The action mechanisms revealed by the biochemical and structural analyses of replicative and translesion synthesis (TLS) DNA polymerases (Pols) are retained in their cellular roles. In this regard, DNA polymerase θ differs from other Pols in that whereas purified Polθ misincorporates an A opposite 1,N6-ethenodeoxyadenosine (ϵdA) using an abasic-like mode, Polθ performs predominantly error-free TLS in human cells. To test the hypothesis that Polθ adopts a different mechanism for replicating through ϵdA in human cells than in the purified Pol, here we analyze the effects of mutations in the two highly conserved tyrosine residues, Tyr-2387 and Tyr-2391, in the Polθ active site. Our findings that these residues are indispensable for TLS by the purified Pol but are not required in human cells, as well as other findings, provide strong evidence that the Polθ active site is reconfigured in human cells to stabilize ϵdA in the syn conformation for Hoogsteen base pairing with the correct nucleotide. The evidence that a DNA polymerase can configure its active site entirely differently in human cells than in the purified Pol establishes a new paradigm for DNA polymerase function.

(Max Planck Institute for the Science of Human History) What makes our species unique compared to other hominins? High profile genetic, fossil and material culture discoveries present scientists working in the Late Pleistocene with an ever-more complex picture of interactions between early hominin populations. One distinctive characteristic of Homo sapiens, however, appears to be its global distribution. Exploring how Homo sapiens colonized most of the world's continents in a relatively short period could reveal the exceptional capacities of humans relative to other hominins.

(University of Plymouth) Researchers say a fossil found on the Jurassic coast of southern England in the 19th century demonstrates the world's oldest known example of a squid-like creature attacking its prey.

Sodium–glucose cotransport 2 inhibitors (SGLT2i) lower plasma glucose but stimulate endogenous glucose production (EGP). The current study examined the effect of dapagliflozin on EGP while clamping plasma glucose, insulin, and glucagon concentrations at their fasting level. Thirty-eight patients with type 2 diabetes received an 8-h measurement of EGP ([3-³H]-glucose) on three occasions. After a 3-h tracer equilibration, subjects received 1) dapagliflozin 10 mg (n = 26) or placebo (n = 12); 2) repeat EGP measurement with the plasma glucose concentration clamped at the fasting level; and 3) repeat EGP measurement with inhibition of insulin and glucagon secretion with somatostatin infusion and replacement of basal plasma insulin and glucagon concentrations. In study 1, the change in EGP (baseline to last hour of EGP measurement) in subjects receiving dapagliflozin was 22% greater (+0.66 ± 0.11 mg/kg/min, P < 0.05) than in subjects receiving placebo, and it was associated with a significant increase in plasma glucagon and a decrease in the plasma insulin concentration compared with placebo. Under glucose clamp conditions (study 2), the change in plasma insulin and glucagon concentrations was comparable in subjects receiving dapagliflozin and placebo, yet the difference in EGP between dapagliflozin and placebo persisted (+0.71 ± 0.13 mg/kg/min, P < 0.01). Under pancreatic clamp conditions (study 3), dapagliflozin produced an initial large decrease in EGP (8% below placebo), followed by a progressive increase in EGP that was 10.6% greater than placebo during the last hour. Collectively, these results indicate that 1) the changes in plasma insulin and glucagon concentration after SGLT2i administration are secondary to the decrease in plasma glucose concentration, and 2) the dapagliflozin-induced increase in EGP cannot be explained by the increase in plasma glucagon or decrease in plasma insulin or glucose concentrations.

Insulin is first produced in pancreatic β-cells as the precursor prohormone proinsulin. Defective proinsulin processing has been implicated in the pathogenesis of both type 1 and type 2 diabetes. Though there is substantial evidence that mouse β-cells process proinsulin using prohormone convertase 1/3 (PC1/3) then prohormone convertase 2 (PC2), this finding has not been verified in human β-cells. Immunofluorescence with validated antibodies reveals that there was no detectable PC2 immunoreactivity in human β-cells and little PCSK2 mRNA by in situ hybridization. Similarly, rat β-cells were not immunoreactive for PC2. In all histological experiments, PC2 immunoreactivity in neighbouring α-cells acts as a positive control. In donors with type 2 diabetes, β-cells had elevated PC2 immunoreactivity, suggesting that aberrant PC2 expression may contribute to impaired proinsulin processing in β-cells of patients with diabetes. To support histological findings using a biochemical approach, human islets were used for pulse-chase experiments. Despite inhibition of PC2 function by temperature blockade, brefeldin-A, chloroquine, and multiple inhibitors that blocked production of mature glucagon from proglucagon, β-cells retained the ability to produce mature insulin. Conversely, suppression of PC1/3 blocked processing of proinsulin but not proglucagon. By demonstrating that healthy human β-cells process proinsulin by PC1/3 but not PC2 we suggest that there is a need to revise the longstanding theory of proinsulin processing.

