Registry versus publication: discrepancy of primary outcomes and possible outcome reporting bias in child and adolescent mental health

Outcome reporting bias is one of the fundamental forms of publication bias. It implies publishing only outcomes that have positive results. The aim of this observational study was to explore primary outcome discrepancies between registry of clinical trials and their corresponding publications, since these can indicate outcome reporting bias in child mental health. Data were extracted from completed interventional clinical trials from ClinicalTrial.gov registry and its Archive site. Trials were registered under “Behaviours and Mental Disorders” category, and conducted on underage participants (0–17 years). Their primary outcomes were compared to those published in publication which had a corresponding NCT number stated in the text. Sixteen percent of trials did not have the minimum information on primary outcome stated in the registry—neither the measure used nor the measurement time points; 38.9% of trials had the minimum information stated to describe primary outcome, while only 3.3% of trials had all the necessary elements stated in the registry. Most of the publication in our sample had positive results (66.4%). Half of the trials registered before completion had non-matching primary outcomes in the registry and publication; 85.4% of trials with non-matching outcomes indicated possible outcome reporting bias for some of the primary outcome. Middle-sized trials and industry-funded trials were related with higher quality of primary outcome registration. Industry funding was related with positive findings in publication. Non-industry funding proved to be the only significant predictor of discrepancy between registered and published primary outcomes, and possible outcome reporting bias. Journal impact factor was not related with any of the outcome measures. The main limitation of the study is that it primarily offers an insight into discrepancy of registered and published outcomes. The methodology does not imply an access to results of unpublished outcomes — therefore, it was not possible to determine the presence of the bias with sufficient certainty in large number of trials. Further research should be done with improved methodology and additional data.

     

An internal carotid artery pseudoaneurysm with neck hematoma: A rare cause of a life-threatening neck mass mimicking an abscess

A neck mass has a broad and complex differential diagnosis, generally divided into neoplastic, congenital and inflammatory categories. An internal carotid artery hemorrhage with pseudoaneurysm formation is a very rare entity that may resemble other common conditions in the differential diagnosis. Large, expanding or symptomatic pseudoaneurysm is critical to efficiently diagnose and manage, due to risk of life-threatening hemorrhage. We present a case of an adult male patient with clinical and laboratory signs of severe neck cellulitis and a large gradually increasing neck mass, primarily suggestive of an abscess. Neck CT and MRI imaging revealed the presence of a disruption of the internal carotid artery resulting in a large hematoma and formation of pseudoaneurysm. A multidisciplinary team of interventional radiologists and ENT surgeons successfully treated the patient by endovascular placement of stents and subsequent surgical drainage. Awareness of such a rare, life-threatening condition and efficient multidisciplinary teamwork are essential for patient management.     

Gibt es das universelle Implantat zur Versorgung trochant?rer Femurfrakturen?

Zusammenfassung Etwa 40 000 trochantäre Femurfrakturen sind jährlich in Deutschland zu erwarten. Die Inzidenz ist steigend. Als typische Fraktur des älteren Menschen ist der unfallbedingte Verlust des Lebens oder der persönlichen Selbstandigkeit zu befürchten und in der Vergangenheit häufig eingetreten. Während in den 70er Jahren bis zu 19 verschiedene Operationsverfahren miteinander konkurrierten, kommen heute fast nur die dynamische Hüftschraube (DHS), ggf. in Kombination mit der Trochanterabstützplatte, und der Gammanagel bzw. seine Weiterentwicklung, der Gleitnagel, zur Anwendung. Berichtet wird ër 217 Patienten, die wegen einer trochantären Femurfraktur mit einer DHS, in 14 Fällen kombiniert mit einer Trochanterabstützplatte, versorgt wurden. Es traten 4,6% implantatspezifische Komplikationen auf, bei sieben Patienten (7,8%) kam es postoperativ zu einem Verlust an persönlicher Selbständigkeit. Die Krankenhausletalität lag bei 0,9%.     

