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Fabian ST, Sondhi Y, Allen PE, Theobald JC, Lin HT. Why flying insects gather at artificial light. Nat Commun 2024; 15:689. [PMID: 38291028 PMCID: PMC10827719 DOI: 10.1038/s41467-024-44785-3] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 01/04/2024] [Indexed: 02/01/2024] Open
Abstract
Explanations of why nocturnal insects fly erratically around fires and lamps have included theories of "lunar navigation" and "escape to the light". However, without three-dimensional flight data to test them rigorously, the cause for this odd behaviour has remained unsolved. We employed high-resolution motion capture in the laboratory and stereo-videography in the field to reconstruct the 3D kinematics of insect flights around artificial lights. Contrary to the expectation of attraction, insects do not steer directly toward the light. Instead, insects turn their dorsum toward the light, generating flight bouts perpendicular to the source. Under natural sky light, tilting the dorsum towards the brightest visual hemisphere helps maintain proper flight attitude and control. Near artificial sources, however, this highly conserved dorsal-light-response can produce continuous steering around the light and trap an insect. Our guidance model demonstrates that this dorsal tilting is sufficient to create the seemingly erratic flight paths of insects near lights and is the most plausible model for why flying insects gather at artificial lights.
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Affiliation(s)
- Samuel T Fabian
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK.
| | - Yash Sondhi
- Institute for Environment, Department of Biology, Florida International University, Miami, FL, 33174, USA.
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA.
| | - Pablo E Allen
- Council on International Educational Exchange, Monteverde Apto, 43-5655, Costa Rica
| | - Jamie C Theobald
- Institute for Environment, Department of Biology, Florida International University, Miami, FL, 33174, USA
| | - Huai-Ti Lin
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
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Chen WR, Wang JH, Zhang Y, Chen H, Lin HT. [Attention should be paid to glaucoma following pediatric cataract surgery]. Zhonghua Yan Ke Za Zhi 2022; 58:321-325. [PMID: 35511657 DOI: 10.3760/cma.j.cn112142-20220217-00061] [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: 06/14/2023]
Abstract
Glaucoma following cataract surgery is one of the common complications after pediatric cataract surgery, and it is the main cause of "second blindness" in children. Since this atypical disease is difficult to diagnose and evaluate, it has been gradually paid more attention by clinicians. There are still some controversies and challenges related to the characteristics of the disease, diagnostic criteria, and treatment options. This article discusses the definition, diagnostic criteria, related risk factors, treatment strategies, follow-up, and prognoses of glaucoma following cataract surgery. Establishment of a diagnosis and treatment system can better improve the visual rehabilitation of pediatric cataract children.
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Affiliation(s)
- W R Chen
- Zhongshan Ophthalmic Center, Sun Yat-sen University, State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - J H Wang
- Zhongshan Ophthalmic Center, Sun Yat-sen University, State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Y Zhang
- Zhongshan Ophthalmic Center, Sun Yat-sen University, State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - H Chen
- Zhongshan Ophthalmic Center, Sun Yat-sen University, State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - H T Lin
- Zhongshan Ophthalmic Center, Sun Yat-sen University, State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
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Fabian J, Siwanowicz I, Uhrhan M, Maeda M, Bomphrey RJ, Lin HT. Systematic characterization of wing mechanosensors that monitor airflow and wing deformations. iScience 2022; 25:104150. [PMID: 35465360 PMCID: PMC9018384 DOI: 10.1016/j.isci.2022.104150] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 02/07/2022] [Accepted: 03/21/2022] [Indexed: 11/30/2022] Open
Abstract
Animal wings deform during flight in ways that can enhance lift, facilitate flight control, and mitigate damage. Monitoring the structural and aerodynamic state of the wing is challenging because deformations are passive, and the flow fields are unsteady; it requires distributed mechanosensors that respond to local airflow and strain on the wing. Without a complete map of the sensor arrays, it is impossible to model control strategies underpinned by them. Here, we present the first systematic characterization of mechanosensors on the dragonfly’s wings: morphology, distribution, and wiring. By combining a cross-species survey of sensor distribution with quantitative neuroanatomy and a high-fidelity finite element analysis, we show that the mechanosensors are well placed to perceive features of the wing dynamics relevant to flight. This work describes the wing sensory apparatus in its entirety and advances our understanding of the sensorimotor loop that facilitates exquisite flight control in animals with highly deformable wings. Dragonfly wings are innervated by an extensive collection of sensory neurons Mechanosensors are spread across the whole span of the wing with consistent patterns The axons of wing sensory neurons are scaled to compensate for transmission latencies Anatomically accurate models reveal wing strain fields that inform sensor distribution
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Affiliation(s)
- Joseph Fabian
- Imperial College London, London, SW7 2AZ, UK.,The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | | | | | | | | | - Huai-Ti Lin
- Imperial College London, London, SW7 2AZ, UK
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Abstract
Dragonflies perform dramatic aerial manoeuvres when chasing targets but glide for periods during cruising flights. This makes dragonflies a great system to explore the role of passive stabilizing mechanisms that do not compromise manoeuvrability. We challenged dragonflies by dropping them from selected inverted attitudes and collected 6-degrees-of-freedom aerial recovery kinematics via custom motion capture techniques. From these kinematic data, we performed rigid-body inverse dynamics to reconstruct the forces and torques involved in righting behaviour. We found that inverted dragonflies typically recover themselves with the shortest rotation from the initial body inclination. Additionally, they exhibited a strong tendency to pitch-up with their head leading out of the manoeuvre, despite the lower moment of inertia in the roll axis. Surprisingly, anaesthetized dragonflies could also complete aerial righting reliably. Such passive righting disappeared in recently dead dragonflies but could be partially recovered by waxing their wings to the anaesthetised posture. Our kinematics data, inverse dynamics model and wind-tunnel experiments suggest that the dragonfly's long abdomen and wing posture generate a rotational tendency and passive attitude recovery mechanism during falling. This work demonstrates an aerodynamically stable body configuration in a flying insect and raises new questions in sensorimotor control for small flying systems.
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Affiliation(s)
| | | | - Huai-Ti Lin
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
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Lin HT, Xiang YF, Cui TX, Chen JJ. [Online learning-related visual impairment and preventive measures during the 2019 novel coronvirus outbreak]. Zhonghua Yan Ke Za Zhi 2020; 56:E004. [PMID: 32077665 DOI: 10.3760/cma.j.cn112142-20200219-00089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- H T Lin
- Zhongshan Ophthalmic Center, Sun Yat-Sen University, State Key Laboratory of Ophthalmology, Guangzhou 510060, China
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Abstract
This work is a synthesis of our current understanding of the mechanics, aerodynamics and visually mediated control of dragonfly and damselfly flight, with the addition of new experimental and computational data in several key areas. These are: the diversity of dragonfly wing morphologies, the aerodynamics of gliding flight, force generation in flapping flight, aerodynamic efficiency, comparative flight performance and pursuit strategies during predatory and territorial flights. New data are set in context by brief reviews covering anatomy at several scales, insect aerodynamics, neuromechanics and behaviour. We achieve a new perspective by means of a diverse range of techniques, including laser-line mapping of wing topographies, computational fluid dynamics simulations of finely detailed wing geometries, quantitative imaging using particle image velocimetry of on-wing and wake flow patterns, classical aerodynamic theory, photography in the field, infrared motion capture and multi-camera optical tracking of free flight trajectories in laboratory environments. Our comprehensive approach enables a novel synthesis of datasets and subfields that integrates many aspects of flight from the neurobiology of the compound eye, through the aeromechanical interface with the surrounding fluid, to flight performance under cruising and higher-energy behavioural modes. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’.
