99 research outputs found
Cell wall modifications during fruit ripening: when a fruit is not the fruit
Textural changes that lead to softening of fruits are accompanied
by loss of neutral sugars, solubilisation and depolymerisation
of the polysaccharides of the cell wall, and
rearrangements of their associations, as the result of the combined
action of several cell wall-modifying enzymes, acting in
both pectic and hemicellulosic fractions. Recent studies on the
structure of the plant cell wall have disclosed a large number
and type of biochemical linkages between the components.
Such linkages are potential targets for enzymatic action and
draw attention to the putative involvement of several members
of enzymes able to act and modify its structure in a developmental
and coordinated way. Extensive work on fruit ripening
has been done using tomato (Solanum lycopersicum [Lycopersicon
esculentum Mill.]) as a plant model and the information
concerning fruits other than model species is fragmented and
incomplete. However, recent data from the literature had disclosed
that differences exist between fruits, and even between
cultivars of the same fruit species. These differences exist in the
type and extent of the modification of the polysaccharides of
the cell wall and in the expression and regulation of cell
wall-modifying enzymes. In addition, genetic manipulation
of cell wall-modifying genes re-opened the discussion about
the real effect of these enzymes in the cell wall and their
role in fruit softening. Moreover, the function of each enzyme
has been proposed based on its homology with other annotated sequences, but, in most cases, confirmation of activity
in planta and substrate specificity remains to be investigated.
This aspect and recognized limitations of the in vitro
enzymatic activity assays also need to be considered when discussing
their role. This paper provides a critical review on the
current knowledge concerning these differences and emphasises
the need of using other species and more accurate methodologies
to investigate general mechanisms and fruit specificities
of softening among different fleshy fruits
Cloning, characterisation and expression analysis of cDNA clones encoding cell wall-modifying enzymes isolated from ripe apples
Fruit softening is accompanied by modifications of the cell wall pectic and hemicellulosic fractions, as the result of the combined action
of several cell wall-modifying enzymes. The objective of this work was to clone specific cDNAs that encode isoforms of cell wall-modifying
enzymes, which are expressed during the final stages of apple softening, and to establish a temporal sequence of their accumulation. A cDNA
library enriched with mRNA isolated from over-ripe fruit was constructed and screened. A pectin methylesterase (MdPME1), a pectate lyase
(MdPL1), an -l-arabinofuranosidase (MdAF1) an endo-1,4- -glucanase (MdEG1), two xyloglucan endotransglucosylase/hydrolases (Md-XTH1
and Md-XTH2), and an alpha-expansin (MdEXPA3) specific cDNAs were identified by homology-based cloning, and their mRNA accumulation
was examined during fruit growth and ripening. The expression of an apple -galactosidase ( -Gal; pABG1) and a polygalacturonase (PG;
pGDPG-1) mRNA previously reported was also investigated using the same biological material. Transcripts of all enzymes, except MdPME1,
could be unambiguously detected by semi-quantitative RT-PCR in fruit during ripening. However, transcripts of MdEG1 were more abundant
at fruit set and MdPL1 exhibited higher expression before commercial maturity. The strongest RT-PCR signals in over-ripe fruit were observed
for PG, -Gal and Md-XTH1 clones. Two XTHs were detected in over-ripe fruit. While Md-XTH1 acts constitutively during fruit development,
Md-XTH2 showed a ripening-related pattern. The Md-XTH2-encoded protein was heterologously expressed in Saccharomyces cerevisiae and
showed both transglycosylase and hydrolase activities. Expression analyses conducted in flowers, peduncles, young and expanded leaves, and
petioles of senescent leaves revealed that none of the cloned cDNAs is fruit specifi
The Value of Preventative Dental Care:A Discrete-Choice Experiment
Acknowledgments We thank all of the respondents to our survey who took the time to share their opinions and preferences with us, as well as all members of the IQuaD study team who provided input, advice, and comments on draft versions of the survey. Open Access via the Jisc Sage Open Access Agreement Funder - national institute for health research 10.13039/501100000272 09/01/45 Funding The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The project was funded by the UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme (project number: 09/01/45). The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Department of Health or the funders that provide institutional support for the authors of this report. The Health Economics Research Unit and the Health Services Research Unit are funded by the Chief Scientist Office of the Scottish Government Health and Social Care DirectoratesPeer reviewedPublisher PD
Early detection of neovascular age-related macular degeneration : an economic evaluation based on data from the EDNA study
Funding: The project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment Programme (grant number: 12/142/07) and will be published in full in Health Technology Assessment. The funder was not involved in the study design; in the collection, analysis and interpretation of the data; in the writing of the report; and in the decision to submit the paper for publication. The Health Services Research Unit (HSRU) and the Health Economics Research Unit (HERU) are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate (HSRU/2021-2024, HERU/2021-2024).Peer reviewedPostprin
