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Chan PY, Ryan NP, Chen D, McNeil J, Hopper I. Novel wearable and contactless heart rate, respiratory rate, and oxygen saturation monitoring devices: a systematic review and meta-analysis. Anaesthesia 2022; 77:1268-1280. [PMID: 35947876 DOI: 10.1111/anae.15834] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 07/08/2022] [Indexed: 11/28/2022]
Abstract
We performed a systematic review and meta-analysis to identify, classify and evaluate the body of evidence on novel wearable and contactless devices that measure heart rate, respiratory rate and oxygen saturations in the clinical setting. We included any studies of hospital inpatients, including sleep study clinics. Eighty-four studies were included in the final review. There were 56 studies of wearable devices and 29 of contactless devices. One study assessed both types of device. A high risk of patient selection and rater bias was present in proportionally more studies assessing contactless devices compared with studies assessing wearable devices (p = 0.023 and p < 0.0001, respectively). There was high but equivalent likelihood of blinding bias between the two types of studies (p = 0.076). Wearable device studies were commercially available devices validated in acute clinical settings by clinical staff and had more real-time data analysis (p = 0.04). Contactless devices were more experimental, and data were analysed post-hoc. Pooled estimates of mean (95%CI) heart rate and respiratory rate bias in wearable devices were 1.25 (-0.31-2.82) beats.min-1 (pooled 95% limits of agreement -9.36-10.08) and 0.68 (0.05-1.32) breaths.min-1 (pooled 95% limits of agreement -5.65-6.85). The pooled estimate for mean (95%CI) heart rate and respiratory rate bias in contactless devices was 2.18 (3.31-7.66) beats.min-1 (pooled limits of agreement -6.71-10.88) and 0.30 (-0.26-0.87) breaths.min-1 (pooled 95% limits of agreement -3.94-4.29). Only two studies of wearable devices measured Sp O2 ; these reported mean measurement biases of 3.54% (limits of agreement -5.65-11.45%) and 2.9% (-7.4-1.7%). Heterogeneity was observed across studies, but absent when devices were grouped by measurement modality and reference standard. We conclude that, while studies of wearable devices were of slightly better quality than contactless devices, in general all studies of novel devices were of low quality, with small (< 100) patient datasets, typically not blinded and often using inappropriate statistical techniques. Both types of devices were statistically equivalent in accuracy and precision, but wearable devices demonstrated less measurement bias and more precision at extreme vital signs. The statistical variability in precision and accuracy between studies is partially explained by differences in reference standards.
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Affiliation(s)
- P Y Chan
- Department of Intensive Care Medicine, Eastern Health, Melbourne, Vic., Australia
| | - N P Ryan
- Department of Intensive Care Medicine, Eastern Health, Melbourne, Vic., Australia
| | - D Chen
- Department of Intensive Care Medicine, Eastern Health, Melbourne, Vic., Australia
| | - J McNeil
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Vic., Australia
| | - I Hopper
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Vic., Australia
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Simpson JP, Wong DN, Verco L, Carter R, Dzidowski M, Chan PY. Measurement of airborne particle exposure during simulated tracheal intubation using various proposed aerosol containment devices during the COVID-19 pandemic. Anaesthesia 2020; 75:1587-1595. [PMID: 32559315 PMCID: PMC7323428 DOI: 10.1111/anae.15188] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2020] [Indexed: 01/25/2023]
Abstract
The COVID‐19 pandemic has led to the production of novel devices intended to protect airway managers during the aerosol‐generating procedure of tracheal intubation. Using an in‐situ simulation model, we evaluated laryngoscopist exposure of airborne particles sized 0.3 ‐ 5.0 microns using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no aerosol containment device. Nebulised saline was used as the aerosol‐generating model for 300 s, at which point, the devices were removed to assess particle spread. Primary outcome was the quantity and size of airborne particles measured at the level of the laryngoscopist’s head at 30, 60, 120 and 300 s, as well as 360 s (60 s after device removal). Airborne particles sizes of 0.3, 0.5, 1.0, 2.5 and 5.0 microns were quantified using an electronic airborne particle counter. Compared with no device use, the sealed intubation box with suction resulted in a decrease in 0.3, 0.5, 1.0 and 2.5 micron, but not 5.0 micron, particle exposure over all time‐periods (p = 0.003 for all time periods). Compared with no device use, the aerosol box showed an increase in 1.0, 2.5 and 5.0 micron airborne particle exposure at 300 s (p = 0.002, 0.008, 0.002, respectively). Compared with no device use, neither horizontal nor vertical drapes showed any difference in any particle size exposure at any time. Finally, when the patient coughed, use of the aerosol box resulted in a marked increase in airborne particle exposure compared with other devices or no device use. In conclusion, novel devices intended to protect the laryngoscopist require objective testing to ensure they are fit for purpose and do not result in increased airborne particle exposure.
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Affiliation(s)
- J P Simpson
- Intensive Care Services and Department of Anaesthesia and Perioperative Medicine, Eastern Health, Melbourne, Victoria, Australia.,Department of Anaesthesia and Perioperative Medicine, Eastern Health, Melbourne, Victoria, Australia
| | - D N Wong
- Department of Anaesthesia and Perioperative Medicine, Eastern Health, Melbourne, Victoria, Australia
| | - L Verco
- Department of Anaesthesia and Perioperative Medicine, Eastern Health, Melbourne, Victoria, Australia
| | - R Carter
- Ascent Vision Systems, Melbourne, Victoria, Australia
| | - M Dzidowski
- Ascent Vision Systems, Melbourne, Victoria, Australia
| | - P Y Chan
- Intensive Care Services and Department of Anaesthesia and Perioperative Medicine, Eastern Health, Melbourne, Victoria, Australia.,Intensive Care Services, Eastern Health, Melbourne, Victoria, Australia
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Terashima S, Yu L, Ong HJ, Tanihata I, Adachi S, Aoi N, Chan PY, Fujioka H, Fukuda M, Geissel H, Gey G, Golak J, Haettner E, Iwamoto C, Kawabata T, Kamada H, Le XY, Sakaguchi H, Sakaue A, Scheidenberger C, Skibiński R, Sun BH, Tamii A, Tang TL, Tran DT, Topolnicki K, Wang TF, Watanabe YN, Weick H, Witała H, Zhang GX, Zhu LH. Dominance of Tensor Correlations in High-Momentum Nucleon Pairs Studied by (p,pd) Reaction. Phys Rev Lett 2018; 121:242501. [PMID: 30608744 DOI: 10.1103/physrevlett.121.242501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Indexed: 06/09/2023]
Abstract
The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.
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Affiliation(s)
- S Terashima
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
| | - L Yu
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
| | - H J Ong
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - I Tanihata
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - S Adachi
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - N Aoi
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - P Y Chan
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - H Fujioka
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - M Fukuda
- Department of Physics, Osaka University, 1-5 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan
| | - H Geissel
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planskstraße 1, 64291 Darmstadt, Germany
- Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - G Gey
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - J Golak
- M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
| | - E Haettner
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planskstraße 1, 64291 Darmstadt, Germany
- Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - C Iwamoto
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - T Kawabata
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Kamada
- Department of Physics, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu 804-8550, Japan
| | - X Y Le
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
| | - H Sakaguchi
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - A Sakaue
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - C Scheidenberger
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planskstraße 1, 64291 Darmstadt, Germany
- Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen, Germany
| | - R Skibiński
- M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
| | - B H Sun
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
- Beijing Advanced Innovation Center for Big Data based Precision Medicine, Beihang University, 100083 Beijing, China
| | - A Tamii
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - T L Tang
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - D T Tran
- RCNP, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Institute of Physics, Vietnam Academy of Science and Technology, Hanoi 100000, Vietnam
| | - K Topolnicki
- M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
| | - T F Wang
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
| | - Y N Watanabe
- Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
| | - H Weick
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planskstraße 1, 64291 Darmstadt, Germany
| | - H Witała
- M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
| | - G X Zhang
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
| | - L H Zhu
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191 Beijing, China
- International Research Center for Nuclei and Particles in Cosmos, Beihang University, 100191 Beijing, China
- Beijing Advanced Innovation Center for Big Data based Precision Medicine, Beihang University, 100083 Beijing, China
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Choi AWM, Chan PY, Lo RTF, Wong LCL, Wong JYH, Tang DHM. Freeing Chinese Abused Women From Stereotype: A Pretest-Posttest Comparison Study on Group Intervention in Refuge Centers. ACTA ACUST UNITED AC 2018; 15:599-616. [PMID: 30142306 DOI: 10.1080/23761407.2018.1509409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVE The efficacy of heal-change group (HCG) intervention-brief trauma-recovery group intervention applying a gender-specific cognitive behavioral approach-for Chinese-abused women in refuge centers was examined in a pretest-posttest comparison study. METHODS A total of 100 women at three refuge centers in Hong Kong participated. Among them, 50 women from two centers joined the HCG and 50 women from the remaining center participated in a comparison mutual support group. Participants and interviewers were blinded to the group assignment. Both groups were six sessions long. Linear regression analyses were performed using the intention-to-treat framework. RESULTS Significant improvements in PTSD symptoms (overall mean change of -1.6, p < .001; subdomain scores; p < .001 to < .01) and depressive symptoms (BDI-II mean change; p < .01) were recorded in the intervention group. CONCLUSION The results suggest HCG is beneficial to Chinese-abused women. Further research is needed to determine the intervention's effectiveness in improving longer-term outcomes in these women.