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Affiliation(s)
- Richard J Bomphrey
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, North Mymms, Hatfield AL9 7TA, UK
| | - Toshiyuki Nakata
- Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba-shi, Chiba 263-8522, Japan
| | - Per Henningsson
- Department of Biology, Lund University, Ecology Building, 223 62 Lund, Sweden
| | - Huai-Ti Lin
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
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Wu XH, Cao QZ, Hu YX, Lin JN, Lin HT, Chen WR, Liu YZ. [Clinical characteristics and surgical effect observation of congenital aniridia combined with cataract]. Zhonghua Yan Ke Za Zhi 2017; 53:821-827. [PMID: 29141386 DOI: 10.3760/cma.j.issn.0412-4081.2017.11.005] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the clinical manifestations, surgical approaches and postoperative prognosis for the cases of congenital aniridia combined with cataract. Methods: In this retrospective case series, 26 patients diagnosed with congenital aniridia combined with cataract were collected from Zhongshan Ophthalmic Center from February 2002 to August 2016. The Clinical data were collected to analyze the clinical features, surgical approaches and postoperative prognosis. T-test was used for statistical analysis. Results: Twenty-six bilateral congenital aniridia patients were included in the case series, with 50% male cases. The average age for the first visit was (8.72±8.06) years old. Hereditary patients constitutes 30.8% (8/26) of the total number. The proportions for bilateral and unilateral cataracts were 88.5% (23/26) and 11.5% (3/26) respectively, and 49 eyes suffering from both congenital aniridia and cataract were therefore included in the final analysis. The most common morphology cataract subtypes were lamellar cataract (24.5%, 12/49), posterior subcapsular cataract (22.4%, 11/49), and total cataract (18.4%,9/49). The observed ocular comorbidities included nystagmus (36.7%, 18/49), vitreous opacity (28.6%, 14/49), foveal hypoplasia (20.4%, 10/49), ametropia (12.2%, 6/49), exotropia (12.2%, 6/49), congenital glaucoma (12.2%, 6/49), esotropia (4.1%, 2/49), congenital ptosis (4.1%, 2/49), lens ectopia (4.1%, 2/49), scleral staphyloma (2.0%, 1/49) and pigmentary degeneration of retina (2.0%, 1/49). 30.6% (15/49) eyes were performed the cataract extraction surgery. The percentage of postoperative best corrected visual acuity (BCVA) for ≥0.1 and ≥0.3 were 93.3% (14/15) and 20.0% (3/15) respectively. Evaluated ocular pressure (33.3%, 5/15), severe posterior capsular opacification (PCO) (13.3%, 2/15) and choroidal hemorrhage combined with choroidal detachment (6.7%, 1/15) were detected as the postoperative complications. Followed by cataract extraction, 80.0% (12/15) eyes were sequentially performed the intraocular lens implantation, while, 20.0% (3/12) eyes remained aphakia due to ocular comorbidities. Conclusions: Congenital aniridia combined with cataract are rare diseases, calling for the precious retrospective researches. This disorder tended to affect both eyes and occurred hereditary. The clinical courses of the cases presented progressive features. Ocular comorbidities were the crucial factors to influence the surgical approaches and postoperative prognosis. (Chin J Ophthalmol, 2017, 53: 821-827).
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Affiliation(s)
- X H Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China
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Lin HT, Leonardo A. Heuristic Rules Underlying Dragonfly Prey Selection and Interception. Curr Biol 2017; 27:1124-1137. [DOI: 10.1016/j.cub.2017.03.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/06/2017] [Accepted: 03/07/2017] [Indexed: 10/19/2022]
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Ros IG, Bhagavatula PS, Lin HT, Biewener AA. Rules to fly by: pigeons navigating horizontal obstacles limit steering by selecting gaps most aligned to their flight direction. Interface Focus 2017; 7:20160093. [PMID: 28163883 DOI: 10.1098/rsfs.2016.0093] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Flying animals must successfully contend with obstacles in their natural environments. Inspired by the robust manoeuvring abilities of flying animals, unmanned aerial systems are being developed and tested to improve flight control through cluttered environments. We previously examined steering strategies that pigeons adopt to fly through an array of vertical obstacles (VOs). Modelling VO flight guidance revealed that pigeons steer towards larger visual gaps when making fast steering decisions. In the present experiments, we recorded three-dimensional flight kinematics of pigeons as they flew through randomized arrays of horizontal obstacles (HOs). We found that pigeons still decelerated upon approach but flew faster through a denser array of HOs compared with the VO array previously tested. Pigeons exhibited limited steering and chose gaps between obstacles most aligned to their immediate flight direction, in contrast to VO navigation that favoured widest gap steering. In addition, pigeons navigated past the HOs with more variable and decreased wing stroke span and adjusted their wing stroke plane to reduce contact with the obstacles. Variability in wing extension, stroke plane and wing stroke path was greater during HO flight. Pigeons also exhibited pronounced head movements when negotiating HOs, which potentially serve a visual function. These head-bobbing-like movements were most pronounced in the horizontal (flight direction) and vertical directions, consistent with engaging motion vision mechanisms for obstacle detection. These results show that pigeons exhibit a keen kinesthetic sense of their body and wings in relation to obstacles. Together with aerodynamic flapping flight mechanics that favours vertical manoeuvring, pigeons are able to navigate HOs using simple rules, with remarkable success.
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Affiliation(s)
- Ivo G Ros
- Department of Organismic and Evolutionary Biology, Concord Field Station, Harvard University, Bedford, MA 01730, USA; Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Partha S Bhagavatula
- Department of Organismic and Evolutionary Biology, Concord Field Station , Harvard University , Bedford, MA 01730 , USA
| | - Huai-Ti Lin
- Department of Organismic and Evolutionary Biology, Concord Field Station, Harvard University, Bedford, MA 01730, USA; HHMI Janelia Research Campus, Ashburn, VA 20147, USA
| | - Andrew A Biewener
- Department of Organismic and Evolutionary Biology, Concord Field Station , Harvard University , Bedford, MA 01730 , USA
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Lin HT, Ros IG, Biewener AA. Correction to 'Through the eyes of a bird: modelling visually guided obstacle flight'. J R Soc Interface 2016; 13:rsif.2016.0934. [PMID: 28003525 DOI: 10.1098/rsif.2016.0934] [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: 11/12/2022] Open
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Talite MJA, Lin HT, Jiang ZC, Lin TN, Huang HY, Heredia E, Flores A, Chao YC, Shen JL, Lin CAJ, Yuan CT. Solid-state, ambient-operation thermally activated delayed fluorescence from flexible, non-toxic gold-nanocluster thin films: towards the development of biocompatible light-emitting devices. Nanotechnology 2016; 27:345701. [PMID: 27405350 DOI: 10.1088/0957-4484/27/34/345701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Luminescent gold nanoclusters (AuNCs) with good biocompatibility have gained much attention in bio-photonics. In addition, they also exhibit a unique photo-physical property, namely thermally activated delayed fluorescence (TADF), by which both singlet and triplet excitons can be harvested. The combination of their non-toxic material property and unique TADF behavior makes AuNCs biocompatible nano-emitters for bio-related light-emitting devices. Unfortunately, the TADF emission is quenched when colloidal AuNCs are transferred to solid states under ambient environment. Here, a facile, low-cost and effective method was used to generate efficient and stable TADF emissions from solid AuNCs under ambient environment using polyvinyl alcohol as a solid matrix. To unravel the underlying mechanism, temperature-dependent static and transient photoluminescence measurements were performed and we found that two factors are crucial for solid TADF emission: small energy splitting between singlet and triplet states and the stabilization of the triplet states. Solid TADF films were also deposited on the flexible plastic substrate with patterned structures, thus mitigating the waveguide-mode losses. In addition, we also demonstrated that warm white light can be generated based on a co-doped single emissive layer, consisting of non-toxic, solution-processed TADF AuNCs and fluorescent carbon dots under UV excitation.
