52 research outputs found
Analysis of the progression of fibroepithelial tumours of the breast by PCR-based clonality assay
Fibroadenoma and phyllodes tumour of the breast are both fibroepithelial tumours. Although progression to epithelial malignancy has been described, the behaviour of most fibroadenomas is benign. Phyllodes tumours, on the other hand, can display locally destructive growth and can even
metastasize. A relationship between the two tumours has been suggested in the literature. This study investigated the clonality of both the stroma and the epithelium of these fibroepithelial
tumours and attempted to construct a model in which fibroadenoma can progress in both an
epithelial and a stromal direction. Fibroadenomas (n=25) and phyllodes tumours (n=12) were selected for analysis. Tissue was microdissected and analysed for clonality using a polymerase chain reaction (PCR)-based assay targeted at an X-linked polymorphic marker, the human androgen receptor gene (HUMARA). Nineteen fibroadenomas and nine phyllodes tumours could be analysed. Normal-appearing epithelium, hyperplastic epithelium, and stroma removed from fibroadenomas were polyclonal. As expected, carcinoma in situ (CIS) removed from four fibroadenomas was monoclonal. Three areas of apparent stromal expansion within fibroadenoma were monoclonal, suggesting stromal progression. Mostly, the stroma of phyllodes tumours was
monoclonal and the epithelium polyclonal. In two cases, however, the epithelium seemed to be monoclonal, whereas in three other cases the stromal component was polyclonal. These findings indicate that fibroadenoma can progress in an epithelial direction to CIS and in a stromal direction to phyllodes tumour
The influence of height and key on the perceptual similarity of transposed melodies
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28525.pdf (publisher's version ) (Open Access)In two experiments, the perceptual similarity between a strong tonal melody and various transpositions was investigated using a paradigm in which listeners compared the perceptual similarity of a melody and its transposition with that of the same melody and another transposition. The paradigm has the advantage that it provides a direct judgment regarding the similarity of transposed melodies. The experimental results indicate that the perceptual similarity of a strong tonal melody and its transposition is mainly determined by two factors: (1) the distance on the height dimension between the original melody and its transposition (pitch distance), and (2) the distance between keys as inferred from the circle of fifths (key distance). The major part of the variance is explained by the factor pitch distance, whereas key distance explains only a small part
Are ECG abnormalities in Noonan syndrome characteristic for the syndrome?
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69906.pdf (publisher's version ) (Open Access)Of all patients with Noonan syndrome, 50-90% have one or more congenital heart defects. The most frequent occurring are pulmonary stenosis (PS) and hypertrophic cardiomyopathy. The electrocardiogram (ECG) of a patient with Noonan syndrome often shows a characteristic pattern, with a left axis deviation, abnormal R/S ratio over the left precordium, and an abnormal Q wave. The objective of this study was to determine if these ECG characteristics are an independent feature of the Noonan syndrome or if they are related to the congenital heart defect. A cohort study was performed with 118 patients from two university hospitals in the United States and in The Netherlands. All patients were diagnosed with definite Noonan syndrome and had had an ECG and echocardiography. Sixty-nine patients (58%) had characteristic abnormalities of the ECG. In the patient group without a cardiac defect (n = 21), ten patients had a characteristic ECG abnormality. There was no statistical relationship between the presence of a characteristic ECG abnormality and the presence of a cardiac defect (p = 0.33). Patients with hypertrophic cardiomyopathy had more ECG abnormalities in total (p = 0.05), without correlation with a specific ECG abnormality. We conclude that the ECG features in patients with Noonan syndrome are characteristic for the syndrome and are not related to a specific cardiac defect. An ECG is very useful in the diagnosis of Noonan syndrome; every child with a Noonan phenotype should have an ECG and echocardiogram for evaluation
