worldwide, there is a concern about the risk of SARS-CoV-2 scattering from the gas outlet port of the membrane oxygenator. Terumo has launched two types of membranes (sample A and sample B), both of which are produced by the microphase separation processes using polymethylpentene (PMP) and polypropylene (PP), respectively. However, the pore structures of these membranes and the SARS-CoV-2 permeability through the membrane wall have not been clarified. In this study, we analyzed the pore structures of these gas exchange membranes using our previous approach and verified the SARS-CoV-2 permeation through the membrane wall. Both have the unique gradient and anisotropic pore structure which gradually become denser from the inside to the outside of the membrane wall, and the inner and outer surfaces of the membrane have completely different pore structures. The pore structure of sample A is also completely different from the other membrane made by the melt-extruded stretch process. From this, the pore structure of the ECMO membrane is controlled by designing various membrane-forming processes using the appropriate materials. In sample A, water vapor permeates through the coating layer on the outer surface, but no pores that allow SARS-CoV-2 to penetrate are observed. Therefore, it is unlikely that SARS-CoV-2 permeates through the membrane wall and scatter from sample A, raising the possibility of secondary ECMO infection. These results provide new insights into the evolution of a next-generation ECMO membrane.

6.
Membranes (Basel) ; 11(7)2021 Jul 14.
Article in English | MEDLINE | ID: mdl-34357179

ABSTRACT

The objective of this study is to clarify the pore structure of ECMO membranes by using our approach and theoretically validate the risk of SARS-CoV-2 permeation. There has not been any direct evidence for SARS-CoV-2 leakage through the membrane in ECMO support for critically ill COVID-19 patients. The precise pore structure of recent membranes was elucidated by direct microscopic observation for the first time. The three types of membranes, polypropylene, polypropylene coated with thin silicone layer, and polymethylpentene (PMP), have unique pore structures, and the pore structures on the inner and outer surfaces of the membranes are completely different anisotropic structures. From these data, the partition coefficients and intramembrane diffusion coefficients of SARS-CoV-2 were quantified using the membrane transport model. Therefore, SARS-CoV-2 may permeate the membrane wall with the plasma filtration flow or wet lung. The risk of SARS-CoV-2 permeation is completely different due to each anisotropic pore structure. We theoretically demonstrate that SARS-CoV-2 is highly likely to permeate the membrane transporting from the patient's blood to the gas side, and may diffuse from the gas side outlet port of ECMO leading to the extra-circulatory spread of the SARS-CoV-2 (ECMO infection). Development of a new generation of nanoscale membrane confirmation is proposed for next-generation extracorporeal membrane oxygenator and system with long-term durability is envisaged.

7.
J Artif Organs ; 23(2): 171-179, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31691039

ABSTRACT

We examined typical commercial poly(ethersulfone) (PESf) hemodialysis and hemoconcentration membranes successfully used in manufacturing, and employed scanning probe microscope (SPM) to achieve a structural observation of the pores in the inner membrane surfaces, as well as measure the pore diameters and their distribution, verifying the relationship between the typical mass transfer properties. We focused on the differences between the PESf membranes which were expected to further improve the advanced pore structure control and functional design for various medical uses. The three-dimensional tortuous capillary pores on the inner surface of hollow fiber hemodialysis and hemoconcentrator membranes were investigated using dynamic force microscopy (DFM), and the pore diameter and distribution were measured through a line analysis. Compared with PUREMA-A, PES-Sα hemodialysis membranes have smaller three-dimensional tortuous capillary pore diameters and pore areas, as well as a smaller pore diameter distribution and pore area distribution, which make the accurate measurements of the pore diameter using FE-SEM impossible. These PESf membranes are almost the same in pure water permeability, but greatly differ in pore diameter and pore diameter distribution. By comparing and verifying as above, we may gain insight into the flexibility, versatility, and superior structural and functional controllability of PESf membrane pore structures, which could advance the development of pore structure control. Pending issues include the fact that, using a line analysis software of SPM devices, it is very difficult to measure hundred pores which clearly reflects the poor quality of pore size distributions obtained in this study, measurement accuracy must be improved further.