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Affiliation(s)
- M J A Talite
- Department of Physics, Chung Yuan Christian University, Chung Li, Taiwan
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Jiang ZC, Lin TN, Lin HT, Talite MJ, Tzeng TT, Hsu CL, Chiu KP, Lin CAJ, Shen JL, Yuan CT. A Facile and Low-Cost Method to Enhance the Internal Quantum Yield and External Light-Extraction Efficiency for Flexible Light-Emitting Carbon-Dot Films. Sci Rep 2016; 6:19991. [PMID: 26822337 PMCID: PMC4731801 DOI: 10.1038/srep19991] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/21/2015] [Indexed: 12/23/2022] Open
Abstract
Solution-processed, non-toxic carbon dots (CDs) have attracted much attention due to their unique photoluminescence (PL) properties. They are promising emissive layers for flexible light-emitting devices. To this end, the CDs in pristine aqueous solutions need to be transferred to form solid-state thin films without sacrificing their original PL characteristics. Unfortunately, solid-state PL quenching induced by extra non-radiative (NR) energy transfer among CDs would significantly hinder their practical applications in optoelectronics. Here, a facile, low-cost and effective method has been utilized to fabricate high-performance CD/polymer light-emitting flexible films with submicron-structured patterns. The patterned polymers can serve as a solid matrix to disperse and passivate CDs, thus achieving high internal quantum yields of 61%. In addition, they can act as an out-coupler to mitigate the waveguide-mode losses, approximately doubling the external light-extraction efficiency. Such CD/polymer composites also exhibit good photo-stability, and thus can be used as eco-friendly, low-cost phosphors for solid-state lighting.
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Affiliation(s)
- Z C Jiang
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - T N Lin
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - H T Lin
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - M J Talite
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - T T Tzeng
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - C L Hsu
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - K P Chiu
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - C A J Lin
- Department of Biomedical Engineering, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - J L Shen
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
| | - C T Yuan
- Department of Physics, Chung Yuan Christian University, Chung Li, 320, Taiwan
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Lin HT, Hsu CH, Tsai HJ, Lin CH, Lo PY, Wang SL, Wang LC. Influenza A plasma and serum virus antibody detection comparison in dogs using blocking enzyme-linked immunosorbent assay. Vet World 2015; 8:580-3. [PMID: 27047138 PMCID: PMC4774716 DOI: 10.14202/vetworld.2015.580-583] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Revised: 03/31/2015] [Accepted: 04/07/2015] [Indexed: 11/18/2022] Open
Abstract
Background and Aim: The influenza A virus (IAV) is an important zoonotic pathogen with infections also reported in dogs. IAV infections can be detected through the presence of antibodies using the enzyme-linked immunosorbent assay (ELISA). Serum is the only standard sample source; however, there is no information on the availability of other sample sources for IAV antibody detection in dogs. Compared with serum, plasma is more widely employed in most animal hospitals. The object of this study is to investigate whether plasma collected in ethylenediaminetetraacetic acid (EDTA) tubes (EDTA plasma) or heparin tubes (heparin plasma) could be used in the ELISA protocol instead of serum for IAV antibody detection in dogs. Materials and Methods: Totally, 82 matched EDTA plasma and serum sample pairs and 79 matched heparin plasma and serum sample pairs were employed using blocking enzyme-linked immunosorbent assay (bELISA). The agreement and correlation between the plasma (EDTA or heparin plasma) and serum were assessed using the agreement index kappa (kD) calculation and Pearson correlation coefficient, respectively. Results: The agreement index kD of EDTA plasma and serum was 1.0, and that of heparin plasma and serum was 0.85. The Pearson correlation coefficient of EDTA plasma and serum was 0.87 (p<0.01), and that of heparin plasma and serum was 0.82 (p<0.01). Conclusion: The results proved that plasma, especially EDTA plasma, could be substituted for serum in the bELISA test. This might greatly expand the clinical applicability of IAV antibody detection in dogs.
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Affiliation(s)
- H T Lin
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - C H Hsu
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - H J Tsai
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - C H Lin
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - P Y Lo
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - S L Wang
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - L C Wang
- Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, 1 Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
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Abstract
Various flight navigation strategies for birds have been identified at the large spatial scales of migratory and homing behaviours. However, relatively little is known about close-range obstacle negotiation through cluttered environments. To examine obstacle flight guidance, we tracked pigeons (Columba livia) flying through an artificial forest of vertical poles. Interestingly, pigeons adjusted their flight path only approximately 1.5 m from the forest entry, suggesting a reactive mode of path planning. Combining flight trajectories with obstacle pole positions, we reconstructed the visual experience of the pigeons throughout obstacle flights. Assuming proportional-derivative control with a constant delay, we searched the relevant parameter space of steering gains and visuomotor delays that best explained the observed steering. We found that a pigeon's steering resembles proportional control driven by the error angle between the flight direction and the desired opening, or gap, between obstacles. Using this pigeon steering controller, we simulated obstacle flights and showed that pigeons do not simply steer to the nearest opening in the direction of flight or destination. Pigeons bias their flight direction towards larger visual gaps when making fast steering decisions. The proposed behavioural modelling method converts the obstacle avoidance behaviour into a (piecewise) target-aiming behaviour, which is better defined and understood. This study demonstrates how such an approach decomposes open-loop free-flight behaviours into components that can be independently evaluated.
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Affiliation(s)
- Huai-Ti Lin
- Department of Organismic and Evolutionary Biology, Harvard University, , Concord Field Station, 100 Old Causeway Road, Bedford, MA 01730, USA
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Chuang SY, Lin HT, Wen YS, Hsu FJ. Pitfalls of CT for deep neck abscess imaging assessment: a retrospective review of 162 cases. B-ENT 2013; 9:45-52. [PMID: 23641590] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
OBJECTIVES To investigate the diagnostic value of contrast-enhanced computed tomography (CT) for the prediction of deep neck abscesses in different deep neck spaces and to evaluate the false-positive results. METHOD We retrospectively analysed the clinical charts, CT examinations, surgical findings, bacteriology, pathological examinations and complications of hospitalised patients with a diagnosis of deep neck abscess from 2004 to 2010. The positive predictive values (PPV) for the prediction of abscesses by CT scan in different deep neck spaces were calculated individually on the basis of surgical findings. RESULTS A total of 162 patients were included in this study. All patients received both intravenous antibiotics and surgical drainage. The parapharyngeal space was the most commonly involved space. The overall PPV for the prediction of deep neck abscess with contrast-enhanced CT was 79.6%. The PPV was 91.3% when more than one deep neck space was involved but only 50.0% in patients with isolated retropharyngeal abscesses. In the false-positive group, cellulitis was the most common final result, followed by cystic degeneration of cervical metastases. Five specimens taken intra-operatively revealed malignancy and four of these were not infected. CONCLUSIONS There are some limitations affecting the differentiation of abscesses and cellulitis, particularly in the retropharyngeal space. A central necrotic cervical metastatic lymph node may sometimes also mimic a simple pyogenic deep neck abscess on both clinical pictures and CT images. Routine biopsy of the tissue must be performed during surgical drainage.
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Affiliation(s)
- S Y Chuang
- Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua, Taiwan
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Lin HT, Trimmer BA. A new bi-axial cantilever beam design for biomechanics force measurements. J Biomech 2012; 45:2310-4. [DOI: 10.1016/j.jbiomech.2012.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 06/08/2012] [Accepted: 06/09/2012] [Indexed: 10/28/2022]
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Lin HT, Trimmer B. Caterpillars use the substrate as their external skeleton: A behavior confirmation. Commun Integr Biol 2011; 3:471-4. [PMID: 21057644 DOI: 10.4161/cib.3.5.12560] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [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: 05/28/2010] [Accepted: 05/28/2010] [Indexed: 11/19/2022] Open
Abstract
Animals that lack rigid structures often employ pressurization to maintain body form and posture. Structural stability is then provided by incompressible fluids or tissues and the inflated morphology is called a hydrostatic skeleton. However, new ground reaction force data from the caterpillar, Manduca sexta suggest an alternate strategy for large soft animals moving in complex three dimensional structures. When crawling, Manduca can keep its body primarily in tension and transmit compressive deformation using the substrate. This effectively allows the caterpillar to minimize reliance on a hydrostatic skeleton and helps it conform to the environment. We call this alternative strategy an "environmental skeleton".
