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Manjur SM, Diaz LRM, Lee IO, Skuse DH, Thompson DA, Marmolejos-Ramos F, Constable PA, Posada-Quintero HF. Detecting Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder Using Multimodal Time-Frequency Analysis with Machine Learning Using the Electroretinogram from Two Flash Strengths. J Autism Dev Disord 2024:10.1007/s10803-024-06290-w. [PMID: 38393437 DOI: 10.1007/s10803-024-06290-w] [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] [Accepted: 02/13/2024] [Indexed: 02/25/2024]
Abstract
PURPOSE Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are conditions that similarly alter cognitive functioning ability and challenge the social interaction, attention, and communication skills of affected individuals. Yet these are distinct neurological conditions that can exhibit diverse characteristics which require different management strategies. It is desirable to develop tools to assist with early distinction so that appropriate early interventions and support may be tailored to an individual's specific requirements. The current diagnostic procedures for ASD and ADHD require a multidisciplinary approach and can be lengthy. This study investigated the potential of electroretinogram (ERG), an eye test measuring retinal responses to light, for rapid screening of ASD and ADHD. METHODS Previous studies identified differences in ERG amplitude between ASD and ADHD, but this study explored time-frequency analysis (TFS) to capture dynamic changes in the signal. ERG data from 286 subjects (146 control, 94 ASD, 46 ADHD) was analyzed using two TFS techniques. RESULTS Key features were selected, and machine learning models were trained to classify individuals based on their ERG response. The best model achieved 70% overall accuracy in distinguishing control, ASD, and ADHD groups. CONCLUSION The ERG to the stronger flash strength provided better separation and the high frequency dynamics (80-300 Hz) were more informative features than lower frequency components. To further improve classification a greater number of different flash strengths may be required along with a discrimination comparison to participants who meet both ASD and ADHD classifications and carry both diagnoses.
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Affiliation(s)
| | | | - Irene O Lee
- Behavioral and Brain Sciences Unit, Population Policy and Practice Program, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - David H Skuse
- Behavioral and Brain Sciences Unit, Population Policy and Practice Program, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Dorothy A Thompson
- Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- UCL Great Ormond Street Institute for Child Health, University College London, London, UK
| | | | - Paul A Constable
- College of Nursing and Health Sciences, Flinders University, Caring Futures Institute, Adelaide, Australia
| | - Hugo F Posada-Quintero
- Department of Biomedical Engineering, University of Connecticut, 06269, Storrs, CT, USA.
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Manjur SM, Hossain MB, Constable PA, Thompson DA, Marmolejo-Ramos F, Lee IO, Skuse DH, Posada-Quintero HF. Detecting Autism Spectrum Disorder Using Spectral Analysis of Electroretinogram and Machine Learning: Preliminary results. Annu Int Conf IEEE Eng Med Biol Soc 2022; 2022:3435-3438. [PMID: 36083945 DOI: 10.1109/embc48229.2022.9871173] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition that impacts language, communication and social interactions. The current diagnostic process for ASD is based upon a detailed multidisciplinary assessment. Currently no clinical biomarker exists to help in the diagnosis and monitoring of this condition that has a prevalence of approximately 1%. The electroretinogram (ERG), is a clinical test that records the electrical response of the retina to light. The ERG is a promising way to study different neurodevelopmental and neurodegenerative disorders, including ASD. In this study, we have proposed a machine learning based method to detect ASD from control subjects using the ERG waveform. We collected ERG signals from 47 control (CO) and 96 ASD individuals. We analyzed ERG signals both in the time and the spectral domain to gain insight into the statistically significant discriminating features between CO and ASD individuals. We evaluated the machine learning (ML) models using a subject independent cross validation-based approach. Time-domain features were able to detect ASD with a maximum 65% accuracy. The classification accuracy of our best ML model using time-domain and spectral features was 86%, with 98% sensitivity. Our preliminary results indicate that spectral analysis of ERG provides helpful information for the classification of ASD.
