1
|
Li F, Lo TY, Miles L, Wang Q, Noristani HN, Li D, Niu J, Trombley S, Goldshteyn JI, Wang C, Wang S, Qiu J, Pogoda K, Mandal K, Brewster M, Rompolas P, He Y, Janmey PA, Thomas GM, Li S, Song Y. The Atr-Chek1 pathway inhibits axon regeneration in response to Piezo-dependent mechanosensation. Nat Commun 2021; 12:3845. [PMID: 34158506 PMCID: PMC8219705 DOI: 10.1038/s41467-021-24131-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 05/25/2021] [Indexed: 02/05/2023] Open
Abstract
Atr is a serine/threonine kinase, known to sense single-stranded DNA breaks and activate the DNA damage checkpoint by phosphorylating Chek1, which inhibits Cdc25, causing cell cycle arrest. This pathway has not been implicated in neuroregeneration. We show that in Drosophila sensory neurons removing Atr or Chek1, or overexpressing Cdc25 promotes regeneration, whereas Atr or Chek1 overexpression, or Cdc25 knockdown impedes regeneration. Inhibiting the Atr-associated checkpoint complex in neurons promotes regeneration and improves synapse/behavioral recovery after CNS injury. Independent of DNA damage, Atr responds to the mechanical stimulus elicited during regeneration, via the mechanosensitive ion channel Piezo and its downstream NO signaling. Sensory neuron-specific knockout of Atr in adult mice, or pharmacological inhibition of Atr-Chek1 in mammalian neurons in vitro and in flies in vivo enhances regeneration. Our findings reveal the Piezo-Atr-Chek1-Cdc25 axis as an evolutionarily conserved inhibitory mechanism for regeneration, and identify potential therapeutic targets for treating nervous system trauma.
Collapse
Affiliation(s)
- Feng Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tsz Y Lo
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Leann Miles
- The Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Qin Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Harun N Noristani
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Dan Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jingwen Niu
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
| | - Shannon Trombley
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jessica I Goldshteyn
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Chuxi Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Shuchao Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jingyun Qiu
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Katarzyna Pogoda
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
| | - Kalpana Mandal
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Megan Brewster
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Ye He
- The City University of New York, Graduate Center - Advanced Science Research Center, Neuroscience Initiative, New York, NY, USA
| | - Paul A Janmey
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Gareth M Thomas
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
2
|
Muir AM, Cohen JL, Sheppard SE, Guttipatti P, Lo TY, Weed N, Doherty D, DeMarzo D, Fagerberg CR, Kjærsgaard L, Larsen MJ, Rump P, Löhner K, Hirsch Y, Zeevi DA, Zackai EH, Bhoj E, Song Y, Mefford HC. Bi-allelic Loss-of-Function Variants in NUP188 Cause a Recognizable Syndrome Characterized by Neurologic, Ocular, and Cardiac Abnormalities. Am J Hum Genet 2020; 106:623-631. [PMID: 32275884 PMCID: PMC7212259 DOI: 10.1016/j.ajhg.2020.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/11/2020] [Indexed: 02/08/2023] Open
Abstract
Nucleoporins (NUPs) are an essential component of the nuclear-pore complex, which regulates nucleocytoplasmic transport of macromolecules. Pathogenic variants in NUP genes have been linked to several inherited human diseases, including a number with progressive neurological degeneration. We present six affected individuals with bi-allelic truncating variants in NUP188 and strikingly similar phenotypes and clinical courses, representing a recognizable genetic syndrome; the individuals are from four unrelated families. Key clinical features include congenital cataracts, hypotonia, prenatal-onset ventriculomegaly, white-matter abnormalities, hypoplastic corpus callosum, congenital heart defects, and central hypoventilation. Characteristic dysmorphic features include small palpebral fissures, a wide nasal bridge and nose, micrognathia, and digital anomalies. All affected individuals died as a result of respiratory failure, and five of them died within the first year of life. Nuclear import of proteins was decreased in affected individuals' fibroblasts, supporting a possible disease mechanism. CRISPR-mediated knockout of NUP188 in Drosophila revealed motor deficits and seizure susceptibility, partially recapitulating the neurological phenotype seen in affected individuals. Removal of NUP188 also resulted in aberrant dendrite tiling, suggesting a potential role of NUP188 in dendritic development. Two of the NUP188 pathogenic variants are enriched in the Ashkenazi Jewish population in gnomAD, a finding we confirmed with a separate targeted population screen of an international sampling of 3,225 healthy Ashkenazi Jewish individuals. Taken together, our results implicate bi-allelic loss-of-function NUP188 variants in a recessive syndrome characterized by a distinct neurologic, ophthalmologic, and facial phenotype.
