The Influence of Salivary Factors on Dental Erosion

The Influence of Salivary Factors on Dental Erosion. Dental erosion appears to be an increasing problem in patients of all ages, with the rising incidence linked to the escalating consumption of soft drinks. The research discussed here has evaluated differences between various soft drinks. Variations between the salivary buffering capacity of normal individuals and subjects with erosion have also been identified. Most soft drinks are acidic and have a low pH value. However, pH determines only the free acid ions, whereas titratable acidity gives an indication of the total acid present in the drink. The acids in a drink also contribute to the drink's buffering capacity. Drinks with a higher buffering capacity resist the rise in pH that saliva attempts to bring about and, therefore, have the potential to keep the pH of the oral cavity lower for longer. Total acidity can be assessed by carrying out an acid-base titration. The slope of the graph, that is the total amount of alkali needed to bring about a rise in pH, gives an estimate of the buffering capacity of the drink. Several different groups of drinks have been tested. Carbonated drinks such as cola, which are not fruit-based, fruit-flavoured carbonated drinks such as Lilt, sparkling mineral waters, both plain and flavoured, still mineral water and pure fruit juices have all been included. The initial pH values showed cola drinks to have the lowest pH and still mineral water the highest. Significant differences in buffering capacity were found between each of the groups of drinks tested. The total acid found in fruit juices and fruit- based drinks was far greater than that found in cola drinks. It is clear that the addition of fruit flavouring, and hence more acid, to drinks increases their buffering capacity. This was despite the fact that the initial pH values of the fruit juices were higher than the cola drinks, indicating that pH values alone do not predict accurately the total amount of acid present in a drink. Caution must be exercised, however, when extrapolating these results to the oral cavity, but it is clear that in terms of acid content, fruit drinks and fruit juices have more potential demineralise tooth tissue. In the mouth, saliva becomes a major modifying factor, as it neutralises and buffers acidic substances and acts in effect as a biological base. By carrying out titrations of saliva with soft drinks, it can be seen how effective saliva is at coping with the challenge of acidic drinks. Drinks from each of the main groups were titrated with saliva from various volunteers. Again, clear differences were seen between the various groups of drinks, with pure fruit juices causing the greatest changes in salivary pH, followed by fruit - based carbonated drinks. Carbonated cola drinks and sparkling mineral waters caused smaller changes in salivary pH. Saliva was also collected from volunteers with diagnosed dental erosion. It was interesting to note that the pH of saliva from those with erosion fell more quickly than that of normal individuals. Saliva from individuals with erosion may, therefore, be less able to cope with the acidic challenge of soft drinks. The oral cavity is a dynamic physiological model. There are many complex factors involved in the interactions of saliva with acidic drinks, which in vitro experiments only go some way to explaining. The monitoring of salivary pH during drinking involved observing changes in pH while consuming an entire can of beverage. A measured sip of the chosen soft drink was taken every minute, with saliva being collected shortly after each sip for pH measurement. Three different drinks were tested, including a pure fruit juice and a diet drink. For most of the volunteers, salivary pH fell during drinking. There were a few individuals for whom the pH values of saliva rose during drinking, highlighting the excellent ability of saliva as a buffering agent. However, the most common finding was a fall in salivary pH, which often extended beyond the drinking time, indicating that the effects of soft drinks on the saliva may continue for some time after drinking has stopped. It was felt important to include patients with diagnosed erosion in this trial, to see how their saliva reacted to an erosive insult. The fall in salivary pH was particularly marked for these volunteers with erosion. Once again, it emerged that there may be some deficiency in the saliva of those who are prone to erosion, in that the buffering capacity of the saliva appeared to be reduced. There were also differences between the various drinks tested. Consumption of the pure fruit juice caused the pH of saliva to fall to a lower value than when the cola drink was taken. These results underline the results from the earlier in vitro tests, indicating that pure fruit juices may have more potential to cause erosion because of their ability to lower the pH of the oral cavity for longer. There is evidence that many factors contribute to the buffering ability of saliva. Salivary proteins are believed to play a role, especially at extremes of acidity

Open Digital Pedagogy: Creating a Game-Based Workshop

Concurrent Session

The Grizzly, February 21, 1986

It\u27s Bid Day!: Three Weeks of Frat Pledging get Underway • Suite Living in Reimert • Unique Paper Sculptures get Positive Reactions • Intra-Mural Season Opens • Demerits, Profanity, Attack on Deans Mark Alcohol Policing in the Past • Disease, Dissent, Dissemblance: Mills of Bureaucracy Grind Exceeding Slow, But Grind Old Folks Exceeding Fine • U.C. Hosts MAC Wrestling Tourney • Men\u27s Track: Strong MAC Lineup • Gym Women get Trimmed • Missing Refs, Fan Riot: The Best Game Ever ? • SAC Funds Available • Women\u27s Studies Surveyhttps://digitalcommons.ursinus.edu/grizzlynews/1158/thumbnail.jp