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Constable PA, Marmolejo-Ramos F, Gauthier M, Lee IO, Skuse DH, Thompson DA. Discrete Wavelet Transform Analysis of the Electroretinogram in Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder. Front Neurosci 2022; 16:890461. [PMID: 35733935 PMCID: PMC9207322 DOI: 10.3389/fnins.2022.890461] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/09/2022] [Indexed: 12/30/2022] Open
Abstract
Background To evaluate the electroretinogram waveform in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) using a discrete wavelet transform (DWT) approach. Methods A total of 55 ASD, 15 ADHD and 156 control individuals took part in this study. Full field light-adapted electroretinograms (ERGs) were recorded using a Troland protocol, accounting for pupil size, with five flash strengths ranging from –0.12 to 1.20 log photopic cd.s.m–2. A DWT analysis was performed using the Haar wavelet on the waveforms to examine the energy within the time windows of the a- and b-waves and the oscillatory potentials (OPs) which yielded six DWT coefficients related to these parameters. The central frequency bands were from 20–160 Hz relating to the a-wave, b-wave and OPs represented by the coefficients: a20, a40, b20, b40, op80, and op160, respectively. In addition, the b-wave amplitude and percentage energy contribution of the OPs (%OPs) in the total ERG broadband energy was evaluated. Results There were significant group differences (p < 0.001) in the coefficients corresponding to energies in the b-wave (b20, b40) and OPs (op80 and op160) as well as the b-wave amplitude. Notable differences between the ADHD and control groups were found in the b20 and b40 coefficients. In contrast, the greatest differences between the ASD and control group were found in the op80 and op160 coefficients. The b-wave amplitude showed both ASD and ADHD significant group differences from the control participants, for flash strengths greater than 0.4 log photopic cd.s.m–2 (p < 0.001). Conclusion This methodological approach may provide insights about neuronal activity in studies investigating group differences where retinal signaling may be altered through neurodevelopment or neurodegenerative conditions. However, further work will be required to determine if retinal signal analysis can offer a classification model for neurodevelopmental conditions in which there is a co-occurrence such as ASD and ADHD.
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Affiliation(s)
- Paul A. Constable
- College of Nursing and Health Sciences, Caring Futures Institute, Flinders University, Adelaide, SA, Australia
- *Correspondence: Paul A. Constable,
| | - Fernando Marmolejo-Ramos
- Centre for Change and Complexity in Learning, The University of South Australia, Adelaide, SA, Australia
| | - Mercedes Gauthier
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine and Health Sciences, McGill University, Montréal, QC, Canada
| | - Irene O. Lee
- Behavioural and Brain Sciences Unit, Population, Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - David H. Skuse
- Behavioural and Brain Sciences Unit, Population, Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Dorothy A. Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom
- UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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Lee IO, Skuse DH, Constable PA, Marmolejo-Ramos F, Olsen LR, Thompson DA. The electroretinogram b-wave amplitude: a differential physiological measure for Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder. J Neurodev Disord 2022; 14:30. [PMID: 35524181 PMCID: PMC9077889 DOI: 10.1186/s11689-022-09440-2] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/12/2022] [Indexed: 12/02/2022] Open
Abstract
