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Kim YH, Kang KC, Kim JN, Park KK, Firouzi K, Khuri-Yakub BT. High-spatial-resolution transcranial focused ultrasound neuromodulation using frequency-modulated pattern interference radiation force. Ultrasonics 2024; 140:107298. [PMID: 38531115 DOI: 10.1016/j.ultras.2024.107298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 07/28/2023] [Accepted: 03/13/2024] [Indexed: 03/28/2024]
Abstract
Stimulating the brain in a precise location is crucial in ultrasound neuromodulation. However, improving the resolution proves a challenge owing to the characteristics of transcranial focused ultrasound. In this paper, we present a new neuromodulation system that overcomes the existing limitations based on an acoustic radiation force with a frequency-modulated waveform and standing waves. By using the frequency-modulated pattern interference radiation force (FM-PIRF), the axial spatial resolution can be reduced to a single wavelength level and the target location can be controlled in axial direction electronically. A linear frequency-modulated chirp waveform used in the experiment was designed based on the simulation results. The displacement of the polydimethylsiloxane (PDMS) cantilever was measured at intervals of 0.1 mm to visualize the distribution of radiation force. These results and methods experimentally show that FM-PIRF has improved spatial resolution and capability of electrical movement.
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Affiliation(s)
- Young Hun Kim
- Mechanical Convergence Engineering, Hanyang University, Seoul 04763, Republic of Korea; Edward. L. Ginzton Lab, Stanford University, Stanford, CA 94305, USA
| | - Ki Chang Kang
- Mechanical Convergence Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Jeong Nyeon Kim
- Edward. L. Ginzton Lab, Stanford University, Stanford, CA 94305, USA
| | - Kwan Kyu Park
- Edward. L. Ginzton Lab, Stanford University, Stanford, CA 94305, USA.
| | - Kamyar Firouzi
- Edward. L. Ginzton Lab, Stanford University, Stanford, CA 94305, USA
| | - Butrus T Khuri-Yakub
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
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Sathe AV, Siu A, Kang KC, Kayne A, Vinjamuri S, Kelly P, Shi W, Evans JJ, Farrell CJ. Early Versus Delayed Fractionated Stereotactic Radiotherapy for Nonfunctioning Pituitary Adenoma. World Neurosurg 2023; 180:e317-e323. [PMID: 37757941 DOI: 10.1016/j.wneu.2023.09.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/15/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023]
Abstract
BACKGROUND Fractionated stereotactic radiotherapy (FSRT) is a common modality used to treat pituitary adenomas with good control rates. It is not known whether FSRT should be performed early or delayed until progression occurs. We compared FSRT in treating nonfunctional pituitary adenomas (NFPA) as an adjuvant (ADJ) or on-progression (PRG) therapy. METHODS A retrospective review of patients who underwent FSRT for an NFPA between January 2004 and December 2022 at a single institution was performed. We compared endocrinologic, ophthalmologic, and radiographic outcomes in FSRT delivered as ADJ and PRG treatment. RESULTS Seventy-five patients were analyzed, with a median follow-up of 53 months. FSRT was administered to 35 and 40 patients as ADJ and PRG, with a median time to treatment of 5.5 and 40 months, respectively. The tumor control rate was 94.3% for ADJ and 95.0% for PRG. Treatment resulted in 4 (11.4%) versus 7 (17.5%) new endocrinopathies and 2 (5.7%) versus 1 (2.5%) new visual deficits for ADJ versus PRG. A survival analysis of time to new endocrinopathy showed no difference between the 2 cohorts. The median time from surgery to new endocrinopathy was significantly different between ADJ and PRG, at 15.5 and 102.0 months, respectively. CONCLUSIONS FSRT is effective in treating NFPA for residual and progressive tumors, with excellent tumor control rates and a low risk of developing new endocrinopathies and visual deficits. Delaying treatment delayed the development of new endocrinopathies, suggesting that observation with FSRT on tumor progression may delay the onset of hypopituitarism and maintain similar effectiveness in tumor control.
