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Mu K, Kitts DD. Gallic acid mitigates intestinal inflammation and loss of tight junction protein expression using a 2D-Caco-2 and RAW 264.7 co-culture model. Arch Biochem Biophys 2024; 756:109978. [PMID: 38636693 DOI: 10.1016/j.abb.2024.109978] [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: 02/23/2024] [Accepted: 03/24/2024] [Indexed: 04/20/2024]
Abstract
A 2D-intestinal epithelial Caco-2/RAW 264.7 macrophage co-culture model was developed to demonstrate the relative efficacy of different phenolic acids to mitigate changes in Caco-2 epithelial cell redox state initiated both directly by autoxidation products, H2O2, and indirectly through cell communication events originating from cytokine stimulated macrophage. An inducer cocktail (lipopolysaccharide + interferon gamma) was used to activate RAW 264.7 cells in the 2D- Caco-2/RAW co-culture and intracellular changes in Caco-2 cell redox signaling occurred in response to positive changes (p < 0.05) in inflammatory biomarkers derived in macrophage that included IL-6, TNF-α, nitric oxide and peroxynitrite, respectively. Phenolic acids varied in relative capacity to reduce NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in cocktail inflamed induced macrophage. This response in addition to the relative predisposition of gallic acid (GA) to undergo autoxidation to generate H2O2 activity (p < 0.05), culminated in downstream cell signaling in Caco-2 nuclear factor erythroid 2-related factor (Nrf2) activity (increase 26.9 %), altered monolayer integrity (increase 33.7 %), and release of interleukin 8 (IL-8) (decrease 80.5 %) (p < 0.05). It can be concluded that the co-culture model described herein was useful to assess the importance of communication between cytokine stimulated macrophage and intestinal cells. Moreover, the relative unique efficacy of GA, compared to other phenolic acids tested to protect against activated macrophage induced changes related to intestinal dysfunction were particularly relevant to epithelial redox signaling, intestinal permeability and regulation of tight junction proteins. This study concludes that phenolic acids are not equal in the capacity to protect against intestinal cell dysfunction despite some indication of biological activity.
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Affiliation(s)
- Kaiwen Mu
- Food Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, V6T-1Z4, B.C, Canada
| | - David D Kitts
- Food Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, V6T-1Z4, B.C, Canada.
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Mu K, Kitts DD. Intestinal polyphenol antioxidant activity involves redox signaling mechanisms facilitated by aquaporin activity. Redox Biol 2023; 68:102948. [PMID: 37922763 PMCID: PMC10643476 DOI: 10.1016/j.redox.2023.102948] [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: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023] Open
Abstract
Ascertaining whether dietary polyphenols evoke an antioxidant or prooxidant activity, which translates to a functional role required to maintain intestinal cell homeostasis continues to be an active and controversial area of research for food chemists and biochemists alike. We have proposed that the paradoxical function of polyphenols to autoxidize to generate H2O2 is a required first step in the capacity of some plant phenolics to function as intracellular antioxidants. This is based on the fact that cell redox homeostasis is achieved by a balance between H2O2 formation and subsequent outcomes of antioxidant systems function. Maintaining optimal extracellular and intracellular H2O2 concentrations is required for cell survival, since low levels are important to upregulate endogenous antioxidant capacity; whereas, concentrations that go beyond homeostatic control typically result in an inflammatory response, growth arrest, or eventual cell death. Aquaporins (AQPs) are a family of water channel membrane proteins that facilitate cellular transportation of water and other small molecule-derived solutes, such as H2O2, in all organisms. In the intestine, AQPs act as gatekeepers to regulate intracellular uptake of H2O2, generated from extracellular polyphenol autoxidation, thus enabling an intracellular cell signaling responses to mitigate onset of oxidative stress and intestinal inflammation. In this review, we highlight the potential role of AQPs to control important underlying mechanisms that define downstream regulation of intestinal redox homeostasis, specifically. It has been established that polyphenols that undergo oxidation to the quinone form, resulting in subsequent adduction to a thiol group on Keap1-Nrf2 complex, trigger Nrf2 activation and a cascade of indirect intracellular antioxidant effects. Here, we propose a similar mechanism that involves H2O2 generated from specific dietary polyphenols with a predisposition to undergo autoxidation. The ultimate bioactivity is regulated and expressed by AQP membrane function and thus, by extension, represents expression of an intracellular antioxidant chemoprotection mechanism.
