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Abdel-Qader DH, Abdel-Qader H, Silverthorne J, Kongkaew C, Meslamani AZA, Hayajneh W, Alwahadneh AM, Hamadi S, Abu-Qatouseh L, Awad R, Al Nsour M, Alhariri A, Shnewer K, Da'ssan M, Obeidat NM, Nusair KE, Jalamdeh MS, Hawari F, Asad M, AbuRuz S. Real-World Effectiveness of Four Types of COVID-19 Vaccines. Vaccines (Basel) 2023; 11:vaccines11050985. [PMID: 37243089 DOI: 10.3390/vaccines11050985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/06/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND There is a scarcity of evidence regarding the real-world effectiveness of coronavirus disease 2019 (COVID-19) vaccines. This was the first study to evaluate the effectiveness of four types of vaccines against asymptomatic and symptomatic infection, and COVID-19 outcomes among the general population. METHODS This was a matched comparison group quasi-experimental study conducted in Jordan between 1 January and 29 August 2021. In the first part of the study, 1200 fully vaccinated individuals were matched with 1200 unvaccinated control participants. In order to measure vaccine effectiveness, the infection rates of both vaccinated and unvaccinated groups were calculated. The second part of the study included measuring specific anti-SARS CoV-2 immune cells and antibodies. RESULTS BNT162b2 (Pfizer, New York, NY, USA) showed a significantly higher effectiveness against asymptomatic COVID-19 infection (91.7%) and hospitalization (99.5%) than BBIBP-CorV (Sinopharm, Beijing, China) (88.4% and 98.7%, respectively) and ChAdOx1 nCoV-19 (AstraZeneca, Cambridge, UK) (84.3%, and 98.9%, respectively). The effectiveness rates of the Sputnik V (Gamaleya Research Institute, Moscow, Russia) vaccine against asymptomatic, symptomatic, and hospitalization were 100%, 100%, and 66.7%, respectively. The highest median anti-spike (S) IgG values were seen in individuals who received BNT162b2 (2.9 AU/mL) and ChAdOx1 nCoV-19 (2.8 AU/mL) vaccines. The levels of anti-S IgG were significantly decreased after 7 months of vaccination with BNT162b2 and BBIBP-CorV. There were significant decreases in the median number of neutralizing antibodies one month and seven months after receiving BNT162b2 (from 88.5 to 75.2 4 Bioequivalent Allergen Unit per milliliter/mL), BBIBP-CorV (from 69.5 to 51.5 BAU/mL), and ChAdOx1 nCoV-19 (from 69.2 to 58.BAU/mL) vaccines. The highest percentage of T cells specific to COVID-19 vaccine was found in individuals who received BNT162b2 (88.5%). CONCLUSION All four vaccines evaluated in this study showed effectiveness against asymptomatic COVID-19 infection, symptomatic infection, hospitalization, and death. Furthermore, BNT162b2, BBIBP-CorV, and ChAdOx1 nCoV-19 induced high levels of immunology markers within one month of vaccination.
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Affiliation(s)
- Derar H Abdel-Qader
- Faculty of Pharmacy & Medical Sciences, University of Petra, Amman 11196, Jordan
- Al Rashid Hospital Center, Amman 11623, Jordan
| | | | - Jennifer Silverthorne
- Division of Pharmacy & Optometry, The University of Manchester, Manchester M13 9PL, UK
| | - Chuenjid Kongkaew
- Department of Pharmacy Practice, Naresuan University, Phitsanulok 65000, Thailand
| | - Ahmad Z Al Meslamani
- AAU Health and Biomedical Research Center, Al Ain University, Abu Dhabi P.O. Box 112612, United Arab Emirates
- College of Pharmacy, Al Ain University, Abu Dhabi P.O. Box 64141, United Arab Emirates
| | - Wail Hayajneh
- School of Medicine, St. Louis University, St. Louis, MO 63104, USA
- School of Medicine, Jordan University of Science & Technology, Irbid 3030, Jordan
| | | | - Salim Hamadi
- Faculty of Pharmacy & Medical Sciences, University of Petra, Amman 11196, Jordan
| | - Luay Abu-Qatouseh
- Faculty of Pharmacy & Medical Sciences, University of Petra, Amman 11196, Jordan
| | - Riad Awad
- Faculty of Pharmacy & Medical Sciences, University of Petra, Amman 11196, Jordan
| | - Mohannad Al Nsour