Collapse
Affiliation(s)
- Alison M Muir
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jennifer L Cohen
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Sarah E Sheppard
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Pavithran Guttipatti
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tsz Y Lo
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Natalie Weed
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Dan Doherty
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Seattle Children's Hospital, Seattle, WA 98105, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA
| | - Danielle DeMarzo
- Department of Pediatrics, University of Oklahoma, Oklahoma City, OK 73104, USA
| | | | - Lars Kjærsgaard
- Hans Christian Andersen Children's Hospital, Odense University Hospital, Denmark
| | - Martin J Larsen
- Department of Clinical Genetics, Odense University Hospital, Denmark
| | - Patrick Rump
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Katharina Löhner
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Yoel Hirsch
- The Committee for Prevention of Jewish Genetic Diseases, Dor Yeshorim, Jerusalem, Israel
| | - David A Zeevi
- The Committee for Prevention of Jewish Genetic Diseases, Dor Yeshorim, Jerusalem, Israel
| | - Elaine H Zackai
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Elizabeth Bhoj
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Seattle Children's Hospital, Seattle, WA 98105, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA.
| |
Collapse
|
3
|
Song Y, Li D, Farrelly O, Miles L, Li F, Kim SE, Lo TY, Wang F, Li T, Thompson-Peer KL, Gong J, Murthy SE, Coste B, Yakubovich N, Patapoutian A, Xiang Y, Rompolas P, Jan LY, Jan YN. The Mechanosensitive Ion Channel Piezo Inhibits Axon Regeneration. Neuron 2019; 102:373-389.e6. [PMID: 30819546 PMCID: PMC6487666 DOI: 10.1016/j.neuron.2019.01.050] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 11/27/2018] [Accepted: 01/23/2019] [Indexed: 01/09/2023]
Abstract
Neurons exhibit a limited ability of repair. Given that mechanical forces affect neuronal outgrowth, it is important to investigate whether mechanosensitive ion channels may regulate axon regeneration. Here, we show that DmPiezo, a Ca2+-permeable non-selective cation channel, functions as an intrinsic inhibitor for axon regeneration in Drosophila. DmPiezo activation during axon regeneration induces local Ca2+ transients at the growth cone, leading to activation of nitric oxide synthase and the downstream cGMP kinase Foraging or PKG to restrict axon regrowth. Loss of DmPiezo enhances axon regeneration of sensory neurons in the peripheral and CNS. Conditional knockout of its mammalian homolog Piezo1 in vivo accelerates regeneration, while its pharmacological activation in vitro modestly reduces regeneration, suggesting the role of Piezo in inhibiting regeneration may be evolutionarily conserved. These findings provide a precedent for the involvement of mechanosensitive channels in axon regeneration and add a potential target for modulating nervous system repair.
Collapse
Affiliation(s)
- Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Dan Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Olivia Farrelly
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Leann Miles
- The Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Feng Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sung Eun Kim
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tsz Y. Lo
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Fei Wang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Tun Li
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Katherine L. Thompson-Peer
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jiaxin Gong
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Swetha E. Murthy
- Department of Neuroscience, The Scripps Research Institute, Howard Hughes Medical Institute, La Jolla, CA 92037, USA
| | - Bertrand Coste
- Department of Neuroscience, The Scripps Research Institute, Howard Hughes Medical Institute, La Jolla, CA 92037, USA,Present address: Aix Marseille Université, CNRS, LNC-UMR 7291, 13344 Marseille, France
| | - Nikita Yakubovich
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ardem Patapoutian
- Department of Neuroscience, The Scripps Research Institute, Howard Hughes Medical Institute, La Jolla, CA 92037, USA
| | - Yang Xiang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Panteleimon Rompolas
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lily Yeh Jan
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuh Nung Jan
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
4
|