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In recent studies on prenatal testing for Noonan syndrome (NS) in fetuses with an increased nuchal translucency (NT) and a normal karyotype, mutations have been reported in 9-16% of cases. In this study, DNA of 75 fetuses with a normal karyotype and abnormal ultrasound findings was tested in a diagnostic setting for mutations in (a subset of) the four most commonly mutated NS genes. A de novo mutation in either PTPN11, KRAS or RAF1 was detected in 13 fetuses (17.3%). Ultrasound findings were increased NT, distended jugular lymphatic sacs (JLS), hydrothorax, renal anomalies, polyhydramnios, cystic hygroma, cardiac anomalies, hydrops fetalis and ascites. A second group, consisting of anonymized DNA of 60 other fetuses with sonographic abnormalities, was tested for mutations in 10 NS genes. In this group, five possible pathogenic mutations have been identified (in PTPN11 (n=2), RAF1, BRAF and MAP2K1 (each n=1)). We recommend prenatal testing of PTPN11, KRAS and RAF1 in pregnancies with an increased NT and at least one of the following additional features: polyhydramnios, hydrops fetalis, renal anomalies, distended JLS, hydrothorax, cardiac anomalies, cystic hygroma and ascites. If possible, mutation analysis of BRAF and MAP2K1 should be considered
Randomized clinical trial of observational versus antibiotic treatment for a first episode of CT-proven uncomplicated acute diverticulitis
Item does not contain fulltextBACKGROUND: Antibiotics are advised in most guidelines on acute diverticulitis, despite a lack of evidence to support their routine use. This trial compared the effectiveness of a strategy with or without antibiotics for a first episode of uncomplicated acute diverticulitis. METHODS: Patients with CT-proven, primary, left-sided, uncomplicated, acute diverticulitis were included at 22 clinical sites in the Netherlands, and assigned randomly to an observational or antibiotic treatment strategy. The primary endpoint was time to recovery during 6 months of follow-up. Main secondary endpoints were readmission rate, complicated, ongoing and recurrent diverticulitis, sigmoid resection and mortality. Intention-to-treat and per-protocol analyses were done. RESULTS: A total of 528 patients were included. Median time to recovery was 14 (i.q.r. 6-35) days for the observational and 12 (7-30) days for the antibiotic treatment strategy, with a hazard ratio for recovery of 0.91 (lower limit of 1-sided 95 per cent c.i. 0.78; P = 0.151). No significant differences between the observation and antibiotic treatment groups were found for secondary endpoints: complicated diverticulitis (3.8 versus 2.6 per cent respectively; P = 0.377), ongoing diverticulitis (7.3 versus 4.1 per cent; P = 0.183), recurrent diverticulitis (3.4 versus 3.0 per cent; P = 0.494), sigmoid resection (3.8 versus 2.3 per cent; P = 0.323), readmission (17.6 versus 12.0 per cent; P = 0.148), adverse events (48.5 versus 54.5 per cent; P = 0.221) and mortality (1.1 versus 0.4 per cent; P = 0.432). Hospital stay was significantly shorter in the observation group (2 versus 3 days; P = 0.006). Per-protocol analyses were concordant with the intention-to-treat analyses. CONCLUSION: Observational treatment without antibiotics did not prolong recovery and can be considered appropriate in patients with uncomplicated diverticulitis. Registration number: NCT01111253 (http://www.clinicaltrials.gov)
Next-generation sequencing identifies rare variants associated with Noonan syndrome
Noonan syndrome (NS) is a relatively common genetic disorder, characterized by typical facies, short stature, developmental delay, and cardiac abnormalities. Known causative genes account for 70–80% of clinically diagnosed NS patients, but the genetic basis for the remaining 20–30% of cases is unknown. We performed next-generation sequencing on germ-line DNA from 27 NS patients lacking a mutation in the known NS genes. We identified gain-of-function alleles in Ras-like without CAAX 1 (RIT1) and mitogen-activated protein kinase kinase 1 (MAP2K1) and previously unseen loss-of-function variants in RAS p21 protein activator 2 (RASA2) that are likely to cause NS in these patients. Expression of the mutant RASA2, MAP2K1, or RIT1 alleles in heterologous cells increased RAS-ERK pathway activation, supporting a causative role in NS pathogenesis. Two patients had more than one disease-associated variant. Moreover, the diagnosis of an individual initially thought to have NS was revised to neurofibromatosis type 1 based on an NF1 nonsense mutation detected in this patient. Another patient harbored a missense mutation in NF1 that resulted in decreased protein stability and impaired ability to suppress RAS-ERK activation; however, this patient continues to exhibit a NS-like phenotype. In addition, a nonsense mutation in RPS6KA3 was found in one patient initially diagnosed with NS whose diagnosis was later revised to Coffin–Lowry syndrome. Finally, we identified other potential candidates for new NS genes, as well as potential carrier alleles for unrelated syndromes. Taken together, our data suggest that next-generation sequencing can provide a useful adjunct to RASopathy diagnosis and emphasize that the standard clinical categories for RASopathies might not be adequate to describe all patients