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Affiliation(s)
- Kaiwen Mu
- Food Science, Food Nutrition and Health Program. Faculty of Land and Food System, The University of British Columbia, 2205 East Mall, Vancouver, B.C, V6T 1Z4, Canada
| | - David D Kitts
- Food Science, Food Nutrition and Health Program. Faculty of Land and Food System, The University of British Columbia, 2205 East Mall, Vancouver, B.C, V6T 1Z4, Canada.
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Mu K, Yao Y, Wang D, Kitts DD. Prooxidant capacity of phenolic acids defines antioxidant potential. Biochim Biophys Acta Gen Subj 2023; 1867:130371. [PMID: 37121280 DOI: 10.1016/j.bbagen.2023.130371] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [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: 03/10/2023] [Revised: 04/20/2023] [Accepted: 04/25/2023] [Indexed: 05/02/2023]
Abstract
Phenolic acids derived from vegetables, fruits and beverages are considered abundant sources of natural antioxidants consumed in the human diet. In addition to having well-known antioxidant activity, phenolic acids also exhibit pro-oxidant activity under selected conditions. We hypothesized that the availability of extracellular H2O2 derived from phenolic acid autoxidation will diffuse across cell membranes to participate as a messenger molecule to activate intracellular redox signaling in response to oxidative stress. We report on the relative activity of structurally different phenolic acids to generate specific changes in the extracellular - intracellular H2O2 flux that induces intracellular redox signaling corresponding to a function to reduce intracellular oxidative stress. HyPer-3 methodology was used to measure increases in intracellular H2O2 in differentiated Caco-2 intestinal cells in response to phenolic acid autoxidation and changes in extracellular H2O2 production. The potential for different phenolic acids to autoxidize and generate H2O2 was dependent on the structure and concentration of phenolic acid. Activation of nuclear factor erythroid 2-related factor (Nrf2) cell signaling was enhanced (p < 0.05) by phenolic acid induced H2O2 production, and mitigated when present along with catalase (p < 0.05), or, alternatively by blocking AQP3 function (p < 0.05) using DFP00173 as the AQP3 inhibitor. The relative capacity of phenolic acids to generate H2O2 on autoxidation was structure specific and corresponded to the level of Nrf2 cell signaling in differentiated Caco-2 epithelial cells. The Nrf2-Keap1 response paralleled the extent of reduced oxidative stress observed in differentiated Caco-2 cells determined by DCFH-DA.
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Affiliation(s)
- Kaiwen Mu
- Food Science, Food Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Yufeng Yao
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai, China; Shanghai Key Laboratory of Emergency Prevention, Diagnosis and Treatment of Respiratory Infectious Diseases, Shanghai, China
| | - Danni Wang
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - David D Kitts
- Food Science, Food Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, BC V6T 1Z4, Canada.