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Affiliation(s)
- Anish V Sathe
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Alan Siu
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Ki Chang Kang
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Allison Kayne
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Shreya Vinjamuri
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Patrick Kelly
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Wenyin Shi
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - James J Evans
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Christopher J Farrell
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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Mandloi S, Syed M, Shoraka O, Ailes I, Kang KC, Sathe A, Heller J, Thalheimer S, Mohamed FB, Sharan A, Harrop J, Krisa L, Matias C, Alizadeh M. The role of the insula in chronic pain following spinal cord injury: A resting-state fMRI study. J Neuroimaging 2023; 33:781-791. [PMID: 37188633 DOI: 10.1111/jon.13117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/23/2023] [Accepted: 05/04/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND AND PURPOSE Spinal cord injury (SCI) results in the loss of motor and sensory function from disconnections between efferent and afferent pathways. Most SCI patients are affected with chronic neuropathic pain, but there is a paucity of data concerning neuroplastic changes following SCI. Chronic pain disrupts default networks and is associated with abnormal insular connectivity. The posterior insula (PI) is associated with the degree of pain and intensity of pain. The anterior insula (AI) is related to signal changes. Comprehension of SCI pain mechanisms is essential to elucidate effective treatment options. METHODS This study examines the insular gyri functional connectivity (FC) of seven (five male, two female) SCI participants with moderate-severe chronic pain compared to 10 (five male, five female) healthy controls (HC). All subjects had 3-Tesla MRI performed and resting-state functional MRI (fMRI) was acquired. FC metrics were obtained from the comparisons of resting-state fMRI among our various groups. A seed-to-voxel analysis was pursued, encompassing six gyri of the insula. For multiple comparisons, a correction was applied with a significance level of p < .05. RESULTS There were significant differences in FC of the insula between SCI participants with chronic pain compared with HC. In the SCI participants, there was hyperconnectivity of the AI and PI to the frontal pole. In addition, there was increased FC noted between the PI and the anterior cingulate cortex. Hyperconnectivity was also observed between the AI and the occipital cortex. CONCLUSIONS These findings illustrate that there is a complex hyperconnectivity and modulation of pain pathways after traumatic SCI.
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Affiliation(s)
- Shreya Mandloi
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Mashaal Syed
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Omid Shoraka
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Isaiah Ailes
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Ki Chang Kang
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Anish Sathe
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Joshua Heller
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sara Thalheimer
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Feroze B Mohamed
- Thomas Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Ashwini Sharan
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - James Harrop
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Laura Krisa
- Department of Physical Therapy, Jefferson College of Rehabilitation Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Caio Matias
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Mahdi Alizadeh
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
- Thomas Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Muller JJ, Wang R, Milddleton D, Alizadeh M, Kang KC, Hryczyk R, Zabrecky G, Hriso C, Navarreto E, Wintering N, Bazzan AJ, Wu C, Monti DA, Jiao X, Wu Q, Newberg AB, Mohamed FB. Machine learning-based classification of chronic traumatic brain injury using hybrid diffusion imaging. Front Neurosci 2023; 17:1182509. [PMID: 37694125 PMCID: PMC10484001 DOI: 10.3389/fnins.2023.1182509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/30/2023] [Indexed: 09/12/2023] Open
Abstract
Background and purpose Traumatic brain injury (TBI) can cause progressive neuropathology that leads to chronic impairments, creating a need for biomarkers to detect and monitor this condition to improve outcomes. This study aimed to analyze the ability of data-driven analysis of diffusion tensor imaging (DTI) and neurite orientation dispersion imaging (NODDI) to develop biomarkers to infer symptom severity and determine whether they outperform conventional T1-weighted imaging. Materials and methods A machine learning-based model was developed using a dataset of hybrid diffusion imaging of patients with chronic traumatic brain injury. We first extracted the useful features from the hybrid diffusion imaging (HYDI) data and then used supervised learning algorithms to classify the outcome of TBI. We developed three models based on DTI, NODDI, and T1-weighted imaging, and we compared the accuracy results across different models. Results Compared with the conventional T1-weighted imaging-based classification with an accuracy of 51.7-56.8%, our machine learning-based models achieved significantly better results with DTI-based models at 58.7-73.0% accuracy and NODDI with an accuracy of 64.0-72.3%. Conclusion The machine learning-based feature selection and classification algorithm based on hybrid diffusion features significantly outperform conventional T1-weighted imaging. The results suggest that advanced algorithms can be developed for inferring symptoms of chronic brain injury using feature selection and diffusion-weighted imaging.