Use of effective contraception following provision of the progestogen-only pill for women presenting to community pharmacies for emergency contraception (Bridge-It): a pragmatic cluster-randomised crossover trial
BACKGROUND: Unless women start effective contraception after oral emergency contraception, they remain at risk of unintended pregnancy. Most women in the UK obtain emergency contraception from community pharmacies. We hypothesised that pharmacist provision of the progestogen-only pill as a bridging interim method of contraception with emergency contraception plus an invitation to a sexual and reproductive health clinic, in which all methods of contraception are available, would result in increased subsequent use of effective contraception. METHODS: We did a pragmatic cluster-randomised crossover trial in 29 UK pharmacies among women receiving levonorgestrel emergency contraception. Women aged 16 years or older, not already using hormonal contraception, not on medication that could interfere with the progestogen-only pill, and willing to give contact details for follow-up were invited to participate. In the intervention group, women received a 3-month supply of the progestogen-only pill (75 μg desogestrel) plus a rapid access card to a participating sexual and reproductive health clinic. In the control group, pharmacists advised women to attend their usual contraceptive provider. The order in which each pharmacy provided the intervention or control was randomly assigned using a computer software algorithm. The primary outcome was the use of effective contraception (hormonal or intrauterine) at 4 months. This study is registered, ISRCTN70616901 (complete). FINDINGS: Between Dec 19, 2017, and June 26, 2019, 636 women were recruited to the intervention group (316 [49·6%], mean age 22·7 years [SD 5·7]) or the control group (320 [50·3%], 22·6 years [5·1]). Three women (one in the intervention group and two in the control group) were excluded after randomisation. 4-month follow-up data were available for 406 (64%) participants, 25 were lost to follow-up, and two participants no longer wanted to participate in the study. The proportion of women using effective contraception was 20·1% greater (95% CI 5·2-35·0) in the intervention group (mean 58·4%, 48·6-68·2), than in the control group (mean 40·5%, 29·7-51·3 [adjusted for recruitment period, treatment group, and centre]; p=0·011).The difference remained significant after adjusting for age, current sexual relationship, and history of effective contraception use, and was robust to the effect of missing data (assuming missingness at random). No serious adverse events occurred. INTERPRETATION: Provision of a supply of the progestogen-only pill with emergency contraception from a community pharmacist, along with an invitation to a sexual and reproductive health clinic, results in a clinically meaningful increase in subsequent use of effective contraception. Widely implemented, this practice could prevent unintended pregnancies after use of emergency contraception. FUNDING: National Institute for Health Research (Health Technology Assessment Programme project 15/113/01)
Use of effective contraception following provision of the progestogen-only pill for women presenting to community pharmacies for emergency contraception (Bridge-It):a pragmatic cluster-randomised crossover trial
BACKGROUND:Unless women start effective contraception after oral emergency contraception, they remain at risk of unintended pregnancy. Most women in the UK obtain emergency contraception from community pharmacies. We hypothesised that pharmacist provision of the progestogen-only pill as a bridging interim method of contraception with emergency contraception plus an invitation to a sexual and reproductive health clinic, in which all methods of contraception are available, would result in increased subsequent use of effective contraception. METHODS:We did a pragmatic cluster-randomised crossover trial in 29 UK pharmacies among women receiving levonorgestrel emergency contraception. Women aged 16 years or older, not already using hormonal contraception, not on medication that could interfere with the progestogen-only pill, and willing to give contact details for follow-up were invited to participate. In the intervention group, women received a 3-month supply of the progestogen-only pill (75 μg desogestrel) plus a rapid access card to a participating sexual and reproductive health clinic. In the control group, pharmacists advised women to attend their usual contraceptive provider. The order in which each pharmacy provided the intervention or control was randomly assigned using a computer software algorithm. The primary outcome was the use of effective contraception (hormonal or intrauterine) at 4 months. This study is registered, ISRCTN70616901 (complete). FINDINGS:Between Dec 19, 2017, and June 26, 2019, 636 women were recruited to the intervention group (316 [49·6%], mean age 22·7 years [SD 5·7]) or the control group (320 [50·3%], 22·6 years [5·1]). Three women (one in the intervention group and two in the control group) were excluded after randomisation. 4-month follow-up data were available for 406 (64%) participants, 25 were lost to follow-up, and two participants no longer wanted to participate in the study. The proportion of women using effective contraception was 20·1% greater (95% CI 5·2-35·0) in the intervention group (mean 58·4%, 48·6-68·2), than in the control group (mean 40·5%, 29·7-51·3 [adjusted for recruitment period, treatment group, and centre]; p=0·011).The difference remained significant after adjusting for age, current sexual relationship, and history of effective contraception use, and was robust to the effect of missing data (assuming missingness at random). No serious adverse events occurred. INTERPRETATION:Provision of a supply of the progestogen-only pill with emergency contraception from a community pharmacist, along with an invitation to a sexual and reproductive health clinic, results in a clinically meaningful increase in subsequent use of effective contraception. Widely implemented, this practice could prevent unintended pregnancies after use of emergency contraception. FUNDING:National Institute for Health Research (Health Technology Assessment Programme project 15/113/01)