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Mu K, Kitts DD. Hydrogen Peroxide Produced from Selective Phenolic Acids in Cell Culture Underlies Caco-2 Changes in Cell Proliferation Parameters. J Agric Food Chem 2023; 71:3022-3032. [PMID: 36748840 DOI: 10.1021/acs.jafc.2c08830] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The physicochemical property of phenolic acids to generate hydrogen peroxide (H2O2) in cell culture media has been underreported when describing multiple biological effects in vitro. Our aim was to focus on examining the relative capacity of four common phenolic acids widely consumed in the Western diet for autoxidation potential to generate H2O2 during in vitro culture. Furthermore, quantifying H2O2 derived from different phenolic acids cultured in Dulbecco's modified Eagle's medium (DMEM) was associated with changes in cell proliferation in non-differentiated human intestinal carcinoma cells. Results showed that the different percentage losses of phenolic acids, namely, caffeic (84.78 ± 1.51), chlorogenic (37.3 ± 0.38), ferulic (1.26 ± 0.78), and gallic (100%), paralleled a relative capacity to generate H2O2 when present in DMEM media for 24 h. The rate and total H2O2 generated was dependent on both phenolic acid type and concentration (p < 0.05). Gallic acid had the greatest capacity to generate H2O2 in culture without the presence of cells (p < 0.05). When cultured with non-differentiated Caco-2 cells, gallic acid evoked the greatest bioactivity that included cytotoxicity, anti-proliferation, apoptosis, and nuclear condensation, respectively (p < 0.05). Corresponding treatments with cells with phenolic acids in the presence of catalase confirmed that H2O2 generated from phenolic acid autoxidation was involved in cell proliferation and apoptosis.
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Affiliation(s)
- Kaiwen Mu
- Food Science, Food Nutrition and Health Program. Faculty of Land and Food Systems; The University of British Columbia, 2205 East Mall, Vancouver V6T 1Z4, British Columbia, Canada
| | - David D Kitts
- Food Science, Food Nutrition and Health Program. Faculty of Land and Food Systems; The University of British Columbia, 2205 East Mall, Vancouver V6T 1Z4, British Columbia, Canada
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Mu K, Kitts DD. Application of a HyPer-3 sensor to monitor intracellular H 2O 2 generation induced by phenolic acids in differentiated Caco-2 cells. Anal Biochem 2022; 659:114934. [PMID: 36206845 DOI: 10.1016/j.ab.2022.114934] [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: 08/23/2022] [Revised: 09/22/2022] [Accepted: 09/24/2022] [Indexed: 12/14/2022]
Abstract
Intestinal epithelial cells (IECs) are an important point of contact between dietary food components consumed and subsequent whole-body utilization for body maintenance and growth. Selective bioactive phenolic acids, widely present in fruits, vegetables and beverages can generate hydrogen peroxide (H2O2) and contribute to the cellular redox balance, hence influencing well-known cellular antioxidant and pro-oxidant mechanisms. Our findings have showed that increasing extracellular H2O2 resulted in associated changes in intracellular H2O2 levels in Caco-2 cells (p < 0.05) which was facilitated by activity of a family of water channel membrane proteins, termed aquaporins (AQPs). To demonstrate this, a HyPer-3 genetically encoded fluorescent H2O2 sensitive indicator was used to enable fluorescent real-time imaging of intracellular H2O2 levels as a measure of changes occurring in extracellular H2O2 in differentiated Caco-2 cells exposed to different phenolic acids. The use of confocal microscopy and flow cytometry, respectively, captured visualization and quantification of H2O2 uptake in differentiated Caco-2 cells. DFP00173, an aquaporin 3 (AQP3) inhibitor was effective at inhibiting the intracellular uptake of H2O2 and was sensitive to varied levels of H2O2 generated when different phenolic acids were added to the culture media. In summary, HyPer-3 was shown to be an effective technique to demonstrate relative capabilities of structurally different dietary phenolic acids that have potential to alter intestinal redox balance by changing intracellular H2O2, and either antioxidant or pro-oxidant activity, respectively.
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Affiliation(s)
- Kaiwen Mu
- Food Science, Food Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, B.C, V6T 1Z4, Canada.
| | - David D Kitts
- Food Science, Food Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, B.C, V6T 1Z4, Canada.