Subject(s)
Membranes, Artificial , Polymers/chemistry , Sulfones/chemistry , Permeability , Renal Dialysis/methods , Water
8.
ACS Appl Mater Interfaces ; 10(9): 8333-8340, 2018 Mar 07.
Article in English | MEDLINE | ID: mdl-29484891

ABSTRACT

We demonstrate the fabrication of a low-loss single-crystalline Ag nanostructure deposited on transparent substrates. Our approach is based on an epitaxial growth technique in which a NaCl(001) substrate is used. The NaCl substrate is dissolved in water to allow the Ag film to be transferred onto the desired substrates. Focused ion beam milling is subsequently employed to pattern a nanoarray structure consisting of 200 nanorods. The epitaxial Ag films with nanoarray structures grown in the study exhibited very flat and smooth surfaces having excellent crystallinity and local misorientation of less than 1°. Further, spectroscopic ellipsometry measurements indicated that the imaginary part of the dielectric constant of the single-crystalline film was smaller than that of a conventional polycrystalline film. Moreover, we used the three-dimensional finite-difference time-domain method to analyze the plasmonic properties of the nanoarray structure by considering the actual processed structure. Characteristically, when the SiO2 substrate was etched by ion beam milling to a depth of 30 nm, the spectrum showed a spectral shape 20% sharper than that of the substrate with no etching (depth: 0 nm). The plasmonic performance of the single-crystalline Ag nanostructure was largely determined by its structural precision and the dielectric properties of the metal.

9.
J Physiol Sci ; 68(4): 483-492, 2018 Jul.
Article in English | MEDLINE | ID: mdl-28667588

ABSTRACT

We investigated the cellular mechanisms and therapeutic effect of post-injury stretch on the recovery process from muscle injury induced by lengthening contractions (LC). One day after LC, a single 15-min bout of muscle stretch was applied at an intensity of 3 mNm. The maximal isometric torque was measured before and at 2-21 days after LC. The myofiber size was analyzed at 21 days after LC. Developmental myosin heavy chain-immunoreactive (dMHC-ir) cells, a marker of regenerating myofibers, were observed in the early recovery stage (2-5 days after LC). We observed that LC-induced injury markedly decreased isometric torque and myofiber size, which recovered faster in rats that underwent stretch than in rats that did not. Regenerating myofiber with dMHC-ir cells was observed earlier in rats that underwent stretch. These results indicate that post-injury stretch may facilitate the regeneration and early formation of new myofibers, thereby promoting structural and functional recovery from LC-induced muscle injury.


Subject(s)
Muscle Contraction/physiology , Muscle, Skeletal/injuries , Muscle, Skeletal/physiology , Animals , Isometric Contraction/physiology , Male , Rats , Rats, Wistar , Torque
10.
Sci Rep ; 7: 42859, 2017 02 20.
Article in English | MEDLINE | ID: mdl-28216626

ABSTRACT

A new experimental technique is developed for producing a high-performance single-crystalline Ag nanostructure on transparent and flexible amorphous substrates for use in plasmonic sensors and circuit components. This technique is based on the epitaxial growth of Ag on a (001)-oriented single-crystalline NaCl substrate, which is subsequently dissolved in ultrapure water to allow the Ag film to be transferred onto a wide range of different substrates. Focused ion beam milling is then used to create an Ag nanoarray structure consisting of 200 cuboid nanoparticles with a side length of 160 nm and sharp, precise edges. This array exhibits a strong signal and a sharp peak in plasmonic properties and Raman intensity when compared with a polycrystalline Ag nanoarray.

11.
Muscle Nerve ; 55(2): 243-253, 2017 02.
Article in English | MEDLINE | ID: mdl-27301985

ABSTRACT

INTRODUCTION: Resistance training promotes recovery from muscle atrophy, but optimum training programs have not been established. We aimed to determine the optimum training intensity for muscle atrophy. METHODS: Mice recovering from atrophied muscles after 2 weeks of tail suspension underwent repeated isometric training with varying joint torques 50 times per day. RESULTS: Muscle recovery assessed by maximal isometric contraction and myofiber cross-sectional areas (CSAs) were facilitated at 40% and 60% maximum contraction strength (MC), but at not at 10% and 90% MC. At 60% and 90% MC, damaged and contained smaller diameter fibers were observed. Activation of myogenic satellite cells and a marked increase in myonuclei were observed at 40%, 60%, and 90% MC. CONCLUSIONS: The increases in myofiber CSAs were likely caused by increased myonuclei formed through fusion of resistance-induced myofibers with myogenic satellite cells. These data indicate that resistance training without muscle damage facilitates efficient recovery from atrophy. Muscle Nerve 55: 243-253, 2017.


