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1.
Sensors (Basel) ; 21(5)2021 Mar 07.
Article in English | MEDLINE | ID: mdl-33799942

ABSTRACT

High intraocular pressure (IOP) is one of the major risk factors for glaucoma, and thus accurate IOP measurements should be performed to diagnose and treat glaucoma early. In this study, a novel technique for measuring the IOP based on acoustic radiation force was proposed, and its potential was experimentally demonstrated. The proposed technique uses the acoustic radiation force to generate axial displacement on the ocular surface while simultaneously measuring the degree of deformation. In order to verify that the ocular displacement induced by the acoustic radiation force is related to the IOP, the experiment was conducted by fabricating a 5 MHz single element transducer and gelatin phantoms with different stiffness values. Our experimental results show that there is a close relationship between the ocular displacement by the acoustic radiation force and the IOP obtained by a commercial tonometer. Therefore, the proposed acoustic radiation force technique can be a promising candidate for measuring the IOP.

2.
Sensors (Basel) ; 20(14)2020 Jul 14.
Article in English | MEDLINE | ID: mdl-32674455

ABSTRACT

In ultrasound tissue harmonic imaging (THI), it is preferred that the bandwidth of the array transducer covers at least the fundamental frequency f0 for transmission and the second harmonic frequency 2f0 for reception. However, it is challenging to develop an array transducer with a broad bandwidth due to the single resonance characteristics of piezoelectric materials. In this study, we present an improved interleaved array transducer suitable for THI and a dedicated transducer fabrication scheme. The proposed array transducer has a novel structure in which conventional elements exhibiting f0 resonant frequency and polarization-inverted elements exhibiting 2f0 resonant frequency are alternately located, and the thicknesses of all piezoelectric elements are identical. The performance of the proposed method was demonstrated by finite element analysis (FEA) simulations and experiments using a fabricated prototype array transducer. Using the proposed technique, f0 and 2f0 frequency ultrasounds can be efficiently transmitted and received, respectively, resulting in a 90% broad bandwidth feature of the transducer. Thus, the proposed technique can be one of the potential ways to implement high resolution THI.


Subject(s)
Transducers , Ultrasonography , Equipment Design , Finite Element Analysis , Humans
3.
Eur Radiol ; 29(4): 1978-1985, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30350161

ABSTRACT

PURPOSE: To evaluate the diagnostic performance and reproducibility of a computer-aided diagnosis (CAD) system for thyroid cancer diagnosis using ultrasonography (US) based on the operator's experience. MATERIALS AND METHODS: Between July 2016 and October 2016, 76 consecutive patients with 100 thyroid nodules (≥ 1.0 cm) were prospectively included. An experienced radiologist performed the US examinations with a real-time CAD system integrated into the US machine, and three operators with different levels of US experience (0-5 years) independently applied the CAD system. We compared the diagnostic performance of the CAD system based on the operators' experience and calculated the interobserver agreement for cancer diagnosis and in terms of each US descriptor. RESULTS: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the CAD system were 88.6, 83.9, 81.3, 90.4, and 86.0%, respectively. The sensitivity and accuracy of the CAD system were not significantly different from those of the radiologist (p > 0.05), while the specificity was higher for the experienced radiologist (p = 0.016). For the less-experienced operators, the sensitivity was 68.8-73.8%, specificity 74.1-88.5%, PPV 68.9-73.3%, NPV 72.7-80.0%, and accuracy 71.0-75.0%. The less-experienced operators showed lower sensitivity and accuracy than those for the experienced radiologist. The interobserver agreement was substantial for the final diagnosis and each US descriptor, and moderate for the margin and composition. CONCLUSIONS: The CAD system may have a potential role in the thyroid cancer diagnosis. However, operator dependency still remains and needs improvement. KEY POINTS: • The sensitivity and accuracy of the CAD system did not differ significantly from those of the experienced radiologist (88.6% vs. 84.1%, p = 0.687; 86.0% vs. 91.0%, p = 0.267) while the specificity was significantly higher for the experienced radiologist (83.9% vs. 96.4%, p = 0.016). • However, the diagnostic performance varied according to the operator's experience (sensitivity 70.5-88.6%, accuracy 72.0-86.0%) and they were lower for the less-experienced operators than for the experienced radiologist. • The interobserver agreement was substantial for the final diagnosis and each US descriptor and moderate for the margin and composition.