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Xing H, Mu K, Kitts DD, Yaylayan VA. Molecular Basis for the Simultaneous Enhancement of the Aroma-Generating Capacity and Bioactivity of Maillard Reaction Precursors through Mechanochemistry. J Agric Food Chem 2022; 70:13637-13650. [PMID: 36226926 DOI: 10.1021/acs.jafc.2c05644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Ball milling at ambient temperatures can accelerate the formation and accumulation of early-stage Maillard reaction intermediates considered important precursors of aromas and antioxidants. In this study, using chemical and biological assays, we explored the potential of sequential milling and heating to enhance the antioxidant and aroma-generating capacity of Maillard model systems. Milling (30 Hz/30 min) followed by dry heating (90 °C/30 min) of glycine or lysine with glucose significantly increased not only the intensity of their aroma-active compounds as analyzed by headspace-gas chromatography/mass spectrometry (HS-GC/MS) but also their free radical scavenging capacity as assessed by 2,2'-azino-bis-(3-ethylbenzothiazoneline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) assays. This was attributed to the increased formation of redox-active endiol moieties and precursors of N,N-dialkyl-pyrazinium radical cation in the lysine system assessed by electrospray ionization-quadrupole time-of-flight/tandem mass spectrometry (ESI-QqTOF/MS/MS) analysis. The test samples also inhibited NO generation and cellular oxidative stress in RAW 264.7 murine macrophage cells, indicating size reduction induced by milling promoted paracellular absorption.
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Affiliation(s)
- Haoran Xing
- Department of Food Science & Agricultural Chemistry, McGill University, 21111 Lakeshore, Sainte Anne de Bellevue, Quebec, CanadaH9X 3V9
| | - Kaiwen Mu
- Food Science, Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, 2205 East Mall, Vancouver, British Columbia, CanadaV6T 1Z4
| | - David D Kitts
- Food Science, Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, 2205 East Mall, Vancouver, British Columbia, CanadaV6T 1Z4
| | - Varoujan A Yaylayan
- Department of Food Science & Agricultural Chemistry, McGill University, 21111 Lakeshore, Sainte Anne de Bellevue, Quebec, CanadaH9X 3V9
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Mu K, Yu S, Kitts DD. The Role of Nitric Oxide in Regulating Intestinal Redox Status and Intestinal Epithelial Cell Functionality. Int J Mol Sci 2019; 20:E1755. [PMID: 30970667 PMCID: PMC6479862 DOI: 10.3390/ijms20071755] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 03/29/2019] [Accepted: 04/03/2019] [Indexed: 12/11/2022] Open
Abstract
Important functions of intestinal epithelial cells (IECs) include enabling nutrient absorption to occur passively and acting as a defense barrier against potential xenobiotic components and pathogens. A compromise to IEC function can result in the translocation of bacteria, toxins, and allergens that lead to the onset of disease. Thus, the maintenance and optimal function of IECs are critically important to ensure health. Endogenous biosynthesis of nitric oxide (NO) regulates IEC functionality both directly, through free radical activity, and indirectly through cell signaling mechanisms that impact tight junction protein expression. In this paper, we review the current knowledge on factors that regulate inducible nitric oxide synthase (iNOS) and the subsequent roles that NO has on maintaining IECs' intestinal epithelial barrier structure, functions, and associated mechanisms of action. We also summarize important findings on the effects of bioactive dietary food components that interact with NO production and affect downstream intestinal epithelium integrity.
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Affiliation(s)
- Kaiwen Mu
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Shengwu Yu
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - David D Kitts
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
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Mu K, Patterson A, Bahle-Lampe, Lohman H, Greiner B, Qi Y. Effect of international rehabilitation visiting student program on students’ professional development. Ann Phys Rehabil Med 2018. [DOI: 10.1016/j.rehab.2018.05.1234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Shi L, Mu K, Arntfield SD, Nickerson MT. Changes in levels of enzyme inhibitors during soaking and cooking for pulses available in Canada. J Food Sci Technol 2017; 54:1014-1022. [PMID: 28303052 PMCID: PMC5336459 DOI: 10.1007/s13197-017-2519-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 01/24/2017] [Accepted: 01/31/2017] [Indexed: 10/20/2022]
Abstract
The effects of processing (soaking and cooking) on enzyme inhibitors (α-amylase, trypsin and chymotrypsin inhibitors) in a range of pulses (4 peas, 9 lentils, 3 chickpeas, 2 faba beans and 4 beans) were investigated, using soybean as a control. Analysis of variance indicated that pulse type, treatment and their interaction had significant effects on levels of all enzyme inhibitors. Soybean contained the highest levels of trypsin inhibitory activity (TIA) and chymotrypsin inhibitory activity (CIA) among all seeds. α-Amylase inhibitory activity was absent from peas, lentils, chickpeas and faba beans, but was present in beans and soybean. TIA was found to be low in peas but high in beans. Beans contained relatively high CIA levels followed by chickpeas, lentils, peas and faba beans. Soaking markedly decreased the activity of enzyme inhibitors. Cooking of presoaked seeds was even more effective as greater reductions (78.7-100%) were observed for all pulses. The content of enzyme inhibitors in pulses varied widely, but levels of protease inhibitors were generally lower that those found in soybean. Processing, in particular heat treatments, drastically reduced these levels.