Sclerosing polycystic adenosis of parotid gland: A unique report of two cases occurring in two sisters

Sclerosing polycystic adenosis (SPA) of salivary glands is a tumorous lesion of salivary glands, with clinical presentation of a slow-growing mass characterized by a combination of histological features, some of which are reminiscent of mammary fibrocystic disease. SPA is mostly unifocal, but rarely may be multifocal and/or bilateral. Recurrences have been reported in up to 19% of cases. Although originally considered pseudoneoplastic, the occurrence of “dysplasia” and carcinoma in situ of ductal epithelium, and recent evidence of clonality suggest a possible neoplastic nature. Herein we describe, for the first time, two cases of SPA in two sisters (7 and 33 years old). The younger patient experienced multiple recurrences. This is the first report of familial occurrence of SPA, suggesting a possible genetic background.     

Sodium-glucose cotransporter 2 inhibitors' mechanisms of action in heart failure

Three major cardiovascular outcome trials(CVOTs) with a new class of antidiabetic drugs-sodium-glucose cotransporter 2(SGLT2) inhibitors(EMPAREG OUTCOME trial with empagliflozin, CANVAS Program with canagliflozin, DECLARE-TIMI 58 with dapagliflozin) unexpectedly showed that cardiovascular outcomes could be improved possibly due to a reduction in heart failure risk, which seems to be the most sensitive outcome of SGLT2 inhibition. No other CVOT to date has shown any significant benefit on heart failure events. Even more impressive findings came recently from the DAPA-HF trial in patients with confirmed and well-treated heart failure: Dapagliflozin was shown to reduce heart failure risk for patients with heart failure with reduced ejection fraction regardless of diabetes status. Nevertheless, despite their possible wide clinical implications, there is much doubt about the mechanisms of action and a lot of questions to unravel, especially now when their benefits translated to nondiabetic patients, rising doubts about the validity of some current mechanistic assumptions.The time frame of their cardiovascular benefits excludes glucoselowering and antiatherosclerotic-mediated effects and multiple other mechanisms, direct cardiac as well as systemic, are suggested to explain their early cardiorenal benefits. These are: Anti-inflammatory, antifibrotic, antioxidative, antiapoptotic properties, then renoprotective and hemodynamic effects, attenuation of glucotoxicity, reduction of uric acid levels and epicardial adipose tissue, modification of neurohumoral system and cardiac fuel energetics, sodiumhydrogen exchange inhibition. The most logic explanation seems that SGLT2 inhibitors timely target various mechanisms underpinning heart failure pathogenesis. All the proposed mechanisms of their action could interfere with evolution of heart failure and are discussed separately within the main text.     

Radiosynovectomy in the treatment of chronic exsudative arthritis

Background. Radiosynovectomy (radiosynoviorthesis) is an important instrument for the effective local treatment of chronic inflammatory joint disease, and provides an alternative to surgical synovectomy. Radiosynovectomy leads to the restoration of synovium in the treated joint, with improved joint function due to reduction of pain, swelling and stiffness. The radiopharmaceutical agent used in the treatment of the knee joint is yttrium90-citrate colloid. Material and methods. We studied 32 patients treated with 90Y -synovectomy of the knee between June and October 2004. 28 of these patients were suffering from rheumatoid arthritis, while 4 had chronic post-traumatic joint synovitis. All patients underwent 2-phase scintigraphy and ultrasound examination of the knee before and 6 months after the administration of 5 mCi 90Y-citrate. Results and Conclusions. Symptomatic relief and functional improvement of the treated knees were observed in 83% of the patients.     