Subject(s)
Thyroid Nodule/diagnostic imaging , Adolescent , Adult , Aged , Computer Systems , Diagnosis, Computer-Assisted/standards , Female , Humans , Male , Margins of Excision , Middle Aged , Observer Variation , Physical Examination/standards , Prospective Studies , Radiologists/standards , Reproducibility of Results , Sensitivity and Specificity , Thyroid Neoplasms/diagnostic imaging , Ultrasonography
4.
BMC Plant Biol ; 15: 110, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25929516

ABSTRACT

BACKGROUND: Sugar plays a central role as a source of carbon metabolism and energy production and a signaling molecule in diverse growth and developmental processes and environmental adaptation in plants. It is known that sugar metabolism and allocation between different physiological functions is intimately associated with flowering transition in many plant species. The INDETERMINATE DOMAIN (IDD)-containing transcription factor IDD8 regulates flowering time by modulating sugar metabolism and transport under sugar-limiting conditions in Arabidopsis. Meanwhile, it has been reported that SUCROSE NONFERMENTING-1-RELATED PROTEIN KINASE 1 (SnRK1), which acts as a sensor of cellular energy metabolism, is activated by sugar deprivation. Notably, SnRK1-overexpressing plants and IDD8-deficient mutants exhibit similar phenotypes, including delayed flowering, suggesting that SnRK1 is involved in the IDD8-mediated metabolic control of flowering. RESULTS: We examined whether the sugar deprivation-sensing SnRK1 is functionally associated with IDD8 in flowering time control through biochemical and molecular genetic approaches. Overproduction of AKIN10, the catalytic subunit of SnRK1, delayed flowering in Arabidopsis, as was observed in IDD8-deficient idd8-3 mutant. We found that AKIN10 interacts with IDD8 in the nucleus. Consequently, AKIN10 phosphorylates IDD8 primarily at two serine (Ser) residues, Ser-178 and Ser-182, which reside in the fourth zinc finger (ZF) domain that mediates DNA binding and protein-protein interactions. AKIN10-mediated phosphorylation did not affect the subcellular localization and DNA-binding property of IDD8. Instead, the transcriptional activation activity of the phosphorylated IDD8 was significantly reduced. Together, these observations indicate that AKIN10 antagonizes the IDD8 function in flowering time control, a notion that is consistent with the delayed flowering phenotypes of AKIN10-overexpressing plants and idd8-3 mutant. CONCLUSION: Our data show that SnRK1 and its substrate IDD8 constitute a sugar metabolic pathway that mediates the timing of flowering under sugar deprivation conditions. In this signaling scheme, the SnRK1 signals are directly integrated into the IDD8-mediated gene regulatory network that governs flowering transition in response to fluctuations in sugar metabolism, further supporting the metabolic control of flowering.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Flowers , Protein Serine-Threonine Kinases/metabolism , Transcription Factors/metabolism , Arabidopsis/physiology , Arabidopsis Proteins/genetics , Cell Nucleus/metabolism , Phosphorylation , Protein Binding , Protein Serine-Threonine Kinases/genetics , Subcellular Fractions/metabolism , Transcriptional Activation
5.
J Pharmacol Sci ; 127(1): 117-26, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25704027