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Affiliation(s)
- Lan Shi
- Department of Food Science, University of Manitoba, Winnipeg, MB R3T 2N2 Canada
| | - Kaiwen Mu
- Department of Food Science, University of Manitoba, Winnipeg, MB R3T 2N2 Canada
| | - Susan D. Arntfield
- Department of Food Science, University of Manitoba, Winnipeg, MB R3T 2N2 Canada
| | - Michael T. Nickerson
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8 Canada
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Mu K, Wang S, D Kitts D. Evidence to indicate that maillard reaction products can provide selective antimicrobial activity. ACTA ACUST UNITED AC 2016. [DOI: 10.15761/ifnm.1000154] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Mackay A, Vinci M, Burford A, Bjerke L, Taylor K, Nandhabalan M, Marshall L, Molinari V, Popov S, Ingram W, Moore A, Trabelsi S, Hmida D, Mu K, Bidinotto L, Reis R, Ng HK, von Bueren A, Baudis M, Jones C. HG-11 * INTEGRATIVE MOLECULAR META-ANALYSIS OF 700 PEDIATRIC HIGH GRADE GLIOMA AND DIPG DEFINES WIDESPREAD INTER- AND INTRA-TUMORAL HETEROGENEITY. Neuro Oncol 2015. [DOI: 10.1093/neuonc/nov061.48] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cao DH, Mu K, Liu DN, Sun JL, Bai XZ, Zhang N, Qiu GB, Ma XW. Identification of novel compound heterozygous RECQL4 mutations and prenatal diagnosis of Baller-Gerold syndrome: a case report. Genet Mol Res 2015; 14:4757-66. [PMID: 25966250 DOI: 10.4238/2015.may.11.8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Birth defects are structural and/or functional malformations present at birth that cause physical or mental disability and are important public health problems. Our study was aimed at genetic analysis and prenatal diagnosis of congenital anomalies to understand the cause of certain birth defects. Karyotypes and array-comparative genomic hybridization (aCGH) were performed on a pregnant woman, surrounding amniotic fluid, and her husband. A short-stature panel genetic test was conducted in accordance with the phenotype of the fetus. Following examination, it was determined that the karyotype and aCGH results were normal. The RECQL4 gene in the fetus showed compound heterozygous mutations, and each parent was found to be a carrier of one of the mutations. The two heterozygous mutations (c.2059-1G>C and c.2141_2142delAG) were detected in the RECQL4 (NM_004260) gene in the fetus; therefore, the fetus was predicted to have Baller-Gerold syndrome. These two mutations have not previously been reported. In addition, these results identified a 25% risk of the parents having a sec-ond conceptus with this congenital disease. Therefore, prenatal genetic diagnosis was highly recommended for future pregnancies.