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Affiliation(s)
- Anna W M Choi
- a Department of Social and Behavioural Sciences , City University of Hong Kong , Hong Kong SAR
| | - P Y Chan
- b Department of Social Work and Social Administration , The University of Hong Kong , Hong Kong SAR
| | - Ruby T F Lo
- b Department of Social Work and Social Administration , The University of Hong Kong , Hong Kong SAR
| | - Liz C L Wong
- b Department of Social Work and Social Administration , The University of Hong Kong , Hong Kong SAR
| | - Janet Y H Wong
- c School of Nursing, Li Ka Shing Faculty of Medicine , The University of Hong Kong, Hong Kong SAR
| | - Debbie H M Tang
- d Integrated Family Services (Family Crisis Support) , Po Leung Kuk, Hong Kong SAR
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Tran DT, Ong HJ, Hagen G, Morris TD, Aoi N, Suzuki T, Kanada-En'yo Y, Geng LS, Terashima S, Tanihata I, Nguyen TT, Ayyad Y, Chan PY, Fukuda M, Geissel H, Harakeh MN, Hashimoto T, Hoang TH, Ideguchi E, Inoue A, Jansen GR, Kanungo R, Kawabata T, Khiem LH, Lin WP, Matsuta K, Mihara M, Momota S, Nagae D, Nguyen ND, Nishimura D, Otsuka T, Ozawa A, Ren PP, Sakaguchi H, Scheidenberger C, Tanaka J, Takechi M, Wada R, Yamamoto T. Evidence for prevalent Z = 6 magic number in neutron-rich carbon isotopes. Nat Commun 2018; 9:1594. [PMID: 29686394 PMCID: PMC5913314 DOI: 10.1038/s41467-018-04024-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [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: 02/03/2018] [Accepted: 03/28/2018] [Indexed: 11/08/2022] Open
Abstract
The nuclear shell structure, which originates in the nearly independent motion of nucleons in an average potential, provides an important guide for our understanding of nuclear structure and the underlying nuclear forces. Its most remarkable fingerprint is the existence of the so-called magic numbers of protons and neutrons associated with extra stability. Although the introduction of a phenomenological spin-orbit (SO) coupling force in 1949 helped in explaining the magic numbers, its origins are still open questions. Here, we present experimental evidence for the smallest SO-originated magic number (subshell closure) at the proton number six in 13-20C obtained from systematic analysis of point-proton distribution radii, electromagnetic transition rates and atomic masses of light nuclei. Performing ab initio calculations on 14,15C, we show that the observed proton distribution radii and subshell closure can be explained by the state-of-the-art nuclear theory with chiral nucleon-nucleon and three-nucleon forces, which are rooted in the quantum chromodynamics.
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Affiliation(s)
- D T Tran
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
- Institute of Physics, Vietnam Academy of Science and Technology, Hanoi, 10000, Vietnam
| | - H J Ong
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan.
| | - G Hagen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - T D Morris
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - N Aoi
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - T Suzuki
- Department of Physics, College of Humanities and Sciences, Nihon University, Tokyo, 156-8550, Japan
- National Astronomical Observatory of Japan, Tokyo, 181-8588, Japan
| | - Y Kanada-En'yo
- Department of Physics, Kyoto University, Kyoto, 606-8502, Japan
| | - L S Geng
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191, Beijing, China
| | - S Terashima
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191, Beijing, China
| | - I Tanihata
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
- School of Physics and Nuclear Energy Engineering, Beihang University, 100191, Beijing, China
| | - T T Nguyen
- Pham Ngoc Thach University of Medicine, Ho Chi Minh, 700000, Vietnam
- Faculty of Physics and Engineering, VNUHCM-University of Science, Ho Chi Minh City, 70250, Vietnam
- Sungkyunkwan University, Gyeonggi-do, 16419, South Korea
| | - Y Ayyad
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - P Y Chan
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - M Fukuda
- Department of Physics, Osaka University, Osaka, 560-0043, Japan
| | - H Geissel
- GSI Helmholtzzentrum für Schwerionenforschung, 64291, Darmstadt, Germany
- Justus Liebig University, 35392, Giessen, Germany
| | - M N Harakeh
- GSI Helmholtzzentrum für Schwerionenforschung, 64291, Darmstadt, Germany
- KVI Center for Advanced Radiation Technology, University of Groningen, 9747 AA, Groningen, The Netherlands
| | - T Hashimoto
- Rare Isotope Science Project, Institute for Basic Science, Daejeon, 34047, Korea
| | - T H Hoang
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
- Institute of Physics, Vietnam Academy of Science and Technology, Hanoi, 10000, Vietnam
| | - E Ideguchi
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - A Inoue
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - G R Jansen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - R Kanungo
- Astronomy and Physics Department, Saint Mary's University, Halifax, NS, B3H 3C3, Canada
| | - T Kawabata
- Department of Physics, Kyoto University, Kyoto, 606-8502, Japan
| | - L H Khiem
- Institute of Physics, Vietnam Academy of Science and Technology, Hanoi, 10000, Vietnam
| | - W P Lin
- Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
| | - K Matsuta
- Department of Physics, Osaka University, Osaka, 560-0043, Japan
| | - M Mihara
- Department of Physics, Osaka University, Osaka, 560-0043, Japan
| | - S Momota
- Kochi University of Technology, Kochi, 782-8502, Japan
| | - D Nagae
- RIKEN Nishina Center, Saitama, 351-0198, Japan
| | - N D Nguyen
- Dong Nai University, Dong Nai, 81000, Vietnam
| | - D Nishimura
- Tokyo University of Science, Chiba, 278-8510, Japan
| | - T Otsuka
- Department of Physics, University of Tokyo, Tokyo, 113-0033, Japan
| | - A Ozawa
- Institute of Physics, University of Tsukuba, Ibaraki, 305-8571, Japan
| | - P P Ren
- Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
| | - H Sakaguchi
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - C Scheidenberger
- GSI Helmholtzzentrum für Schwerionenforschung, 64291, Darmstadt, Germany
- Justus Liebig University, 35392, Giessen, Germany
| | - J Tanaka
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
| | - M Takechi
- Department of Physics, Niigata University, Niigata, 950-2181, Japan
| | - R Wada
- Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
- Cyclotron Institute, Texas A&M University, College Station, TX, 77840, USA
| | - T Yamamoto
- Research Center for Nuclear Physics, Osaka University, Osaka, 567-0047, Japan
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Ng TW, Chan PY, Chan TT, Wu H, Lai KM. Skin squames contribute to ammonia and volatile fatty acid production from bacteria colonizing in air-cooling units with odor complaints. Indoor Air 2018; 28:258-265. [PMID: 29130534 DOI: 10.1111/ina.12439] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/05/2017] [Indexed: 06/07/2023]
Abstract
One of the most notable Indoor Air Quality problems is odor emission. This study investigated the potential contribution of skin squames to the production of ammonia (NH3 ) and volatile organic acids (VFAs) by 7 bacteria isolated from air-cooling (AC) units with complaints of urine and body odors. Our previous study showed that keratinolytic activity is higher in AC units with odor complaints than those without. In the offices where these units are located, the most likely source of keratins is from human skin squames. Most bacteria can produce NH3 and VFAs in the skin squame culture. Some correlations between the levels of NH3 , NH4+, VFAs, and keratinolytic activity were found. The odor production pathway with skin squames was proposed. Staphylococcus haemolyticus was abundant in the AC units with odor problems and had a high level of keratinolytic activity in addition to odor production. For long-term odor control, it is important to reduce the level of skin squames entering the AC units.
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Affiliation(s)
- T W Ng
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region, China
| | - P Y Chan
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region, China
| | - T T Chan
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region, China
| | - H Wu
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region, China
| | - K M Lai
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region, China
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Tai PH, Lau WS, Chan PY, Ng SY, Lam YC, Mak HT, Mak YT. Nurse Performed Ultrasonography in Confirming the Position of Nasogastric Tube in the Emergency Department: A Prospective Single Group Diagnostic Test Study. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490791602300603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Introduction Emergency nurses often encounter patients with nasogastric tube (NGT) dislodgements who require reinsertion. Empirical evidence supporting the use of ultrasonography in verifying the position of NGT in local accident and emergency departments (AED) is scanty. There is also a lack of validation of nurse performed ultrasonography in Hong Kong. With the support from hospitals and medical personnel, a prospective, single group diagnostic test study was conducted to review the possibility of nurse performed ultrasonography in verifying the position of NGT in AED. Methods This study was conducted in the AED of three local hospitals. Investigators with specific ultrasound training performed ultrasonography scans to the subjects in addition to conventional pH test and “whoosh” test. Results were compared with chest or abdominal X-ray for evaluation of accuracies. Results This study confirmed a high sensitivity and specificity of nurse performed ultrasonography in confirming the position of NGT in the AED. The high positive predictive value and positive likelihood ratio supported the confirmation of NGT position by bedside ultrasound. The high specificities and minimal negative likelihood ratios of ultrasonography tests also suggested the application of bedside ultrasound in ruling out patients with misplaced NGTs. Conclusions Nurse performed ultrasonography allows immediate bedside confirmation of the position of NGT in the overcrowded AED. Considered the limitations of conventional methods, nurse performed ultrasonography can be incorporated into daily practice for providing extra evidence for the confirmation of NGT position.