- Eastern Mediterranean Public Health Network (EMPHNET), Amman 11195, Jordan
| | | | | | | | - Nathir M Obeidat
- School of Medicine, The University of Jordan, Amman 11942, Jordan
| | | | | | | | - Mohammad Asad
- Eastern Mediterranean Public Health Network (EMPHNET), Amman 11195, Jordan
| | - Salah AbuRuz
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, The United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Department of Clinical Pharmacy, Faculty of Pharmacy, The University of Jordan, Amman 11942, Jordan
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Al Jomaa EE, Abdel-Qader DH, Silverthorne J, Hamadi S, Al Meslamani AZ. Pharmacy students' attitude towards providing pharmaceutical care to patients with anxiety and their knowledge of psychotropic medicines in Jordan. Int J Pharm Pract 2021; 29:196-199. [PMID: 33729530 DOI: 10.1093/ijpp/riaa015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 11/04/2020] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To describe pharmacy students' attitude towards providing pharmaceutical care (PC) to patients with anxiety and their knowledge of psychotropic medicines (PM). METHODS A cross-sectional emailed survey was sent to all 200 pharmacy students (fourth and fifth year) in one Jordanian university. Statistical analysis included descriptive statistics and chi-square test. KEY FINDINGS A total of 134 responses were received (response rate 67%). About two-thirds of students (87, 64.9%) would like to give enough time to patients with anxiety to discuss their medications. Only half of students knew correctly that alprazolam (53.7%) and diazepam (50.0%) are categorized as anxiolytics. Undertaking a course in psychiatry was significantly associated with better students' knowledge in PM (P < 0.05). CONCLUSION Despite positive attitudes towards providing PC to patients with anxiety, policy makers should include courses on psychiatric pharmacotherapy in pharmacy curricula to improve pharmacy students' knowledge of PM.
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Affiliation(s)
- Esraa E Al Jomaa
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Derar H Abdel-Qader
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Jennifer Silverthorne
- Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Manchester, UK
| | - Salim Hamadi
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Ahmad Z Al Meslamani
- College of Pharmacy, Al Ain University of Science and Technology, Abu Dhabi, United Arab Emirates
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Abdel-Qader DH, Al Jomaa EE, Silverthorne J, Shnaigat W, Hamadi S, Al Meslamani AZ. Evaluating psychiatrists’ attitudes and expectations about pharmacists’ role in psychiatry in Jordan. Journal of Pharmaceutical Health Services Research 2021. [DOI: 10.1093/jphsr/rmab007] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Objectives
Evaluating Jordanian pharmacists’ roles in psychiatry from psychiatrists perspective.
Methods
An electronic survey was sent to 100 psychiatrists registered in the Jordanian Psychiatrists Association. Statistical analysis included descriptive statistics and multivariate logistic regression.
Key findings
A total of 80 psychiatrists completed the survey (response rate 80%). Most psychiatrists thought that pharmacists are unable to give individuals with mental illness enough time to discuss their medications (62/80, 77.6%) and to monitor psychotropic medications (PM) efficacy (50/80, 62.6%). Around half of respondents thought that, in the future, pharmacists would not be able to suggest PM for patients (42/80, 52.6%), nor changes in PM dosages (37/80, 46.3%). Most psychiatrists emphasized the importance of psychiatric courses to improve pharmacists’ role.
Conclusion
Although psychiatrists were generally not satisfied with the current role of pharmacists, they had positive expectations about pharmacists’ competency to do certain activities and to assist them in designing drug therapy plans.