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Affiliation(s)
- D H Cao
- Aristogenesis Center, Hospital of PLA, Shenyang, China
| | - K Mu
- Genetic Disease Laboratory, Zibo Maternal and Child Health Hospital, Zibo, China
| | - D N Liu
- Aristogenesis Center, Hospital of PLA, Shenyang, China
| | - J L Sun
- Aristogenesis Center, Hospital of PLA, Shenyang, China
| | - X Z Bai
- Aristogenesis Center, Hospital of PLA, Shenyang, China
| | - N Zhang
- Aristogenesis Center, Hospital of PLA, Shenyang, China
| | - G B Qiu
- Department of Laboratory Medicine, Hospital of PLA, Shenyang, China
| | - X W Ma
- Aristogenesis Center, Hospital of PLA, Shenyang, China
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Tantibhedhyangkul J, Hawkins KC, Dai Q, Mu K, Dunn CN, Miller SE, Price TM. Expression of a mitochondrial progesterone receptor in human spermatozoa correlates with a progestin-dependent increase in mitochondrial membrane potential. Andrology 2014; 2:875-83. [PMID: 25187426 DOI: 10.1111/j.2047-2927.2014.00263.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 06/23/2014] [Revised: 07/28/2014] [Accepted: 07/31/2014] [Indexed: 12/23/2022]
Abstract
The hyperactivation of human spermatozoa necessary for fertilization requires a substantial increase in cellular energy production. The factors responsible for increasing cellular energy remain poorly defined. This article proposes a role for a novel mitochondrial progesterone receptor (PR-M) in modulation of mitochondrial activity. Basic science studies demonstrate a 38 kDa protein with western blot analysis, consistent with PR-M; whereas imaging studies with confocal and immunoelectron microscopy demonstrate a PR on the mitochondria. Treatment with a PR-specific progestin shows increased mitochondrial membrane potential, not related to induction of an acrosome reaction. The increase in mitochondrial membrane potential was inhibited by a specific PR antagonist, but not affected by an inhibitor to the progesterone-dependent Catsper voltage-activated channel. In conclusion, these studies suggest expression of a novel mitochondrial PR in human spermatozoa with a progestin-dependent increase in mitochondrial activity. This mechanism may serve to enhance cellular energy production as the spermatozoa traverse the female genital tract being exposed to increasing concentrations of progesterone.
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Scheirton LS, Mu K, Lohman H, Cochran TM. Error and patient safety: ethical analysis of cases in occupational and physical therapy practice. Med Health Care Philos 2007; 10:301-11. [PMID: 17310308 DOI: 10.1007/s11019-007-9049-3] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 01/10/2007] [Indexed: 05/14/2023]
Abstract
Compared to other health care professions such as medicine, nursing and pharmacy, few studies have been conducted to examine the nature of practice errors in occupational and physical therapy. In an ongoing study to determine root causes, typographies and impact of occupational and physical therapy error on patients, focus group interviews have been conducted across the United States. A substantial number of harmful practice errors and/or other patient safety events (deviations or accidents) have been identified. Often these events have had moral dimensions that troubled the therapist involved. In this article, six of these transcribed cases are analyzed, using predominant bioethical theories, ethical principles and professional codes of ethics. The cases and their analyses are intended to be exemplary, improving the readers' ability to discern and critically address similar such events. Several patient safety strategies are suggested that might have prevented the events described in these cases.
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Affiliation(s)
- Linda S Scheirton
- School of Pharmacy and Health Professions, Occupational Therapy, Creighton University Medical Center, 2500 California Plaza, Omaha, NE 68178, USA.
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Crabtree JL, Royeen CB, Mu K. The effects of learning through discussion in a course in occupational therapy: a search for deep learning. J Allied Health 2002; 30:243-7. [PMID: 11828587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
This preliminary educational research study examined occupational therapy students' perceptions of the learning through discussion (LTD) method. The study incorporated both quantitative and qualitative strategies. A convenience sample of nine post-professional occupational therapy doctoral students participated. Overall, participating students reported positive experiences when engaging in LTD, reporting that they had actively engaged in critical thinking and learning and experienced transformative learning. However, the results of nonparametric analysis revealed no significant change in the perceptions of the students of their classroom performances. Findings are discussed in light of current educational programs in occupational therapy. Future research studies are recommended to further examine the efficacy of LTD and explore its utility for training allied health professionals.