ABSTRACT

Cisplatin is a chemotherapeutic drug but induces acute kidney injury (AKI). Cisplatin-induced AKI depends on several signaling pathways leading to apoptosis in tubular epithelial cells. Glutamine is a substrate for the synthesis of glutathione, the most abundant intracellular thiol and antioxidant, and plays an important role in protecting cells from apoptosis induced by different stimuli. In the present study, we investigated the protective effect of glutamine on cisplatin-induced AKI. Rats were divided into control, glutamine, cisplatin, and cisplatin plus glutamine groups. Glutamine ameliorated renal dysfunction, tissue injury, and cisplatin-induced apoptosis. Cisplatin increased cell death, caspase-3 cleavage, activation of MAPKs and p53, oxidative stress, and mRNA expression of TNF-α and TNFR1 in HK-2 cells. Glutamine treatment reduced cisplatin-induced these changes in HK-2 cells. Notably, glutamine reduced the cisplatin-induced expression of organic cation transporter 2 (OCT2) and cisplatin accumulation. Our results suggest that the protective effect of glutamine on cisplatin is specific for proximal tubular cells and the initial effects may be related to attenuation of cisplatin uptake. Thus, glutamine administration might represent a new strategy for the treatment of cisplatin-induced AKI.


Subject(s)
Acute Kidney Injury/prevention & control , Cisplatin/metabolism , Glutamine/pharmacology , Acute Kidney Injury/chemically induced , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Animals , Apoptosis/drug effects , Caspase 3/metabolism , Cell Death/drug effects , Cell Line , Cisplatin/adverse effects , Glutathione/metabolism , Humans , Kidney Tubules/drug effects , Kidney Tubules/pathology , Male , Organic Cation Transport Proteins/biosynthesis , Organic Cation Transporter 2 , Oxidative Stress/drug effects , Rats , Receptors, Tumor Necrosis Factor, Type I/biosynthesis , Tumor Necrosis Factor-alpha/biosynthesis
6.
Antioxidants (Basel) ; 13(9)2024 Sep 14.
Article in English | MEDLINE | ID: mdl-39334769

ABSTRACT

Oxidative stress caused by reactive oxygen species (ROS) is one of the major causes of senescence. Strategies to reduce ROS are known to be important factors in reversing senescence, but effective strategies have not been found. In this study, we screened substances commonly used as cosmetic additives to find substances with antioxidant effects. Polygonum cuspidatum (P. cuspidatum) extract significantly reduced ROS levels in senescent cells. A novel mechanism was discovered in which P. cuspidatum extract reduced ROS, a byproduct of inefficient oxidative phosphorylation (OXPHOS), by increasing OXPHOS efficiency. The reduction in ROS by P. cuspidatum extract restored senescence-associated phenotypes and enhanced skin protection. Then, we identified polydatin as the active ingredient of P. cuspidatum extract that exhibited antioxidant effects. Polydatin, which contains stilbenoid polyphenols that act as singlet oxygen scavengers through redox reactions, increased OXPHOS efficiency and subsequently restored senescence-associated phenotypes. In summary, our data confirmed the effects of P. cuspidatum extract on senescence rejuvenation and skin protection through ROS reduction. This novel finding may be used as a treatment in senescence rejuvenation in clinical and cosmetic fields.

7.
Biosens Bioelectron ; 258: 116328, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38692223

ABSTRACT

Implantable bioelectronics, integrated directly within the body, represent a potent biomedical solution for monitoring and treating a range of medical conditions, including chronic diseases, neural disorders, and cardiac conditions, through personalized medical interventions. Nevertheless, contemporary implantable bioelectronics rely heavily on rigid materials (e.g., inorganic materials and metals), leading to inflammatory responses and tissue damage due to a mechanical mismatch with biological tissues. Recently, soft electronics with mechanical properties comparable to those of biological tissues have been introduced to alleviate fatal immune responses and improve tissue conformity. Despite their myriad advantages, substantial challenges persist in surgical handling and precise positioning due to their high compliance. To surmount these obstacles, softening implantable bioelectronics has garnered significant attention as it embraces the benefits of both rigid and soft bioelectronics. These devices are rigid for easy standalone implantation, transitioning to a soft state in vivo in response to environmental stimuli, which effectively overcomes functional/biological problems inherent in the static mechanical properties of conventional implants. This article reviews recent research and development in softening materials and designs for implantable bioelectronics. Examples featuring tissue-penetrating and conformal softening devices highlight the promising potential of these approaches in biomedical applications. A concluding section delves into current challenges and outlines future directions for softening implantable device technologies, underscoring their pivotal role in propelling the evolution of next-generation bioelectronics.