Background Attention Deficit Hyperactivity Disorder (ADHD) is the most prevalent childhood neurodevelopmental disorder. It shares some genetic risk with Autism Spectrum Disorder (ASD), and the conditions often occur together. Both are potentially associated with abnormal glutamate and GABA neurotransmission, which can be modelled by measuring the synaptic activity in the retina with an electroretinogram (ERG). Reduction of retinal responses in ASD has been reported, but little is known about retinal activity in ADHD. In this study, we compared the light-adapted ERGs of individuals with ADHD, ASD and controls to investigate whether retinal responses differ between these neurodevelopmental conditions. Methods Full field light-adapted ERGs were recorded from 15 ADHD, 57 ASD (without ADHD) and 59 control participants, aged from 5.4 to 27.3 years old. A Troland protocol was used with a random series of nine flash strengths from −0.367 to 1.204 log photopic cd.s.m−2. The time-to-peak and amplitude of the a- and b-waves and the parameters of the Photopic Negative Response (PhNR) were compared amongst the three groups of participants, using generalised estimating equations. Results Statistically significant elevations of the ERG b-wave amplitudes, PhNR responses and faster timings of the b-wave time-to-peak were found in those with ADHD compared with both the control and ASD groups. The greatest elevation in the b-wave amplitudes associated with ADHD were observed at 1.204 log phot cd.s.m−2 flash strength (p < .0001), at which the b-wave amplitude in ASD was significantly lower than that in the controls. Using this measure, ADHD could be distinguished from ASD with an area under the curve of 0.88. Conclusions The ERG b-wave amplitude appears to be a distinctive differential feature for both ADHD and ASD, which produced a reversed pattern of b-wave responses. These findings imply imbalances between glutamate and GABA neurotransmission which primarily regulate the b-wave formation. Abnormalities in the b-wave amplitude could provisionally serve as a biomarker for both neurodevelopmental conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s11689-022-09440-2.
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Affiliation(s)
- Irene O Lee
- Behavioural and Brain Sciences Unit, Population Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK.
| | - David H Skuse
- Behavioural and Brain Sciences Unit, Population Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Paul A Constable
- Caring Futures Institute, College of Nursing and Health Sciences, Flinders University, Adelaide, South Australia, Australia
| | - Fernando Marmolejo-Ramos
- Centre for Change and Complexity in Learning, University of South Australia, Adelaide, Australia
| | - Ludvig R Olsen
- Department of Molecular Medicine (MOMA), Aarhus University, Aarhus, Denmark
| | - Dorothy A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Sight and Sound Centre, Great Ormond Street Hospital for Children NHS Trust, London, UK.,UCL Great Ormond Street Institute of Child Health, University College London, London, UK
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Abstract
CLINICAL RELEVANCE To ascertain if the photopic negative response of the electroretinogram is different in autism spectrum disorder as a potential clinical marker. BACKGROUND Visual function can be atypical in autism spectrum disorder and structural imaging of the ganglion cell layers has been reported to differ in these individuals. Therefore, we sought to investigate if the photopic negative response of the full field electroretinograms, a measure of ganglion cell function, could help explain the visual perceptual differences in autism spectrum disorder and support the structural changes observed. METHODS Participants (n = 55 autism spectrum disorder, aged 5.4-26.7 years) and control (n = 87, aged 5.4-27.3 years) were recruited for the study. Full-field light-adapted electroretinograms using a Troland protocol with 10 flash strengths from -0.367 to 1.204 log photopic cd.s.m-2 were recorded in each eye. The photopic negative response amplitudes at Tmin and at t = 72 ms were compared between groups along with the a- and b-wave values. RESULTS There were no significant interactions between groups for the Photopic Negative Response measures of amplitude or time (p > 0.30). There was a group interaction between groups and flash strengths for the b-wave amplitude as previously reported (p < 0.001). CONCLUSION The photopic negative response results suggest that there are no significant differences in the summed retinal ganglion cell responses produced by a full-field stimulus.