We conducted a two-sample Mendelian randomisation study to investigate the causal associations of type 2 diabetes mellitus (T2DM) with risk of overall cancer and 22 site-specific cancers. Summary-level data for cancer were extracted from the Breast Cancer Association Consortium and UK Biobank. Genetic predisposition to T2DM was associated with higher odds of pancreatic, kidney, uterine and cervical cancer, lower odds of oesophageal cancer and melanoma, but not associated with 16 other site-specific cancers or overall cancer. The odds ratios (95% confidence interval) were 1.13 (1.04, 1.22), 1.08 (1.00, 1.17), 1.08 (1.01, 1.15), 1.07 (1.01, 1.15), 0.89 (0.81, 0.98), and 0.93 (0.89, 0.97) for pancreatic, kidney, uterine, cervical, and oesophageal cancer and melanoma, respectively. The association between T2DM and pancreatic cancer was also observed in a meta-analysis of this and a previous Mendelian randomisation study (odds ratio 1.08; 1.02, 1.14; p=0.009). There was limited evidence supporting causal associations between fasting glucose and cancer. Genetically predicted fasting insulin levels were positively associated with cancers of the uterus, kidney, pancreas and lung. The present study found causal detrimental effects of T2DM on several cancers. We suggested to reinforce the cancers screening in T2DM patients to enable the early detection of cancer.

Mariam Alatrach
Apr 1, 2020; 69:681-688
Pathophysiology

Doctors considering strike action may worry about the effect on patients. David Metcalfe and colleagues examine the evidence and find that “patients do not come to serious harm during industrial action provided that provisions are made for emergency care.” Read the full analysis: http://www.bmj.com/content/351/bmj.h6231

Global evidence indicates that mandated treatment of drug dependence conflicts with drug users’ human rights and is not effective in treating addiction. Karsten Lunze, associate professor at the Boston University School of Medicine, joins us to describe the evidence, and why he is convinced seemingly counter intuitive hard reduction...

The same piece of evidence may reach you via a journalist, or via your doctor - but the way in which that evidence is communicated is changed by your relationship between that person. Julia Beluz from Vox and Victor Montori from the Mayo Clinic join us to discuss if it's possible to reconcile those competing points of view.

Despite high quality systematic reviews reporting ineffectiveness, many guideline groups continue to recommend vitamin D supplementation (with or without calcium) for fall or fracture prevention. Recently Public Health England recommended that everyone needs vitamin D equivalent to an average daily intake of 10 μg (400 IU) to protect bone and...

We're creating a manifesto for better evidence. The centre for Evidence Based Medicine at the University of Oxford, and the BMJ, are asking what are the problem with medical evidence, and how can we fix them? In this second discussion we went to Nottingham​ University, to find out what the people who create the bread and butter of EBM -...

We're creating a manifesto for better evidence. The centre for Evidence Based Medicine at the University of Oxford, and the BMJ, are asking what are the problem with medical evidence, and how can we fix them? In this third discussion we went to Scotland, to find out what the people who create policy think about the issues with evidence synthesis,...

"Too many research studies are poorly designed or executed. Too much of the resulting research evidence is withheld or disseminated piecemeal. As the volume of clinical research activity has grown the quality of evidence has often worsened, which has compromised the ability of all health professionals to provide affordable, effective, high value...

There’s been a lot of attention given to the new antirviral drugs which target Hepatitis C - partly because of the burden of infection of the disease, and the lack of a treatment that can be made easily accessible to around the world, and partly because of the incredible cost of a course of treatment. But a new article on BMJ talks about the...

At evidence live this year, one of the sessions was about the work of Evidence Aid - and their attempt to bring high quality evidence to the frontline of a humanitarian crisis. In that situation, it’s very difficult to know what will work - a conflict, or even immediately post-conflict situation is characterised by chaos - and merely doing...

If you’re of a scientific persuasion, watching policy debates around Brexit, or climate change, or drug prohibition are likely to cause feelings of intense frustration about the dearth of evidence in those discussions. In this podcast we're joined by Chris Bonell, professor of public health sociology - in this podcast he airs those frustrations,...

Welcome to this, trial run, of a new kind of BMJ podcast - here we’re going to be focusing on all things EBM. Duncan Jarvies, Helen Macdonald and Carl Heneghan - and occasional guests- will be back every month to discuss what's been happening in the world of evidence. We'll bring you our Verdict on what you should start or stop doing, geek out...

In the second of our EBM round-ups, Carl Heneghan, Helen Macdonald and Duncan Jarvies are joined by Deborah Cohen, investigative journalist and scourge of device manufacturers. We're giving our verdict on the sensitivity and specificity of ketone testing for hyperemesis, and the advice to drinking more water to prevent recurrent UTIs in...

In this EBM round-up, Carl Heneghan, Helen Macdonald and Duncan Jarvies are back to give you an update Dual vs single therapy for prevention of TIA or minor stroke - how does the advice that dual work better translate in the UK? Carl explains why Japan can teach us to get active and, how GPs can use that information to "drop a decade" in...

Helen Macdonald and Carl Heneghan are back again talking about what's happened in the world of evidence this month. They start by talking about how difficult a task it is to find evidence that's definitely practice changing, what GPs can learn from Malawian children with nonsevere fast-breathing pneumonia, how radiation dosage varies...