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Affiliation(s)
| | | | - PY Chan
- Yan Chai Hospital, Accident and Emergency Department, 7-11 Yan Chai Street, Tsuen Wan, N.T., Hong Kong
| | - SY Ng
- Yan Chai Hospital, Accident and Emergency Department, 7-11 Yan Chai Street, Tsuen Wan, N.T., Hong Kong
| | - YC Lam
- Tseung Kwan O Hospital, Accident and Emergency Department, 2 Po Ning Lane, Hang Hau, Tseung Kwan O, N.T., Hong Kong
| | - HT Mak
- Tseung Kwan O Hospital, Accident and Emergency Department, 2 Po Ning Lane, Hang Hau, Tseung Kwan O, N.T., Hong Kong
| | - YT Mak
- Tseung Kwan O Hospital, Accident and Emergency Department, 2 Po Ning Lane, Hang Hau, Tseung Kwan O, N.T., Hong Kong
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Chan PY, Latip LS. A case control study in factors that affect mammogram compliance. Med J Malaysia 2011; 66:456-461. [PMID: 22390101] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- P Y Chan
- Hospital Pakar Sultanah Fatimah, Jalan Salleh, Muar, Johor 84000, Malaysia.
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Ho PL, Chow KH, Lai EL, Lo WU, Yeung MK, Chan J, Chan PY, Yuen KY. Extensive dissemination of CTX-M-producing Escherichia coli with multidrug resistance to 'critically important' antibiotics among food animals in Hong Kong, 2008-10. J Antimicrob Chemother 2011; 66:765-8. [DOI: 10.1093/jac/dkq539] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstract
In the sequencing process, reads of the sequence are generated, then assembled to form contigs. New technologies can produce reads faster with lower cost and higher coverage. However, these reads are shorter. With errors, short reads make the assembly step more difficult. Chaisson et al. (2004) proposed an algorithm to correct the reads prior to the assembly step. The result is not satisfactory when the error rate is high (e.g., >or=3%). We improve their approach to handle reads of higher error rates. Experimental results show that our approach is much more effective in correcting errors, producing contigs of higher quality.
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Affiliation(s)
- Thomas K F Wong
- Faculty of Engineering, Department of Computer Science, The University of Hong Kong, Pokfulam Road, Hong Kong.
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Abstract
BACKGROUND AND OBJECTIVES The para-Bombay phenotype (also known as H-deficient secretor) is characterized by a lack of ABH antigens on red cells, but ABH substances are found in saliva. Molecular genetic analysis was performed for five Chinese individuals serologically typed as para-Bombay. MATERIALS AND METHODS ABO genotyping and mutational analysis of both FUT1 (or H) and FUT2 (or Se) loci were performed for these individuals using the polymerase chain reaction, single-strand conformation polymorphism analysis and direct DNA sequencing. RESULTS The ABO genotypes of these para-Bombay individuals correlated with the types of ABH substances found in the saliva. Their FUT1 genotypes were h1h2 (three individuals), h2h2 (one individual) and h2h6 (one individual). Alleles h1 (547-552delAG) and h2 (880-882delTT) were known frameshift mutations, while h6 (522C > A) was a missense mutation (Phe174Leu) not previously reported. These three mutations were rare sequence variations, each with an allele frequency of less than 0.005. Phe174 might be functionally important because this residue is conserved from mouse to human. Their FUT2 genotypes were Se357se357,385 for the h2h6 individual and Se357Se357) for the others. Both FUT2 alleles were known: one functional (Se357) and one weakly functional (se357,385). That they carried at least one copy of a functional FUT2 allele was consistent with their secretor status. As FUT1 and FUT2 are adjacent on 19q13.3, there are three possible haplotypes in these para-Bombay individuals: h1-Se357; h2-Se357; and h6-se357,385. CONCLUSIONS A novel non-functional FUT1 allele (522C > A, or Phe174Leu) was identified in a para-Bombay individual and on a se357,385 haplotype background.
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Affiliation(s)
- S P Yip
- Department of Nursing and Health Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
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12
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Zhu P, Ong SY, Chan PY, Poon YF, Leung KH, Phillips DL. Transient-resonance Raman and density functional theory investigation of 4-biphenylylnitrenium, 2-fluorenylnitrenium, and diphenylnitrenium ions. Chemistry 2001; 7:4928-36. [PMID: 11763461 DOI: 10.1002/1521-3765(20011119)7:22<4928::aid-chem4928>3.0.co;2-c] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We present transient-resonance Raman spectra for the 4-biphenylylnitrenium, diphenylnitrenium, and 2-fluorenylnitrenium ions. These spectra display a number of fundamental vibrational bands whose frequencies exhibit good agreement with those computed using BPW91/cc-PVDZ density functional theory calculations for the singlet ground states of the 4-biphenylylnitrenium, diphenylnitrenium, and 2-fluorenylnitrenium ions. Comparison of these arylnitrenium ions with each other and with previous results for structurally similar biphenyl radical cations indicates that the degree of iminocyclohexadienyl character observed in these arylnitrenium ions depends on the relative orientation of the two phenyl rings, the nature of the nitrenium ion moiety, and the ability of the biphenyl-like group to accommodate positive charge through formation of a more planar-like structure with quinoidal-like character.
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Affiliation(s)
- P Zhu
- Department of Chemistry, University of Hong Kong, Hong Kong
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13
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Zhu P, Ong SY, Chan PY, Leung KH, Phillips DL. Transient resonance Raman and density functional theory investigation of the 2-fluorenylnitrenium ion. J Am Chem Soc 2001; 123:2645-9. [PMID: 11456934 DOI: 10.1021/ja003839n] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a transient resonance Raman spectrum for the 2-fluorenylnitrenium ion obtained after photolysis of 2-azidofluorene. The 10 experimental Raman band frequencies of the transient spectrum show very good agreement with the computed frequencies from BPW91/cc-PVDZ density functional theory calculations for the 2-fluorenylnitrenium ion. Our results confirm the assignment of the approximately 460 nm transient absorption band formed after photolysis of 2-azidofluorene in water/acetonitrile or water solution to the singlet ground electronic state 2-fluorenylnitrenium ion. Our study indicates the 2-fluorenylnitrenium has a large degree of iminocyclohexadienyl cation character with significant delocalization of the charge over both phenyl rings of the fluorene moiety. We compare our results for the 2-fluoreneylnitrenium ion to those previously reported for several other arylnitrenium ions.
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Affiliation(s)
- P Zhu
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
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14
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Murukeshan VM, Chan PY, Ong LS, Asundi A. Intracore fiber bragg gratings for strain measurement in embedded composite structures. Appl Opt 2001; 40:145-149. [PMID: 18356985 DOI: 10.1364/ao.40.000145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
An intracore Bragg grating written on a photosensitive fiber core is used for strain measurement in composite specimens under load. The strain information is directly related to the absolute change in the Bragg-reflected wavelength. Fiber Bragg grating (FBG) sensors (fibers with intracore gratings) are thus sensitive to strain that is caused by changes in temperature as well as to load-induced changes. Thus these sensors can be made to be independent of source intensity variations and losses. FBG sensors used for load-induced strain sensing in composite structures and the effects of temperature on them are discussed. A detailed account of the use of such embedded structures as self-monitoring nondestructive testing devices is given.
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15
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Affiliation(s)
- A K Leung
- Department of Pediatrics, University of Calgary, Alberta Children's Hospital, and Asian Medical Centre (affiliated with the University of Calgary Medical Clinic), Canada
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16
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Leung AK, Wong BE, Chan PY, Cho HY. Nocturnal leg cramps in children: incidence and clinical characteristics. J Natl Med Assoc 1999; 91:329-32. [PMID: 10388258 PMCID: PMC2608508] [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: 02/13/2023]
Abstract
The records of 2527 healthy children seen in an ambulatory care clinic were evaluated for nocturnal leg cramps in the preceding 12 months, frequency and duration of the cramps, whether the cramps affected one leg or both legs at a time, whether there was associated muscle cramps in feet, whether the cramps occurred when the child was awake or asleep, and whether there was residual tenderness in the affected muscles. Nocturnal leg cramps were present in 185 children for an overall incidence of 7.3%. Leg cramps were noted only in children aged > or = 8 years. The incidence increased at 12 years and peaked at 16 to 18 years of age. A majority (81.6%) of the affected children had nocturnal leg cramps 1 to 4 times per year. The mean duration of episodes was 1.7 minutes. Leg cramps were unilateral in 98.9% of cases and the ipsilateral foot also was involved in 18.9% of cases. One hundred thirty-five (73%) children had leg cramps while asleep, and the remaining 23 (12.4%) children had leg cramps in either state. Fifty-seven (30.8%) children had residual tenderness in the affected muscles. The mean duration of residual tenderness was 33.2 minutes (range: 2 minutes-1 day). We conclude that nocturnal leg cramps are common in children aged > 12 years. A majority of the affected children have leg cramps 1 to 4 times per year. The cramps are usually unilateral and occur when the children are asleep. Normal duration of the leg cramp is < 2 minutes. Residual tenderness is present in approximately 30% of the affected children. Residual tenderness, if present, usually lasts for half an hour.
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Affiliation(s)
- A K Leung
- Department of Pediatrics, University of Calgary, Alberta, Canada
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17
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Abstract
Hypohidrosis has many causes. The condition may be generalised or segmental, acute or progressive and central or peripheral in origin. Most of the causes can be diagnosed from the history and physical examination. Laboratory investigations are usually not necessary. Treatment should be directed at the underlying cause whenever possible.
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Affiliation(s)
- A K Leung
- Department of Pediatrics, University of Calgary, Asian Medical Centre
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18
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Abstract
Pruritus is the most common of all dermatological complaints. Although pruritus is usually due to a primary skin disease, it may be a manifestation of a systemic illness. The majority of causes can be diagnosed from the history and physical examination. Laboratory investigations are usually not necessary. Treatment should be directed at the underlying cause whenever possible.