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Affiliation(s)
- Derar H Abdel-Qader
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Esraa E Al Jomaa
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Jennifer Silverthorne
- Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Manchester, UK
| | | | - Salim Hamadi
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
| | - Ahmad Z Al Meslamani
- Faculty of Pharmacy and Medical Sciences, University of Petra, Amman, Jordan
- College of Pharmacy, Al Ain University of Science and Technology, Abu Dhabi, United Arab Emirates
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Ferguson J, Astbury J, Willis S, Silverthorne J, Schafheutle E. Implementing, embedding and sustaining simulation-based education: What helps, what hinders. Med Educ 2020; 54:915-924. [PMID: 32306437 DOI: 10.1111/medu.14182] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 03/30/2020] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVES Although there is much evidence to support the use of simulation-based education (SBE) in undergraduate education of health care professionals, less attention has been paid to how SBE, viewed as a complex intervention, is implemented and becomes embedded and sustained. This paper aims to explore factors that inhibited or promoted SBE becoming normal practice in undergraduate health care professional programmes. METHODS Participants involved in the organisation, design and delivery of SBE in the north of England were recruited purposefully from higher education institutions (HEI) and National Health Service (NHS) Trusts through local networks for qualitative telephone interviews. Transcripts were analysed inductively using a hybrid approach involving simultaneous inductive open coding and deductive coding using normalisation process theory (NPT) as a theoretical lens. FINDINGS A total of 12 NHS staff from 11 trusts and seven individuals from four HEIs were interviewed. There was considerable variation in the approach taken to implementation across organisations, which resulted in varying degrees of embeddedness. Implementation was challenged or enabled by organisational leadership, professional buy-in and the development and maturity of the strategic approach. Variation in understanding of the scope and pedagogical aims of SBE led to inequity between professions and organisations in investment and participation, as well as design and delivery of SBE. CONCLUSIONS Given the complexity of SBE, best practice in implementation should be considered fundamental to the successful delivery of SBE. The findings provide an explanation of how contextual factors can support or hinder implementation to maximise potential benefits and learning outcomes; this understanding can be used to better inform development of SBE strategies and highlight potential factors needed to navigate contextual barriers so that learning outcomes can be maximised.
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Affiliation(s)
- Jane Ferguson
- Division of Pharmacy and Optometry, School of Health Sciences, Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | - Jayne Astbury
- Division of Pharmacy and Optometry, School of Health Sciences, Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | - Sarah Willis
- Division of Pharmacy and Optometry, School of Health Sciences, Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | - Jennifer Silverthorne
- Division of Pharmacy and Optometry, School of Health Sciences, Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | - Ellen Schafheutle
- Division of Pharmacy and Optometry, School of Health Sciences, Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
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Astbury J, Ferguson J, Silverthorne J, Willis S, Schafheutle E. High-fidelity simulation-based education in pre-registration healthcare programmes: a systematic review of reviews to inform collaborative and interprofessional best practice. J Interprof Care 2020; 35:622-632. [PMID: 32530344 DOI: 10.1080/13561820.2020.1762551] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [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: 10/24/2022]
Abstract
Simulation-based education (SBE) is recognized as an effective interprofessional teaching and learning method. Whilst there is a large volume of research evidence concerning elements of SBE there is a lack of clarity concerning foundational principles of best practice. This is important for educators wishing to utilize high-quality SBE to deliver interprofessional education. The aim of this review is to synthesize review evidence of SBE best practice in a broad range of pre-registration healthcare programs and contextualize findings in light of relevant educational theory. A systematic search of PubMed, Scopus, Medline/Ovid, British Nursing Index, and the Cochrane Library databases was undertaken in February 2020. Data extraction and quality evaluation were undertaken by two authors. Fifteen reviews were included. In addition to identifying barriers and enablers to implementation, three interdependent themes regarding SBE best practice were found: curriculum level integration and planning (curriculum level integration, the opportunity for deliberate repeated practice, distribution, and sequencing); simulation design and delivery (clearly defined learning outcomes and benchmarks, pre-brief, multiple learning strategies, interactivity and individualized learning, feedback, and debrief); and resources (facilitator competency, controlled environments). These themes broadly align with the social constructivist theory of experiential learning whereby structured opportunities to learn via concrete experience, reflective observation, abstract conceptualization, and active experimentation are provided through effective planning, design, and delivery of SBE. Interdependencies suggest that integration of SBE at curriculum-level enables planning and implementation of best practice principles which are associated with effective learning, which also inform and facilitate the availability of adequate simulation resources.
