Are scientific findings exaggerated? study finds steady increase of superlatives in PubMed abstracts.

Are scientists using language aimed at convincing editors and reviewers to publish their work? Joeri Tijdink, Christiaan Vinkers and Wim Otte present findings which suggest a rise in potentially exaggerated language. Potentially conflicting with the core values of science, the pressure to publish in high impact publications may be contributing to a paradigm of over-interpretation, overstatement and misreporting of scientific results

Albumin-derived peptides efficiently reduce renal uptake of radiolabelled peptides

Contains fulltext : 88022.pdf (publisher's version ) (Closed access)PURPOSE: In peptide-receptor radionuclide therapy (PRRT), the maximum activity dose that can safely be administered is limited by high renal uptake and retention of radiolabelled peptides. The kidney radiation dose can be reduced by coinfusion of agents that competitively inhibit the reabsorption of radiolabelled peptides, such as positively charged amino acids, Gelofusine, or trypsinised albumin. The aim of this study was to identify more specific and potent inhibitors of the kidney reabsorption of radiolabelled peptides, based on albumin. METHODS: Albumin was fragmented using cyanogen bromide and six albumin-derived peptides with different numbers of electric charges were selected and synthesised. The effect of albumin fragments (FRALB-C) and selected albumin-derived peptides on the internalisation of (111)In-albumin, (111)In-minigastrin, (111)In-exendin and (111)In-octreotide by megalin-expressing cells was assessed. In rats, the effect of Gelofusine and albumin-derived peptides on the renal uptake and biodistribution of (111)In-minigastrin, (111)In-exendin and (111)In-octreotide was determined. RESULTS: FRALB-C significantly reduced the uptake of all radiolabelled peptides in vitro. The albumin-derived peptides showed different potencies in reducing the uptake of (111)In-albumin, (111)In-exendin and (111)In-minigastrin in vitro. The most efficient albumin-derived peptide (peptide #6), was selected for in vivo testing. In rats, 5 mg of peptide #6 very efficiently inhibited the renal uptake of (111)In-minigastrin, by 88%. Uptake of (111)In-exendin and (111)In-octreotide was reduced by 26 and 33%, respectively. CONCLUSIONS: The albumin-derived peptide #6 efficiently inhibited the renal reabsorption of (111)In-minigastrin, (111)In-exendin and (111)In-octreotide and is a promising candidate for kidney protection in PRRT.1 februari 201

Renal uptake of different radiolabelled peptides is mediated by megalin: SPECT and biodistribution studies in megalin-deficient mice

Contains fulltext : 98302.pdf (publisher's version ) (Closed access)PURPOSE: Radiolabelled peptides used for peptide receptor radionuclide therapy are excreted mainly via the kidneys and are partly reabsorbed and retained in the proximal tubular cells. The resulting high renal radiation dose can cause nephrotoxicity, limiting the maximum activity dose and the effectiveness of peptide receptor radionuclide therapy. The mechanisms of kidney reabsorption of these peptides are incompletely understood, but the scavenger receptor megalin has been shown to play a role in the reabsorption of (111)In-octreotide. In this study, the role of megalin in the renal reabsorption of various relevant radiolabelled peptides was investigated. METHODS: Groups of kidney-specific megalin-deficient mice and wild-type mice were injected with (111)In-labelled somatostatin, exendin, neurotensin or minigastrin analogues. Single photon emission computed tomographic (SPECT) images of the kidneys were acquired and analysed quantitatively, or the animals were killed 3 h after injection and the activity concentration in the kidneys was measured. RESULTS: Megalin-deficient mice showed significantly lower uptake of all studied radiolabelled peptides in the kidneys, ranging from 22% ((111)In-octreotide) to 65% ((111)In-exendin) of uptake in wild-type kidneys. Quantitative analysis of renal uptake by SPECT and ex vivo measurements showed a very good correlation. CONCLUSION: Megalin is involved in the renal reabsorption of radiolabelled octreotide, octreotate, exendin, neurotensin and minigastrin. This knowledge may help in the design of strategies to reduce this reabsorption and the resulting nephrotoxicity in peptide receptor radionuclide therapy, enabling more effective therapy. Small-animal SPECT is an accurate tool, allowing in vivo quantification of renal uptake and serial measurements in individual mice

CHRISTMAS 2015 : THE PUBLICATION GAME Use of positive and negative words in scientific PubMed abstracts between 1974 and 2014: retrospective analysis

Objective To investigate whether language used in science abstracts can skew towards the use of strikingly positive and negative words over time. Design Retrospective analysis of all scientific abstracts in PubMed between 1974 and 2014. Methods The yearly frequencies of positive, negative, and neutral words (25 preselected words in each category), plus 100 randomly selected words were normalised for the total number of abstracts. Subanalyses included pattern quantification of individual words, specificity for selected high impact journals, and comparison between author affiliations within or outside countries with English as the official majority language. Frequency patterns were compared with 4% of all books ever printed and digitised by use of Google Books Ngram Viewer. Main outcome measures Frequencies of positive and negative words in abstracts compared with frequencies of words with a neutral and random connotation, expressed as relative change since 1980. Results The absolute frequency of positive words increased from 2.0% (1974-80) to 17.5% (2014), a relative increase of 880% over four decades. All 25 individual positive words contributed to the increase, particularly the words "robust," "novel," "innovative," and "unprecedented," which increased in relative frequency up to 15 000%. Comparable but less pronounced results were obtained when restricting the analysis to selected journals with high impact factors. Authors affiliated to an institute in a non-English speaking country used significantly more positive words. Negative word frequencies increased from 1.3% (1974-80) to 3.2% (2014), a relative increase of 257%. Over the same time period, no apparent increase was found in neutral or random word use, or in the frequency of positive word use in published books. Conclusions Our lexicographic analysis indicates that scientific abstracts are currently written with more positive and negative words, and provides an insight into the evolution of scientific writing. Apparently scientists look on the bright side of research results. But whether this perception fits reality should be questioned