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Affiliation(s)
- Jennifer J. Muller
- College of Engineering, Villanova University, Villanova, PA, United States
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ruixuan Wang
- College of Engineering, Villanova University, Villanova, PA, United States
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Devon Milddleton
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Mahdi Alizadeh
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ki Chang Kang
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ryan Hryczyk
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - George Zabrecky
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Chloe Hriso
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Emily Navarreto
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Nancy Wintering
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Anthony J. Bazzan
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Chengyuan Wu
- Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, PA, United States
| | - Daniel A. Monti
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Xun Jiao
- College of Engineering, Villanova University, Villanova, PA, United States
| | - Qianhong Wu
- College of Engineering, Villanova University, Villanova, PA, United States
| | - Andrew B. Newberg
- Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, PA, United States
| | - Feroze B. Mohamed
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States
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Kang KC, Joung DY, Hun Kim Y, Kyu Park K, Firouzi K, Khuri-Yakub BT. Measurement of the acoustic reflectance function based on Lamb wave using high f-number transducers. Ultrasonics 2023; 132:107003. [PMID: 37099939 PMCID: PMC10569739 DOI: 10.1016/j.ultras.2023.107003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/20/2023] [Accepted: 03/31/2023] [Indexed: 05/29/2023]
Abstract
Ultrasonic reflectivity using a V(z) technique is a powerful characterization method in acoustic microscopy to measure the elastic properties of materials. Conventional techniques generally use a low f-number with high frequency; however, to measure the reflectance function of the highly attenuative material, a low frequency is essential. In this study, the transducer-pair method based on Lamb waves is used to measure the reflectance function of a highly attenuative material. The results demonstrate the feasibility of the proposed method using a commercial ultrasound transducer with high f-number.
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Affiliation(s)
- Ki Chang Kang
- E. L. Ginzton Lab, Dept. of Electrical Engineering, Stanford University, Stanford, CA, USA; Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Do Yeong Joung
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Young Hun Kim
- E. L. Ginzton Lab, Dept. of Electrical Engineering, Stanford University, Stanford, CA, USA; Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Kwan Kyu Park
- E. L. Ginzton Lab, Dept. of Electrical Engineering, Stanford University, Stanford, CA, USA; Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea.
| | - Kamyar Firouzi
- E. L. Ginzton Lab, Dept. of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Burtus T Khuri-Yakub
- E. L. Ginzton Lab, Dept. of Electrical Engineering, Stanford University, Stanford, CA, USA
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Kang KC, Kim YH, Kim JN, Kabir M, Zhang Y, Ghanouni P, Park KK, Firouzi K, Khuri-Yakub BT. Increasing the transmission efficiency of transcranial ultrasound using a dual-mode conversion technique based on Lamb waves. J Acoust Soc Am 2022; 151:2159. [PMID: 35364946 PMCID: PMC8957390 DOI: 10.1121/10.0009849] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/24/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Transcranial focused ultrasound (FUS) is a noninvasive treatment for brain tumors and neuromodulation. Based on normal incidence, conventional FUS techniques use a focused or an array of ultrasonic transducers to overcome the attenuation and absorption of ultrasound in the skull; however, this remains the main limitation of using FUS. A dual-mode conversion technique based on Lamb waves is proposed to achieve high transmission efficiency. This concept was validated using the finite element analysis (FEA) and experiments based on changes in the incident angle. Aluminum, plexiglass, and a human skull were used as materials with different attenuations. The transmission loss was calculated for each material, and the results were compared with the reflectance function of the Lamb waves. Oblique incidence based on dual-mode conversion exhibited a better transmission efficiency than that of a normal incidence for all of the specimens. The total transmission losses for the materials were 13.7, 15.46, and 3.91 dB less than those associated with the normal incidence. A wedge transducer was designed and fabricated to implement the proposed method. The results demonstrated the potential applicability of the dual-mode conversion technique for the human skull.