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Abstract
Most leg cramps are benign and self-limited. Idiopathic nocturnal leg cramp is the most common from of cramps. Occasionally, leg cramps may signify a significant systemic disorder. Investigations are usually not necessary unless indicated by the history or physical examination. Symptomatic treatment consists of stretching the affected calf muscle by forcible dorsiflexion of the foot.
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Affiliation(s)
- A K Leung
- Department of Pediatrics, Alberta Children's Hospital, University of Calgary, Alberta, Canada
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20
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Leung AK, Chan PY, Cho HY. Constipation in children. Am Fam Physician 1996; 54:611-8, 627. [PMID: 8701840] [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: 02/01/2023]
Abstract
Constipation is a common childhood condition, estimated to occur in 5 to 10 percent of children. In most cases, the cause is functional. However, constipation may occasionally indicate a significant organic disorder, which can usually be determined by a thorough history and physical examination. Constipation that is present from birth or that begins in the neonatal period is most likely to be congenital in origin. Acute constipation usually has an organic cause, while chronic constipation usually has a functional cause. Failure to thrive and gross distention of the abdomen suggest the diagnosis of Hirschsprung's disease. Rectal examination of a child with constipation usually reveals a distended rectum that is full of stool. In patients with Hirschsprung's disease, the rectum is usually empty and tight. Laboratory investigations are usually not necessary in patients with mild constipation. Treatment should be directed at the underlying cause. Functional constipation can be managed by changes in diet, regular bowel habits and, if necessary, pharmacologic therapy and biofeedback training.
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Affiliation(s)
- A K Leung
- Alberta Children's Hospital, Calgary, Canada
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21
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Dustin ML, Ferguson LM, Chan PY, Springer TA, Golan DE. Visualization of CD2 interaction with LFA-3 and determination of the two-dimensional dissociation constant for adhesion receptors in a contact area. J Biophys Biochem Cytol 1996; 132:465-74. [PMID: 8636222 PMCID: PMC2120727 DOI: 10.1083/jcb.132.3.465] [Citation(s) in RCA: 205] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Many adhesion receptors have high three-dimensional dissociation constants (Kd) for counter-receptors compared to the KdS of receptors for soluble extracellular ligands such as cytokines and hormones. Interaction of the T lymphocyte adhesion receptor CD2 with its counter-receptor, LFA-3, has a high solution-phase Kd (16 microM at 37 degrees C), yet the CD2/LFA-3 interaction serves as an effective adhesion mechanism. We have studied the interaction of CD2 with LFA-3 in the contact area between Jurkat T lymphoblasts and planar phospholipid bilayers containing purified, fluorescently labeled LFA-3. Redistribution and lateral mobility of LFA-3 were measured in contact areas as functions of the initial LFA-3 surface density and of time after contact of the cells with the bilayers. LFA-3 accumulated at sites of contact with a half-time of approximately 15 min, consistent with the previously determined kinetics of adhesion strengthening. The two-dimensional Kd for the CD2/LFA-3 interaction was 21 molecules/microns 2, which is lower than the surface densities of CD2 on T cells and LFA-3 on most target or stimulator cells. Thus, formation of CD2/LFA-3 complexes should be highly favored in physiological interactions. Comparison of the two-dimensional (membrane-bound) and three-dimensional (solution-phase) KdS suggest that cell-cell contact favors CD2/LFA-3 interaction to a greater extent than that predicted by the three-dimensional Kd and the intermembrane distance at the site of contact. LFA-3 molecules in the contact site were capable of lateral diffusion in the plane of the phospholipid bilayer and did not appear to be irreversibly trapped in the contact area, consistent with a rapid off-rate. These data provide insights into the function of low affinity interactions in adhesion.
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Affiliation(s)
- M L Dustin
- Center for Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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22
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Chalupny NJ, Aruffo A, Esselstyn JM, Chan PY, Bajorath J, Blake J, Gilliland LK, Ledbetter JA, Tepper MA. Specific binding of Fyn and phosphatidylinositol 3-kinase to the B cell surface glycoprotein CD19 through their src homology 2 domains. Eur J Immunol 1995; 25:2978-84. [PMID: 7589101 DOI: 10.1002/eji.1830251040] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [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
CD19 is a B cell surface protein capable of forming non-covalent molecular complexes with a number of other B cell surface proteins including the CD21/CD81/Leu-13 complex as well as with surface immunoglobulin. CD19 tyrosine phosphorylation increases after B cell activation, and is proposed to play a role in signal transduction through its cytoplasmic domain, which contains nine tyrosine residues. Several second messenger proteins have been shown to immunoprecipitate with CD19, including p59 Fyn (Fyn), p59 Lyn (Lyn) and phosphatidylinositol-3 kinase (PI-3 kinase). These associations are predicted to occur via the src-homology 2 (SH2) domains of the second messenger proteins. Two of the cytoplasmic tyrosines in the CD19 cytoplasmic region contain the consensus binding sequence for the PI-3 kinase SH2 domain (YPO4-X-X-M). However, the reported consensus binding sequence for the Fyn and Lyn SH2 domains (YPO4-X-X-I/L) is not found in CD19. We investigated the capacity of CD19 cytoplasmic tyrosines to bind both Fyn and PI-3 kinase SH2-domain fusion proteins. In activated B cells, both Fyn and PI-3 kinase SH2-domain fusion proteins precipitate CD19. Using synthetic tyrosine-phosphorylated peptides comprising each of the CD19 cytoplasmic tyrosines and surrounding amino acids, we investigated the ability of the Fyn SH2 and PI-3 kinase SH2 fusion proteins to bind to the different CD19 cytoplasmic phosphotyrosine peptides. ELISA revealed that the two CD19 cytoplasmic tyrosine residues contained within the Y-X-X-M sequences (Y484 and Y515) bound preferentially to the PI-3 kinase SH2-domain fusion proteins. Two different tyrosines (Y405 and Y445) bound preferentially to the Fyn SH2-domain fusion protein via a novel sequence, Y-E-N-D/E, different from that previously reported for the Fyn SH2 domain. In precipitation studies, peptide Y484 was able to compete with tyrosine phosphorylated CD19 specifically for binding to the PI-3 kinase SH2 domain fusion proteins, while peptides Y405 and Y445 were able to compete specifically for binding to the Fyn SH2 domain fusion proteins. These results indicate that CD19 may be capable of binding both Fyn and PI-3 kinase concurrently, suggesting a mechanism for CD19 signal transduction, in which binding of PI-3 kinase to the Fyn SH3 domain results in activation of PI-3 kinase.
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Affiliation(s)
- N J Chalupny
- Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, USA
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23
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Kanner SB, Aruffo A, Chan PY. Lymphocyte antigen receptor activation of a focal adhesion kinase-related tyrosine kinase substrate. Proc Natl Acad Sci U S A 1994; 91:10484-7. [PMID: 7524094 PMCID: PMC45045 DOI: 10.1073/pnas.91.22.10484] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [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: 01/25/2023] Open
Abstract
One of the earliest responses of T and B lymphocytes to stimulation through their antigen receptors is the activation of protein tyrosine kinases and the tyrosine phosphorylation of multiple cellular substrates. Here we describe a tyrosine kinase substrate, fakB, a putative homologue of the focal adhesion kinase pp125FAK. Tyrosine phosphorylation of fakB was rapidly augmented in human T and B cells following antigen receptor cross-linking with antibody, while pp125FAK was nonresponsive. Costimulation of the T-cell antigen receptor (TCR/CD3) with either the CD2 or CD4 costimulatory receptors induced synergistic fakB tyrosine phosphorylation in normal human T cells. Engagement of TCR/CD3 induced the stable association of fakB with ZAP-70, the TCR/CD3 sigma-chain-associated tyrosine kinase involved in antigen receptor-induced T-cell activation. In addition, preformed complexes of fakB and ZAP-70 were observed in T-cell leukemia lines. Phosphorylation of fakB on serine, threonine, and tyrosine residues was observed both in vivo and in vitro, where a functional increase of in vitro kinase activity was observed following TCR/CD3 stimulation. fakB is thus a focal adhesion kinase-related tyrosine kinase substrate that is differentially regulated from that of pp125FAK and likely plays a role in antigen-induced lymphocyte signaling.
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Affiliation(s)
- S B Kanner
- Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, WA 98121
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24
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Dietsch MT, Chan PY, Kanner SB, Gilliland LK, Ledbetter JA, Linsley PS, Aruffo A. Coengagement of CD2 with LFA-1 or VLA-4 by bispecific ligand fusion proteins primes T cells to respond more effectively to T cell receptor-dependent signals. J Leukoc Biol 1994; 56:444-52. [PMID: 7523557 DOI: 10.1002/jlb.56.4.444] [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: 01/25/2023] Open
Abstract
To examine the effects of ligand engagement and accessory molecule juxtaposition on T cell receptor (TCR) signaling, we prepared LFA-3/ICAM-1 Rg and LFA-3/VCAM-1 Rg bispecific immunoglobulin fusion proteins (Rg, recombinant globulin). These novel fusion proteins allowed us to examine the effects of ligand driven co-engagement of T cell proteins CD2 and LFA-1 or CD2 and VLA-4 on TCR-dependent mobilization of intracellular Ca2+. We observed that preincubation of resting T cells with LFA-3/ICAM-1 Rg or LFA-3/VCAM-1 Rg fusion proteins resulted in significantly enhanced mobilization of intracellular Ca2+ following TCR-accessory molecule cross-linking relative to T cells preincubated with each of the monospecific Rgs alone or with combinations of the monospecific Rg fusion proteins. In addition, such coengagement stimulated TCR-dependent activation and tyrosine phosphorylation of phospholipase C gamma 1 (PLC gamma 1). These results suggest that when T cells interact with antigen presenting cells the engagement of multiple cell adhesion molecules such as CD2, LFA-1, and VLA-4 primes the T cell to respond more effectively to signals delivered through the TCR.