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Affiliation(s)
- Paul A Constable
- Caring Futures Institute, College of Nursing and Health Sciences, Flinders University, Adelaide, Australia
| | - Irene O Lee
- Behavioural and Brain Sciences Unit, Population Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Fernando Marmolejo-Ramos
- Centre for Change and Complexity in Learning, The University of South Australia, Adelaide, Australia
| | - David H Skuse
- Behavioural and Brain Sciences Unit, Population Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Dorothy A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, London, UK.,UCL Great Ormond Street Institute of Child Health, University College London, London, UK
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Lee CS, Kim JY, Kim BK, Lee IO, Park NH, Kim SH. Lactobacillus-fermented milk products attenuate bone loss in an experimental rat model of ovariectomy-induced post-menopausal primary osteoporosis. J Appl Microbiol 2020; 130:2041-2062. [PMID: 32920885 DOI: 10.1111/jam.14852] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 04/09/2020] [Revised: 07/09/2020] [Accepted: 09/03/2020] [Indexed: 01/08/2023]
Abstract
AIM In this study, we investigated the anti-osteoporotic effect of two fermented milk products (FMPs) fermented by Lactobacillus plantarum A41 and Lactobacillus fermentum SRK414 on a rat model of ovariectomy-induced post-menopausal primary osteoporosis. METHODS AND RESULTS The two Lactobacillus FMPs increased the bone volume and bone mineral density (BMD) in ovariectomized (OVX) rats, and normalized the bone biomarkers in the serum. Additionally, they altered the gene expression levels of bone-metabolism-related markers. Furthermore, the two Lactobacillus FMPs downregulated bone-apoptosis-related genes stimulated by ovariectomy. Interestingly, the Lactobacillus FMPs decreased the levels of inflammation markers in the serum, bone, ileum and colon of the rats. Gut bacterial populations were also affected upon FMP treatment due to increase in the abundance of the genus Lactobacillus and Faecalibacterium prausnitzii. CONCLUSIONS Milk products fermented by L. plantarum A41 and L. fermentum SRK414 can exhibit anti-osteoporotic effects on post-menopausal osteoporosis via regulating the expression of bone-metabolism-related markers. SIGNIFICANCE AND IMPACT OF THE STUDY The two Lactobacillus FMPs used in the study can be an ideal method that has its potential of treating post-menopausal osteoporosis instead of drug treatments.
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Affiliation(s)
- C S Lee
- College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - J-Y Kim
- College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - B K Kim
- Probiotic Research Laboratory, CKD Bio Research Institute, Ansan, Republic of Korea
| | - I O Lee
- Probiotic Research Laboratory, CKD Bio Research Institute, Ansan, Republic of Korea
| | - N H Park
- Probiotic Research Laboratory, CKD Bio Research Institute, Ansan, Republic of Korea
| | - S H Kim
- College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
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Abstract
BACKGROUND AND OBJECTIVES This study was designed to investigate whether single epidural droperidol or continuous epidural droperidol inhibit pruritus and postoperative nausea and vomiting induced by postoperative continuous epidural fentanyl administration, and to identify the optimal method of administering epidural droperidol. METHODS 120 ASA I-II patients undergoing subtotal gastrectomy with general anaesthesia combined with epidural anaesthesia were randomly allocated into three groups: control (no droperidol), single injection (droperidol 2.5 mg) and continuous group (droperidol 2.5 mg 2 day(-1)). Postoperatively the frequency and severity of pruritus and postoperative nausea and vomiting in all groups were compared during 48 h. RESULTS The frequency and severity of pruritus was significantly lower in both single injection and continuous groups than control group after epidural fentanyl administration (P < 0.05). The frequency and severity of postoperative nausea and vomiting was significantly lower in single injection group than control group after epidural fentanyl administration (P < 0.05). CONCLUSION Epidural continuous droperidol is effective for reducing pruritus, and single epidural droperidol injection is effective for reducing pruritus and postoperative nausea and vomiting induced by postoperative continuous epidural fentanyl analgesia.