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Abstract
Rolling locomotion using an external force such as gravity has evolved many times. However, some caterpillars can curl into a wheel and generate their own rolling momentum as part of an escape repertoire. This change in body conformation occurs well within 100 ms and generates a linear velocity over 0.2 m s(-1), making it one of the fastest self-propelled wheeling behaviors in nature. Inspired by this behavior, we construct a soft-bodied robot to explore the dynamics and control issues of ballistic rolling. This robot, called GoQBot, closely mimics caterpillar rolling. Analyzing the whole body kinematics and 2D ground reaction forces at the robot ground anchor reveals about 1G of acceleration and more than 200 rpm of angular velocity. As a novel rolling robot, GoQBot demonstrates how morphing can produce new modes of locomotion. Furthermore, mechanical coupling of the actuators improves body coordination without sensory feedback. Such coupling is intrinsic to soft-bodied animals because there are no joints to isolate muscle-generated movements. Finally, GoQBot provides an estimate of the mechanical power for caterpillar rolling that is comparable to that of a locust jump. How caterpillar musculature produces such power in such a short time is yet to be discovered.
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Affiliation(s)
- Huai-Ti Lin
- Department of Biology, Tufts University, 163 Packard Avenue, Medford, MA 02155, USA.
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Lin HT, Slate DJ, Paetsch CR, Dorfmann AL, Trimmer BA. Scaling of caterpillar body properties and its biomechanical implications for the use of a hydrostatic skeleton. J Exp Biol 2011; 214:1194-204. [DOI: 10.1242/jeb.051029] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
SUMMARY
Caterpillars can increase their body mass 10,000-fold in 2 weeks. It is therefore remarkable that most caterpillars appear to maintain the same locomotion kinematics throughout their entire larval stage. This study examined how the body properties of a caterpillar might change to accommodate such dramatic changes in body load. Using Manduca sexta as a model system, we measured changes in body volume, tissue density and baseline body pressure, and the dimensions of load-bearing tissues (the cuticle and muscles) over a body mass range from milligrams to several grams. All Manduca biometrics relevant to the hydrostatic skeleton scaled allometrically but close to the isometric predictions. Body density and pressure were almost constant. We next investigated the effects of scaling on the bending stiffness of the caterpillar hydrostatic skeleton. The anisotropic non-linear mechanical response of Manduca muscles and soft cuticle has previously been quantified and modeled with constitutive equations. Using biometric data and these material laws, we constructed finite element models to simulate a hydrostatic skeleton under different conditions. The results show that increasing the internal pressure leads to a non-linear increase in bending stiffness. Increasing the body size results in a decrease in the normalized bending stiffness. Muscle activation can double this stiffness in the physiological pressure range, but thickening the cuticle or increasing the muscle area reduces the structural stiffness. These non-linear effects may dictate the effectiveness of a hydrostatic skeleton at different sizes. Given the shared anatomy and size variation in Lepidoptera larvae, these mechanical scaling constraints may implicate the diverse locomotion strategies in different species.
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Affiliation(s)
- Huai-Ti Lin
- Department of Biology, Tufts University, 165 Packard Avenue, Dana Lab, Medford, MA 02155, USA
| | - Daniel J. Slate
- Department of Biology, Tufts University, 165 Packard Avenue, Dana Lab, Medford, MA 02155, USA
| | - Christopher R. Paetsch
- Department of Civil & Environmental Engineering, Tufts University, 200 College Avenue, Anderson Hall, Medford, MA 02155, USA
| | - A. Luis Dorfmann
- Department of Civil & Environmental Engineering, Tufts University, 200 College Avenue, Anderson Hall, Medford, MA 02155, USA
| | - Barry A. Trimmer
- Department of Biology, Tufts University, 165 Packard Avenue, Dana Lab, Medford, MA 02155, USA
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Shu GW, Lin CC, Lin HT, Lin TN, Shen JL, Chiu CH, Li ZY, Kuo HC, Lin CC, Wang SC, Lin CAJ, Chang WH. Energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding. Opt Express 2011; 19 Suppl 2:A194-A200. [PMID: 21445220 DOI: 10.1364/oe.19.00a194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present the first observation of resonance energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding. Steady-state and time-resolved photoluminescence measurements provide conclusive evidence of resonance energy transfer and obtain an optimum transfer efficiency of ~72%. A set of rate equations is successfully used to model the kinetics of resonance energy transfer.
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Affiliation(s)
- G W Shu
- Department of Physics and Center for Nanotechnology at CYCU, Chung Yuan Christian University, 32023 Chung-Li, Taiwan
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Lee SC, Lin HT, Yang TY. Artificial neural network analysis for reliability prediction of regional runoff utilization. Environ Monit Assess 2010; 161:315-326. [PMID: 19234752 DOI: 10.1007/s10661-009-0748-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 01/15/2009] [Indexed: 05/27/2023]
Abstract
Many factors in the reliability analysis of planning the regional rainwater utilization tank capacity need to be considered. Based on the historical daily rainfall data, the following four analyzing procedures will be conducted: the regional daily rainfall frequency, the amount of runoff, the water continuity, and the reliability. Thereafter, the suggested designed storage capacity can be obtained according to the conditions with the demand and supply reliability. By using the output data, two different types of artificial neural network models are used to build up small area rainfall-runoff supply systems for the simulation of reliability and the prediction model. They are also used for the testing of stability and learning speed assessment. Based on the result of this research, the radial basis function neural network (RBFNN) model, using the Gaussian function that has a similar trend as the nature as basic function, has better stability than using the back-propagation neural network (BPNN) model. Despite the fact that RBFNN was more reliable than BPNN, it still made a conservative estimate for the actual monitoring data. The error rate of RBFNN was still higher than the correction of BPNN 4-3-1-1. This should have significant benefit in the future application of the instantaneous prediction or the development of related intelligent instantaneous control equipment.
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Affiliation(s)
- S C Lee
- Department of Architecture, National Cheng-Kung University, Tainan, Taiwan.
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Lin HT, Dorfmann AL, Trimmer BA. Soft-cuticle biomechanics: a constitutive model of anisotropy for caterpillar integument. J Theor Biol 2008; 256:447-57. [PMID: 19014955 DOI: 10.1016/j.jtbi.2008.10.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 10/05/2008] [Accepted: 10/09/2008] [Indexed: 11/29/2022]
Abstract
The mechanical properties of soft tissues are important for the control of motion in many invertebrates. Pressurized cylindrical animals such as worms have circumferential reinforcement of the body wall; however, no experimental characterization of comparable anisotropy has been reported for climbing larvae such as caterpillars. Using uniaxial, real-time fluorescence extensometry on millimeter scale cuticle specimens we have quantified differences in the mechanical properties of cuticle to circumferentially and longitudinally applied forces. Based on these results and the composite matrix-fiber structure of cuticle, a pseudo-elastic transversely isotropic constitutive material model was constructed with circumferential reinforcement realized as a Horgan-Saccomandi strain energy function. This model was then used numerically to describe the anisotropic material properties of Manduca cuticle. The constitutive material model will be used in a detailed finite-element analysis to improve our understanding of the mechanics of caterpillar crawling.
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Affiliation(s)
- Huai-Ti Lin
- Department of Biology, Tufts University, Medford, MA 02155, USA.
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Lin HT, Chen SW, Shen CJ, Chu C. Dissipation of pendimethalin in the garlic (Allium sativum L.) under subtropical condition. Bull Environ Contam Toxicol 2007; 79:84-6. [PMID: 17522749 DOI: 10.1007/s00128-007-9100-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Accepted: 03/15/2007] [Indexed: 05/15/2023]
Affiliation(s)
- H T Lin
- Residue Control Department, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, 11. Kuang-Ming Rd, Wufeng, Taichung Hsien, Taiwan.