Subject(s)
Muscle, Skeletal/physiology , Muscular Atrophy/rehabilitation , Recovery of Function/physiology , Resistance Training/methods , Analysis of Variance , Electric Stimulation , Female , Hindlimb Suspension , Histocompatibility Antigens Class I/metabolism , Humans , Isometric Contraction , Male , Muscular Atrophy/physiopathology , MyoD Protein/metabolism , Myogenin/metabolism , PAX7 Transcription Factor/metabolism
12.
Pharmacol Rep ; 68(6): 1358-1365, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27710865

ABSTRACT

BACKGROUND: Besides their anti-inflammatory properties, corticosteroid drugs exert anti-allergic effects. Exocytosis of mast cells is electrophysiologically detected as the increase in the whole-cell membrane capacitance (Cm). Therefore, the lack of such increase after exposure to the drugs suggests their mast cell-stabilizing effects. METHODS: We examined the effects of 1, 10, 100 and 200µM hydrocortisone or dexamethasone on the degranulation from rat peritoneal mast cells. Employing the whole-cell patch-clamp recording technique, we also tested their effects on the Cm during exocytosis. RESULTS: At relatively lower concentrations (1, 10µM), both hydrocortisone and dexamethasone did not significantly affect the degranulation from mast cells and the increase in the Cm induced by GTP-γ-S. Nevertheless, at higher doses (100, 200µM), these drugs inhibited the degranulation from mast cells and markedly suppressed the GTP-γ-S-induced increase in the Cm. CONCLUSIONS: Our results provided electrophysiological evidence for the first time that corticosteroid drugs, such as hydrocortisone and dexamethasone, inhibited the exocytotic process of mast cells in a dose-dependent manner. The mast cell-stabilizing effects of these drugs may be attributable to their "non-genomic" action, by which they exert rapid anti-allergic effects.


Subject(s)
Cell Degranulation/drug effects , Dexamethasone/pharmacology , Hydrocortisone/pharmacology , Mast Cells/drug effects , Peritoneum/drug effects , Animals , Anti-Inflammatory Agents/pharmacology , Cell Degranulation/physiology , Dose-Response Relationship, Drug , Glucocorticoids/pharmacology , Male , Mast Cells/physiology , Peritoneum/physiology , Rats , Rats, Wistar
13.
Chemotherapy ; 61(6): 295-303, 2016.
Article in English | MEDLINE | ID: mdl-27088971

ABSTRACT

BACKGROUND: Macrolides, such as clarithromycin, have antiallergic properties. Since exocytosis in mast cells is detected electrophysiologically via changes in membrane capacitance (Cm), the absence of such changes due to the drug indicates its mast cell-stabilizing effect. METHODS: Employing the whole-cell patch clamp technique in rat peritoneal mast cells, we examined the effects of clarithromycin on Cm during exocytosis. Using a water-soluble fluorescent dye, we also examined its effect on deformation of the plasma membrane. RESULTS: Clarithromycin (10 and 100 µM) significantly inhibited degranulation from mast cells and almost totally suppressed the GTP-x03B3;-S-induced increase in Cm. It washed out the trapping of the dye on the surface of mast cells. CONCLUSIONS: This study provides for the first time electrophysiological evidence that clarithromycin dose-dependently inhibits the process of exocytosis. The mast cell-stabilizing action of clarithromycin may be attributable to its counteractive effect on plasma membrane deformation induced by exocytosis.