Subject(s)
Biocompatible Materials , Biosensing Techniques , Prostheses and Implants , Humans , Biosensing Techniques/instrumentation , Biocompatible Materials/chemistry , Equipment Design , Animals
8.
Plant J ; 72(1): 162-72, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22672153

ABSTRACT

Transcription factors are central constituents of gene regulatory networks that control diverse aspects of plant development and environmental adaptability. Therefore they have been explored for decades as primary targets for agricultural biotechnology. A gene of interest can readily be introduced into many crop plants, whereas targeted gene inactivation is practically difficult in many cases. Here, we developed an artificial small interfering peptide (a-siPEP) approach, which is based on overexpression of specific protein domains, and evaluated its application for the targeted inactivation of transcription factors in the dicot model, Arabidopsis, and monocot model, Brachypodium. We designed potential a-siPEPs of two representative MADS box transcription factors, SUPPRESSOR OF OVEREXPRESSOR OF CONSTANS 1 (SOC1) and AGAMOUS (AG), and a MYB transcription factor, LATE ELONGATED HYPOCOTYL (LHY). Transgenic plants overproducing the a-siPEPs displayed phenotypes comparable to those of gene-deficient mutants. The a-siPEPs attenuate nuclear import and DNA-binding of target transcription factors. Our data demonstrate that the a-siPEP tool is an efficient genetic means of inactivating specific transcription factors in plants.


Subject(s)
Arabidopsis/genetics , Brachypodium/genetics , Peptides/genetics , Transcription Factors/genetics , AGAMOUS Protein, Arabidopsis/metabolism , Active Transport, Cell Nucleus , Arabidopsis/growth & development , Arabidopsis/metabolism , Arabidopsis/ultrastructure , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Biotechnology , Brachypodium/growth & development , Brachypodium/metabolism , Brachypodium/ultrastructure , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Flowers/genetics , Flowers/growth & development , Flowers/metabolism , Gene Expression , MADS Domain Proteins/genetics , MADS Domain Proteins/metabolism , Models, Molecular , Peptides/metabolism , Phenotype , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified , Protein Multimerization , Protoplasts , Transcription Factors/metabolism , Two-Hybrid System Techniques
9.
J Cell Physiol ; 227(3): 1157-67, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21567405

ABSTRACT

Clusterin (CLU), a glycoprotein, is involved in apoptosis, producing two alternatively spliced isoforms in various cell types. The pro-apoptotic CLU appears to be a nuclear isoform (nuclear clusterin; nCLU), and the secretory CLU (sCLU) is thought to be anti-apoptotic. The detailed molecular mechanism of nCLU as a pro-apoptotic molecule has not yet been clear. In the current study, overexpressed nCLU induced apoptosis in human kidney cells. Biochemical studies revealed that nCLU sequestered Bcl-XL via a putative BH3 motif in the C-terminal coiled coil (CC2) domain, releasing Bax, and promoted apoptosis accompanied by activation of caspase-3 and cytochrome c release. These results suggest a novel mechanism of apoptosis mediated by nCLU as a pro-apoptotic molecule.


Subject(s)
Apoptosis , Cell Survival , Clusterin/physiology , bcl-X Protein/metabolism , Amino Acid Motifs/genetics , Amino Acid Sequence , Apoptosis/genetics , Cell Line, Tumor , Cell Survival/genetics , Clusterin/chemistry , Clusterin/genetics , HEK293 Cells , Humans , Keratinocytes/cytology , Keratinocytes/physiology , Male , Molecular Sequence Data , Prostatic Neoplasms , Protein Interaction Domains and Motifs/genetics , Protein Structure, Tertiary/physiology , bcl-X Protein/chemistry , bcl-X Protein/genetics
10.
Article in English | MEDLINE | ID: mdl-34464259