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Affiliation(s)
- I H Lee
- Department of Anesthesiology, Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea
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Lee IO, Lee IH. Systemic, but not intrathecal, ketamine produces preemptive analgesia in the rat formalin model. Acta Anaesthesiol Sin 2001; 39:123-7. [PMID: 11688102] [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: 02/22/2023]
Abstract
BACKGROUND We investigated the antinociceptive effects of pre- or posttreatment of intrathecal or intravenous ketamine on formalin-induced pain behaviors. METHODS Rats were divided into 4 groups of 7 rats each and 2 control groups (saline). Rats received ketamine 1 mg/kg intrathecally (i.t.) through a catheter either 15 min before or 5 min after formalin. In the other groups, they received ketamine 1 mg/kg intravenously (i.v.) through a catheter either 1 min before or 5 min after the formalin. Pain related behavior was quantified by counting the incidence of flinching of the injected paw for 60 min. Formalin induced a biphasic fliching (phase 1, 0-5 min; phase 2, 10-60 min after formalin injection) of injected paw. The inter-group (control, pre, and posttreatment groups) comparisons were performed separately for route of administration (i.t. or i.v.) and phase 1 and 2 using one-way ANOVA and Tukey test. RESULTS Flinches of phase 1 were not different among the three i.t. groups. The total flinches of phase 2 were reduced by posttreatment with i.t. ketamine (P < 0.05); In contrast, i.v. ketamine was effective only when given as a pretreatment. Flinches of phase 1 and 2 were reduced by pretreatment with i.v. ketamine (P < 0.05). CONCLUSIONS Intrathecal ketamine was an analgesic even when administered as a posttreatment, whereas intravenous ketamine produced effective preemption only when given as a pretreatment.
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Affiliation(s)
- I O Lee
- Department of Anaesthesia, College of Medicine, Korea University Guro Hospital, 80 Guro-dong, Guro-ku, Seoul, South Korea 152-703.
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Lee IO, Kim SH, Kong MH, Lee MK, Kim NS, Choi YS, Lim SH. Pain after laparoscopic cholecystectomy: the effect and timing of incisional and intraperitoneal bupivacaine. Can J Anaesth 2001; 48:545-50. [PMID: 11444448 DOI: 10.1007/bf03016830] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [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: 01/12/2023] Open
Abstract
PURPOSE To examine the combined preemptive effects of somatovisceral blockade during laparoscopic cholecystectomy (LC). METHODS One hundred fifty-seven patients under general anesthesia receiving local infiltration and/or topical peritoneal local anesthesia were studied. Patients were randomized to receive a total of 150 mg (0.25% 60 mL) bupivacaine via periportal (20 mL) and intraperitoneal (40 mL with 1:200,000 epinephrine) administration of each. Group A received preoperative periportal bupivacaine before incision and intraperitoneal bupivacaine immediately after the pneumoperitoneum. Group B received periportal and intraperitoneal bupivacaine at the end of the operation. Group C (preoperative) and Group D (postoperative) received only periportal bupivacaine and Group E (preoperative) and Group F (post-operative) received only intraperitoneal bupivacaine. The control group received no treatment. Pain and nausea were recorded at one, two, three, six, nine, 12, 24, 36, and 48 hr postoperatively. RESULTS Throughout the postoperative 48 hr, incisional somatic pain dominated over other pain localizations in the control group (P <0.05). The incisional pain of groups A, B, C and D was significantly lower than that of the control group in the first and second hours. The incisional pain of groups A and C was significantly lower than that of the control group in the first three hours. CONCLUSION Incisional pain dominated during the first two post-operative days after LC. Preoperative somato-visceral or somatic local anesthesia reduced incisional pain during the first three post-operative hours. A combination of somato-visceral local anesthetic treatment did not reduce intraabdominal pain, shoulder pain or nausea more than somatic treatment alone. Preoperative incisional infiltration of local anesthetics is recommended.