Martin DM, Teng JZ, Lo TY, Alonzo A, Goh T, Iacoviello BM, Hoch MM, Loo CK. Clinical pilot study of transcranial direct current stimulation combined with Cognitive Emotional Training for medication resistant depression. J Affect Disord 2018; 232:89-95. [PMID: 29477590 DOI: 10.1016/j.jad.2018.02.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 01/19/2018] [Accepted: 02/15/2018] [Indexed: 01/23/2023]
Abstract
BACKGROUND While the clinical results from transcranial direct current stimulation (tDCS) for the treatment of depression have been promising, antidepressant effects in patients with medication resistance have been suboptimal. There is therefore a need to further optimise tDCS for medication resistant patients. In this clinical pilot study we examined the feasibility, safety, and clinical efficacy of combining tDCS with a psychological intervention which targets dysfunctional circuitry related to emotion regulation in depression, Cognitive Emotional Training (CET). METHODS tDCS was administered during CET three times a week for a total of 18 sessions over 6 weeks. Mood, cognition and emotion processing outcomes were examined at baseline and after 3 and 6 weeks of treatment. RESULTS Twenty patients with medication resistant depression participated, of whom 17 were study completers. tDCS combined with CET was found to be feasible, safe, and associated with significant antidepressant efficacy at 6 weeks, with 41% of study completers showing treatment response (≥ 50% improvement in depression score). There were no significant cognitive enhancing effects with the exception of improved emotion recognition. Responders demonstrated superior recognition for the emotions fear and surprise at pre-treatment compared to non-responders, suggesting that better pre-treatment emotion recognition may be associated with antidepressant efficacy. LIMITATIONS This was an open label study. CONCLUSIONS tDCS combined with CET has potential as a novel method for optimising the antidepressant efficacy of tDCS in medication resistant patients. Future controlled studies are required to determine whether tDCS combined with CET has greater antidepressant efficacy compared to either intervention alone.
Collapse
Affiliation(s)
- D M Martin
- School of Psychiatry, University of New South Wales, Sydney, Australia; The Black Dog Institute, Sydney, Australia.
| | - J Z Teng
- School of Psychiatry, University of New South Wales, Sydney, Australia; The Black Dog Institute, Sydney, Australia
| | - T Y Lo
- School of Psychiatry, University of New South Wales, Sydney, Australia; The Black Dog Institute, Sydney, Australia
| | - A Alonzo
- School of Psychiatry, University of New South Wales, Sydney, Australia; The Black Dog Institute, Sydney, Australia
| | - T Goh
- School of Psychiatry, University of New South Wales, Sydney, Australia; The Black Dog Institute, Sydney, Australia
| | - B M Iacoviello
- Click Therapeutics, Inc., New York, United States; Icahn School of Medicine at Mount Sinai, New York, United States
| | - M M Hoch
- Icahn School of Medicine at Mount Sinai, New York, United States
| | - C K Loo
- School of Psychiatry, University of New South Wales, Sydney, Australia; The Black Dog Institute, Sydney, Australia
| |
Collapse
|
5
|
Hindin D, Baharlou SM, Gerstenhaber J, Lo TY, Har-El YE, Bradley JP, Lelkes PI. Electrospun soy protein scaffolds enhance skin regeneration in a rat wound model. J Am Coll Surg 2015. [DOI: 10.1016/j.jamcollsurg.2015.08.213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
6
|
Lo TY, Sim KS, Tso CP, Nia ME. Improvement to the scanning electron microscope image adaptive Canny optimization colorization by pseudo-mapping. Scanning 2014; 36:530-539. [PMID: 25139061 DOI: 10.1002/sca.21152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/27/2014] [Indexed: 06/03/2023]
Abstract
An improvement to the previously proposed adaptive Canny optimization technique for scanning electron microscope image colorization is reported. The additional feature, called pseudo-mapping technique, is that the grayscale markings are temporarily mapped to a set of pre-defined pseudo-color map as a mean to instill color information for grayscale colors in chrominance channels. This allows the presence of grayscale markings to be identified; hence optimization colorization of grayscale colors is made possible. This additional feature enhances the flexibility of scanning electron microscope image colorization by providing wider range of possible color enhancement. Furthermore, the nature of this technique also allows users to adjust the luminance intensities of selected region from the original image within certain extent.