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Affiliation(s)
- M T Dietsch
- Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121
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25
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Chan PY, Kanner SB, Whitney G, Aruffo A. A transmembrane-anchored chimeric focal adhesion kinase is constitutively activated and phosphorylated at tyrosine residues identical to pp125FAK. J Biol Chem 1994; 269:20567-74. [PMID: 8051157] [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: 01/28/2023] Open
Abstract
Focal adhesion kinase, pp125FAK, is a nonmyristylated cytosolic tyrosine kinase unrelated to protein-tyrosine kinase families categorized to date. The kinase activity and tyrosine phosphorylation of pp125FAK are induced by beta 1 and beta 3 integrin-mediated cell adherence or aggregation. pp125FAK is also a tyrosine phosphorylation substrate in v-src-transformed cells and is localized to focal adhesion contracts of adherent fibroblasts and carcinoma cells. In this report, we have transiently expressed in COS cells a transmembrane-anchored chimeric receptor kinase, CD2FAK, consisting of CD2 and pp125FAK. We analyzed its kinase activity and tyrosine phosphorylation and compared to those of pp125FAK. We found that CD2FAK exhibited constitutive kinase activity and a high basal tyrosine phosphorylation level when COS transfectants were suspended in serum-free media. The kinase activity of CD2FAK was similarly up-regulated upon beta 1 integrin-mediated cell adherence as the endogenous pp125FAK. Both CD2FAK and pp125FAK appeared to be active as autophosphorylating kinases as shown by mutation of the ATP binding site. We determined the major tyrosine phosphorylation site, Tyr397, identical for both the constitutively activated CD2FAK and pp125FAK in response to beta 1 integrin-mediated cell adherence by site-directed mutagenesis. Deletions of the NH2- or the COOH-terminal noncatalytic domain of FAK, including Tyr397 did not lead to abolition of the kinase activity of pp125FAK or CD2FAK. Taken together, CD2FAK exhibits properties of an activated pp125FAK and the kinase activity does not appear to require tyrosine phosphorylation in vitro or in vivo.
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Affiliation(s)
- P Y Chan
- Department of Inflammation, Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121
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26
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Chan PY, Aruffo A. VLA-4 integrin mediates lymphocyte migration on the inducible endothelial cell ligand VCAM-1 and the extracellular matrix ligand fibronectin. J Biol Chem 1993; 268:24655-64. [PMID: 7693704] [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: 01/26/2023] Open
Abstract
We herein tested the ability of lymphocytes to utilize the beta 1 integrin VLA-4 to mediate cell migration when adhering to its cytokine-inducible endothelial cell ligand VCAM-1 or its extracellular matrix ligand fibronectin. We used an in vitro system consisting of purified VCAM-1/Fc fusion protein or fibronectin immobilized on porous polycarbonate membranes to quantitatively measure the migration efficiency of an Epstein-Barr virus-transformed B cell line (SLA) and T lymphoblasts derived from normal donors. We found that both SLA cells and T lymphoblasts migrated across membranes coated with VCAM-1/Fc or fibronectin in a site density-dependent manner. Above and below an optimal site density of VCAM-1/Fc or fibronectin, the migration efficiency decreased. A 6-20-fold higher number of lymphocytes migrated across membranes coated with VCAM-1/Fc than with fibronectin. The differential migration efficiency is consistent with a higher number of adherent lymphocytes and a higher avidity of adhesion for VCAM-1/Fc than for fibronectin when the ligands were immobilized on plastic, and is independent of the activation state of the cells. These results demonstrated a stringent regulation of migratory response by cell adhesion strength and a delicate balance between stationary and migratory behaviors of a cell on the adhesive substrates. Like the beta 2 integrin LFA-1, VLA-4 may be a locomotive adhesion receptor which is involved in the transendothelial migration of lymphocytes and the infiltration of lymphocytes into lymphoid or peripheral tissues by binding to VCAM-1 and fibronectin.
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Affiliation(s)
- P Y Chan
- Department of Cellular Interactions, Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121
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Whitney GS, Chan PY, Blake J, Cosand WL, Neubauer MG, Aruffo A, Kanner SB. Human T and B lymphocytes express a structurally conserved focal adhesion kinase, pp125FAK. DNA Cell Biol 1993; 12:823-30. [PMID: 7692878 DOI: 10.1089/dna.1993.12.823] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [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: 01/26/2023] Open
Abstract
Clustering of beta 1-integrins on adherent cells with antibodies or ligands results in increased tyrosine phosphorylation and activation of a novel focal adhesion tyrosine kinase, pp125FAK. The genes encoding pp125FAK have been cloned previously from both chicken and mouse cDNA libraries, and the deduced amino acid sequences are nearly identical (94%). Two synthetic peptides derived from sequences at the carboxyl terminus of chicken pp125FAK were conjugated to ovalbumin to generate rabbit heteroantisera. Human pp125FAK was immunodetected in both T and B lymphocytes with these antisera. A basal state of pp125FAK tyrosine phosphorylation was observed in T and B lymphocytes, and its expression level was in general augmented among human T- and B-cell leukemia/lymphoma lines. Additionally, the full-length sequence of human T-cell pp125FAK (huT-FAK) was derived from a Jurkat T-cell cDNA library. huT-FAK is structurally identical with both mouse and chicken FAK, and shares 95% amino acid identity with chicken pp125FAK and has 97% homology with the mouse sequence. This high degree of evolutionary conservation between species suggests that pp125FAK is likely to have a crucial function in the cell. Expression of the full-length huT-FAK gene in COS cells showed an immunologically indistinct human pp125FAK protein compared with the endogenous primate pp125FAK. Taken together, the data indicate that this structurally conserved human T-cell pp125FAK likely functions in T- and B-cell lineages, and its altered expression in human lymphocyte tumor cell lines may contribute to their transformed phenotype.
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Affiliation(s)
- G S Whitney
- Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, WA 98121
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28
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Tözeren A, Mackie LH, Lawrence MB, Chan PY, Dustin ML, Springer TA. Micromanipulation of adhesion of phorbol 12-myristate-13-acetate-stimulated T lymphocytes to planar membranes containing intercellular adhesion molecule-1. Biophys J 1992; 63:247-58. [PMID: 1358239 PMCID: PMC1262142 DOI: 10.1016/s0006-3495(92)81578-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
This paper presents an analytical and experimental methodology to determine the physical strength of cell adhesion to a planar membrane containing one set of adhesion molecules. In particular, the T lymphocyte adhesion due to the interaction of the lymphocyte function associated molecule 1 on the surface of the cell, with its counter-receptor, intercellular adhesion molecule-1 (ICAM-1), on the planar membrane, was investigated. A micromanipulation method and mathematical analysis of cell deformation were used to determine (a) the area of conjugation between the cell and the substrate and (b) the energy that must be supplied to detach a unit area of the cell membrane from its substrate. T lymphocytes stimulated with phorbol 12-myristate-13-acetate (PMA) conjugated strongly with the planar membrane containing purified ICAM-1. The T lymphocytes attached to the planar membrane deviated occasionally from their round configuration by extending pseudopods but without changing the size of the contact area. These adherent cells were dramatically deformed and then detached when pulled away from the planar membrane by a micropipette. Detachment occurred by a gradual decrease in the radius of the contact area. The physical strength of adhesion between a PMA-stimulated T lymphocyte and a planar membrane containing 1,000 ICAM-1 molecules/micron 2 was comparable to the strength of adhesion between a cytotoxic T cell and its target cell. The comparison of the adhesive energy density, measured at constant cell shape, with the model predictions suggests that the physical strength of cell adhesion may increase significantly when the adhesion bonds in the contact area are immobilized by the actin cytoskeleton.
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Affiliation(s)
- A Tözeren
- Department of Mechanical Engineering, Catholic University of America, Washington, DC 20064
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29
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Staunton DE, Gaur A, Chan PY, Springer TA. Internalization of a major group human rhinovirus does not require cytoplasmic or transmembrane domains of ICAM-1. J Immunol 1992; 148:3271-4. [PMID: 1349619] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Intercellular adhesion molecule-1 (CD54), a cell adhesion molecule and the receptor for the major group of rhinoviruses, is a class 1 membrane protein with five Ig-like domains in its extracellular region, a transmembrane domain, and a short cytoplasmic domain. The amino-terminal domains (D1 and D2) are sufficient for virus binding and the first is most important (1). We have investigated whether other extracellular domains, transmembrane or cytoplasmic domains are required for virus entry as determined by postinfection virion protein biosynthesis. We demonstrate that cytoplasmic, transmembrane, and Ig-like domains 3, 4, and 5 are not essential for rhinovirus entry into transfected COS cells. The efficiency of rhinovirus infection directly correlates with the efficiency of rhinovirus binding and a form of intercellular adhesion molecule-1 that is glycophosphatidyl-inositol anchored, and thus does not extend into the inner leaflet of the membrane bilayer or the cytoplasm efficiently supports virus entry.