Helen Macdonald and Carl Heneghan are back again talking about what's happened in the world of evidence this month. They start by talking about shoulders - what does the evidence say about treating subacromial pain, and why the potential for a subgroup effect shouldn't change our views about stop surgery (for now, more research needed). (16.00)...

Helen Macdonald and Carl Heneghan are back again talking about what's happened in the world of evidence this month. (1.20) Carl grinds his gears over general health checks, with an update in the Cochrane Library. (9.15) Helen is surprised by new research which looks at over prescription of antibiotics - but this time because the courses...

Helen Macdonald and Carl Heneghan are back again talking about what's happened in the world of evidence this month. (1.05) Carl rants about bacon causing cancer (7.10) Helen talks about prostate cancer, and we hear from the author of the research paper which won Research Paper Of The Year at the BMJ awards. We also cover disease definition and...

This week on the podcast, (2.02) a listener asks, when we suggest something to stop, should we suggest an alternative instead? (8.24) Helen tells us to stop putting people on treatment for subclinical hypothyroidism, but what does that mean for people who are already receiving thyroxine? (20.55) Carl has a black box warning about z drugs, and...

This month we have some more feedback from our listeners (2.20) Carl says it's time to start smoking cessation (or stop the reduction in funding for smoking reduction) (11.40) and marvels at how pretty Richard Doll's seminal smoking paper is. It's gloves off for infection control (22.20) Andrew George, a non-executive director of the Health...

Welcome back to Talk Evidence - where Helen Macdonald and Carl Heneghan take you through what's happening in the world of Evidence. This month we'll be discussing tramadol being prescripted postoperatively, and a new EBM verdict says that should change(1.36). How much preventable harm does healthcare causes (11.20. A canadian project to help...

Helen talks about new research on prevention of recurrent VTE - and Carl things the evidence goes further, and we can extend prophylaxis for a year. 13.00 - CRP testing for antibiotic prescription in COPD exacerbations, should we start doing it in primary care settings - and what will that mean. We also hear from Chris Butler, one of the...

Talk Evidence is back, with your monthly take on the world of EBM with Duncan Jarvies and GPs Carl Heneghan (also director for the Centre of Evidence Based Medicine at the University of Oxford) and Helen Macdonald (also The BMJ's UK research Editor). This month Carl talks about evidence that restricting your diet might improve health at a...

Statins are now the most commonly used drug in the UK and one of the most commonly used medicines in the world, but debate remains about their use for primary prevention for people without cardiovascular disease. Paula Byrne from the National University of Ireland Galway, joins us to talk about the evidence of benefit for low risk individuals,...

Talk Evidence is back, with your monthly take on the world of EBM with Duncan Jarvies and GPs Carl Heneghan (also director for the Centre of Evidence Based Medicine at the University of Oxford) and Helen Macdonald (also The BMJ's UK research Editor). This month Helen talks about the messy business of colon cancer screening - which modality is...

In this special edition of talk evidence, Helen Macdonald and Carl Henneghan talk about creating an evidence base from harms. We hear from a member of the pubic who experienced harm from a drug, and now advises the FDA. A former regulator who explains why reporting harms is so important. And finally, an investigative journalist who explains what...

We’re back for the December Talk Evidence, and this month we’re being very digital Firstly,(1.20) Helen tells us about arthritic fingers - should we be using prednisolone for treatment when people have painful osteoarthritis of the hand Then (13.30) Carl gets us all to check our fingers for clubbing, and we find out how useful it is as a test...

Welcome to the festive talk evidence, giving you a little EBM to take you into the new year. As always Duncan Jarvies is joined by Helen Macdonald (resting GP and editor at The BMJ) and Carl Heneghan (active GP, director of Oxford University’s CEBM and editor of BMJ Evidence) This month: (2.00) Helen look back at a Christmas article, which...

Welcome to the festive talk evidence, giving you a little EBM to take you into the new year. As always Duncan Jarvies is joined by Helen Macdonald (resting GP and editor at The BMJ) and Carl Heneghan (active GP, director of Oxford University’s CEBM and editor of BMJ Evidence)* This month: (1.20) Carl tells us about new research on treating...

We're taking a break from the usual Talk Evidence to focus on the new corona virus that has emerged in China. With a brand new disease, we have to build our evidence base from scratch - basic virology, epidemiology, pathogenicity, transmissibility, and ultimately treatment are all unknowns. In this episode of Talk Evidence, we're trying to get...

The NHS is a world leader in sustainable healthcare - and it's the staff who have have been leading the charge. The For A Greener NHS campaign is asking everyone who has made a change to the way they work, to submit evidence and help shape the whole organisation's response to the climate emergency. In this podcast, Isobel Braithwaite, public...

This edition of talk evidence was recorded before the big increase in covid-19 infections in the UK, and then delayed by some self isolation. We'll be back with more evidence on the pandemic very soon. As always Duncan Jarvies is joined by Helen Macdonald (resting GP and editor at The BMJ) and Carl Heneghan (active GP, director of Oxford...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give you...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give you...

Tatsuya Hayashi
Aug 1, 1998; 47:1369-1373
Rapid Publications

Steven E Kahn
Nov 1, 1993; 42:1663-1672
Original Article