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Affiliation(s)
- Jayne Astbury
- Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | - Jane Ferguson
- Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | | | - Sarah Willis
- Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
| | - Ellen Schafheutle
- Centre for Pharmacy Workforce Studies, The University of Manchester, Manchester, UK
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Abstract
Abstract
Focal points
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Affiliation(s)
- S Ansar
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester M13 9PL
| | - J Silverthorne
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester M13 9PL
- Hope Hospital, Salford Royal Hospitals NHS Trust, Stott Lane, Salford M6 8HD
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Abstract
We have developed an in vitro transcription system that uses nuclei isolated from Lemna gibba G-3. The in vitro transcripts include sequences homologous to hybridization probes for the small subunit of ribulose-1,5-bisphosphate carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39], the light-harvesting chlorophyll a/b-protein, and rRNA. Light-harvesting chlorophyll a/b-protein sequences are transcribed to a greater extent in nuclei isolated from plants grown in darkness with 2 min of red light every 8 hr than in nuclei isolated from dark-treated plants. Furthermore, the amount of these transcripts measured in plants given a single minute of red light after dark treatment is increased over the amount measured in dark-treated plants. The effect of red light is at least partially reversible by 10 min of far-red light given immediately after the red light pulse. Transcription of both rRNA and small subunit sequences is also stimulated by a single minute of red light as compared to dark-treated tissue. However, the relative magnitudes of the increases compared to the dark levels are smaller than the increase seen for the chlorophyll a/b-protein, possibly because of the higher level of transcription of these sequences in the dark. The effect of red light on the transcription of small subunit and rRNA sequences is also reversible by immediate treatment with 10 min of far-red light. Pulse chase studies of dark-treated nuclei for up to 110 min do not show substantial turnover of in vitro labeled small subunit and chlorophyll a/b-protein transcripts. We therefore conclude that phytochrome action has induced specific changes in transcription of these genes.
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Affiliation(s)
- J Silverthorne
- Department of Biology and Molecular Biology Institute, University of California, Los Angeles, CA 90024
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Christensen S, Silverthorne J. Origins of phytochrome-modulated Lhcb mRNA expression in seed plants. Plant Physiol 2001; 126:1609-1618. [PMID: 11500559 PMCID: PMC117160 DOI: 10.1104/pp.126.4.1609] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2000] [Revised: 03/07/2001] [Accepted: 05/02/2001] [Indexed: 05/23/2023]
Abstract
The levels of Lhcb mRNA in higher plants are regulated by phytochrome, cryptochrome, and an endogenous circadian oscillator. To determine whether similar regulatory mechanisms operate in the ancient gymnosperm Ginkgo biloba, we measured Lhcb mRNA levels in seedlings in response to different light conditions. Removal of a diurnally oscillating light stimulus caused dampening of maximal Lhcb mRNA accumulation levels, with little change in periodicity. Although low fluence pulses of both red and blue light given to etiolated seedlings caused maximal accumulation of Lhcb mRNAs characteristic of the phasic/circadian response seen in flowering plants, the additional initial acute response seen in flowering plants was absent. The induction of Lhcb gene expression in both cases was at least partially reversible by far-red light, and appeared biphasic over a range of red fluences. Together, these data indicate that Lhcb genes in G. biloba appear to be regulated in a manner similar to that of flowering plants, whereas signaling and attenuation of mRNA levels through the photoreceptor systems and circadian clock show features distinct from those characterized to date. The implications for these findings are discussed in light of the evolution of circadian clock input signaling.
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Affiliation(s)
- S Christensen
- Department of Molecular, Cell, and Developmental Biology, Sinsheimer Laboratories, University of California, Santa Cruz, California 95064, USA
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Okamoto H, Silverthorne J, Wada M. Spatial patterns of phytochrome expression in young leaves of the fern Adiantum capillus-veneris. Plant Cell Physiol 1997; 38:1397-1402. [PMID: 9522470 DOI: 10.1093/oxfordjournals.pcp.a029135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The spatial distribution of phytochrome (PHY1) mRNA in the fern Adiantum was investigated by in situ hybridization. PHY1 mRNAs are expressed predominantly in the abaxial rather than the adaxial part of the petiole of leaf croziers. Moreover, the signals in light-grown croziers are predominantly nuclear in location rather than cytoplasmic.