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Staunton DE, Gaur A, Chan PY, Springer TA. Internalization of a major group human rhinovirus does not require cytoplasmic or transmembrane domains of ICAM-1. The Journal of Immunology 1992. [DOI: 10.4049/jimmunol.148.10.3271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Intercellular adhesion molecule-1 (CD54), a cell adhesion molecule and the receptor for the major group of rhinoviruses, is a class 1 membrane protein with five Ig-like domains in its extracellular region, a transmembrane domain, and a short cytoplasmic domain. The amino-terminal domains (D1 and D2) are sufficient for virus binding and the first is most important (1). We have investigated whether other extracellular domains, transmembrane or cytoplasmic domains are required for virus entry as determined by postinfection virion protein biosynthesis. We demonstrate that cytoplasmic, transmembrane, and Ig-like domains 3, 4, and 5 are not essential for rhinovirus entry into transfected COS cells. The efficiency of rhinovirus infection directly correlates with the efficiency of rhinovirus binding and a form of intercellular adhesion molecule-1 that is glycophosphatidyl-inositol anchored, and thus does not extend into the inner leaflet of the membrane bilayer or the cytoplasm efficiently supports virus entry.
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Affiliation(s)
| | - A Gaur
- Center for Blood Research, Boston, MA 02115
| | - P Y Chan
- Center for Blood Research, Boston, MA 02115
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Abstract
The effect of lengthening the distance in an adhesion molecule between the receptor binding site and the membrane anchor was studied by inserting four Ig-like domains into the two Ig domain lymphocyte function-associated antigen 3 (LFA-3) molecule. The extended molecule expressed in Chinese hamster ovary (CHO) cells bound to CD2 on T lymphocytes 4- to 20-fold more efficiently than the wild-type molecule at 4 degrees C. Treatment of the CHO clones with neuraminidase to remove sialic acid, or with deoxymannojirimycin to reduce the bulk of N-linked glycosylation, showed that adhesion to both the wild-type and the chimeric LFA-3 molecules was under the influence of cell-cell repulsive forces to a similar extent and that these treatments had less effect than lengthening LFA-3. At higher temperatures, such as 22 and 37 degrees C, the efficiency of binding to the wild-type LFA-3 increased to levels comparable with binding to extended LFA-3. Our results suggest that more distal locations of the adhesive binding site from the cell membrane anchor increase the efficiency of cell-cell adhesion by enhancing the frequency of receptor encounter with ligand and that more proximal locations of the adhesive binding site can provide efficient cell-cell adhesion at physiological temperatures.
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Affiliation(s)
- P Y Chan
- Harvard Medical School, Boston, Massachusetts
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Tözeren A, Sung KL, Sung LA, Dustin ML, Chan PY, Springer TA, Chien S. Micromanipulation of adhesion of a Jurkat cell to a planar bilayer membrane containing lymphocyte function-associated antigen 3 molecules. J Cell Biol 1992; 116:997-1006. [PMID: 1370839 PMCID: PMC2289335 DOI: 10.1083/jcb.116.4.997] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cell adhesion plays a fundamental role in the organization of cells in differentiated organs, cell motility, and immune response. A novel micromanipulation method is employed to quantify the direct contribution of surface adhesion receptors to the physical strength of cell adhesion. In this technique, a cell is brought into contact with a glass-supported planar membrane reconstituted with a known concentration of a given type of adhesion molecules. After a period of incubation (5-10 min), the cell is detached from the planar bilayer by pulling away the pipette holding the cell in the direction perpendicular to the glass-supported planar bilayer. In particular, we investigated the adhesion between a Jurkat cell expressing CD2 and a glass-supported planar bilayer containing either the glycosyl- phosphatidylinositol (GPI) or the transmembrane (TM) isoform of the counter-receptor lymphocyte function-associated antigen 3 (LFA-3) at a concentration of 1,000 molecules/microns 2. In response to the pipette force the Jurkat cells that adhered to the planar bilayer containing the GPI isoform of LFA-3 underwent extensive elongation. When the contact radius was reduced by approximately 50%, the cell then detached quickly from its substrate. The aspiration pressure required to detach a Jurkat cell from its substrate was comparable to that required to detach a cytotoxic T cell from its target cell. Jurkat cells that had been separated from the substrate again adhered strongly to the planar bilayer when brought to proximity by micromanipulation. In experiments using the planar bilayer containing the TM isoform of LFA-3, Jurkat cells detached with little resistance to micromanipulation and without changing their round shape.
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Affiliation(s)
- A Tözeren
- Department of Mechanical Engineering, Catholic University of America, Washington, DC 20064
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Chan PY, Lawrence MB, Dustin ML, Ferguson LM, Golan DE, Springer TA. Influence of receptor lateral mobility on adhesion strengthening between membranes containing LFA-3 and CD2. J Biophys Biochem Cytol 1991; 115:245-55. [PMID: 1717480 PMCID: PMC2289925 DOI: 10.1083/jcb.115.1.245] [Citation(s) in RCA: 176] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have used an in vitro model system of glass-supported planar membranes to study the effects of lateral mobility of membrane-bound receptors on cell adhesion. Egg phosphatidylcholine (PC) bilayers were reconstituted with two anchorage isoforms of the adhesion molecule lymphocyte function-associated antigen 3 (LFA-3). The diffusion coefficient of glycosyl phosphatidylinositol (GPI)-anchored LFA-3 approached that of phospholipids in the bilayers, whereas the transmembrane (TM)-anchored isoform of LFA-3 was immobile. Both static and laminar flow assays were used to quantify the strength of adherence to the lipid bilayers of the T lymphoma cell line Jurkat that expresses the counter-receptor CD2. Cell adhesion was dependent on LFA-3 density and was more efficient on membranes containing the GPI isoform than the TM isoform. Kinetic measurements demonstrated an influence of contact time on the strength of adhesion to the GPI isoform at lower site densities (25-50 sites/microns2), showing that the mobility of LFA-3 is important in adhesion strengthening. At higher site densities (1,500 sites/microns2) and longer contact times (20 min), Jurkat cell binding to the TM and GPI isoforms of LFA-3 showed equivalent adhesion strengths, although adhesion strength of the GPI isoform developed twofold more rapidly than the TM isoform. Reduction of CD2 mobility on Jurkat cells at 5 degrees C greatly decreased the rate of adhesion strengthening with the TM isoform of LFA-3, resulting in a 30-fold difference between the two LFA-3 isoforms. Our results demonstrate that the ability of a membrane receptor and its membrane-bound counter-receptor to diffuse laterally enhances cell adhesion both by allowing accumulation of ligands in the cell contact area and by increasing the rate of receptor-ligand bond formation.
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Affiliation(s)
- P Y Chan
- Center for Blood Research, Boston, Massachusetts 02115
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Chan PY, Takei F. Molecular cloning and characterization of a novel murine T cell surface antigen, YE1/48. J Immunol 1989; 142:1727-36. [PMID: 2783949] [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: 01/02/2023]
Abstract
YE1/48 is a murine cell surface disulphide-linked dimeric Ag consisting of two 45,000-50,000 Mr subunits. It is expressed on some T lymphoma lines at high levels but its expression on normal lymphocytes is very low. The functional significance of this Ag is currently unknown. We have now cloned a cDNA encoding the YE1/48. Sequence analysis revealed that it encodes a Type II membrane protein of 262 amino acids (30,500 MW), with 44 amino acids in the N-terminal cytoplasmic domain, 22 amino acids in the transmembrane domain and 196 amino acids in the C-terminal extracellular domain. There are three potential N-linked glycosylation sites in the extracellular domain all of which are probably used in the mature protein. No significant homology can be identified with other known protein sequences in the data base or with human CD28(T44), a human T cell activation antigen consisting of two 44,000 Mr subunits. The protein sequence includes in its extracellular domain the arginine-glycine-aspartic acid tripeptide, a potential cell-adhesive binding site, and a sequence similar to the consensus domain of any metal-binding proteins. However, whether these sequences are functional is unknown. Genomic Southern analysis of C57BL/6, BALB/c and C3H mice has demonstrated a restriction fragment length polymorphism. The analysis has also strongly suggested the existence of some other genes with sequences highly homologous to the YE1/48 gene. The YE1/48 gene appears to be expressed at very low levels in a wide range of lymphoid cells with no restriction to their differentiation stages. Interestingly, YE1/48 expression appears to be induced in pre-B cells after transformation by Abelson virus, suggesting an association of YE1/48 expression with the transformation of T and pre-B Cells.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/isolation & purification
- B-Lymphocytes/analysis
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Cell Line, Transformed
- Cloning, Molecular
- DNA/isolation & purification
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Molecular Sequence Data
- Stem Cells/analysis
- T-Lymphocytes/analysis
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Affiliation(s)
- P Y Chan
- Terry Fox Laboratory, B.C. Cancer Research Centre, Vancouver, Canada
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Chan PY, Takei F. Molecular cloning and characterization of a novel murine T cell surface antigen, YE1/48. The Journal of Immunology 1989. [DOI: 10.4049/jimmunol.142.5.1727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
YE1/48 is a murine cell surface disulphide-linked dimeric Ag consisting of two 45,000-50,000 Mr subunits. It is expressed on some T lymphoma lines at high levels but its expression on normal lymphocytes is very low. The functional significance of this Ag is currently unknown. We have now cloned a cDNA encoding the YE1/48. Sequence analysis revealed that it encodes a Type II membrane protein of 262 amino acids (30,500 MW), with 44 amino acids in the N-terminal cytoplasmic domain, 22 amino acids in the transmembrane domain and 196 amino acids in the C-terminal extracellular domain. There are three potential N-linked glycosylation sites in the extracellular domain all of which are probably used in the mature protein. No significant homology can be identified with other known protein sequences in the data base or with human CD28(T44), a human T cell activation antigen consisting of two 44,000 Mr subunits. The protein sequence includes in its extracellular domain the arginine-glycine-aspartic acid tripeptide, a potential cell-adhesive binding site, and a sequence similar to the consensus domain of any metal-binding proteins. However, whether these sequences are functional is unknown. Genomic Southern analysis of C57BL/6, BALB/c and C3H mice has demonstrated a restriction fragment length polymorphism. The analysis has also strongly suggested the existence of some other genes with sequences highly homologous to the YE1/48 gene. The YE1/48 gene appears to be expressed at very low levels in a wide range of lymphoid cells with no restriction to their differentiation stages. Interestingly, YE1/48 expression appears to be induced in pre-B cells after transformation by Abelson virus, suggesting an association of YE1/48 expression with the transformation of T and pre-B Cells.