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Affiliation(s)
- J L Crabtree
- School of Allied Health, College of Health Sciences, University of Texas at El Paso, 1101 N. Campbell Street, El Paso, Texas 79902, USA.
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Abstract
Parkinson's disease (PD) profoundly affects activities of daily living (ADL) and quality of human life. Although unilateral pallidotomy has become a common surgical treatment for persons with advanced PD, functional outcome data from previous reports have failed to uniformly support this procedure. In the present investigation, results from 12 studies meeting specific inclusion criteria were subjected to meta-analysis. Only reports featuring unilateral pallidotomy as the exclusive surgery, a sample size of at least five patients, explicit assessment of ADL, and sufficient quantitative data were subjected to analysis. Type of research design was not a factor in the selection process. The results of our analysis suggest that unilateral pallidotomy successfully enhances functional outcome in patients with clinically advanced PD.
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Affiliation(s)
- S O Ahmad
- Department of Occupational Therapy, School of Pharmacy and Allied Health Professions, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
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17
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Mu K. [Chronic pulmonary diseases: trend and research methods]. Zhonghua Nei Ke Za Zhi 1997; 36:436-7. [PMID: 10436940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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18
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Mu K. [Control of chronic obstructive pulmonary disease]. Zhonghua Nei Ke Za Zhi 1996; 35:365-6. [PMID: 9387620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Affiliation(s)
- M N Chong
- School of Applied Science, Nanyang Technological University, Singapore
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Zhao M, Qi G, Mu K. [Comparative observation on the relationship between the MEFV and the visual inspection of small airway]. Zhonghua Jie He He Hu Xi Za Zhi 1996; 19:18-21. [PMID: 9275382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To compare the relationship between the MEFV and the visual inspection of small airway. METHODS According to the result on small airway function test (MEFV), the patients were divided into two group: MEFV abnormal group and MEFV normal group. Their bronchus and peripheral airway were observed with bronchofiberscope and ultra-thin bronchofiberscope. The visual appearance of the airways was scored in the light of the presence or absence of erythema, edema, secretions, etc. RESULTS The score of visual appearance observed or bronchitis index (BI) in small airway was 7.7 +/- 0.8 (BI: 3.0 +/- 0.8) and 4.7 +/- 1.6 (BI: 1.5 +/- 0.5) respectively in MEFV abnormal group and in MEFV normal group, namely the score in MEFV abnormal group was significantly higher than that of normal group (P < 0.01). The degree of pathological change in small airway was significantly correlated with the results of V25, V50, r = -0.6271, (P < 0.05) and r = 0.6964, (P < 0.02). CONCLUSION The abnormal of MEFV may reflect inflamative pathological changes of small airway.
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Affiliation(s)
- M Zhao
- Department of Respiratory Disease, 3rd Hospital, Beijing Medical University
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Gao L, Mu K. [Relation between emphysema and diaphragmatic fatigue]. Zhonghua Yi Xue Za Zhi 1992; 72:147-50, 190. [PMID: 1319806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Emphysematous rats induced by elastase were divided into 5 groups: N (control), P1 (elastase for 3 mo.), P2 (elastase for 4.5 mo.; NS intraperitoneally for 1 mo. after 3.5 mo. elastase); A and C, aminophylline and ginseng preparation were respectively given in the same fashion as P2. The results were: 1. tension and endurance of diaphragm muscle decreased under low frequency stimulation in P2, while those no change in P1. DNA, RNA and ATPase increased, cross-sectional areas and glycogen decreased in P1, while ATPase and RNA reduced with increase of cross-sectional areas in P2; 2. in A, no change in tension, with enhanced endurance; 3. in C, tension increased with no change in endurance; 4. glycogen and cross-sectional areas increased in both A and C; 5. RNA and ATPase increased in C and no change in A.
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Affiliation(s)
- L Gao
- First Hospital, Beijing Medical University
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