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Manwar R, Kratkiewicz K, Mahmoodkalayeh S, Hariri A, Papadelis C, Hansen A, Pillers DAM, Gelovani J, Avanaki K. Development and characterization of transfontanelle photoacoustic imaging system for detection of intracranial hemorrhages and measurement of brain oxygenation: Ex-vivo. Photoacoustics 2023; 32:100538. [PMID: 37575972 PMCID: PMC10413353 DOI: 10.1016/j.pacs.2023.100538] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 06/28/2023] [Accepted: 07/19/2023] [Indexed: 08/15/2023]
Abstract
We have developed and optimized an imaging system to study and improve the detection of brain hemorrhage and to quantify oxygenation. Since this system is intended to be used for brain imaging in neonates through the skull opening, i.e., fontanelle, we called it, Transfontanelle Photoacoustic Imaging (TFPAI) system. The system is optimized in terms of optical and acoustic designs, thermal safety, and mechanical stability. The lower limit of quantification of TFPAI to detect the location of hemorrhage and its size is evaluated using in-vitro and ex-vivo experiments. The capability of TFPAI in measuring the tissue oxygenation and detection of vasogenic edema due to brain blood barrier disruption are demonstrated. The results obtained from our experimental evaluations strongly suggest the potential utility of TFPAI, as a portable imaging modality in the neonatal intensive care unit. Confirmation of these findings in-vivo could facilitate the translation of this promising technology to the clinic.
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Affiliation(s)
- Rayyan Manwar
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, IL, United States
| | - Karl Kratkiewicz
- Barbara Ann Karmanos Cancer Institute, Detroit, MI, United States
| | | | - Ali Hariri
- Department of Nanoengineering, University of California, San Diego, CA, United States
| | - Christos Papadelis
- Jane and John Justin Neurosciences Center, Cook Children’s Health Care System, Fort Worth, TX, United States
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, United States
| | - Anne Hansen
- Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - De-Ann M. Pillers
- Department of Pediatrics, UI Health Children’s Hospital of the University of Illinois at Chicago, Chicago, IL, United States
| | - Juri Gelovani
- College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
- Department of Biomedical Engineering, College of Engineering and School of Medicine, Wayne State University, Detroit, MI 48201, United States
- Dept. Radiology, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Kamran Avanaki
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, IL, United States
- Department of Pediatrics, UI Health Children’s Hospital of the University of Illinois at Chicago, Chicago, IL, United States
- Department of Dermatology, University of Illinois at Chicago, Chicago, IL, United States
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Pattnaik BR, Tokarz S, Asuma MP, Schroeder T, Sharma A, Mitchell JC, Edwards AO, Pillers DAM. Snowflake vitreoretinal degeneration (SVD) mutation R162W provides new insights into Kir7.1 ion channel structure and function. PLoS One 2013; 8:e71744. [PMID: 23977131 PMCID: PMC3747230 DOI: 10.1371/journal.pone.0071744] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/02/2013] [Indexed: 01/08/2023] Open
Abstract
Snowflake Vitreoretinal Degeneration (SVD) is associated with the R162W mutation of the Kir7.1 inwardly-rectifying potassium channel. Kir7.1 is found at the apical membrane of Retinal Pigment Epithelial (RPE) cells, adjacent to the photoreceptor neurons. The SVD phenotype ranges from RPE degeneration to an abnormal b-wave to a liquid vitreous. We sought to determine how this mutation alters the structure and function of the human Kir7.1 channel. In this study, we expressed a Kir7.1 construct with the R162W mutation in CHO cells to evaluate function of the ion channel. Compared to the wild-type protein, the mutant protein exhibited a non-functional Kir channel that resulted in depolarization of the resting membrane potential. Upon co-expression with wild-type Kir7.1, R162W mutant showed a reduction of IKir7.1 and positive shift in ‘0’ current potential. Homology modeling based on the structure of a bacterial Kir channel protein suggested that the effect of R162W mutation is a result of loss of hydrogen bonding by the regulatory lipid binding domain of the cytoplasmic structure.