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Affiliation(s)
- P Y Chan
- Terry Fox Laboratory, B.C. Cancer Research Centre, Vancouver, Canada
| | - F Takei
- Terry Fox Laboratory, B.C. Cancer Research Centre, Vancouver, Canada
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Quek DK, Ong SB, Chan PY. Marked junctional bradycardia, prolonged QT interval and torsade de pointes in acute phenothiazine intoxication in a schizophrenic patient. A case report. Med J Malaysia 1988; 43:173-7. [PMID: 2907093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Chan PY, Takei F. Characterization of a murine T cell surface disulfide-linked dimer of 45-kDa glycopeptides (YE1/48 antigen). Comparison with T cell receptor, purification, and partial amino acid sequences. J Immunol 1988; 140:161-9. [PMID: 3121737] [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: 01/04/2023]
Abstract
The YE1/48 antigen, defined by two rat monoclonal antibodies YE1/48 and YE1/32, is a disulfide-linked dimer of 45- to 50-kDa subunits expressed on murine T cells. It has previously been described as a T cell receptor alpha/beta-like molecule because of its similar m.w., dimeric structure, and isoelectric points comparable to those of the murine T cell receptor. We have now further characterized this antigen, directly compared it with the T cell receptor, and obtained internal amino acid sequences from the purified and trypsin-digested antigen. Endoglycosidase F treatment revealed the peptide cores of the antigen to be approximately 32 to 38kDa under reducing conditions and they possess at least three glycosylation side-chains. On diagonal gel analysis (nonreducing vs reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis), the YE1/48 antigen and the T cell antigen receptor alpha/beta immunoprecipitated from thymocytes are indistinguishable. However, the two molecules can be distinguished on EL-4 cells by sequential immunoprecipitation using the YE1/48 monoclonal antibody and a rabbit antiserum reactive with the murine T cell receptor. Furthermore, two MBL-2 variant clones, which differ in the level of YE1/48 antigen expression by more than 200-fold, express comparable level of the T cell receptor. Therefore, the YE1/48 antigen and the T cell antigen receptor alpha/beta seem to be different molecules. The YE1/48 antigen was purified from MBL-2(4.1) cells by affinity chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis, digested with trypsin and the resultant peptides were separated by reverse phase high performance liquid chromatography. The amino acid sequences of several of the YE1/48 tryptic peptides were determined. Upon comparison with the protein sequences in the data base, no identical sequences were detected. These results demonstrated that the YE1/48 antigen is clearly different from the T cell receptor alpha-, beta-, or gamma- chain gene products, and it is a novel T cell antigen not previously described. However, the possibility of homology with other proteins remains undetermined because the tryptic peptides are too short to yield meaningful statistical comparison with the data base.
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Affiliation(s)
- P Y Chan
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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38
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Chan PY, Takei F. Characterization of a murine T cell surface disulfide-linked dimer of 45-kDa glycopeptides (YE1/48 antigen). Comparison with T cell receptor, purification, and partial amino acid sequences. The Journal of Immunology 1988. [DOI: 10.4049/jimmunol.140.1.161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
The YE1/48 antigen, defined by two rat monoclonal antibodies YE1/48 and YE1/32, is a disulfide-linked dimer of 45- to 50-kDa subunits expressed on murine T cells. It has previously been described as a T cell receptor alpha/beta-like molecule because of its similar m.w., dimeric structure, and isoelectric points comparable to those of the murine T cell receptor. We have now further characterized this antigen, directly compared it with the T cell receptor, and obtained internal amino acid sequences from the purified and trypsin-digested antigen. Endoglycosidase F treatment revealed the peptide cores of the antigen to be approximately 32 to 38kDa under reducing conditions and they possess at least three glycosylation side-chains. On diagonal gel analysis (nonreducing vs reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis), the YE1/48 antigen and the T cell antigen receptor alpha/beta immunoprecipitated from thymocytes are indistinguishable. However, the two molecules can be distinguished on EL-4 cells by sequential immunoprecipitation using the YE1/48 monoclonal antibody and a rabbit antiserum reactive with the murine T cell receptor. Furthermore, two MBL-2 variant clones, which differ in the level of YE1/48 antigen expression by more than 200-fold, express comparable level of the T cell receptor. Therefore, the YE1/48 antigen and the T cell antigen receptor alpha/beta seem to be different molecules. The YE1/48 antigen was purified from MBL-2(4.1) cells by affinity chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis, digested with trypsin and the resultant peptides were separated by reverse phase high performance liquid chromatography. The amino acid sequences of several of the YE1/48 tryptic peptides were determined. Upon comparison with the protein sequences in the data base, no identical sequences were detected. These results demonstrated that the YE1/48 antigen is clearly different from the T cell receptor alpha-, beta-, or gamma- chain gene products, and it is a novel T cell antigen not previously described. However, the possibility of homology with other proteins remains undetermined because the tryptic peptides are too short to yield meaningful statistical comparison with the data base.
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Affiliation(s)
- P Y Chan
- Department of Microbiology, University of British Columbia, Vancouver, Canada
| | - F Takei
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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Ryoo MC, Kagan AR, Wollin M, Nussbaum H, Chan PY, Hintz BL, Rao AR, McMahon J. Observations on the treatment of mediastinal masses in Hodgkin's disease emphasizing site of failure. Am J Clin Oncol 1987; 10:185-93. [PMID: 3591736 DOI: 10.1097/00000421-198706000-00001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Of 244 patients with Hodgkin's disease, 126 (52%) had an abnormal mediastinum. Sixty-four patients were treated with radiation, 36 with radiation and chemotherapy, and 25 with chemotherapy alone as an initial treatment. Twenty of 52 (38%) with stage I or II who received initially radiation alone relapsed, and 70% (14 of 20) of them were salvaged with chemotherapy. Therefore, the ultimate failure rate was 12% (6 of 52). Forty percent (8 of 20) of these patients failed within or at the margin of the radiation portal, and 60% failed predominantly outside of the radiation field. Even though we did not treat the whole lung prophylactically, there was only one true peripheral lung recurrence. Nine of 20 (45%) recurred in more than one site. Of 36 patients treated with combined radiation and chemotherapy, 21 patients had stage I, II, or IIIA disease. Of these, two patients relapsed. Of 86 patients with accessible x-ray films, 30 patients had large masses with a ratio of mass to transverse diameter greater than .33 at the broadest level. Fifty-six patients had small masses. Survival at 96 months in patients with stages I-IIIA with either large or small masses is 94% (p = 0.80). Their relapse-free survival at 96 months is 79% for large masses and 95% for small masses (p = 0.18). The site of relapse is discussed in detail in the text. There were five treatment-related deaths; three patients died of acute myelogenous leukemia. Our data do not support the role of whole-lung prophylactic irradiation or initial combined radiotherapy and chemotherapy in patients with large mediastinal masses.
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Chan PY, Takei F. Expression of a T cell receptor-like molecule on normal and malignant murine T cells detected by rat monoclonal antibodies to nonclonotypic determinants. J Immunol 1986; 136:1346-53. [PMID: 2418112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A T cell receptor-like molecule with a dimer structure of 45 kilodaltons (Kd) under reducing and 90 Kd under nonreducing conditions was detected on the surface of two murine T lymphoma lines, EL-4 and MBL-2, by two rat monoclonal antibodies. The two antibodies seemed to react with different determinants on the same molecule. The antibodies did not react with the surface of normal T cells as tested by flow cytometric analysis of cell surface staining. Two-dimensional gel electrophoresis (IEF vs SDS-PAGE) and tryptic peptide analysis revealed the molecule to consist of two chains with different isoelectric points and different tryptic peptides. A conventional antiserum was raised against the heterodimer purified from EL-4 cells. The immune serum did not bind to the surface of normal T cells. However, the immune serum as well as the monoclonal antibodies immunoprecipitated the dimer molecules from detergent-solubilized normal thymocytes and spleen cells. The dimer molecule was detected on both immature and mature thymocytes. These results suggest that the antibodies detect non-clonotypic determinants on a T cell receptor-like protein. The determinants are masked on the surface of normal T cells, whereas they are exposed on the surface of at least two T lymphoma cell lines. Three polypeptides of 30 Kd, 25 Kd, and 15 Kd were also coprecipitated with the heterodimer from MBL-2 cells. These proteins may associate with the heterodimer and may be masking the antigenic determinants on normal T cells. The relationship between the heterodimer molecule described here and the T cell antigen receptor or the human T cell antigen 9.3 is still unknown.