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Affiliation(s)
- I O Lee
- Department of Anesthesia, College of Medicine, Korea University Guro Hospital, Seoul
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Abstract
Permanent ischemic injury of the hand after radial artery cannulation is rare, but several cases of thromboembolism after the cannulation leading to amputation of affected limb or digits have been reported. A 48-yr-old man undergoing spine surgery showed normal modified Allen's test and had no preoperative vascular disease. We inserted 20-G radial artery catheter for the continuous monitoring of the blood flow and serial blood sampling. There was no specific event during the operation and the catheter was removed immediately after the operation. The signs and symptoms of the circulatory impairment of the radial artery developed four days after the operation and aggravated thereafter. Through the angiographic study, we found the total occlusion of the radial artery and some of its branches. After an emergent surgical exploration of the radial artery for removal of the thrombus and vein graft for the defect of the artery on the 8th postoperative day, the ischemic signs and symptoms disappeared and the radial pulse was restored.
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Affiliation(s)
- M K Lee
- Department of Anesthesiology, Guro Hospital, Korea University College of Medicine, Seoul, Korea
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Lee MK, Lee IO, Kong MH, Kim NS, Choi YS, Lim SH. Comparative effects of diltiazem with enflurane or desflurane on myocardial contractility and heart rate in the isolated rat hearts. Acta Anaesthesiol Sin 2000; 38:173-9. [PMID: 11392064] [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: 02/20/2023]
Abstract
BACKGROUND The volatile anesthetics may reduce cardiac contractility by limiting both membrane Ca2+ entry and altering intracellular Ca2+ release. Additional pharmacological effects of calcium channel blockers could potentially enhance anesthetic-induced depression. The aim of this study was to compare the direct cardiac effects of enflurane and a new volatile anesthetic, desflurane, in combination with diltiazem on the isolated Sprague-Dawley rat heart. METHODS After stabilization period isolated rat hearts (n = 40) were perfused with an oxygenated modified Krebs' solution at 55 mmHg equilibrated with 1, 2 and 3 MAC of enflurane (1.7, 3.4 and 5.1 vol% respectively) or desflurane (6, 12 and 18 vol% respectively) in combination with 100 ng/mL diltiazem at 36 degrees C. Isovolumetric left ventricular pressure (LVP), rate of change of ventricular pressure (dp/dt), spontaneous heart rate and coronary flow were measured. To examine the indirect metabolic effect due to autoregulation of coronary flow, O2 delivery (DO2), myocardial O2 consumption (MVO2) and percent O2 extraction (POE) were also monitored. RESULTS Diltiazem plus enflurane or desflurane depressed LVP and dp/dt dose-dependently. Enflurane plus diltiazem significantly decreased heart rate more than desflurane plus diltiazem in a dose-dependent manner. Desflurane plus diltiazem significantly increased coronary flow more than enflurane plus diltiazem and oxygen delivery increased proportionally with coronary flow. But there were statistically insignificant dose-dependent increases in both groups. Myocardial oxygen consumption and percentage of oxygen extraction were also decreased dose-dependently in both groups. Bradydysrhythmia that accompanied atrioventricular dissociation occurred with diltiazem plus high enflurane or desflurane concentration at an incidence of 46% and 40% respectively. CONCLUSIONS These in vitro results demonstrate that diltiazem plus enflurane or desflurane depresses left ventricular contractile function and diltiazem plus enflurane causes higher incidence of bradydysrhythmia more than equivalent levels of diltiazem plus desflurane.