ABSTRACT

Ultrasound transducer with polarization inversion technique (PIT) can provide dual-frequency feature for tissue harmonic imaging (THI) and frequency compound imaging (FCI). However, in the conventional PIT, the ultrasound intensity is reduced due to the multiple resonance characteristics of the combined piezoelectric element, and it is challenging to handle the thin piezoelectric layer required to make a PIT-based acoustic stack. In this study, an improved PIT using a piezo-composite layer was proposed to compensate for those problems simultaneously. The novel PIT-based acoustic stack also consists of two piezoelectric layers with opposite poling directions, in which the piezo-composite layer is located on the front side and the bulk-type piezoelectric layer is located on the back side. The thickness ratio between two piezoelectric layers is 0.5:0.5, but unlike a typical PIT model, it can generate dual-frequency spectrum. A finite element analysis (FEA) simulation was conducted, and subsequently, the prototype transducer was fabricated for performance demonstration. In the simulation and experiment, the intensity was increased by 56.76% and 30.88% compared to the conventional PIT model with the thickness ratio of 0.3:0.7. Thus, the proposed PIT-based transducer is expected to be useful in implementation of THI and FCI.


Subject(s)
Acoustics , Transducers , Equipment Design , Finite Element Analysis , Ultrasonography
11.
J Nanosci Nanotechnol ; 10(1): 227-32, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20352838

ABSTRACT

Side chain alkylation of toluene with methanol was studied over mesoporous zeolite supported MgO catalysts. MgO were supported onto the carbon templated mesoporous silicalite-1 by direct synthesis route under microwave conditions. This direct synthesis route yields the majority of MgO highly dispersed into the mesopores of the silicalite-1 crystals. The vapor phase alkylation of toluene with methanol was performed over these catalysts under vapor phase conditions at atmospheric pressure. Mesoporous silicalite-1 supported MgO catalysts gave improved yields towards side chain alkylated products compared to the bulk MgO. The higher activity exhibited by 5% MgO supported on mesoporous silicalite compared to the one with 1% MgO can be attributed to the large number of weak basic sites observed from the CO2 TPD.


Subject(s)
Magnesium Oxide/chemistry , Methanol/chemistry , Toluene/chemistry , Zeolites/chemistry , Alkylation , Benzene Derivatives/chemical synthesis , Nanoparticles , Nitrogen , Particle Size , Porosity , Spectrum Analysis, Raman , Styrene/chemical synthesis , X-Ray Diffraction
12.
IEEE Trans Biomed Eng ; 67(12): 3380-3391, 2020 12.
Article in English | MEDLINE | ID: mdl-32286955

ABSTRACT

Intravascular ultrasound (IVUS) tissue harmonic imaging (THI) is a useful vessel imaging technique that can provide deep penetration depth as well as high spatial and contrast resolution. Typically, a high-frequency IVUS transducer for THI requires a broad bandwidth or dual-frequency bandwidth. However, it is very difficult to make an IVUS transducer with a frequency bandwidth covering from the fundamental frequency to the second harmonic or a dual-peak at the desired frequency. To solve this problem, in this study, we applied the polarization inversion technique (PIT) to the IVUS transducer for THI. The PIT makes it relatively easy to design IVUS transducers with suitable frequency characteristics for THI depending on the inversion ratio of the piezoelectric layer and specifications of the passive materials. In this study, two types of IVUS transducers based on the PIT were developed for THI. One is a front-side inversion layer (FSIL) transducer with a broad bandwidth, and the other is a back-side inversion layer (BSIL) transducer with a dual-frequency bandwidth. These transducers were designed using finite element analysis (FEA)-based simulation, and the prototype transducers were fabricated. Subsequently, the performance was evaluated by not only electrical impedance and pulse-echo response tests but also B-mode imaging tests with a 25 µm tungsten wire and tissue-mimicking gelatin phantoms. The FEA simulation and experimental results show that the proposed scheme can successfully implement the tissue harmonic IVUS image, and thus it can be one of the promising techniques for developing IVUS transducers for THI.