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Affiliation(s)
- H Okamoto
- Department of Biology, Tokyo Metropolitan University, Japan
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10
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Peer W, Silverthorne J, Peters JL. Developmental and light-regulated expression of individual members of the light-harvesting complex b gene family in Pinus palustris. Plant Physiol 1996; 111:627-34. [PMID: 8787030 PMCID: PMC157875 DOI: 10.1104/pp.111.2.627] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Angiosperms requires light for multiple aspects of chloroplast development, including chlorophyll synthesis and induction of expression of the mRNAs encoding the major polypeptides of the light-harvesting complex of photosystem II (Lhcb genes). In contrast, many conifers, including pines, firs, and spruces, can accumulate chlorophyll and the light-harvesting chlorophyll a/b-binding proteins of photosystem II in complete darkness. To understand the factors responsible for the regulation of expression of individual Lhcb mRNAs in the pine Pinus palustris, we have prepared sequence-specific cDNA probes for each of three family members, Lhcb1*Pp1, Lhcb2*Pp1, and Lhcb2*Pp2, and have studied the expression of two of these, Lhcb1*Pp1 and Lhcb2*Pp2, in detail. The levels of expression of each sequence were disparate, and Lhcb1*Pp1-encoded transcripts were the most abundant in the light. Both Lhcb1*Pp1 and Lhcb2*Pp2 mRNAs were expressed in stems and cotyledons, but Lhcb1*Pp1 mRNA was present at about 10-fold lower levels in stems than in cotyledons, in contrast to Lhcb2*Pp2 mRNA, which was expressed at higher levels in stems than in cotyledons. Both Lhcb1*Pp1 and Lhcb2*Pp2 mRNAs were absent in embryos but were expressed during seedling development. The levels increased with age in both the light and the dark and in both cases were about 2-fold higher in the light than in the dark. Despite the expression of Lhcb1*Pp1 and Lhcb2*Pp2 mRNAs during development in darkness, the levels of both mRNAs increased in dark-grown seedlings given red light in the low fluence range within 2 h of treatment.
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Affiliation(s)
- W Peer
- Department of Biology, University of California, Santa Cruz 95064, USA
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Chinn E, Silverthorne J, Hohtola A. Light-regulated and organ-specific expression of types 1, 2, and 3 light-harvesting complex b mRNAs in Ginkgo biloba. Plant Physiol 1995; 107:593-602. [PMID: 7724674 PMCID: PMC157163 DOI: 10.1104/pp.107.2.593] [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] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In a prior study (E. Chinn and J. Silverthorne [1993] Plant Physiol 103: 727-732) we showed that the gymnosperm Ginkgo biloba was completely dependent on light for chlorophyll synthesis and chloroplast development and that expression of light-harvesting complex b (Lhcb) mRNAs was substantially increased by light. However, dark-grown seedlings that were transferred to constant white light took significantly longer than angiosperm seedlings to initiate a program of photomorphogenesis and the stems failed to green completely. We have prepared type-specific probes for mRNAs encoding major polypeptides of light-harvesting complex II (Lhcb1, Lhcb2, and Lhcb3) and have used these to analyze the expression of individual Lhcb mRNAs during greening. All three sequences accumulated in the top portions of dark-grown seedlings transferred to light, but, as was seen previously for total Lhcb mRNAs, there was a transient, reproducible decline in the levels of all three mRNAs after 4 d in the light. This transient decrease in Lhcb mRNA levels was not paralleled by a decrease in Chl accumulation. By contrast, there were significantly lower levels of all three Lhcb mRNAs in the lower portions of greening dark-grown stems as well as lower Chl levels. We conclude that although the tops of the plants have the capacity to etiolate and green, Gingko seedling stems continue a program of development into woody tissue in darkness that precludes greening when the seedlings are transferred to the light.
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Affiliation(s)
- E Chinn
- Department of Biology, University of California, Santa Cruz 95064
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12
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Peters JL, Silverthorne J. Organ-Specific Stability of Two Lemna rbcS mRNAs Is Determined Primarily in the Nuclear Compartment. Plant Cell 1995; 7:131-140. [PMID: 12242353 PMCID: PMC160770 DOI: 10.1105/tpc.7.1.131] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
It has previously been shown that the organ-specific expression of two members of the ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (rbcS) gene family is post-transcriptionally regulated in Lemna gibba. While both small subunit genes encoding SSU1 and SSU5B were transcribed at comparable levels in root and frond nuclei, SSU1 mRNA accumulated to high levels in both roots and fronds in contrast to SSU5B mRNA, which was of very low abundance in the roots compared with the fronds. In this study, we have used two approaches to pinpoint the step(s) at which SSU1 and SSU5B mRNAs are differentially accumulated in these organs. In the first approach, total nuclear steady state mRNA was isolated from roots and fronds, and the amount of each transcript was measured by RNase protection assays and compared with the transcription rates in isolated nuclei. In the second approach, cordycepin was used to inhibit mRNA synthesis in Lemna fronds or roots, and the rate of decay of each mRNA was measured by RNA gel blot analysis or RNase protection assays. Our findings indicate that the differential accumulation of SSU1 and SSU5B mRNAs in the fronds versus the roots is determined primarily in the nuclear compartment. In addition, SSU1 was found to have a longer half-life in total steady state mRNA than SSU5B had in both organs. This feature probably accounts for SSU1 being the predominantly expressed family member.