A search for dispersed radio bursts in archival Parkes Multibeam Pulsar Survey data

A number of different classes of potentially extra-terrestrial bursts of radio emission have been observed in surveys with the Parkes 64m radio telescope, including "Rotating Radio Transients", the "Lorimer burst" and "perytons". Rotating Radio Transients are radio pulsars which are best detectable in single-pulse searches. The Lorimer burst is a highly dispersed isolated radio burst with properties suggestive of extragalactic origin. Perytons share the frequency-swept nature of the Rotating Radio Transients and Lorimer burst, but unlike these events appear in all thirteen beams of the Parkes Multibeam receiver and are probably a form of peculiar radio frequency interference. In order to constrain these and other radio source populations further, we searched the archival Parkes Multibeam Pulsar Survey data for events similar to any of these. We did not find any new Rotating Radio Transients or bursts like the Lorimer burst. We did, however, discover four peryton-like events. Similar to the perytons, these four bursts are highly dispersed, detected in all thirteen beams of the Parkes multibeam receiver, and have pulse widths between 20--30 ms. Unlike perytons, these bursts are not associated with atmospheric events like rain or lightning. These facts may indicate that lightning was not responsible for the peryton phenomenon. Moreover, the lack of highly dispersed celestial signals is the evidence that the Lorimer burst is unlikely to belong to a cosmological source population.Comment: Accepted for publication in MNRAS; 7 pages, 3 figures, 1 tabl

Treatment of irritable bowel syndrome with diarrhoea using titrated ondansetron (TRITON): study protocol for a randomised controlled trial

Background: Irritable bowel syndrome with diarrhoea (IBS-D) affects up to 4% of the general population. Symptoms include frequent, loose, or watery stools with associated urgency, resulting in marked reduction of quality of life and loss of work productivity. Ondansetron, a 5HT3 receptor antagonist, has had an excellent safety record for over 20 years as an antiemetic, yet is not widely used in the treatment of IBS-D. It has, however, been shown to slow colonic transit and in a small randomised, placebo-controlled, cross-over pilot study, benefited patients with IBS-D. Methods: This trial is a phase III, parallel group, randomised, double-blind, multi-centre, placebo-controlled trial, with embedded mechanistic studies. Participants (n = 400) meeting Rome IV criteria for IBS-D will be recruited from outpatient and primary care clinics and by social media to receive either ondansetron (dose titrated up to 24 mg daily) or placebo for 12 weeks. Throughout the trial, participants will record their worst abdominal pain, worst urgency, stool frequency, and stool consistency on a daily basis. The primary endpoint is the proportion of “responders” in each group, using Food and Drug Administration (FDA) recommendations. Secondary endpoints include pain intensity, stool consistency, frequency, and urgency. Mood and quality of life will also be assessed. Mechanistic assessments will include whole gut transit, faecal tryptase and faecal bile acid concentrations at baseline and between weeks 8 and 11. A subgroup of participants will also undergo assessment of sensitivity (n = 80) using the barostat, and/or high-resolution colonic manometry (n = 40) to assess motor patterns in the left colon and the impact of ondansetron. Discussion: The TRITON trial aims to assess the effect of ondansetron across multiple centres. By defining ondansetron’s mechanisms of action we hope to better identify patients with IBS-D who are likely to respond

Randomised controlled trial and economic evaluation of a targeted cancer awareness intervention for adults living in deprived areas of the UK

Background: Cancer outcomes are poor in socioeconomically deprived communities, with low symptom awareness contributing to prolonged help-seeking and advanced disease. Targeted cancer awareness interventions require evaluation. Methods: Randomised controlled trial involving adults aged 40+ recruited in community and healthcare settings in deprived areas of South Yorkshire and South-East Wales. Intervention: personalised behavioural advice facilitated by a trained lay advisor. Control: usual care. Follow-up at 2-weeks and 6-months post-randomisation. Primary outcome: total cancer symptom recognition score 2-weeks post-randomisation. Results: 234 participants were randomised. The difference in total symptom recognition at 2-weeks [adjusted mean difference (AMD) 0.6, 95% CI:-0.03, 1.17, p=0.06] was not statistically significant. Intervention participants reported increased symptom recognition (AMD 0.8, 95% CI:0.18, 1.37, p=0.01) and earlier intended presentation (AMD -2.0, 95% CI:-3.02, -0.91, p<0.001) at 6-months. “Lesser known” symptom recognition was higher in the intervention arm (2-weeks AMD 0.5, 95% CI:0.03, 0.97 and 6-months AMD 0.7, 95% CI:0.16, 1.17). Implementation cost per participant was £91.34, with no significant between-groups differences in healthcare resource use post-intervention. Conclusions: Improved symptom recognition and earlier anticipated presentation occurred at longer-term follow-up. The ABACus Health Check is a viable low-cost intervention to increase cancer awareness in socioeconomically deprived communities. Clinical Trial Registration: ISRCTN1687254

Pan-cancer analysis of whole genomes identifies driver rearrangements promoted by LINE-1 retrotransposition.