Subject(s)
Transducers , Ultrasonography, Interventional , Equipment Design , Phantoms, Imaging , Ultrasonography
13.
Article in English | MEDLINE | ID: mdl-31689189

ABSTRACT

In this study, a phase-canceled backing layer for ultrasound linear array transducer is presented. The proposed backing layer is composed of multiple blocks operated by a phase inversion technique. Inside the proposed backing layer, the phase of the reflected signals can be canceled by adjusting acoustic impedance, piezoelectric layer contact area, and thickness of each block constituting the backing layer. Therefore, the total thickness of the backing layer can be significantly reduced while maintaining the performance. Using finite element analysis (FEA) simulation, its performance was verified based on an 8-MHz linear array transducer. Two types of bulk-type backing layers with different thicknesses were also simulated to compare the performance of the proposed method. In the case of a narrow bandwidth signal without the matching layers, the 10-mm-thick bulk-type backing layer yielded a -6-dB bandwidth of 37.2%. When its thickness was reduced to 2 mm, the -6-dB bandwidth was decreased to 17.3% due to the reflected back-wall signals. However, the -6-dB bandwidth of the proposed backing layer with 2-mm thickness was 39.5%, which is similar to the thick bulk-type backing layer. In the case of broad bandwidth signal with the matching layers, the proposed transducer also exhibits similar performance compared with the thick bulk-type backing layer. The narrow bandwidth signal was experimentally implemented by using a prototype array transducer with the proposed technique, and the performance was similar to the simulation. Thus, the proposed method can reduce the thickness of the backing layer of various array transducers.

14.
J Food Prot ; 72(8): 1686-91, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19722401

ABSTRACT

The acaricidal activities of major constituents from the oil of Juniperus chinensis (var. globosa) leaves were compared with those of DEET (N,N-diethyl-m-toluamide) by using impregnated fabric disk bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae. Toxicity varied with doses as well as chemical composition. The 50% lethal doses (LD50) of J. chinensis oil against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and T. putrescentiae were 21.60, 19.89, and 38.10 microg/cm2, respectively. The active constituent was purified using silica gel chromatography and high-performance liquid chromatography. The acaricidal component was identified as bomyl acetate through gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C-NMR, 1H-13C shift correlation spectrum-NMR, and distortionless enhancement by polarization transfer-NMR. The LD50 of bornyl acetate (2.94 microg/cm2) against D. farinae was significantly lower than those of DEET (37.13 microg/cm2) and alpha-eudesmol (29.72 microg/cm2). Similar results were observed when bomyl acetate and alpha-eudesmol were tested against D. pteronyssinus and T. putrescentiae. The lower LD50 of bornyl acetate indicates that it may be responsible for the major acaricidal activity against house dust and stored food mites, even though it constitutes only 19.5% of J. chinensis oil. Overall, these findings indicated that bornyl acetate and c-eudesmol have potential for use as control agents against house dust and stored food mites.


Subject(s)
Acaridae/drug effects , Food Preservation/methods , Juniperus/chemistry , Oils, Volatile/pharmacology , Pyroglyphidae/drug effects , Acaridae/growth & development , Animals , Biological Assay , DEET/pharmacology , Dose-Response Relationship, Drug , Insecticides , Pest Control, Biological , Plant Leaves/chemistry , Pyroglyphidae/growth & development , Species Specificity
15.
Pest Manag Sci ; 65(3): 327-31, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19051215

ABSTRACT

BACKGROUND: Various attempts to control the populations of house-dust and stored-food mites have been implemented using synthetic chemicals. Although effective, the repeated use of these chemicals has led to resistance owing to the mite's high reproductive potential and short life cycle. Therefore, this study aimed to develop natural acaricides using oils derived from Leptospermum scoparium JR & G Forst., which may affect the overall biological activity of a mite without adverse effects. Results were compared with those from using benzyl benzoate and N,N-diethyl-3-methylbenzamide (DEET). RESULTS: The LD(50) values of L. scoparium oil were 0.54, 0.67 and 1.12 microg cm(-2) against Dermatophagoides farinae (Hughes), D. pteronyssinus (Troussart) and Tyrophagus putrescentiae (Schrank) respectively. The active constituent isolated from L. scoparium was identified as leptospermone (6-isovaleryl-2,2,4,4-tetramethyl-1,3,5-cyclohexanetrione) by spectroscopic analysis. Based on the LD(50) values of leptospermone and its derivatives, the most toxic compound against D. farinae was leptospermone (0.07 microg cm(-2)), followed by 2,2,4,4,6,6-hexamethyl-1,3,5-cyclohexanetrione (1.21 microg cm(-2)), benzyl benzoate (10.03 microg cm(-2)) and DEET (37.12 microg cm(-2)). Furthermore, similar results were observed when the leptospermone and its derivatives were tested against D. pteronyssinus and T. putrescentiae. CONCLUSIONS: These results indicate that L. scoparium oil-derived materials, particularly leptospermone and 2,2,4,4,6,6-hexamethyl-1,3,5-cyclohexanetrione, have potential for development as new agents for the control of three species of mite.