Collapse
Affiliation(s)
- T Y Lo
- Faculty of Engineering & Technology, Multimedia University, Melaka, Malaysia
| | | | | | | |
Collapse
|
7
|
Lo TY, Cui HZ, Li ZG. Influence of aggregate pre-wetting and fly ash on mechanical properties of lightweight concrete. Waste Manag 2004; 24:333-338. [PMID: 15081059 DOI: 10.1016/j.wasman.2003.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/19/2003] [Indexed: 05/24/2023]
Abstract
This study has examined the mechanical properties of lightweight aggregate concrete with a density of 1800 kg/m3. The effects of the following parameters on the concrete properties have been analyzed: the pre-wetting time of the lightweight aggregate and the percentage of pulverized fly ash used as cementitious replacement material. The strength of the lightweight aggregate was found to be the primary factor controlling the strength of high-strength lightweight concrete. An increase in the cementitious content from 420 to 450 kg/m3 does not significantly increase the strength of lightweight aggregate concrete. The relationship between the flexural and compressive strength at 28 days can be represented by the equation fr=0.69/fck. The elastic modulus was found to be much lower than that of normal weight concrete, ranging from 15.0 to 20.3 GPa. The addition of PFA increases the slump and density of lightweight aggregate concrete.
Collapse
Affiliation(s)
- T Y Lo
- Department of Building and Construction, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
| | | | | |
Collapse
|
8
|
Affiliation(s)
- N Y Ali
- St Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary College, London EC1A 7BE
| | | | | | | |
Collapse
|
9
|
Yu KN, Lau BM, Guan ZJ, Lo TY, Young EC. Bronchial Rn dose survey for residences. J Environ Radioact 2001; 54:221-229. [PMID: 11378916 DOI: 10.1016/s0265-931x(00)00134-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The bronchial dosimeter for Rn progeny proposed by Yu and Guan in 1998 was employed to survey the bronchial dose from Rn progeny in 30 residences in Hong Kong. An average bronchial deposition fraction of Rn progeny was obtained as 0.0334, which gave an average dose conversion factor (DCF) of 8.5 mSv WLM-1. The mean values of potential alpha energy concentration (PAEC) deposited in the tracheobronchial region (PAECT-B), total PAEC in air (PAECT), annual effective dose (E), concentration of Rn gas (RC) and annual dose conversion factor (ADCF) for all the residential sites combined were 0.11 +/- 0.05, 3.1 +/- 1.4 mWL, 1.2 +/- 0.5 mSv yr-1, 23 +/- 10 Bq m-3 and 0.055 +/- 0.020 (mSv yr-1 per Bqm-3), respectively, with air-conditioned sites (AC sites) and non-AC sites having significantly different mean ADCF values. The indoor relative humidity affected PAECT and RC with high confidence levels (> 95%).
Collapse
Affiliation(s)
- K N Yu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong.
| | | | | | | | | |
Collapse
|
10
|
Abstract
We investigated the electrophysiological effect and antiarrhythmic potential of cinnamophilin (Cinn), a thromboxane A(2) antagonist isolated from Cinnamomum philippinense, on rat cardiac tissues. Action potential and ionic currents in single rat ventricular cells were examined by current clamp or voltage clamp in a whole-cell configuration. In 9 episodes of ischemia-reperfusion arrhythmia, 10 microM Cinn converted 6 of them to normal sinus rhythm. Cinn suppressed the maximal rate of rise of the action potential upstroke (V(max)) and prolonged the action potential duration at 50% repolarization (APD(50)). Voltage clamp study showed that the suppression of V(max) by Cinn was associated with an inhibition of sodium inward current (I(Na), IC(50) = 10.0 +/- 0.4 microM). At 30 microM, V(1/2) for the steady-state inactivation curve of I(Na) was shifted from -84.1 +/- 0.2 to -93.0 +/- 0.5 mV. Cinn also reduced calcium inward current (I(Ca)) dose-dependently with an IC(50) value of 9.5 +/- 0.3 microM. Cinn (10 microM) reduced the I(Ca) with a negative shift of V(1/2) for the steady-state inactivation curve of I(Ca) from -32.2 +/- 0.3 to -50.7 +/- 0.4 mV. The prolongation of APD(50) was associated with an inhibition of the integral of potassium outward current with IC(50) values between 4.8 and 7.1 microM. At 10 microM, Cinn reduced I(Na) without a negative shift of its voltage-dependent steady-state inactivation curves. The inhibition of transient outward current (I(to)) by Cinn (3-30 microM) was associated with an acceleration of its time constant of inactivation and negative shift of its potential-dependent steady-state inactivation curves. The equilibrium dissociation constant (K(d)) of Cinn to inhibit open state I(to) channels, as calculated from the time constant of developing block, was 18.3 microM. The time constant of recovery of I(to) from inactivation state was unaffected by Cinn. The rate constant for the relief from the depolarization-dependent block of I(to) was calculated to be 23. 9 ms. As compared with its effect on I(to), Cinn exerted about half the potency to block I(Na) and I(Ca). These results indicate that the inhibition of I(Na), I(Ca) and I(to) may contribute to the antiarrhythmic activity of Cinn against ischemia-reperfusion arrhythmia.