About half of all cancers have somatic integrations of retrotransposons. Here, to characterize their role in oncogenesis, we analyzed the patterns and mechanisms of somatic retrotransposition in 2,954 cancer genomes from 38 histological cancer subtypes within the framework of the Pan-Cancer Analysis of Whole Genomes (PCAWG) project. We identified 19,166 somatically acquired retrotransposition events, which affected 35% of samples and spanned a range of event types. Long interspersed nuclear element (LINE-1; L1 hereafter) insertions emerged as the first most frequent type of somatic structural variation in esophageal adenocarcinoma, and the second most frequent in head-and-neck and colorectal cancers. Aberrant L1 integrations can delete megabase-scale regions of a chromosome, which sometimes leads to the removal of tumor-suppressor genes, and can induce complex translocations and large-scale duplications. Somatic retrotranspositions can also initiate breakage-fusion-bridge cycles, leading to high-level amplification of oncogenes. These observations illuminate a relevant role of L1 retrotransposition in remodeling the cancer genome, with potential implications for the development of human tumors

Improving cancer symptom awareness and help-seeking among adults living in socioeconomically deprived communities in the UK using a facilitated health check: A protocol for the Awareness and Beliefs About Cancer (ABACus) Randomised Control Trial

Background Cancer survival is lower in socioeconomically deprived communities, partly due to low awareness of symptoms, negative beliefs and delayed help-seeking. We developed an interactive health check questionnaire facilitated by trained lay advisors. It entails 29 questions about background, lifestyle and health with tailored behaviour change advice. Personalised results are printed using a traffic light (red/amber/green) system, highlighting areas where action should be taken. This is an individually randomised control trial to test effectiveness of the health check on symptom recognition. Methods A total 246 participants aged 40+ years will be recruited from community and healthcare settings in socioeconomically deprived areas of Yorkshire and South Wales. Participants will be randomised to receive the health check or standard care (1:1 ratio). Outcome measures include: adapted Awareness and Beliefs about Cancer (primary outcome), brief State Trait Anxiety Inventory, intentions and motivation to adopt recommended health behaviours (early symptom presentation, cancer screening and lifestyle behaviours), adapted Client Service Receipt Inventory, brief medical history/screening and demographic questionnaire at: baseline; 2-weeks; and 6-months post-randomisation. A purposive sample of intervention sessions will be audio-recorded (n = 24) and half will additionally be observed (n = 12). Semi-structured interviews will take place at 2-weeks (n = 30) and 6-months (n = 15–20) post-randomisation. The primary analysis will compare cancer symptom recognition scores between arms at 2-weeks. Secondary analysis will assess cancer beliefs, barriers/time to presentation, screening and lifestyle behaviours, anxiety and costs. A process evaluation will assess intervention fidelity, dose and contamination

The NANOGrav Nine-year Data Set:Mass and Geometric Measurements of Binary Millisecond Pulsars

We analyze 24 binary radio pulsars in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) nine-year data set. We make 14 significant measurements of the Shapiro delay, including new detections in four pulsar-binary systems (PSRs J0613−0200, J2017+0603, J2302+4442, and J2317+1439), and derive estimates of the binary-component masses and orbital inclination for these MSP-binary systems. We find a wide range of binary pulsar masses, with values as low as ${m}_{{\rm{p}}}={1.18}_{-0.09}^{+0.10}\,{M}_{\odot }$ for PSR J1918−0642 and as high as ${m}_{{\rm{p}}}={1.928}_{-0.017}^{+0.017}\,{M}_{\odot }$ for PSR J1614−2230 (both 68.3% credibility). We make an improved measurement of the Shapiro timing delay in the PSR J1918−0642 and J2043+1711 systems, measuring the pulsar mass in the latter system to be ${m}_{{\rm{p}}}={1.41}_{-0.18}^{+0.21}\,{M}_{\odot }$ (68.3% credibility) for the first time. We measure secular variations of one or more orbital elements in many systems, and use these measurements to further constrain our estimates of the pulsar and companion masses whenever possible. In particular, we used the observed Shapiro delay and periastron advance due to relativistic gravity in the PSR J1903+0327 system to derive a pulsar mass of ${m}_{{\rm{p}}}={1.65}_{-0.02}^{+0.02}\,{M}_{\odot }$ (68.3% credibility). We discuss the implications that our mass measurements have on the overall neutron-star mass distribution, and on the "mass/orbital-period" correlation due to extended mass transfer