Subject(s)
Insecticides/pharmacology , Leptospermum/chemistry , Mites/drug effects , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Animals , Insecticides/chemistry , Oils, Volatile/chemistry , Phloroglucinol/analogs & derivatives , Plant Oils/chemistry
16.
J Neurosci Res ; 86(14): 3221-9, 2008 Nov 01.
Article in English | MEDLINE | ID: mdl-18521936

ABSTRACT

Activation of the c-jun N-terminal kinase (JNK) is known to be an important step during ethanol-induced cell death, but it has yet to be identified how JNK regulates apoptosis. Therefore, we investigated the mechanism by which JNK induces cell death following ethanol treatment. Ethanol (6 g/kg, 20% in saline) was administered subcutaneously to postnatal 7 day rat pups. Twelve hours after the first ethanol administration, rat pups were decapitated, and extracts of total protein from cerebral cortices were prepared. Ethanol exposure induced phosphorylation of JNK but did not affect the expression levels of pro- and antiapoptotic proteins. Furthermore, interactions of phospho-JNK (p-JNK) with 14-3-3 as well as with Bad were enhanced in the cerebral cortices of ethanol-treated rats. Pretreatment with JNK inhibitor (SP600125) of SH-SY5Y cells inhibited JNK phosphorylation and interaction between p-JNK and 14-3-3 resulting from ethanol. Furthermore, 14-3-3 interaction with Bad was diminished in the cerebral cortices of ethanol-treated rats. These findings suggest that JNK induces Bad release from 14-3-3 by inhibiting their interaction. After this event, Bad binds to Bcl-xL, releasing Bax from Bcl-xL and leading to cell death. We hypothesize that JNK may play an important role during ethanol-induced cell death via the inhibition of antiapoptotic function of 14-3-3 as well as activation of proapoptotic function of Bad.


Subject(s)
14-3-3 Proteins/metabolism , Apoptosis/drug effects , Central Nervous System Depressants/toxicity , Ethanol/toxicity , JNK Mitogen-Activated Protein Kinases/metabolism , bcl-Associated Death Protein/metabolism , Animals , Blotting, Western , Brain/drug effects , Brain/metabolism , Humans , Immunoprecipitation , Neurons/drug effects , Neurons/metabolism , Phosphorylation , Rats , Rats, Sprague-Dawley
17.
J Immunol Methods ; 463: 84-88, 2018 12.
Article in English | MEDLINE | ID: mdl-30237054

ABSTRACT

Rubella virus is a critical infectious pathogen to healthcare workers but is preventable by vaccination. In this study, we used three immunoassays - LIAISON Rubella IgG, ARCHITECT Rubella IgG, and AtheNA Multi-Lyte MMRV IgG - to detect rubella virus IgG and tested 182 serum specimens. The percentage of positives with the three Rubella tests were as follows: LIAISON, 71.9%; ARCHITECT, 83.5%; and AtheNA, 99.5%. The three assays showed an overall agreement rate of 71.9%. The rates of seropositive detection with LIAISON, ARCHITECT, and AtheNA among healthcare workers with and without self-reporting history of past infection or vaccination were 70.7% and 90.9%, 83.6% and 81.8%, and 99.4% and 100%, respectively. The three immunoassays showed a low agreement rate for rubella virus IgG. Therefore, choosing accurate and appropriate IgG assay methods is very important for effective infection control and prevention.