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Affiliation(s)
- Ki Chang Kang
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Young Hun Kim
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jeong Nyeon Kim
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Minoo Kabir
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Yichi Zhang
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Stanford, California 94305, USA
| | - Kwan Kyu Park
- Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Kamyar Firouzi
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Burtus T Khuri-Yakub
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
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Kim YH, Kang KC, Kim JN, Pai CN, Zhang Y, Ghanouni P, Park KK, Firouzi K, Khuri-Yakub BT. Patterned Interference Radiation Force for Transcranial Neuromodulation. Ultrasound Med Biol 2022; 48:497-511. [PMID: 34955292 DOI: 10.1016/j.ultrasmedbio.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 11/06/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
Compared with the conventional method of transcranial focused ultrasound stimulation using a single transducer or a focused beam, the compression and tensile forces are generated from the high-pressure gradient of a standing wave that can generate increased stimulation. We experimentally verified a neuromodulation system using patterned interference radiation force (PIRF) and propose a method for obtaining the magnitude of the radiation force, which is considered the main factor influencing ultrasound neuromodulation. The radiation forces generated using a single focused transducer and a standing wave created via two focused transducers were compared using simulations. Radiation force was calculated based on the relationship between the acoustic pressure, radiation force and time-averaged second-order pressure obtained using an acoustic streaming simulation. The presence of the radiation force was verified by measuring the time-averaged second-order pressure generated due to the radiation force, by using a glass tube.
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Affiliation(s)
- Young Hun Kim
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA; Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Ki Chang Kang
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA; Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jeong Nyeon Kim
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Chi Nan Pai
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA; Department of Mechatronics Engineering, Polytechnic School of the University of Sao Paulo, Sao Paulo, Brazil
| | - Yichi Zhang
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Kwan Kyu Park
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA; Mechanical Convergence Engineering, Hanyang University, Seoul, Republic of Korea.
| | - Kamyar Firouzi
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Burtus T Khuri-Yakub
- E. L. Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
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Choi WY, Kwon SW, Kim YH, Kang KC, Park KK. Single-Shot Near-Field Volumetric Imaging System for Optical Ultrasound and Photoacoustics Using Capacitive Micromachined Ultrasonic Transducer Without Transmission Mode. IEEE Trans Ultrason Ferroelectr Freq Control 2020; 67:1151-1158. [PMID: 31976884 DOI: 10.1109/tuffc.2020.2965600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this article, we present a single-shot dual-mode imaging system that uses optical ultrasound (US) as an ultrasonic pulser without a transmission circuit. The ultrasonic pulse-echo system comprises an optical US pulser generated by carbon nanotubes (CNTs), which generate a high-power photoacoustic (PA) signal and a capacitive micromachined ultrasonic transducer (CMUT) receiver. By fabricating a thin CNT-polydimethylsiloxane (PDMS) composite capable of semiabsorption of the laser, a single-shot imaging system was developed. By transmitting a semipenetration light to the object, US and PA imaging were performed in a single shot. A CNT thickness of [Formula: see text] produced a maximum pressure of 154 kPa, and US was received by CMUT with a 2-MHz center frequency in PDMS. Additionally, a low-profile and near-depth imaging system was constructed with an intermediate layer of the 6-mm PDMS for the dry contact method. We performed a single-shot dual-mode imaging experiment on point and line phantoms, as well as the particle spread in the soft tissue. Thus, we examined the feasibility of the near-depth and single-shot dual-mode (US and PA) imaging system capable of a dry contact.