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Affiliation(s)
- Bikash R. Pattnaik
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
| | - Sara Tokarz
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Matti P. Asuma
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Tyler Schroeder
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Anil Sharma
- Department of Experimental Pathology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Julie C. Mitchell
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Albert O. Edwards
- Institute for Molecular Biology, University of Oregon, and Oregon Retina, Eugene, Oregon, United States of America
| | - De-Ann M. Pillers
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin, United States of America
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Pattnaik BR, Asuma MP, Spott R, Pillers DAM. Genetic defects in the hotspot of inwardly rectifying K(+) (Kir) channels and their metabolic consequences: a review. Mol Genet Metab 2012; 105:64-72. [PMID: 22079268 PMCID: PMC3253982 DOI: 10.1016/j.ymgme.2011.10.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/11/2011] [Accepted: 10/12/2011] [Indexed: 02/07/2023]
Abstract
Inwardly rectifying potassium (Kir) channels are essential for maintaining normal potassium homeostasis and the resting membrane potential. As a consequence, mutations in Kir channels cause debilitating diseases ranging from cardiac failure to renal, ocular, pancreatic, and neurological abnormalities. Structurally, Kir channels consist of two trans-membrane domains, a pore-forming loop that contains the selectivity filter and two cytoplasmic polar tails. Within the cytoplasmic structure, clusters of amino acid sequences form regulatory domains that interact with cellular metabolites to control the opening and closing of the channel. In this review, we present an overview of Kir channel function and recent progress in the characterization of selected Kir channel mutations that lie in and near a C-terminal cytoplasmic 'hotspot' domain. The resultant molecular mechanisms by which the loss or gain of channel function leads to organ failure provide potential opportunities for targeted therapeutic interventions for this important group of channelopathies.
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Affiliation(s)
- Bikash R. Pattnaik
- Department of Pediatrics, University of Wisconsin, Madison
- Department of Ophthalmology & Visual Sciences, University of Wisconsin, Madison
- Department of Eye Research Institute, University of Wisconsin, Madison
| | - Matti P. Asuma
- Department of Pediatrics, University of Wisconsin, Madison
| | - Ryan Spott
- Department of Pediatrics, University of Wisconsin, Madison
| | - De-Ann M. Pillers
- Department of Pediatrics, University of Wisconsin, Madison
- Department of Eye Research Institute, University of Wisconsin, Madison
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Nkadi PO, Merritt TA, Pillers DAM. An overview of pulmonary surfactant in the neonate: genetics, metabolism, and the role of surfactant in health and disease. Mol Genet Metab 2009; 97:95-101. [PMID: 19299177 PMCID: PMC2880575 DOI: 10.1016/j.ymgme.2009.01.015] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 01/27/2009] [Accepted: 01/27/2009] [Indexed: 11/19/2022]
Abstract
Pulmonary surfactant is a complex mixture of phospholipids (PL) and proteins (SP) that reduce surface tension at the air-liquid interface of the alveolus. It is made up of about 70-80% PL, mainly dipalmitoylphosphatidylcholine (DPPC), 10% SP-A, B, C and D, and 10% neutral lipids, mainly cholesterol. Surfactant is synthesized, assembled, transported and secreted into the alveolus where it is degraded and then recycled. Metabolism of surfactant is slower in newborns, especially preterm, than in adults. Defective pulmonary surfactant metabolism results in respiratory distress with attendant morbidity and mortality. This occurs due to accelerated breakdown by oxidation, proteolytic degradation, inhibition or inherited defects of surfactant metabolism. Prenatal corticosteroids, surfactant replacement, whole lung lavage and lung transplantation have yielded results in managing some of these defects. Gene therapy could prove valuable in treating inherited defects of surfactant metabolism.
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Affiliation(s)
- Paul O. Nkadi
- Departments of Pediatrics and Physiology & Pharmacology, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd., NRC-5, Portland, OR 97239
| | - T. Allen Merritt
- Division of Neonatology, Loma Linda University Children’s Hospital, 11175 Campus Street, Coleman Pavilion 11121, Loma Linda, CA 92354
| | - De-Ann M. Pillers
- Chief, Division of Neonatology, Department of Pediatrics, University of Wisconsin, Meriter Hospital, 202 South Park St. Madison, WI 53715
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