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Holmberg DG, Chen GS, Lin HT, Wo AM. Thermal modeling and performance analysis of a thermoacoustic refrigerator. J Acoust Soc Am 2003; 114:782-791. [PMID: 12942961 DOI: 10.1121/1.1590971] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A heat-driven thermoacoustic refrigerator has been designed and tested. A detailed thermal model of the device is presented. Energy balances within the system are discussed using external, heat exchanger, and stack control volumes in order to clarify the relationships of work and heat fluxes below and above onset. Thermal modeling is discussed as a tool for performance analysis as well as for determining system heat losses and finding input heat flows required by a thermoacoustic code. A method of using the control volume balance equations to find stack work and device efficiencies is presented. Experimental measurements are compared to DELTAE thermoacoustic modeling predictions. Modeling results show that viscous losses within the system have a significant impact on the device performance as well as on the ability of DELTAE to accurately predict performance. Modeling has led to an understanding of system performance and highlighted loss sources that are areas for improvement in a redesign.
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Affiliation(s)
- David G Holmberg
- Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan
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Abstract
The environmental fate and distribution of fungicide epoxiconazole were studied by a rice paddy field model ecosystem. One week before the head-sprouting stage, rice plant was treated separately once with OPUS (tradename of epoxiconazole) 12% SC 2.1 kg ha(-1) and 1.4 kg ha(-1), respectively. Soil, water and rice plant were sampled seven days intervals nine times after application. The bioconcentration factor of epoxiconazole on mosquito fish in the ecosystem was also determined, based on the amounts of epoxiconazole content both in fish and water. This was initiated one day after the fungicide treatment, and continued for four days. In addition, the residue of epoxiconazole in rice grains was analyzed after harvest. After harvest, both planted water spinach (Ipomoea aquatica Forsk) and edible amaranth (Amaranthus mangostanüs L.) were analyzed. The results showed that epoxiconazole degraded in the local environment under the experimental conditions described. The degradation equations were in accordance with the first order kinetics. The DT50 of soil, field water and rice plant were 20-69 days, 11-20 days and 14-39 days, respectively. The bioconcentration factors of epoxiconazole on mosquito fish were 12.9 and 10.6 from 2.1 kg ha(-1) and 1.4 kg ha(-1) treatment, respectively. Residues of epoxiconazole in both rice and harvest vegetables were non-detectable. This indicates that epoxiconazole applied to rice at the recommended rates and application frequencies will not accumulate on rice grain and successive cropping vegetables.
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Affiliation(s)
- H T Lin
- Residue Control Department, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Wufeng, ROC.
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Chin C, Chiueh TS, Yang WC, Yang TH, Shih CM, Lin HT, Lin KC, Lien JC, Tsai TF, Ruo SL, Nichol ST, Ksiazek TG, Rollin PE, Peters CJ, Wu TN, Shen CY. Hantavirus infection in Taiwan: the experience of a geographically unique area. J Med Virol 2000; 60:237-47. [PMID: 10596027 DOI: 10.1002/(sici)1096-9071(200002)60:2<237::aid-jmv21>3.0.co;2-b] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 11/11/2022]
Abstract
Hantaviruses are rodent-borne viruses, and they, mainly the Hantaan (HTN) serotype, are the causative agents of a group of febrile nephropathies known as "hemorrhagic fever with renal syndrome (HFRS). " Despite the fact that HFRS is frequently reported in China, with an annual incidence of 50,000-100,000 cases, one puzzling observation that no local case of HFRS has been confirmed in Taiwan has yet to be explained. We hypothesized that the hantavirus strain prevailing in Taiwan mainly belongs to the mild strain, the Seoul (SEO) strain, and the absence of severe disease was related to the absence of HTN. To test these hypotheses, this epidemiologic study was performed, including a seroprevalence survey and phylogenetic analysis on hantavirus isolated from the rodent population trapped in major seaports, rural, and mountainous areas of Taiwan. This study also included rodents and viruses from two isolated islands, Kinmen and Matzu, which are geographically adjacent to the east coast of mainland China. There were a total of 5,461 rodents of 16 species captured, and R. norvegicus was the most common species, with an antibody prevalence much higher in international seaports (20%) than in rural regions (approximately 5%) and intermediate in some domestic seaports. By reverse transcriptase polymerase chain reaction (RT-PCR), 33.9% of the seropositive R. norvegicus were found to have amplifiable hantavirus sequences in their lung tissues, and subsequent phylogenetic analyses indicated that almost all hantavirus in Taiwan was most closely related to the prototype SEO strain, and no HTN strain was recovered from any rodent species indigenous to Taiwan. The seroprevalence of SEO infection in R. norvegicus on Kinmen and Matzu was also different from that in southern provinces of China but closely resembled that in seaports in Taiwan, and the SEO identified was genetically linked to Taiwanese SEO strains. These results substantiate our hypotheses, and suggest that the epidemiology of hantavirus infection in Taiwan are different from that in China, where the HTN and SEO strains and HFRS concurrently prevail.
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Affiliation(s)
- C Chin
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
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Yen GC, Lin HT. Changes in volatile flavor components of guava juice with high-pressure treatment and heat processing and during storage. J Agric Food Chem 1999; 47:2082-2087. [PMID: 10552500 DOI: 10.1021/jf9810057] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The changes in volatile flavor components of guava juice during pressure processing (25 degrees C, 600 MPa, 15 min), heat processing (95 degrees C, 5 min), and storage at 4 and 25 degrees C were evaluated by purge and trap/gas chromatography/mass spectrometry. Esters were the major volatile fraction in guava juice, and alcohols were the second. Pressure processing could maintain the original flavor distribution of the juice. Heat processing (95 degrees C, 5 min) caused decreases in the majority of flavor components in the juice when compared with freshly extracted juice. High-pressure treatment at 600 MPa for 15 min can effectively sterilize microbes but partially inactivate enzymes of guava juice; therefore, volatile components in pressure-treated juice gradually changed during storage periods. Pressure-treated guava juice showed increases in methanol, ethanol, and 2-ethylfuran with decreases in the other components during storage period. Nevertheless, the volatile distribution of 600 MPa treated guava juice was similar to that of freshly extracted juice when stored at 4 degrees C for 30 days.
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Affiliation(s)
- G C Yen
- Department of Food Science, National Chung Hsing University, Taiwan, Republic of China.
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Abstract
Effects of high pressure treatment on changes in pectic substances in guava juice were investigated and compared with those of heat treated samples. The viscosity and turbidity of guava juice pressurized at 6000 atm and 25 degrees C for 10 min increased slightly, whereas the viscosity of juice heated at 95 degrees C for 5 min decreased from 362 to 285 cps while turbidity increased from 0.87 to 1.15 (OD 600 nm). There were no apparent changes in water soluble, oxalate soluble and alkali soluble pectins in the pressurized juice. However, heat treated juice exhibited a decrease in its water and alkali soluble pectins and a slight increase in oxalate soluble pectin. The DEAE-cellulose profiles of pectic substances in guava juice were apparently unchanged after high pressure treatment while they were markedly changed by heat treatment, due to coagulation or degradation. During thermal processing, the degradation of pectin in guava juice caused a decrease in viscosity while the coagulation of pectin resulted in an increase in turbidity and cloud content. High pressure treatment showed no marked changes in pectic substances and cloud content in guava juice and maintained its natural viscous properties.