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Park KS, Kang KC, Kim KY, Jeong PY, Kim JH, Adams DJ, Kim JH, Paik YK. HWY-289, a novel semi-synthetic protoberberine derivative with multiple target sites in Candida albicans. J Antimicrob Chemother 2001; 47:513-9. [PMID: 11328760 DOI: 10.1093/jac/47.5.513] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The antifungal properties of 515 synthetic and semi-synthetic protoberberines were investigated. HWY-289 was chosen for further study because it exhibited the most significant anti-Candida activity (MICs were 1.56 mg/L for Candida albicans and Candida krusei; 6.25 mg/L for Candida guilliermondii) but did not demonstrate toxicity in rats. HWY-289 inhibited the incorporation of L-[methyl-(14)C]methionine into the C-24 of ergosterol in whole cells of C. albicans (IC(50) 20 microM). However, HWY-289 (100 microM) had no effect on mammalian cholesterol biosynthesis in rat microsomes while miconazole (100 microM) was a potent inhibitor of cholesterol biosynthesis under identical assay conditions. A second major target site for HWY-289 was identified that involves cell wall biosynthesis in C. albicans. HWY-289 was a potent inhibitor of the chitin synthase isozymes CaCHS1 and CaCHS2, with IC(50) values of 22 microM for each enzyme. The effect was highly specific in that HWY-289 had no significant effect on C. albicans CaCHS3 (IC(50) > 200 microM). Thus, HWY-289 compared favourably with well-established antifungal agents as an inhibitor of the growth of Candida species in vitro, and may have considerable potential as a new class of antifungal agent that lacks toxic side effects in the human host.
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Affiliation(s)
- K S Park
- Department of Biochemistry, Bioproducts Research Center and Yonsei Proteome Research Center, Yonsei University, 134 Shinchon-dong, Sudaemoon-ku, Seoul, Korea
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Park KS, Kang KC, Kim JH, Adams DJ, Johng TN, Paik YK. Differential inhibitory effects of protoberberines on sterol and chitin biosyntheses in Candida albicans. J Antimicrob Chemother 1999; 43:667-74. [PMID: 10382888 DOI: 10.1093/jac/43.5.667] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The anti-Candida potentials of 12 Korean medicinal plants were explored: methanol extracts from Coptis rhizoma and Phellodendron amurense caused significant inhibition of growth of Candida albicans, Candida glabrata, Candida krusei and Candida parapsilosis. The predominant active components of the extracts were the protoberberines berberine and palmatine; the most potent inhibition of growth was exhibited by berberine on C. krusei (MIC <4 mg/L) and palmatine on C. parapsilosis (MIC 16 mg/L). Both berberine and palmatine inhibited the in-vivo rate of incorporation of L-[methyl-14C]methionine into C-24 of ergosterol in C. albicans (50% inhibition concentration (IC50 values), 25 microM and 300 microM, respectively); this result suggests that sterol 24-methyl transferase (24-SMT) is one of the cellular targets for the antifungal activity of the protoberberines. In-vitro 24-SMT activity in microsomes from the yeast growth form of C. albicans was inhibited by both berberine (inhibition constant (Ki) 232 microM) and palmatine (Ki 257 microM) in a non-competitive manner; inhibition of 24-SMT was more marked for the mycelial form than for the yeast growth form of this organism. Palmatine inhibited chitin synthase from both the yeast and mycelial growth phases of C. albicans in a non-competitive manner (Ki 780 microM). The effects of protoberberines, extracted from established medicinal plants, on both sterol and cell wall biosyntheses in pathogenic fungi indicate that the potential of these compounds, or their semi-synthetic derivatives, as a novel class of antifungal agents should be investigated more fully.