Subject(s)
Antibodies, Viral/blood , Health Personnel , Immunoglobulin G/blood , Rubella virus , Rubella/blood , Adult , Female , Humans , Immunoassay/methods , Male , Reproducibility of Results
18.
Neurosci Lett ; 548: 249-54, 2013 Aug 26.
Article in English | MEDLINE | ID: mdl-23714241

ABSTRACT

A previous study using a mouse model of depression showed that chronic immobilization stress (CIS) reduces levels of insulin-like growth factor (IGF)-2, IGF binding protein 2 (IGFBP2), osteoglycin, and fibromodulin in the amygdala. Here, using human neuroblastoma cells, we tested whether these four proteins cooperatively modulate neuronal plasticity. We found that IGF-2 and IGFBP2 synergistically increased neurite outgrowth via enhanced early signaling through the IGF type 1 receptor. Furthermore, we found that osteoglycin, a small leucine-rich proteoglycan, significantly increased IGF-2/IGFPB2-induced neurite outgrowth, but fibromodulin had no effect. We also found that central amygdala neurons of CIS-induced depressive mouse showed a decreased total dendritic length. These findings suggest that CIS-responsive proteins modulate neuronal morphology during chronic stress.


Subject(s)
Insulin-Like Growth Factor Binding Protein 2/metabolism , Insulin-Like Growth Factor II/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Neurites/pathology , Neuroblastoma/pathology , Neuroblastoma/physiopathology , Neuronal Plasticity , Cell Line, Tumor , Cell Proliferation , Humans , Receptor, IGF Type 1/metabolism
19.
J Food Prot ; 75(1): 118-22, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22221363

ABSTRACT

The aim of this study was to examine the acaricidal activity of Periploca sepium oil and its active component against Tyrophagus putrescentiae. Based on its 50% lethal dose (LD(50) ) value, P. sepium oil (8.45 µg/cm(2)) was highly active against T. putrescentiae. The active constituent of P. sepium was isolated by chromatographic techniques and identified as 2-hydroxy-4-methoxybenzaldehyde. In the comparison with synthetic acaricides, the acaricidal activity of 2-hydroxy-4-methoxybenzaldehyde (0.94 µg/cm(2)) against T. putrescentiae was 12.2- and 31.2-fold greater than those of benzyl benzoate (11.45 µg/cm(2)) and N,N-diethyl-m-toluamide (29.33 µg/cm(2)), respectively. To establish structure-activity relationships, the acaricidal activities of 2-hydroxy-4-methoxybenzaldehyde and its derivatives against T. putrescentiae were determined by using an impregnated fabric disk bioassay. On the basis of LD(50) values, 4-methoxybenzaldehyde (0.48 µg/cm(2)) was the most effective against T. putrescentiae, followed by 3-methoxybenzaldehyde (0.82 µg/cm(2)), 2-hydroxy-5-methoxybenzaldehyde (0.92 µg/cm(2)), 2-methoxybenzaldehyde (0.95 µg/cm(2)), 2-hydroxybenzaldehyde (0.97 µg/cm(2)), and 2-hydroxy-3-methoxybenzaldehyde (2.35 µg/cm(2)). These results indicate that the introduction of a hydroxyl and/or methoxy group into the benzaldehyde skeleton increased the acaricidal activity. Therefore, 2-hydroxy-4-methoxybenzaldehyde and its derivatives could potentially be used as potent mite control agents.


Subject(s)
Acaricides/pharmacology , Food Preservation/methods , Mites/drug effects , Periploca/chemistry , Plant Oils/pharmacology , Animals , Food Microbiology , Lethal Dose 50 , Mites/growth & development , Pest Control, Biological/methods
20.
Chem Commun (Camb) ; 48(25): 3079-81, 2012 Mar 25.
Article in English | MEDLINE | ID: mdl-22344411

ABSTRACT

trans-1,2-Diaminocyclohexane functionalized mesoporous silica was applied as an ideal catalyst for asymmetric Michael addition of various nitroalkane derivatives. Short channels and plugs in the pore structure offered chiral enhancement in Michael addition.


Subject(s)
Cyclohexylamines/chemistry , Silicon Dioxide/chemistry , Catalysis , Stereoisomerism
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