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Affiliation(s)
- G C Yen
- Department of Food Science, National Chung Hsing University, Taiwan, Republic of China
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Yu CJ, Shew JY, Shun CT, Lin HT, Kuo SH, Luh KT, Yang PC. Quantitative analysis of mRNA encoding MUC1, MUC2, and MUC5AC genes: a correlation between specific mucin gene expression and sialomucin expression in non-small cell lung cancer. Am J Respir Cell Mol Biol 1998; 18:643-52. [PMID: 9569234 DOI: 10.1165/ajrcmb.18.5.3051] [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: 01/08/2023] Open
Abstract
The expression of mucins is important for tumor invasiveness and metastasis. In our previous report (Am. J. Respir. Crit. Care Med. 1997; 155:1419-1427), non-small cell lung cancers bearing sialomucin expression tended to relapse earlier than those without sialomucin. However, it remained unclear whether the expression of sialomucin in lung cancer is caused by an abnormal glycosylation process or by the expression of a specific mucin gene product. To address this problem, we established a modified quantitative competitive polymerase chain reaction (QC-PCR) analysis. RNA internal standards of MUC1, MUC2, and MUC5AC non-tandem repeat sequences were constructed, and known copy numbers of mucin RNA internal standards were introduced into reverse transcription-polymerase chain reactions (RT-PCR) for each mucin gene in order to compete with native mucin gene RNA during the reaction. The RNA of Gbeta-like gene (a housekeeping gene) was used as internal control for the RNA analysis. Twenty-five lung cancer tissues (13 adenocarcinomas and 12 squamous cell carcinomas) were used for analysis. Mann-Whitney rank sum test was applied to compare the expression amounts of different mucin genes in tissues. The results revealed that adenocarcinoma expressed higher amounts of MUC5AC gene than did squamous cell carcinoma (P = 0.03). The expression amount of MUC5AC correlated positively with the expression status of sialomucin (P = 0.012). Further studies are anticipated to elucidate the underlying mechanism contributing to this phenomenon.
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Affiliation(s)
- C J Yu
- Departments of Internal Medicine, Pathology, and Laboratory Medicine, National Taiwan University Hospital, National Taiwan University, Taiwan, Republic of China
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Lin WY, Kao CH, Lin HT, Wang YL, Wang SJ, Liu TJ. 99Tcm-HMPAO-labelled white blood cell scans to detect acute appendicitis in older patients with an atypical clinical presentation. Nucl Med Commun 1997; 18:75-8. [PMID: 9061706 DOI: 10.1097/00006231-199701000-00015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 02/03/2023]
Abstract
Forty-nine patients (age > 50 years) with an acute abdomen and suspected appendicitis, but with atypical findings, were included in the study. After the intravenous injection of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) labelled white blood cells (WBCs), serial anterior images of the abdomen and pelvis were obtained after 30, 60, 120 and 240 min. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen equal to or greater than bone marrow activity was considered positive. Twenty-five patients had positive WBC scans, all of whom underwent laparotomy. Twenty-three of these patients were shown to have appendicitis; the other 2 did not. The other 24 patients had a negative WBC scan, 2 of whom underwent laparotomy and were shown to have appendicitis; the other 22 patients did not undergo surgery and showed no evidence of appendicitis during follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values of WBC scans for diagnosing appendicitis were as follows: 92.0%, 91.7%, 91.8%, 92.0% and 91.7% respectively. In conclusion, 99Tcm-HMPAO-labelled WBC scans provide a rapid and highly accurate method for diagnosing appendicitis in older patients with equivocal clinical findings.
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Affiliation(s)
- W Y Lin
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Abstract
Fifty female patients with acute abdomen and suspected appendicitis but atypical findings were included in this study. After intravenous injection of Tc-99m HMPAO-labeled WBCs, serial anterior abdominal/pelvic images at 30, 60, 120, and 240 minutes were obtained by a gamma camera. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen with equal to or greater than bone marrow activity was considered as a positive scan. Thirty patients had positive WBC scans and underwent laparotomy, 28 had proven appendicitis, and 2 were not related to appendicitis. Twenty patients had negative WBC scans, 2 patients underwent laparotomy and were proved to have appendicitis. The remaining 18 patients did not undergo surgery and revealed no evidence of appendicitis after follow-up. The overall sensitivity, specificity, accuracy, and positive and negative predictive values for WBC scans to diagnose appendicitis is 93.3%, 90.0%, 92.0%, 93.3%, and 90.0%, respectively. In conclusion, Tc-99m HMPAO-labeled WBC imaging provides a rapid and highly accurate method for diagnosis of appendicitis in female patients with equivocal clinical examinations.
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Affiliation(s)
- C H Kao
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Tang Y, Lin HT, Rich DH, Colter P, Vernon SM. Nonlinear optical effects in strain-induced laterally ordered (InP)2/(GaP)2 quantum wires. Phys Rev B Condens Matter 1996; 53:R10501-R10504. [PMID: 9982716 DOI: 10.1103/physrevb.53.r10501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Abstract
The speed of Tc-99m DTPA/HMPAO radioaerosol clearance from the lungs that is represented as a slope from lungs to blood was measured in 23 male normal controls using commercial lung radioaerosol delivery units in the supine position in order to avoid the influences of gravity. The right lung was selected and three regions of interest were created for equal subdivisions of the upper, middle, and lower third. The results show that the clearance of Tc-99m DTPA/HMPAO aerosols in the upper lung is slowest. The differences between upper and lower lungs for Tc-99m DTPA/HMPAO aerosol clearances are significant. The clearance of Tc-99m DTPA aerosols was significantly faster than those of Tc-99m HMPAO in any region. The authors conclude that, although the effect of gravity disappears in the supine position in our study, the differences of aerosol clearance in different regions are still significant. Lipophilic Tc-99m HMPAO aerosols were slower than those of hydrophilic Tc-99m DTPA, which suggests there are at least two different mechanisms.
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Affiliation(s)
- C H Kao
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Kao CH, Lin HT, Yu SL, Wang SJ, Lan JL. Effects of corticosteroid inhalation therapy on the deposition pattern of Tc-99m human serum albumin radioaerosols in asthma. Lung 1995; 173:291-6. [PMID: 7564487 DOI: 10.1007/bf00176892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 01/26/2023]
Abstract
This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.
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Affiliation(s)
- C H Kao
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Kao CH, Wang RC, Lin HT, Yu SL, Wang SJ, Chiang CD. Alveolar integrity in pulmonary emphysema using technetium-99m-DTPA and technetium-99m-HMPAO radioaerosol inhalation lung scintigraphy. J Nucl Med 1995; 36:68-72. [PMID: 7799085] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
UNLABELLED The alveolar integrity (AI) in 17 male patients with pulmonary emphysema (EMPH) diagnosed by chest x-ray was measured by 99mTc-DTPA and 99mTc-HMPAO radioaerosol inhalation lung scintigraphy. METHODS The patients were divided into two groups: (A) nine patients with pulmonary emphysema and normal carbon monoxide diffusion capacity (DLCO) and (B) eight patients with pulmonary emphysema and abnormal DLCO. The degree of AI damage in EMPH was presented as the slope of the time-activity curves from the dynamic left lung imagings in DTPA and HMPAO. The AI of EMPH patients were compared with the AI of 16 normal controls. RESULTS The results show that: (1) the slope of DTPA is larger than that of HMPAO in each of the portions of the left lung for any of the study groups; (2) statistical differences were found between the normal controls and EMPH patients in HMPAO but not in DTPA; and (3) the correlation was not good between DLCO and DTPA/HMPAO in EMPH patients. CONCLUSION Our results suggest that: (1) at least two different mechanisms in the lungs were at work; (2) the AI damage in EMPH developed mainly in the lipophilic part of the alveoli; and (3) the AI damage presented as slopes of DTPA/HMPAO in our study was different from the traditional pulmonary function such as DLCO.
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Affiliation(s)
- C H Kao
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Kao CH, Lin HT, Yu SL, Wang SJ, Lan JL. Lung inflammation in patients with systemic lupus erythematosus detected by quantitative 67Ga-citrate lung scanning. Nucl Med Commun 1994; 15:928-31. [PMID: 7870401 DOI: 10.1097/00006231-199411000-00012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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
The severity of lung inflammation in 34 patients with systemic lupus erythematosus (SLE) was measured by quantitative 67Ga-citrate lung scanning. The severity of lung inflammation in SLE was represented by the 67Ga uptake index (GUI). Quantitative 67Ga lung scanning was also performed on 20 normal controls for comparison with the SLE patients. The patients were divided into two subgroups according to the following two criteria: (a) stable or flare stage according to clinical features; or (b) positive or negative results of chest X-ray. The GUI values of the subgroups were also compared. The results revealed a trend towards higher values of GUI in SLE patients than in the normal controls. The GUI values were also higher for SLE cases with a flare stage or a negative chest X-ray than in SLE cases with a stable stage or a positive chest X-ray. The statistical results reveal that the differences in the GUI values are not significant. However, we found that (1) positive chest X-ray findings may be a later manifestation of a lung inflammation and (2) the values of GUI parallel clinical features in SLE patients.