CHRISTMAS 2015 : THE PUBLICATION GAME Use of positive and negative words in scientific PubMed abstracts between 1974 and 2014: retrospective analysis

Objective To investigate whether language used in science abstracts can skew towards the use of strikingly positive and negative words over time. Design Retrospective analysis of all scientific abstracts in PubMed between 1974 and 2014. Methods The yearly frequencies of positive, negative, and neutral words (25 preselected words in each category), plus 100 randomly selected words were normalised for the total number of abstracts. Subanalyses included pattern quantification of individual words, specificity for selected high impact journals, and comparison between author affiliations within or outside countries with English as the official majority language. Frequency patterns were compared with 4% of all books ever printed and digitised by use of Google Books Ngram Viewer. Main outcome measures Frequencies of positive and negative words in abstracts compared with frequencies of words with a neutral and random connotation, expressed as relative change since 1980. Results The absolute frequency of positive words increased from 2.0% (1974-80) to 17.5% (2014), a relative increase of 880% over four decades. All 25 individual positive words contributed to the increase, particularly the words "robust," "novel," "innovative," and "unprecedented," which increased in relative frequency up to 15 000%. Comparable but less pronounced results were obtained when restricting the analysis to selected journals with high impact factors. Authors affiliated to an institute in a non-English speaking country used significantly more positive words. Negative word frequencies increased from 1.3% (1974-80) to 3.2% (2014), a relative increase of 257%. Over the same time period, no apparent increase was found in neutral or random word use, or in the frequency of positive word use in published books. Conclusions Our lexicographic analysis indicates that scientific abstracts are currently written with more positive and negative words, and provides an insight into the evolution of scientific writing. Apparently scientists look on the bright side of research results. But whether this perception fits reality should be questioned

Differentiating epileptic from non-epileptic high frequency intracerebral EEG signals with measures of wavelet entropy

OBJECTIVE: To assess whether there is a difference in the background activity in the ripple band (80-200Hz) between epileptic and non-epileptic channels, and to assess whether this difference is sufficient for their reliable separation. METHODS: We calculated mean and standard deviation of wavelet entropy in 303 non-epileptic and 334 epileptic channels from 50 patients with intracerebral depth electrodes and used these measures as predictors in a multivariable logistic regression model. We assessed sensitivity, positive predictive value (PPV) and negative predictive value (NPV) based on a probability threshold corresponding to 90% specificity. RESULTS: The probability of a channel being epileptic increased with higher mean (p=0.004) and particularly with higher standard deviation (p<0.0001). The performance of the model was however not sufficient for fully classifying the channels. With a threshold corresponding to 90% specificity, sensitivity was 37%, PPV was 80%, and NPV was 56%. CONCLUSIONS: A channel with a high standard deviation of entropy is likely to be epileptic; with a threshold corresponding to 90% specificity our model can reliably select a subset of epileptic channels. SIGNIFICANCE: Most studies have concentrated on brief ripple events. We showed that background activity in the ripple band also has some ability to discriminate epileptic channels

Clearly written, easily comprehended? The readability of websites providing information on epilepsy

There is a general need for high-quality, easily accessible, and comprehensive health-care information on epilepsy to better inform the general population about this highly stigmatized neurological disorder. The aim of this study was to evaluate the health literacy level of eight popular English-written websites that provide information on epilepsy in quantitative terms of readability. Educational epilepsy material on these websites, including 41 Wikipedia articles, were analyzed for their overall level of readability and the corresponding academic grade level needed to comprehend the published texts on the first reading. The Flesch Reading Ease (FRE) was used to assess ease of comprehension while the Gunning Fog Index, Coleman-Liau Index, Flesch-Kincaid Grade Level, Automated Readability Index, and Simple Measure of Gobbledygook scales estimated the corresponding academic grade level needed for comprehension. The average readability of websites yielded results indicative of a difficult-to-fairly-difficult readability level (FRE results: 44.0. ±. 8.2), with text readability corresponding to an 11th academic grade level (11.3. ±. 1.9). The average FRE score of the Wikipedia articles was indicative of a difficult readability level (25.6. ±. 9.5), with the other readability scales yielding results corresponding to a 14th grade level (14.3. ±. 1.7). Popular websites providing information on epilepsy, including Wikipedia, often demonstrate a low level of readability. This can be ameliorated by increasing access to clear and concise online information on epilepsy and health in general. Short "basic" summaries targeted to patients and nonmedical users should be added to articles published in specialist websites and Wikipedia to ease readability