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Affiliation(s)
- J. L. Peters
- Department of Biology, University of California, Santa Cruz, California 95064
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13
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Chinn E, Silverthorne J. Light-dependent chloroplast development and expression of a light-harvesting chlorophyll a/b-binding protein gene in the gymnosperm Ginkgo biloba. Plant Physiol 1993; 103:727-732. [PMID: 8022934 PMCID: PMC159042 DOI: 10.1104/pp.103.3.727] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Unlike conifers, the gymnosperm Ginkgo biloba is dependent on light for chlorophyll (Chl) synthesis and initiation of chloroplast development. Dark-grown seedlings show complete etiolation, including no detectable Chl accumulation, no leaf expansion, and increased hypocotyl elongation. When dark-grown seedlings are placed in white light, Chl synthesis and leaf expansion are initiated, but unlike angiosperms, which initiate rapid photomorphogenesis, Ginkgo takes at least 1 week to change to a normal light-regulated pattern of growth. A cDNA clone (pLhcb*Gb1) encoding a Chl a/b-binding protein of light-harvesting complex II from Ginkgo mRNA has been used as a probe for the expression of this family of mRNAs. We have found that, in common with angiosperms but in marked contrast to pines, Lhcb mRNA is expressed in a highly light-dependent manner. In addition to being expressed in light-grown leaves, this sequence is also expressed in the green tissues of immature seeds. The Lhcb mRNA appears during greening in parallel with the onset of Chl synthesis. The complete sequence of pLhcb*Gb1 has been determined and the deduced amino acid sequence was found to be of type I based on comparison with signature sequences of angiosperm and gymnosperm sequences.
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Affiliation(s)
- E Chinn
- Department of Biology, University of California, Santa Cruz 95064
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14
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Canovas F, McLarney B, Silverthorne J. Light-independent synthesis of LHC IIb polypeptides and assembly of the major pigmented complexes during the initial stages of Pinus palustris seedling development. Photosynth Res 1993; 38:89-97. [PMID: 24317834 DOI: 10.1007/bf00015065] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/1993] [Accepted: 08/09/1993] [Indexed: 06/02/2023]
Abstract
Pinus palustris has a greatly reduced need for light to initiate chloroplast development in comparison to angiosperms. Light is not required for chlorophyll synthesis in dark-grown Pinus palustris seedlings. However, embryos do not contain chlorophyll, and synthesis is limited to seedlings having cotyledon lengths between about 0.5 cm and 2.0 cm. The final amount of chlorophyll accumulated by dark-grown seedlings is about one fifth of that in light-grown seedlingsat the same stage. The major light-harvesting chlorophyll a/b-polypeptides of Photosystem II (LHC IIb) are absent in the embryos but begin to accumulate in seedlings of 0.5 cm cotyledon length, irrespective of the light conditions. Although dark-grown seedlings accumulate most of the pigmented complexes seen in light-grown seedlings, there are differences in the subunit structure of some of them. These findings suggest that the majority of the components of the photosynthetic membrane do not require light for induction of synthesis or assembly into complexes, but that the final forms seen in light-grown seedlings may require light.