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Affiliation(s)
- C H Kao
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Kao CH, Lin HT, Yu SL, Wang SJ, Yeh SH. Relationship of alveolar permeability and lung inflammation in patients with active diffuse infiltrative lung disease detected by 99Tcm-DTPA radioaerosol inhalation lung scintigraphy and quantitative 67Ga lung scans. Nucl Med Commun 1994; 15:850-4. [PMID: 7838450 DOI: 10.1097/00006231-199410000-00012] [Citation(s) in RCA: 8] [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
The alveolar permeability (AP) in 21 patients with active diffuse infiltrative lung disease (ILD) was measured by 99Tcm-diethylenetriaminapentaacetate (DTPA) radioaerosol inhalation lung scintigraphy. The degree of AP damage in ILD was presented as the slope (% min-1) of the time-activity curve from the dynamic lung image. Meanwhile, the quantitative Ga lung scan (GA) was performed as a Ga uptake index (GUI) to evaluate the severity of lung inflammation in active ILD. The results show that no good correlation between the degree of AP damage and lung inflammation was found. When the patients were divided into two groups of (A) eight active ILD with normal chest X-ray (X-ray) and (B) 13 active ILD with abnormal X-ray, there was no significant difference between groups A and B for the DTPA and Ga results. In conclusion, the relationship between the degree of AP damage and lung inflammation in active ILD is not significant. This was not consistent with X-ray findings. There was, however, a significant difference between those with ILD and normal controls.
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Affiliation(s)
- C H Kao
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China
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Kao YH, Lin HT. Influences of noise on the occurrence of period doubling in distributed-feedback laser diodes under direct-current modulation. Appl Opt 1993; 32:5962-5965. [PMID: 20856420 DOI: 10.1364/ao.32.005962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The influences of Langevin noise on period doubling (PD) of a strongly modulated distributed-feedback laser have been investigated. The onset of PD was confirmed to be reduced through the use of the rate equations as a model. The threshold values of PD were examined in terms of driving frequency and rf power and have been compared with the measurements of PD.
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Huang TJ, Roan RT, Lin HT. [The management of sinus tracts of dental origin]. Gaoxiong Yi Xue Ke Xue Za Zhi 1992; 8:89-95. [PMID: 1404529] [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
The purpose of this study was to evaluate the results of conservative endodontic therapy of 86 fistulous cases of dental origin at the Department of Conservative Dentistry, Kaohsiung Medical College Hospital. Approximately 60% (52/86) endodontically treated teeth, with a minimum recall period of 6 months, were evaluated for success or failure. The results are as follows: (1) The overall success rate was 82.7% (43/52) fistulous cases. There was no significant statistical difference between male and female patients. (2) There was a better success rate with cases over a 2-year recall period than with cases under a 2-year recall period, but there was no significant statistical difference between these two groups. (3) Cases with periapical pathosis less than 5 mm in diameter, had a better success rate than those with periapical pathosis larger than 5 mm in diameter, but there was no significant statistical difference between these two groups. (4) There was a 79.1% (34/43) success rate in non-surgically treated cases, and a 66.7% success rate (6/9, excluding three successfully retreated cases which had been originally treated with a non-surgical technique) in surgically treated cases.
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Affiliation(s)
- T J Huang
- Department of Dentistry, Kaohsiung Medical College, Taiwan, Republic of China
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Huang TJ, Roan RT, Lin HT. [Sinus tracts of dental origin. A clinical study. Part I]. Gaoxiong Yi Xue Ke Xue Za Zhi 1990; 6:653-60. [PMID: 2266570] [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: 12/31/2022]
Abstract
Chronic draining sinus tracts on the oral mucosa or the skin of the face frequently have dental pathosis. The purpose of this study was to investigate the incidence and the distribution of age, sex, opening, and tooth position of sinus tract cases with dental origin. A total of 678 teeth requiring endodontic treatment and having periapical pathosis at the Department of Conservative Dentistry, Kaohsiung Medical College Hospital, were studied. There were 86 (12.7%) teeth associated with sinus tracts, among these 47 (16.3%, 47/288) were from males and 39 (10.0%, 39/390) were from females. Of the openings of the sinus tracts, 70 were on the facial, 2 were on the palatal, 1 was on the distal, 4 were on the lingual, 2 were on both facial and lingual surfaces of teeth, and 7 were extraorally. The sinus tracts occurred more frequently in the mandibular than maxillary teeth. The maximum number of 34 cases (39.5%, 34/86) were from the 21-30 years of age group. In addition, we also found that the teeth with periapical lesions of larger than 5 mm in diameter are more frequently associated with sinus tracts than those teeth with lesions of smaller than 5 mm in diameter.
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Affiliation(s)
- T J Huang
- Department of Dentistry, Kaohsiung Medical College, Taiwan, Republic of China
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Manrique RV, Lin HT. Optimization of the blood sample filter paper technique for cyclosporine determination. Transplant Proc 1990; 22:1231-3. [PMID: 2349685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- R V Manrique
- Instituto Dante Pazzanese de Cardiologia, Laboratorio de Pesquisa, Sao Paulo, Brazil
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Beckman KJ, Velasco CE, Krafchek J, Lin HT, Magro SA, Wyndham CR. Significant variability in the mode of ventricular tachycardia induction and its implications for interpretation of acute drug testing. Am Heart J 1988; 116:718-26. [PMID: 3414487 DOI: 10.1016/0002-8703(88)90329-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Fifty-four patients with previous myocardial infarction and sustained ventricular tachycardia on fibrillation underwent two electrophysiologic studies in the drug-free state within 72 hours. Although the concordance of overall ventricular tachycardia induction over the 2 days was good (87% of patients), there was variability in the number of extrastimuli needed to induce sustained ventricular tachycardia on each day in 60% of patients. Of those in whom ventricular tachycardia was inducible on both days, 40% required additional extrastimuli and 20% required fewer extrastimuli. A change by two or more extrastimuli was found in 12% of patients. There was no correlation between the variability observed and multiple clinical and laboratory parameters (including the aggressiveness of the stimulation protocol); however, the direction of the variability (easier or harder to induce) correlated with changes in ventricular refractoriness. Inherent day-to-day variability may affect the reproducibility of electrophysiologic studies and influence the results of serial drug testing.
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Affiliation(s)
- K J Beckman
- Department of Medicine, Baylor College of Medicine, Houston, Texas
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Abstract
Pulmonary toxicity developed in 15 (17%) of 89 patients treated with amiodarone during a follow-up period of 2 weeks to 54 (mean 20 +/- 15) months. Prospective evaluation of serial pulmonary function tests in 67 patients demonstrated both a significant decrease from baseline in three of six variables in patients with toxicity at the time of diagnosis and a significant difference compared with the same variables in patients without toxicity. The most significant of these was the diffusing capacity for carbon monoxide (DLCO). An individual decrease in DLCO greater than or equal to 15% gave an optimal sensitivity of 100% and a specificity of 89% for the diagnosis of pulmonary toxicity. However, a decrease in DLCO greater than or equal to 15% did not alone warrant a change in therapy in asymptomatic patients. Although higher maintenance doses of amiodarone appeared to be related to the development of this complication, an abnormal baseline DLCO (less than 60% of predicted) with or without an initial abnormal chest roentgenogram did not predispose to pulmonary toxicity.