Randomized clinical trial of observational versus antibiotic treatment for a first episode of CT-proven uncomplicated acute diverticulitis
Background: Antibiotics are advised in most guidelines on acute diverticulitis, despite a lack of evidence to support their routine use. This trial compared the effectiveness of a strategy with or without antibiotics for a first episode of uncomplicated acute diverticulitis. Methods: Patients with CT-proven, primary, left-sided, uncomplicated, acute diverticulitis were included at 22 clinical sites in the Netherlands, and assigned randomly to an observational or antibiotic treatment strategy. The primary endpoint was time to recovery during 6 months of follow-up. Main secondary endpoints were readmission rate, complicated, ongoing and recurrent diverticulitis, sigmoid resection and mortality. Intention-to-treat and per-protocol analyses were done. Results: A total of 528 patients were included. Median time to recovery was 14 (i.q.r. 6–35) days for the observational and 12 (7–30) days for the antibiotic treatment strategy, with a hazard ratio for recovery of 0·91 (lower limit of 1-sided 95 per cent c.i. 0·78; P = 0·151). No significant differences between the observation and antibiotic treatment groups were found for secondary endpoints: complicated diverticulitis (3·8 versus 2·6 per cent respectively; P = 0·377), ongoing diverticulitis (7·3 versus 4·1 per cent; P = 0·183), recurrent diverticulitis (3·4 versus 3·0 per cent; P = 0·494), sigmoid resection (3·8 versus 2·3 per cent; P = 0·323), readmission (17·6 versus 12·0 per cent; P = 0·148), adverse events (48·5 versus 54·5 per cent; P = 0·221) and mortality (1·1 versus 0·4 per cent; P = 0·432). Hospital stay was significantly shorter in the observation group (2 versus 3 days; P = 0·006). Per-protocol analyses were concordant with the intention-to-treat analyses. Conclusion: Observational treatment without antibiotics did not prolong recovery and can be considered appropriate in patients with uncomplicated diverticulitis. Registration number: NCT01111253 (http://www.clinicaltrials.gov)
Randomized clinical trial of observational versus antibiotic treatment for a first episode of CT-proven uncomplicated acute diverticulitis
Background: Antibiotics are advised in most guidelines on acute diverticulitis, despite a lack of evidence to support their routine use. This trial compared the effectiveness of a strategy with or without antibiotics for a first episode of uncomplicated acute diverticulitis. Methods: Patients with CT-proven, primary, left-sided, uncomplicated, acute diverticulitis were included at 22 clinical sites in the Netherlands, and assigned randomly to an observational or antibiotic treatment strategy. The primary endpoint was time to recovery during 6 months of follow-up. Main secondary endpoints were readmission rate, complicated, ongoing and recurrent diverticulitis, sigmoid resection and mortality. Intention-to-treat and per-protocol analyses were done. Results: A total of 528 patients were included. Median time to recovery was 14 (i.q.r. 6–35) days for the observational and 12 (7–30) days for the antibiotic treatment strategy, with a hazard ratio for recovery of 0·91 (lower limit of 1-sided 95 per cent c.i. 0·78; P = 0·151). No significant differences between the observation and antibiotic treatment groups were found for secondary endpoints: complicated diverticulitis (3·8 versus 2·6 per cent respectively; P = 0·377), ongoing diverticulitis (7·3 versus 4·1 per cent; P = 0·183), recurrent diverticulitis (3·4 versus 3·0 per cent; P = 0·494), sigmoid resection (3·8 versus 2·3 per cent; P = 0·323), readmission (17·6 versus 12·0 per cent; P = 0·148), adverse events (48·5 versus 54·5 per cent; P = 0·221) and mortality (1·1 versus 0·4 per cent; P = 0·432). Hospital stay was significantly shorter in the observation group (2 versus 3 days; P = 0·006). Per-protocol analyses were concordant with the intention-to-treat analyses. Conclusion: Observational treatment without antibiotics did not prolong recovery and can be considered appropriate in patients with uncomplicated diverticulitis. Registration number: NCT01111253 (http://www.clinicaltrials.gov)
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