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Affiliation(s)
- F Canovas
- Department of Biology, Sinsheimer Laboratories, University of California at Santa Cruz, 95064, Santa Cruz, CA, USA
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15
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Abstract
Many studies of nuclear genes encoding chloroplast proteins have focused on the transcriptional regulation of their expression. The genes (rbcS) encoding the small subunit (SSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase, a major stromal protein, comprise one such group. We have examined the role played by post-transcriptional events in determining the relative levels of individual rbcS mRNAs in different organs of the aquatic monocot Lemna gibba. L. gibba is unusual among angiosperms in that its roots are normally exposed to light during growth and contain chloroplasts. We have found that such roots transcribe rbcS genes and contain rbcS mRNA. We have used sequence-specific probes from the 3'-untranslated region of six rbcS genes from L. gibba to analyze the expression of the individual genes in different organs. All six genes were expressed in steady-state mRNA in fronds grown in constant white light. However, only five of these were easily detectable in steady-state mRNA isolated from roots of the same plants, and the relative expression of each gene varied between the roots and the fronds. In steady-state mRNA, SSU1 was found to be highly expressed in both roots and fronds, whereas SSU40B was expressed at low levels in the roots as compared with the fronds, and SSU5B RNA was barely detectable in the roots. The extremely low level of SSU5B RNA in steady-state root mRNA is likely to be a consequence of post-transcriptional events because this gene was transcribed at comparable rates in vitro in nuclei isolated from either roots or fronds. Localization of individual gene transcripts by in situ hybridization showed that SSU1 and SSU5B are expressed in the same cells in the fronds. Thus, the mechanism of differential expression is likely to involve an organ-specific post-transcriptional mechanism.
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Affiliation(s)
- J Silverthorne
- Department of Biology, University of California, Los Angeles 90024
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Phinney BO, Freeling M, Robertson DS, Spray CR, Silverthorne J. Dwarf Mutants in Maize — The Gibberellin Biosynthetic Pathway and its Molecular Future. Proceedings in Life Sciences 1986. [DOI: 10.1007/978-3-642-71018-6_7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Stiekema WJ, Wimpee CF, Silverthorne J, Tobin EM. Phytochrome Control of the Expression of Two Nuclear Genes Encoding Chloroplast Proteins in Lemna gibba L. G-3. Plant Physiol 1983; 72:717-24. [PMID: 16663073 PMCID: PMC1066308 DOI: 10.1104/pp.72.3.717] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Hybridization probes for two nuclear-coded chloroplast proteins of Lemna gibba L. G-3 have been constructed in order to investigate phytochrome regulation of specific sequences. The first probe is a cDNA clone encoding the small subunit of ribulose 1,5-bisphosphate carboxylase. This probe was isolated from a set of Lemna cDNA clones in the bacterial plasmid pBR322. The second probe is a subclone of a genomic clone encoding the light-harvesting chlorophyll a/b-protein. This clone was isolated from a set of genomic clones constructed in the lambda vector Charon 4 with L. gibba DNA fragments generated by partial EcoR1 digestion. The identity of these clones was confirmed by in vitro translation of RNA which hybridized to the cloned DNA. Plants grown under continuous white light contain high concentrations of both RNA sequences; however, when these plants are put into darkness the concentration of these RNAs decreases rapidly relative to the total amount of RNA. Plants grown in the dark with intermittent red light (2 minutes/8 hours) and put into complete darkness for 8 days also contain lower concentrations of the sequences in the total RNA. One minute of red light after this dark period results in a rapid increase in the levels of RNA hybridizing to the probes. The effect of red light can be reversed by far-red light. These experiments demonstrate that phytochrome action can rapidly influence either the rates of transcription or the rates of degradation of these mRNAs.
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Affiliation(s)
- W J Stiekema
- Department of Biology and Molecular Biology Institute, University of California, Los Angeles, California 90024
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Silverthorne J, Ellis RJ. Protein synthesis in chloroplasts. VIII. Differential synthesis of chloroplast proteins during spinach leaf development. Biochim Biophys Acta 1980; 607:319-30. [PMID: 6154482 DOI: 10.1016/0005-2787(80)90084-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [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
Excised primary leaves of spinach (Spinacia oleracea) incorporate [35S]-methionine into a number of chloroplast polypeptides. The ratio of incorporation of isotope into the large subunit of ribulose bisphosphate carboxylase relative to a thylakoid polypeptide (peak D) decreases during leaf development in whole leaves; this changing pattern of incorporation is also observed in isolated chloroplasts where these two polypeptides are the major products of protein synthesis. Chloroplast RNA prepared from developing leaves was translated in a reticulocyte lysate extract to yield full-length carboxylase large subunit and peak D polypeptides. The fidelity of translation of these two polypeptides was checked by partial protease digestion. Changes in the synthesis of the large subunit of the carboxylase and peak D in developing leaves are reflected in changes in the amount of translatable mRNA for these two polypeptides.
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