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Chan PY, Takei F. Expression of a T cell receptor-like molecule on normal and malignant murine T cells detected by rat monoclonal antibodies to nonclonotypic determinants. The Journal of Immunology 1986. [DOI: 10.4049/jimmunol.136.4.1346] [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: 01/01/2023]
Abstract
Abstract
A T cell receptor-like molecule with a dimer structure of 45 kilodaltons (Kd) under reducing and 90 Kd under nonreducing conditions was detected on the surface of two murine T lymphoma lines, EL-4 and MBL-2, by two rat monoclonal antibodies. The two antibodies seemed to react with different determinants on the same molecule. The antibodies did not react with the surface of normal T cells as tested by flow cytometric analysis of cell surface staining. Two-dimensional gel electrophoresis (IEF vs SDS-PAGE) and tryptic peptide analysis revealed the molecule to consist of two chains with different isoelectric points and different tryptic peptides. A conventional antiserum was raised against the heterodimer purified from EL-4 cells. The immune serum did not bind to the surface of normal T cells. However, the immune serum as well as the monoclonal antibodies immunoprecipitated the dimer molecules from detergent-solubilized normal thymocytes and spleen cells. The dimer molecule was detected on both immature and mature thymocytes. These results suggest that the antibodies detect non-clonotypic determinants on a T cell receptor-like protein. The determinants are masked on the surface of normal T cells, whereas they are exposed on the surface of at least two T lymphoma cell lines. Three polypeptides of 30 Kd, 25 Kd, and 15 Kd were also coprecipitated with the heterodimer from MBL-2 cells. These proteins may associate with the heterodimer and may be masking the antigenic determinants on normal T cells. The relationship between the heterodimer molecule described here and the T cell antigen receptor or the human T cell antigen 9.3 is still unknown.
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Hintz BL, Kagan AR, Wollin M, Miles J, Chan PY, Nussbaum H, Rao AR, Ryoo MC. Reassessment of technical and biological factors in paranasal sinus carcinoma. J Surg Oncol 1984; 27:59-66. [PMID: 6482455 DOI: 10.1002/jso.2930270114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Twenty-seven patients with paranasal sinus carcinoma were analyzed. Local control with radiation alone was poor, with most patients failing centrally within the primary site. With preoperative radiation local control is 60%. Previous reports have emphasized failure at superior sites--particularly the orbit. The pattern of local failure in our series is predominantly various medial sites inclusive of intact or exenterated orbit. The surgically nonremovable medial structures are best encompassed by a three-field radiotherapy technique (weighted anterior and two laterals).
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Kwan DK, Kagan AR, Olch AJ, Chan PY, Hintz BL, Wollin M. Single- and double-plane iridium-192 interstitial implants: implantation guidelines and dosimetry. Med Phys 1983; 10:456-61. [PMID: 6888357 DOI: 10.1118/1.595308] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Computerized dosimetric studies of single- and double-plane iridium-192 (Ir-192) planar implants were performed. With respect to dose homogeneity, we found that the optimal source and ribbon separation for single-plane implants was 1.0 cm. For double-plane implants, the preferred ribbon and plane separation was 1.5 cm, maintaining a 1-cm separation for the sources. Using these separations, standard dose rate curves for single- and double-plane Ir-192 implants were generated by computer calculations. These standard curves are useful for quickly and fairly accurately estimating the dose from any size planar implant, without requiring more time-consuming individual computer dosimetry. We believe that the curves will prove to be of practical clinical value to physicists and radiotherapists.
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Hintz BL, Kagan AR, Wollin M, Miles J, Flores L, Nussbaum H, Rao AR, Chan PY, Ryoo MC. Local control of T1 vocal cord cancer with radiation therapy: the importance of tumor character vs. treatment parameters. Head Neck Surg 1983; 5:204-10. [PMID: 6841117 DOI: 10.1002/hed.2890050304] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Ninety-one patients with T1 vocal cord carcinoma received primary irradiation treatment. The 5- and 10-year determinate disease-free survival was 80%; the 5- and 10-year determinate survival including surgical salvage was 92%. Tumors involving more than one-half of a vocal cord or involving the anterior commissure or exhibiting an exophytic growth pattern had numerically, but not statistically, higher local failure rates than tumors without these characteristics. Precise radiation treatment technique appears more important for local control (LC) than tumor character. The crucial treatment factors for high LC with few radiation complications are reproducible daily patient positioning, use of contour-compensating devices (wedges), field size of 5 X 5 cm, and a radiation prescription with a time-dose fractionation value of 101 to 106.
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Cossins EA, Chan PY. Folylpolyglutamate synthetase activities of Neurospora crassa: nature of products formed by soluble and particulate enzymes in the wild type and polyglutamate-deficient mutants. Adv Exp Med Biol 1983; 163:183-97. [PMID: 6193684 DOI: 10.1007/978-1-4757-5241-0_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The folylpolyglutamate synthetase activities of Neurospora crassa wild type (FGSC 853) and two polyglutamate-deficient mutants (met-6, 35809, FGSC 1330 and mac, 65108, FGSC 3609) were examined using dialyzed extracts prepared during exponential mycelial growth. Enzyme assay was based on incorporation of [U-3H]glutamate in folylpolyglutamates that were separated by gradient elution from DEAE-cellulose. Extracts of the wild type produced H4PteGlu2 (15%), H4PteGlu3 (35%) and H4PteGlu6 (50%) when anaerobically incubated with glutamate, ATP, and H4PteGlu. Under these conditions, the met-6 produced only H4PteGlu2 and higher polyglutamates (H4PteGlu4 and H4PteGlu5) were not utilized. The mac mutant failed to catalyze addition of glutamate to H4PteGlu. However, H4PteGlu2 was effectively converted to the tri-, and hexaglutamates. Mixing wild type and met-6 protein stimulated the formation of tri-, and hexaglutamates. Mixing mac and met-6 extracts resulted in H4PteGlu3 and H4PteGlu6 labeling when glutamate and H4PteGlu were provided. Fractionation of wild type extracts by addition of (NH4)2SO4 or by differential centrifugation provided evidence for different synthetase activities. Protein of the 0-35% (NH4)2SO4 fraction and that associated with the mitochondrial pellet, catalyzed an H4PteGlu2 leads to H4PteGlu3 reaction. These fractions failed to utilize H4PteGlu or the corresponding tetra-, and pentagluatmates. This triglutamate-forming activity was lacking in mac and met-6. The 45-60% (NH4)2SO4 fraction of the wild type catalyzed formation of di-, tri-, and hexaglutamate from H4PteGlu and glutamate. Hexaglutamate was also formed when the folate substrate wa H4PteGlu2, H2PteGlu4, or H4PteGlu5. These activities were associated with the cytosolic fraction when crude isotonic extracts were centrifuged to remove mitochondria. The characteristic synthetase activities of met-6 and mac were associated with protein of the 45-60% (NH4)2SO4 and cytosolic fractions. It is suggested that folypolyglutamate synthesis in N. crassa involves more than one synthetase-catalyzed reaction. Production of cellular folylhexaglutamate appears to involve two steps, catalyzed by cytosolic enzymes; viz: H4PteGlu leads to H2PteGlu2 followed by H4PteGlu2 leads to H4PteGlu6. These partial reactions are lacking in mac and met-6 respectively. The mitochondrial synthetase of the wild type may not represent a mandatory step in the biosynthesis of folylhexaglutamate but could have significance in generation of compartmented folylpolyglutamates.
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Hintz BL, Kagan AR, Nussbaum H, Rao AR, Chan PY, Miles J. A 'watchful waiting' policy for in situ carcinoma of the vocal cords. Arch Otolaryngol 1981; 107:746-51. [PMID: 7316856 DOI: 10.1001/archotol.1981.00790480022006] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Forty-five patients with vocal cord (VC) carcinoma in situ diagnosed by biopsy or VC stripping have been retrospectively analyzed. Eighteen patients received irradiation therapy immediately on diagnosis. The initial local control (LC) rate was 72% (13/18); the salvage-augmented LC rate was 94% (17/18). Twenty-seven patients with in situ carcinoma were treated expectantly ("watchful waiting"), receiving definitive radiotherapy or definitive surgery only if invasion was subsequently verified histologically. One third of the patients' carcinomas have not become invasive (mean follow-up, 50 months). Of the two thirds that became invasive, one third were more advanced than T1N0 when treated--often because patients missed scheduled follow-up appointments. Nevertheless, the initial LC rate was 65% (11/17); the salvage-augmented LC rate was 88% (15/17). Total laryngectomy was required twice as often in the watchful waiting group as in the immediately treated group.
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Silverberg IJ, Phillips TL, Fu KK, Chan PY. Combined radiotherapy and bleomycin for advanced head and neck cancers: results of a phase I pilot study. Cancer Treat Rep 1981; 65:697-8. [PMID: 6166375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Forty-two patients with inoperable stage III or IV head and neck epithelial tumors were entered in a phase I pilot study to evaluate the toxicity and efficacy of combined radiotherapy and bleomycin for advanced head and neck cancers. Twenty-three patients (52%) achieved complete remissions and 18 patients (42%) had greater than 50% regression. Most patients tolerated bleomycin at a dose of 5 units twice a week, with a full course of radiotherapy delivered at 1809 rads/day, 5 days/week. Although the complete remission rate appears to be higher than with radiotherapy alone and 13 of the 23 complete remissions (57%) lasted greater than 1 year, methods of prolonging the duration of remission need to be developed.
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Chan PY, Cossins EA. Polyglutamylfolate synthesis in Neurospora crassa: changes in pool size following growth in glycine- and methionine-supplemented media. Arch Biochem Biophys 1980; 200:346-56. [PMID: 6449176 DOI: 10.1016/0003-9861(80)90364-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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