Subject(s)
Clarithromycin/pharmacology , Exocytosis/drug effects , Mast Cells/drug effects , Animals , Fluorescent Dyes/chemistry , Male , Mast Cells/cytology , Mast Cells/physiology , Microscopy, Confocal , Patch-Clamp Techniques , Peritoneum/cytology , Rats , Rats, Wistar
14.
Physiol Rep ; 2(11)2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25413330

ABSTRACT

Exercise involving lengthening contraction (LC) often results in delayed myofiber damage and functional deficits over the ensuing days. The present study examined whether the stretch speed of LC is a determinant of damage severity. Under isoflurane anesthesia, LC was repeatedly induced in rat ankle extensor muscles at different stretch speeds (angular velocities of 50, 100, 200, and 400 deg/sec) over a fixed stretch range of motion (90°). The number of muscle fibers labeled with Evans blue dye, a marker of muscle fiber damage associated with increased membrane permeability, increased with the angular velocity of LC (by 20% of all myofibers at 400 deg/sec). Muscle fibers with cross-sectional areas in the range of 3600-4800 µm(2), corresponding to type IIb fiber size, exhibited the most severe damage as revealed by the largest decrease in the number of fibers 3 days after LC at 200 deg/sec, suggesting that muscle damage occurred preferentially in type IIb myofibers. Isometric torque of dorsiflexion measured 2 days after LC decreased progressively with LC angular velocity (by 68% reduction at 400 deg/sec). The angular velocity of muscle stretch during LC is thus a critical determinant of the degree of damage, and LC appears to damage type IIb fibers preferentially, resulting in a disproportionate reduction in isometric torque. This LC response is an important consideration for the design of physical conditioning and rehabilitation regimens.

15.
Physiol Rep ; 2(11)2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25367692

ABSTRACT

Determining the cellular and molecular recovery processes in inactivity - or unloading -induced atrophied muscles should improve rehabilitation strategies. We assessed the effects of stand-up exercise (SE) training on the recovery of atrophied skeletal muscles in male mice. Mice were trained to stand up and press an elevated lever in response to a light-tone cue preceding an electric foot shock and then subjected to tail suspension (TS) for 2 weeks to induce disuse atrophy in hind limb muscles. After release from TS, mice were divided into SE-trained (SE cues: 25 times per set, two sets per day) and non-SE-trained groups. Seven days after the training, average myofiber cross-sectional area (CSA) of the soleus muscle was significantly greater in the SE-trained group than in the non-SE-trained group (1843 ± 194 µm(2) vs. 1315 ± 153 µm(2)). Mean soleus muscle CSA in the SE trained group was not different from that in the CON group subjected to neither TS nor SE training (2005 ± 196 µm(2)), indicating that SE training caused nearly complete recovery from muscle atrophy. The number of myonuclei per myofiber was increased by ~60% in the SE-trained group compared with the non-SE-trained and CON groups (0.92 ± 0.03 vs. 0.57 ± 0.03 and 0.56 ± 0.11, respectively). The number of proliferating myonuclei, identified by 5-ethynyl-2'-deoxyuridine staining, increased within the first few days of SE training. Thus, it is highly likely that myogenic satellite cells proliferated rapidly in atrophied muscles in response to SE training and fused with existing myofibers to reestablish muscle mass.

16.
Biol Pharm Bull ; 30(2): 371-4, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17268083

ABSTRACT

Bisphenol A (BpA) is widely used in industry and dentistry. Its effects on the embryonic development of Xenopus laevis were investigated. Xenopus embryos at stage 10.5 were treated with BpA. Developmental abnormalities were observed at stage 35; malformation of the head region including eyes and scoliosis. The expression of several markers of embryonic development was investigated by reverse transcription-polymerase chain reaction (RT-PCR). The pan-neural marker SOX-2, the neural stem cell marker nrp-1, the mesodermal marker MyoD, and the endodermal marker sox17alpha, were used. Although the expression of marker genes was not changed by treatment with BpA, that of Pax-6, a key regulator of the morphogenesis of the eyes, was decreased by BpA. Pax-6 is a downstream factor of Notch signaling. So, the expression of a typical Notch-dependent factor, ESR-1, was investigated in the presence of BpA. The expression of ESR-1 was efficiently suppressed by BpA. In whole mount in situ hybridization (WISH), Pax-6 was expressed in the central nervous system and eyes. The expression was lost completely on treatment with BpA. The expression of ESR-1 in the central nervous system and eyes also disappeared with BpA treatment. Injection of the intracellular domain of Notch efficiently recovered ESR-1 expression in the presence of BpA although injection of a ligand for notch, Delta, did not. These results suggest that BpA decreased the expression of ESR-1 by disrupting the Notch signal.