Collapse
Affiliation(s)
- M J Su
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | | | | | | |
Collapse
|
11
|
|
12
|
Yip TT, Lau WH, Chan JK, Ngan RK, Poon YF, Lung CW, Lo TY, Ho JH. Prognostic significance of DNA flow cytometric analysis in patients with nasopharyngeal carcinoma. Cancer 1998; 83:2284-92. [PMID: 9840527] [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: 02/09/2023]
Abstract
BACKGROUND Nasopharyngeal carcinoma (NPC) is a prevalent malignant tumor among Southern Chinese. Previously, the authors described the prognostic significance of a serum antibody assay to a recombinant Epstein-Barr virus Bam HI-Z replication activator protein (ZEBRA) in NPC patients with long term follow-up. In this study, the authors further reported the use of DNA flow cytometry (DNA-FCM) as an additional technique for determining the prognosis of NPC patients in the same series. METHODS One hundred and forty-three archival biopsies from 110 NPC patients were deparaffinized and subjected to DNA-FCM analysis. DNA ploidy state and various proliferative indices (PI) of the tumors were correlated with patient survival and frequency of recurrence. RESULTS Among the biopsies analyzed, 119 were histologically positive NPC and 24 were negative. Fifty-one tumor biopsies that fulfilled the guideline criteria of the DNA Cytometry Consensus Conference were correlated with the clinical manifestations of the patients. Among them, 43 tumors (84%) were DNA diploid and 8 (16%) were aneuploid. Two PI, S-phase fraction (SPF) and proliferation fraction (PF), appear to be potentially useful prognostic indicators. For example, PF in patients who developed locoregional recurrence (15.1%) and distant recurrence (16.4%) after radiation therapy both were significantly higher than PF in patients who were in complete remission (8.2%) (P = 0.0005 and P = 0.004, respectively). Significant differences in SPF between patients with distant recurrence (10.6%) and those in remission (5.7%) also was found (P = 0.005). Using Kaplan-Meier analysis, patients with high PF, high SPF, and aneuploid tumors had significantly poorer 12-year survival rates (35%, 26%, and 28%, respectively) than those patients with low PF, low SPF, and diploid tumors (77%, 67%, and 59%, respectively) (P < 0.0009, P < 0.004, and P < 0.01, respectively). CONCLUSIONS Determination of tumor PI and DNA ploidy state by DNA-FCM at diagnosis of NPC can be potentially useful in selecting a poor prognostic subgroup of NPC patients. These parameters may enable oncologists to plan for more stringent treatment strategies such as hyperfractionated and accelerated radiation therapy or concomitant chemoradiotherapy for these patients.
Collapse
Affiliation(s)
- T T Yip
- Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Au LC, Lo TY, Wang HH, Choo KB. Single-step hybridization screening for recombinant DNA clones with correct insert orientation and intact junction using a junctional oligonucleotide probe. Proc Natl Sci Counc Repub China B 1996; 20:27-30. [PMID: 8931341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cloning of DNA fragments with blunt ends or identical protruding ends results in colonies with the insertion sequence existing in two possible orientations. The orientation and the junctional sequence of the positive clones need to be established by means of restriction analysis and/or sequencing. Here, we proposed a rapid one-step method for the screening of clones not only with the desired orientation, but also with an intact junctional sequence. In this method, a 16-18 meric oligonucleotide probe synthesized according to the expected vector-insert junctional sequence is used as a probe in colony hybridization screening. Using this strategy, only recombinant clones which fulfill the above criteria will show positive signals in hybridization.
Collapse
Affiliation(s)
- L C Au
- Department of Medical Research, National Yang-Ming University Taipei, Taiwan, Republic of China
| | | | | | | |
Collapse
|
14
|
Mo LR, Liao CC, Chiou CY, Hwang MH, Lin KT, Lo TY. Bleeding jejunal varices in a cirrhotic patient with hepatocellular carcinoma. Taiwan Yi Xue Hui Za Zhi 1987; 86:549-52. [PMID: 3040888] [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]
|