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Affiliation(s)
- K S Park
- Department of Biochemistry and Bioproducts Research Center, Yonsei University, Seoul, South Korea
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Brauns T, Cai ZW, Kimball SD, Kang KC, Haugland RP, Berger W, Berjukov S, Hering S, Glossmann H, Striessnig J. Benzothiazepine binding domain of purified L-type calcium channels: direct labeling using a novel fluorescent diltiazem analogue. Biochemistry 1995; 34:3461-9. [PMID: 7880840 DOI: 10.1021/bi00010a039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have synthesized a series of N-propylamino-substituted benzazepinones (NPSBs) as specific probes for the benzothiazepinone (BTZ) binding domain of muscle L-type calcium channels (LTCCs). NPSBs were identified which possess high affinity for the channel after purification. We synthesized a fluorescent NPSB, DMBODIPY-BAZ, as the first benz(othi)azepinone derivative known to reversibly label partially purified LTCCs. DMBODIPY-BAZ binds to the partially purified channel with high affinity (Kd = 25 nM, Bmax = 580 pmol/mg of protein). Fluorescence resonance energy transfer (FRET) occurred between tryptophan residues of the channel protein and the DMBODIPY fluorophore upon specific drug binding. FRET was exploited to allow highly time-resolved detection of specific drug binding kinetics. We found that the dissociation half-life (t1/2) of DMBODIPY-BAZ decreased with the concentration of an unlabeled competitor, which indicates ligand-induced accelerated dissociation. In contrast, t1/2 was concentration-dependently increased by the dihydropyridine (DHP) (+)-isradipine. These kinetic properties of DMBODIPY-BAZ indicate that a high-affinity BTZ binding domain also exists on purified LTCCs. NPSBs represent novel tools to provide further insight into the molecular pharmacology of the BTZ binding domain on LTCCs.
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Affiliation(s)
- T Brauns
- Institut für Biochemische Pharmakologie, Innsbruck, Australia
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12
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Abstract
An embryo-derived platelet activating factor has been demonstrated to play an important role in reproduction. This report examined the effect of various doses of a synthetic platelet activating factor on the production of progesterone by porcine granulosa cells in culture. Granulosa cells aspirated from ovarian follicles of prepubertal gilts were grown for 24 hours in Dulbecco's Modified Eagles Media: Ham's F-12 with 5% fetal bovine serum and 1 micrograms/ml insulin. Cells were washed once in serum-free media and then cultured for an additional 48 hours with 0 to 5000 ng/ml of the platelet activating factor in media containing either 0.25% bovine serum albumin or 1% fetal bovine serum. Cells grown with fetal bovine serum produced 50% of the amount of progesterone that was produced in the absence of serum. Low doses of the platelet activating factor caused a slight decrease in progesterone production. Higher doses (greater than 500 ng/ml) in serum-free media caused a marked decrease in progesterone production. Serum had a protective effect at high doses of platelet activating factor which was probably mediated by enzymatic degradation of the platelet activating factor. In summary, platelet activating factor had no stimulatory effect on production of progesterone by porcine granulosa cells in culture.
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Affiliation(s)
- K C Kang
- Department of Obstetrics and Gynecology, College of Medicine, Ohio State University, Columbus 43210
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13
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Kim DS, Kang KC. Successful pregnancy after transabdominal cervical evacuation of cervical pregnancy. Obstet Gynecol 1983; 62:522. [PMID: 6888831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cervical pregnancy was managed by transabdominal cervical evacuation. Three years later, the woman was delivered of a healthy male infant by cesarean section.
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14
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Kim DS, Hwang YY, Kang KC, Park MI. Migration of the Lippes loop into the fallopian tube. Obstet Gynecol 1982; 60:393-4. [PMID: 6750472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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