Subject(s)
Head/abnormalities , Phenols/pharmacology , Teratogens/pharmacology , Xenopus laevis/abnormalities , Animals , Benzhydryl Compounds , Embryo, Nonmammalian/drug effects , Eye Proteins/genetics , Gene Expression/drug effects , Homeodomain Proteins/genetics , Intracellular Signaling Peptides and Proteins , Membrane Proteins/metabolism , Metamorphosis, Biological/drug effects , PAX6 Transcription Factor , Paired Box Transcription Factors/genetics , RNA, Messenger/metabolism , Receptors, Notch/metabolism , Repressor Proteins/genetics , Xenopus Proteins/genetics
17.
Life Sci ; 79(3): 247-51, 2006 Jun 13.
Article in English | MEDLINE | ID: mdl-16483612

ABSTRACT

NADPH-P450 reductase (NPR) was purified from hepatic microsomes of Xenopus laevis. The electron transfer activity of purified NPR was 23.8 units/min/mg with horse cytochrome c. The aminopyrine demethylation activity of rat CYP2B1 with Xenopus NPR was 58.1 nmol/min/nmol. The corresponding cDNA was isolated from Xenopus liver. The homology in amino acid sequence deduced from NPR cDNA isolated from Xenopus liver was 80%, 78%, and 81% with human, rat, and rabbit NPR, respectively. Antibody against Xenopus NPR was prepared. The expression of NPR was investigated in various tissues and in early development by Western blotting. NPR was most abundantly expressed in the kidney, followed by the liver, lung, and heart. The brain had very low levels of NPR. The level of NPR protein was almost the same at all stages, 2-cell stage (st. 2), blastula (st. 8), gastrula (st. 12), tail bud (st. 26) and larva (st.35), examined in this study. We further investigated the distribution of NPR using whole-mount in situ hybridization. NPR mRNA was expressed in cement gland, lens placode, ear vesicle, mesencephalon, rhombencephalon, lymphatic vessel, and heart anlage in the embryo at stage 29. Xenopus NPR has similar properties to mouse and rat NPRs. Localization of NPR in Xenopus embryo was consistent with the abnormal region caused by NPR deficiency in mice.


Subject(s)
NADPH-Ferrihemoprotein Reductase/chemistry , NADPH-Ferrihemoprotein Reductase/metabolism , Xenopus Proteins/chemistry , Xenopus Proteins/metabolism , Xenopus laevis/embryology , Animals , Antibodies/immunology , Catalysis , Embryo, Nonmammalian/enzymology , Horses , Humans , In Situ Hybridization , Mice , Microsomes, Liver/enzymology , NADPH-Ferrihemoprotein Reductase/isolation & purification , RNA, Messenger/analysis , RNA, Messenger/metabolism , Rats , Tissue Distribution , Xenopus Proteins/isolation & purification
19.
J Med Chem ; 45(11): 2150-9, 2002 May 23.
Article in English | MEDLINE | ID: mdl-12014953

ABSTRACT

Beta-adrenergic receptor kinase 1 (betaARK1) and cyclic adenosine 5'-monophosphate-dependent protein kinase A (PKA) have structurally similar adenine-binding pockets but have different physiologic functions. To obtain specific betaARK1 inhibitors, a two step rational drug design process was used. First, a search was conducted on three-dimensional models of commercially available compounds to find compounds that fit the adenine-binding pocket of betaARK1. Second, a comparative docking study that focused on the differences between the adenine-binding pockets of the two enzymes was used to evaluate the binding specificity of each compound that inhibited betaARK1 activity. The results of these analyses yielded three betaARK1-selective inhibitor leads from 11 candidates, a hit rate for selectivity of 27%. Although the IC50 values of these compounds for betaARK1 ranged from only 1.3 x 10(-4) M to 5.6 x 10(-4) M, the compounds did not inhibit PKA at concentrations up to 1.0 x 10(-3) M. Thus, the present study shows the usefulness of a rational drug design strategy in finding specific kinase inhibitors for proteins with similar drug target binding sites.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Enzyme Inhibitors/chemistry , Binding Sites , Cyclic AMP-Dependent Protein Kinases/chemistry , Databases, Factual , Drug Design , Models, Molecular , Protein Conformation , Structure-Activity Relationship , beta-Adrenergic Receptor Kinases
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