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Affiliation(s)
- M K Lee
- Department of Anesthesia, College of Medicine, Korea University, Seoul, Korea
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Lee IO, Kong MH, Kim NS, Choi YS, Lim SH, Lee MK. Effects of different concentrations and volumes of formalin on pain response in rats. Acta Anaesthesiol Sin 2000; 38:59-64. [PMID: 11000667] [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: 02/17/2023]
Abstract
BACKGROUND Formalin test is commonly used in animal model to assess injury-produced pain response. If the total amount of formaldehyde is fixed, its concentration and volume can be easily adjusted. We evaluated the effect of two sets of three solutions of formalin (one set of same dose of formaldehyde at different concentration and volume, i.e. 2.5%--100 microL, 5%--50 microL, 10%--25 microL, and another set of same volume but at different concentrations, i.e. 2.5%--100 microL, 5%--100 microL, and 10%--100 microL) on the injury-produced pain response in rat. METHODS Male Sprague-Dawley rats weighing 250-300 g were used. Following injection of formalin (n = 8 in each group) or saline (n = 6, control), the flinching frequencies and time spent in licking or biting the injected hind-paw in the early phase 1 (0-5 min after injection) and the late phase 2 (20-60 min after injection) were recorded. Sham-injection rats (n = 5) underwent subcutaneous insertion of the needle, but no substance was injected. RESULTS Flinching in phase 1 and 2 was more frequent in the 2.5%--100 microL and 5%--50 microL groups than in the control group (P < 0.05). Licking (or biting) time in phase 2 in all these three groups was longer than the control group (P < 0.05). In the groups of another set of three different solutions (2.5%--100 microL, 5%--100 microL, and 10%--100 microL), flinching in phase 1 and phase 2 was also more frequent than the control group (P < 0.05). Regarding lick behavior of another set, it occurred more frequently in 2.5%--100 microL group in phase 1 and in 2.5%--100 microL group as well as 5%--100 microL group in phase 2 than the control group (P < 0.05). CONCLUSIONS The 10%--25 microL formalin produces fewer flinching responses than other concentrations. Flinching was a biphasic behavior which was more spontaneous and active than was licking. The volume of formalin was a more important factor than the concentration of formalin in the generation of the active biphasic flinching response in the rat model.
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Affiliation(s)
- I O Lee
- Department of Anesthesia, College of Medicine, Korea University, Seoul.
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Abstract
The formalin test is a model of injury-produced inflammatory pain. Anesthetics, in clinically relevant concentrations, affect neutrophils and immune suppression. This study was to determine whether halothane reliably inhibits inflammatory reaction and formalin induced pain behavior or does not. Rats were exposed to 100% oxygen (control) or halothane, respectively for 30 min and then 24 hr later five percent formalin test was assessed. The base values of the paw's diameter were obtained earlier, and then formalin induced edema was assessed by measuring diameters of the injected paws at 5 min, 1 hr, 4 hr and 24 hr after the injection. Nociceptive behavior was quantified by counting the number of times with the paw flinched at 5 min intervals for 60 min. The diameters of edema in the halothane group lessened more than those in the oxygen group at 1 and 24 hr in each following of the injection (p<0.05). The rats pre-administered with oxygen or halothane were similar appearances in nociceptive behaviors. It suggests that halothane anesthesia might inhibit slightly the inflammatory reaction with the formalin-induced edema but might not inhibit the formalin-induced pain behavior in the event of pre-administration halothane 24 hr earlier before the formalin test of rat.
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Affiliation(s)
- I O Lee
- Department of Anesthesiology, College of Medicine, Korea University, Seoul.
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Abstract
In prior work, a 50 kDa protein was purified to homogeneity from rat urine. This protein reduces food intake when injected into rats and is the only natural substance other than satietin known to be effective for long (24 hour) time periods and which does not make animals ill. However, when attempts were made to repeat the purification, contamination appeared in the 50 kDa fraction. The present contribution documents successful reisolation of the 50 kDa anorexigen by an improved method. Reisolation involved Cibacron blue-Sepharose, DEAE-Sephacel and Sephacryl S-200 chromatography, and SDS disc preparatory electrophoresis. The reisolated 50 kDa anorexigen contains no detectable carbohydrate. Partially purified preparations of the 50 kDa anorexigen were fragmented with trypsin and proteinase K without loss of anorexigenic activity. It is concluded that the 50 kDa anorexigen may be reproducibly purified to homogeneity and may contain within its amino acid sequence a peptide which is the basis of its anorexigenic activity.
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Affiliation(s)
- H Ako
- Department of Agricultural Biochemistry, University of Hawaii, Honolulu 96822
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