Preventing fibril formation of a protein by selective mutation

The origins of formation of an intermediate state involved in amyloid formation and ways to prevent it are illustrated with the example of the Formin binding protein 28 (FBP28) WW domain, which folds with biphasic kinetics. Molecular dynamics of protein folding trajectories are used to examine local and global motions and the time dependence of formation of contacts between C^αs and C^βs of selected pairs of residues. Focus is placed on the WT FBP28 WW domain and its six mutants (L26D, L26E, L26W, E27Y, T29D, and T29Y), which have structures that are determined by high-resolution NMR spectroscopy. The origins of formation of an intermediate state are elucidated, viz. as formation of hairpin 1 by a hydrophobic collapse mechanism causing significant delay of formation of both hairpins, especially hairpin 2, which facilitates the emergence of an intermediate state. It seems that three-state folding is a major folding scenario for all six mutants and WT. Additionally, two-state and downhill folding scenarios were identified in ∼15% of the folding trajectories for L26D and L26W, in which both hairpins are formed by the Matheson–Scheraga mechanism much faster than in three-state folding. These results indicate that formation of hairpins connecting two antiparallel β-strands determines overall folding. The correlations between the local and global motions identified for all folding trajectories lead to the identification of the residues making the main contributions in the formation of the intermediate state. The presented findings may provide an understanding of protein folding intermediates in general and lead to a procedure for their prevention.An intermediate state in protein folding is involved in amyloid fibril formation, which is responsible for a number of neurodegenerative diseases (1–7). Therefore, prevention of the aggregation of folding intermediates is one of the most important problems to surmount. Hence, it is necessary to determine the mechanism by which an intermediate state is formed. For example, one of the members of the WW domain family (8, 9), the triple β-stranded WW domain from the Formin binding protein 28 (FBP28; Protein Data Bank ID code 1E0L) (10) (Fig. 1N), has been shown to fold with biphasic kinetics exhibiting intermediates during folding (3, 5, 6, 11–16). We address this problem here with the design of new FBP28 WW domain mutants and by examining their structural properties and folding kinetics.Open in a separate windowFig. 1.FELs (kilocalories per mole) along the first two PCs with representative structures at the minima, and contributions of the principal modes (defined in SI Materials and Methods) [νikλk; black lines with black circles (principal mode 1) and red lines with white circles (principal mode 2)] to the MSFs along the θ- and γ-angles for the (A–C) three-state, (D–F) two-state, and (G–I) downhill folding trajectories of L26D and (J–L) the downhill folding trajectory of L26W. The black lines on the bottoms of B, C, E, F, H, I, K, and L correspond to the β-strand regions. I, intermediate; N, native; U, unfolded. M represents percentages of the total fluctuations captured by the PCs for three-state (black line), two-state (red line), and downhill (blue line) trajectories of L26D and the downhill folding trajectory (green line; indistinguishable from the blue line) of L26W. N represents the experimental structure of FBP28, in which the mutated residues are represented by spheres, and hairpins 1 and 2 are represented by blue and red, respectively (the purple region corresponds to the overlap of these hairpins). C, C terminus; E, glutamic acid; L, leucine; N, N terminus; T, threonine.Because of the small size, fast folding kinetics, and biological importance, the formation of intermolecular β-sheets is thought to be a crucial event in the initiation and propagation of amyloid diseases, such as Alzheimer’s disease, and spongiform encephalopathy, FBP28, and other WW domain proteins (e.g., Pin1 and FiP35) have been the subjects of extensive experimental (4, 11, 17–23) and theoretical (3, 5, 6, 12–16, 24–27) studies. However, a folding mechanism of the FBP28 was debatable for a long time because of its complexity. There are not only discrepancies between experimental and theoretical results but also, different experiments that reveal different folding scenarios.In particular, Nguyen et al. (11) studied the folding kinetics of the WT FBP28 and its full-size and truncated mutants by temperature denaturation and laser temperature–jump relaxation experiments. Nguyen et al. (11) found that the folding of the WT FBP28 involves intermediates (three-state folding) below the melting temperature and that the strand-crossing hydrophobic cluster of Tyr11, Tyr19, and Trp30 residues, which were mutated, is not a likely origin of the three-state scenario; also, truncation at the C terminus and an increase of temperature can modulate the two- and three-state folding behavior. The conclusion regarding three-state folding was challenged by Ferguson et al. (4), who observed single-exponential folding kinetics for the FBP28 by using fluorescence measurements and concluded that the biphasic kinetics observed by Nguyen et al. (11) might be related to aggregation and rapidly forming ribbon-like fibrils at physiological temperature and pH, with morphology typical of amyloid fibrils.Our recent theoretical studies (12–16) of the same systems (11) showed that (i) folding of all of these systems involves intermediates; (ii) the strand-crossing hydrophobic cluster of residues 11, 19, and 30 is not associated with biphasic kinetics; and (iii) neither an increase of temperature nor truncation can alter the folding scenario. Moreover, discrepancies between experimental and theoretical results for some of these mutants caused by experimental limitations were clarified (16).It also was found (3, 5) that the WT FBP28 folds with biphasic kinetics attributed to independence in the slow formation of turn 2 contacts with respect to the remainder of the protein and identified a key surface-exposed hydrophobic contact (Tyr21 with Leu26) for enforcing the correct registry of the residues of turn 2. To show the importance of the surface-exposed hydrophobic contact (Tyr21 with Leu26) and the involvement of turn 2 in a slow formation phase, the L26A mutant was studied (3). The fast phase (formation of hairpin 1) was not affected by this mutation, whereas the slow phase became even slower, which also was confirmed experimentally (11). These results suggested that the replacement of leucine by alanine actually stabilizes the misregistered turn 2 conformations relative to the WT; hence, it was concluded (3) that the surface-exposed hydrophobic contact (Tyr21 with Leu26) might be responsible for tying down turn 2 with a correctly formed hairpin. It should be noted that this surface-exposed hydrophobic contact is not present in other members of the WW domain family, which fold with monophasic kinetics.Later theoretical studies (6, 12–16) of the WT FBP28 confirmed the results of ref. 3, showing biphasic folding kinetics with a stable intermediate state. Therefore, to prevent the formation of the intermediate state, it is logical to make mutations in the region of turn 2 and the third β-strand to speed up the formation of hairpin 2 as implemented here. However, based on the results of mutant L26A (3), it is not an easy task to ensure the elimination of intermediates and therefore, requires a detailed understanding of folding/misfolding mechanisms, folding/misfolding pathways, and effect of temperature on folding mechanism, etc., to identify proper sites for mutations.Based on previous studies (3, 15), Leu26 is one of the main residues in which mutation might speed up the correct registry of turn 2. Moreover, the FBP28 is the only WW domain among 200 WW domain sequences that contains leucine at this position (3). Usually, this position is almost always occupied by a charged residue or glycine; therefore, following the natural tendency of the WW domain family, two mutants were designed, replacing leucine 26 with negatively charged polar amino acids: aspartic acid and glutamic acid (L26D and L26E, respectively). Also, replacement of leucine by alanine (the smallest nonpolar aliphatic amino acid) was found to slow down the process (3, 11); hence, for replacement of leucine 26, we also selected a very nonpolar and larger aromatic amino acid, tryptophan (L26W). It should be noted that leucine at position 26 is not a reflection of negative design by evolution but rather, is a result of pressure to maximize specificity through use of polar residues (3). Based on earlier results on the binding affinity of the WW domain, it was proposed (3) that requirements for ligand specificity have led to a local sequence with a strong propensity for a misregistered turn.The next mutant was made by substituting a negatively charged polar amino acid, glutamic acid 27, with a nonpolar aromatic amino acid, tyrosine (E27Y). Finally, two more mutants were designed by replacing a neutral polar amino acid, threonine 29, with a negatively charged polar amino acid, aspartic acid (T29D) and a nonpolar aromatic amino acid, tyrosine (T29Y). Both Glu27 and Thr29 are critically placed residues contributing the most to the mean-square fluctuations (MSFs) (15), and mutation of these residues by disfavored amino acids might destabilize the misregistered turn 2 and β-strand 3 and speed up the correct registry.To characterize the effects of these mutations, the six recombinant proteins carrying a single-point mutation were expressed, and their structures were studied by high-resolution NMR spectroscopy (SI Materials and Methods). All mutants adopt the triple-stranded antiparallel β-sheet characteristic of the WW fold, with slight variations caused by each specific mutation (Fig. S1). The experimental and theoretical melting temperatures (T_m values) for each mutant were determined with differential scanning calorimetry and multiplexed replica exchange molecular dynamics (MD) simulations, respectively (Table S1). We also ran simulations consisting of 120 (for WT and L26D) and 96 (for L26E, L26W, E27Y, T29D, and T29Y) canonical MD trajectories generated with the coarse-grained united residue (UNRES) force field (SI Materials and Methods) (28–30) at five and four different temperatures, respectively (24 MD trajectories, with ∼1.4 μs formal time and effectively ∼1.4 ms of each at each temperature), which were below, very close to, and above (for some mutants) the melting temperatures. The folding dynamics of each system were analyzed in terms of principal component analysis (PCA) (SI Materials and Methods) (12, 15, 31) describing the global motions of the protein, local motions of each residue [free-energy profiles (FEPs) along the amino acid sequence], and distances between the C^αs and C^βs of selected pairs of residues forming hairpins 1 and 2 over time.