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Affiliation(s)
- S A Magro
- Department of Medicine, Baylor College of Medicine, Houston, Texas
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Abstract
Although successful operative treatment of atrial focal tachycardia has been reported in children, there are only isolated reports of surgical treatment of this arrhythmia in adults. In this case series of eight patients (aged 10 to 53 years) with drug-resistant right atrial focal tachycardia, results of electrophysiologic studies, surgical techniques and long-term follow-up are described. Atrial focal tachycardia was reproduced during electrophysiologic study, and endocardial mapping localized the earliest onset of atrial activation in the right atrium in all patients. Epicardial mapping confirmed the location of atrial tachycardia foci in seven of eight patients whose tachycardia was inducible intraoperatively. Of four patients treated with epicardial cryoablation alone, two had recurrent tachycardia and required a second procedure. None have had arrhythmia recurrence. In all four patients after right atrial excision (two of whom had intraoperative recurrence of atrial focal tachycardia after epicardial cryoablation alone), there has been no recurrence during a clinical follow-up period of 11 to 67 months (mean 30). It is concluded that in adult patients 1) electrophysiologic study with endocardial and epicardial mapping permits successful surgical treatment of atrial focal tachycardia; 2) epicardial cryoablation alone may be associated with recurrence of atrial focal tachycardia either intraoperatively or postoperatively; and 3) subtotal right atrial resection appears to be a well tolerated procedure with no long-term recurrence of atrial focal tachycardia.
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Affiliation(s)
- A A Seals
- Department of Medicine, Methodist Hospital, Baylor College of Medicine, Houston, Texas 77030
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Krafchek J, Lin HT, Beckman KJ, Nielsen AP, Magro SA, Hargis J, Wyndham CR. Cumulative effects of amiodarone on inducibility of ventricular tachycardia: implications for electrophysiological testing. Pacing Clin Electrophysiol 1988; 11:434-44. [PMID: 2453040 DOI: 10.1111/j.1540-8159.1988.tb06004.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To determine whether the slow onset of action of amiodarone might result in a delayed effect on the inducibility of sustained ventricular arrhythmias, 45 patients with ischemic heart disease and inducible sustained monomorphic ventricular tachycardia were prospectively studied. Each patient had at least one initial repeat study on amiodarone and those with persistently inducible arrhythmias were rescheduled for further studies over the following 24 weeks. After 2-3 weeks of amiodarone therapy, nine patients no longer had inducible tachycardias, and tachycardia in another eight patients (18%) later became noninducible. Using life-table methods, analysis based on the results of the first re-study showed 18-month recurrence rates of 43% in the inducible vs 17% in the noninducible groups (p = 0.056). When the results of additional testing were then used to reclassify patients, the recurrence rates for these two groups were 50% and 17%, respectively (p = 0.004). Observation of blood pressure and level of consciousness during induced arrhythmias was also predictive of clinical tolerance in patients having recurrences; 16 of 19 patients experienced symptoms of similar severity to those produced during testing. We conclude: (1) early testing of amiodarone may result in misclassification of some patients as remaining inducible; (2) re-testing at a later time more accurately predicts tachycardia recurrence; (3) observation of hemodynamic response also provides important prognostic information.
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Affiliation(s)
- J Krafchek
- Department of Medicine, Baylor College of Medicine, Methodist Hospital, Houston, Texas
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Abstract
Over 6 years, recurrent drug-refractory supraventricular arrhythmias were treated by electrophysiologically guided surgical procedures in 67 patients. There were 57 patients, age 10-72 years, with accessory pathways who had 61 operations. The perioperative mortality rate was 3.5%, with deaths occurring in two patients with complex problems. Four patients with multiple but one or more silent accessory pathways had successful reoperation, and modified surgical technique has eliminated this problem. All patients are free of arrhythmias 2-70 months after operation. The survival and primary cure rates were 100% for 36 patients with solitary accessory pathways. Eight patients, age 10-53 years, were operated on for atrial focal tachycardia. Right atrial cryothermic lesions without excision or cardiopulmonary bypass were used in four patients: local excision was used in two patients and combined procedures were used in two patients. Because of recurrence in two of four patients treated by isolated cryoablation, a new technique was applied subsequently to one of these patients and two other patients: wide atrial excision and PTFE patch replacement during cardiopulmonary bypass. All patients are free of arrhythmias at a follow-up of 9-72 months. Intractable atrial flutter or fibrillation occurred in 11 patients who had 15 attempts at transvenous A-V node electroshock ablation. In three patients in whom this failed, subsequent open cryoablation of the A-V node during cardiopulmonary bypass and epicardial pacemaker implantation were performed successfully. Two patients had A-V nodal modification for control of A-V nodal re-entry tachycardia: one patient with cryothermia at the time of ablation of atrial focal tachycardia and the other patient with sharp dissection at the time of accessory pathway division. Of the initial 67 patients, 65 (97%) survived operation and all were cured of their presenting arrhythmia. Surgery for drug-refractory supraventricular arrhythmias is safe and effective in selected cases.
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Lin HT, Mann DE, Luck JC, Krafchek J, Magro SA, Sakun V, Wyndham CR. Prospective comparison of right and left ventricular stimulation for induction of sustained ventricular tachycardia. Am J Cardiol 1987; 59:559-63. [PMID: 3825894 DOI: 10.1016/0002-9149(87)91169-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Thirty-eight patients who had sustained monomorphic ventricular tachycardia (VT) or sudden cardiac death underwent programmed ventricular stimulation. To assess the relative efficacy of right and left ventricular (RV and LV) stimulation, a tandem protocol with 1 to 4 extrastimuli and burst pacing was used. Each step of the protocol was performed in a rotating sequence at the RV apex, basal RV septum and LV apex. Sustained VT was induced from the RV apex in 26 patients, right ventricle (either site) in 27, and LV apex in 24, and spontaneous VT was reproduced from those sites in 11, 14 and 12 patients, respectively. In the 23 patients who had sustained VT induced from both ventricles, RV stimulation always required fewer or the same number of extrastimuli for induction. At every stage of the protocol, the cumulative yield of sustained VT was consistently greater from the right ventricle than from the left ventricle. After delivering 4 extrastimuli and burst pacing, LV stimulation only increased the yield of sustained VT by 1 patient, and spontaneous VT by 3 patients. Inducibility or noninducibility in the right ventricle generally predicted the same outcome in the left ventricle. Previously undocumented VT or ventricular fibrillation was induced from the right ventricle in 19 patients and from the left ventricle in 13. Thus, LV stimulation was less efficacious than RV stimulation. LV stimulation increased the yield over RV stimulation only minimally and did not reduce the number of extrastimuli required to induce sustained VT.
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Lin HT, Teng SC. 125I-triiodothyronine plasma binding ratio test in assessment of thyroid function. AJNR Am J Neuroradiol 1987; 4:286-90. [PMID: 81121 PMCID: PMC8332341] [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: 12/12/2022]
Abstract
Twenty patients with vertebral arteriovenous fistulas (eight spontaneous, six traumatic without vertebral artery transection, and six traumatic with vertebral artery transection) were treated by transvascular embolization techniques, resulting in complete fistula closure in all patients. The fistulas were located at C1–C2 in 45%, C2–C3 in 25%, C4–C5 in 15%, C5–C6 in 10%, and C6–C7 in 5%. Trauma was the most common cause: 30% followed knife wounds, 20% followed gunshot injuries, and 10% followed blunt trauma. Eight patients had spontaneous fistulas, two associated with fibromuscular dysplasia. Three patients—all with large, long-standing fistulas—developed neurologic deficits coincident with the abrupt closure of the fistula, which resolved with reestablishment of fistula flow. Two of these patients were treated by staged closure; the other one by gradual closure. In all three cases the result was complete fistula closure without neurologic sequelae. The remaining spontaneous fistulas were all closed by balloon embolization with preservation of the vertebral artery and without deficits. The six patients with traumatic fistulas without transection were cured by balloon embolization, without deficits; in four there was also preservation of vertebral flow. The other six patients had traumatic fistulas with transection and were all cured by balloon embolization with preservation of flow in two. Four patients required bilateral approaches to the fistula to achieve complete fistula closure. The only complication was a mild residual Wallenberg syndrome after occlusion of the posterior inferior cerebellar artery in the treatment of a transection located at C1. In our opinion, transvascular techniques are the treatment of choice for vertebral arteriovenous fistulas.
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