Protocol for a Randomised controlled trial to Evaluate the effectiveness and cost benefit of prescribing high dose FLuoride toothpaste in preventing and treating dEntal Caries in high-risk older adulTs (reflect trial)
Background Dental caries in the expanding elderly, predominantly-dentate population is an emerging public health concern. Elderly individuals with heavily restored dentitions represent a clinical challenge and significant financial burden for healthcare systems, especially when their physical and cognitive abilities are in decline. Prescription of higher concentration fluoride toothpaste to prevent caries in older populations is expanding in the UK, significantly increasing costs for the National Health Services (NHS) but the effectiveness and cost benefit of this intervention are uncertain. The Reflect trial will evaluate the effectiveness and cost benefit of General Dental Practitioner (GDP) prescribing of 5000ppm fluoride toothpaste and usual care compared to usual care alone in individuals 50years and over with high-risk of caries.Methods/designA pragmatic, open-label, randomised controlled trial involving adults aged 50years and above attending NHS dental practices identified by their dentist as having high risk of dental caries. Participants will be randomised to prescription of 5000ppm fluoride toothpaste (frequency, amount and duration decided by GDP) and usual care only. 1200 participants will be recruited from approximately 60 dental practices in England, Scotland and Northern Ireland and followed up for 3years. The primary outcome will be the proportion of participants receiving any dental treatment due to caries. Secondary outcomes will include coronal and root caries increments measured by independent, blinded examiners, patient reported quality of life measures, and economic outcomes; NHS and patient perspective costs, willingness to pay, net benefit (analysed over the trial follow-up period and modelled lifetime horizon). A parallel qualitative study will investigate GDPs' practises of and beliefs about prescribing the toothpaste and patients' beliefs and experiences of the toothpaste and perceived impacts on their oral health-related behaviours.DiscussionThe Reflect trial will provide valuable information to patients, policy makers and clinicians on the costs and benefits of an expensive, but evidence-deficient caries prevention intervention delivered to older adults in general dental practice.Trial registrationISRCTN: 2017-002402-13 registered 02/06/2017, first participant recruited 03/05/2018.Ethics Reference No: 17/NE/0329/233335.Funding Body: Health Technology Assessment funding stream of National Institute for Health Research.Funder number: HTA project 16/23/01.Trial Sponsor: Manchester University NHS Foundation Trust, Oxford Road, Manchester, M13 9WL.The Trial was prospectively registered
Physiological and ultrastructural analysis reveal the absence of a defined abscission zone in coffee fruits
Reference gene validation for quantitative RT-PCR during biotic and abiotic stresses in Vitis vinifera
Grapevine is one of the most cultivated fruit crop worldwide with Vitis vinifera being the species with the highest
economical importance. Being highly susceptible to fungal pathogens and increasingly affected by environmental factors, it
has become an important agricultural research area, where gene expression analysis plays a fundamental role. Quantitative
reverse transcription polymerase chain reaction (qRT-PCR) is currently amongst the most powerful techniques to perform
gene expression studies. Nevertheless, accurate gene expression quantification strongly relies on appropriate reference
gene selection for sample normalization. Concerning V. vinifera, limited information still exists as for which genes are the
most suitable to be used as reference under particular experimental conditions. In this work, seven candidate genes were
investigated for their stability in grapevine samples referring to four distinct stresses (Erysiphe necator, wounding and UV-C
irradiation in leaves and Phaeomoniella chlamydospora colonization in wood). The expression stability was evaluated using
geNorm, NormFinder and BestKeeper. In all cases, full agreement was not observed for the three methods. To provide
comprehensive rankings integrating the three different programs, for each treatment, a consensus ranking was created
using a non-weighted unsupervised rank aggregation method. According to the last, the three most suitable reference
genes to be used in grapevine leaves, regardless of the stress, are UBC, VAG and PEP. For the P. chlamydospora treatment,
EF1, CYP and UBC were the best scoring genes. Acquaintance of the most suitable reference genes to be used in grapevine
samples can contribute for accurate gene expression quantification in forthcoming studiesinfo:eu-repo/semantics/publishedVersio
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