919 research outputs found

    Structural Evolution of Gene Promoters Driven by Primate-Specific KRAB Zinc Finger Proteins

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    Krüppel-associated box (KRAB) zinc finger proteins (KZNFs) recognize and repress transposable elements (TEs); TEs are DNA elements that are capable of replicating themselves throughout our genomes with potentially harmful consequences. However, genes from this family of transcription factors have a much wider potential for genomic regulation. KZNFs have become integrated into gene-regulatory networks through the control of TEs that function as enhancers and gene promoters; some KZNFs also bind directly to gene promoters, suggesting an additional, more direct layer of KZNF co-option into gene-regulatory networks. Binding site analysis of ZNF519, ZNF441, and ZNF468 suggests the structural evolution of KZNFs to recognize TEs can result in coincidental binding to gene promoters independent of TE sequences. We show a higher rate of sequence turnover in gene promoter KZNF binding sites than neighboring regions, implying a selective pressure is being applied by the binding of a KZNF. Through CRISPR/Cas9 mediated genetic deletion of ZNF519, ZNF441, and ZNF468, we provide further evidence for genome-wide co-option of the KZNF-mediated gene-regulatory functions; KZNF knockout leads to changes in expression of KZNF-bound genes in neuronal lineages. Finally, we show that the opposite can be established upon KZNF overexpression, further strengthening the support for the role of KZNFs as bona-fide gene regulators. With no eminent role for ZNF519 in controlling its TE target, our study may provide a snapshot into the early stages of the completed co-option of a KZNF, showing the lasting, multilayered impact that retrovirus invasions and host response mechanisms can have upon the evolution of our genomes

    Flap reconstruction of the hypopharynx: a defect orientated approach

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    The present retrospective analysis evaluated the outcomes of different flap reconstructions for several hypopharyngeal defects in 136 patients who underwent hypopharyngeal reconstruction with a free or pedicled flap after excision of pharyngeal or laryngeal carcinoma.Functional and oncological outcome were the main measures. Nine patients had a type I-a hypopharyngeal defect (partial with larynx preserved), 33 type I-b (partial without larynx preserved), 85 type II (circumferential), 5 type III (extensive superior) and 4 vertical hemipharyngolaryngectomy. The flaps used to reconstruct these defects were pectoralis major (n = 34), free radial forearm (n = 25), jejunum (n = 72), pedicled latissimus dorsi (n = 2), sternocleidomastoid (n = 1), lateral thigh (n = 1) and deltopectoral (n = 1). Twelve defects (9%) needed a secondary flap reconstruction. Surgical and medical complications were seen in 29% and 8% of patients, respectively; 18% of patients developed a fistula. No difference in complication rate or admission days was found for pre-operative versus no previous radiotherapy, type of defect or free versus pedicled flap. After 12 months follow-up, 38% of patients had a tracheo-oesophageal voice prosthesis, in 82% a fully oral diet was obtained and the average body weight gain was 0.9 kg. Five-year overall and disease-specific survival rates were 35% and 49%, respectively, while local and regional control rates were 65% and 91%, respectively. Considering these results, a defect orientated approach may be helpful for deciding which flap should be used for reconstruction of the hypopharynx. An algorithm is proposed with similar functional and oncological outcomes for the different groups. The choice of flap should be based on expected morbidity and functional outcome

    Mental health and behavioural problems in children with XXYY: a comparison with intellectual disabilities

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    Background The phenotype of children with XXYY has predominantly been defined by comparison to other sex chromosome aneuploidies trisomies affecting male children; however, the intellectual ability of children with XXYY is lower than children with other sex chromosome aneuploidies trisomies. It is not known to what extent the phenotype identified to date is specific to XXYY, rather than a reflection of lower IQ. This study evaluates the mental health and behaviour of children with XXYY, in comparison to children with intellectual disabilities of heterogeneous genetic origin. Methods Fifteen children with XXYY and 30 controls matched for age (4–14 years), sex and intellectual ability were ascertained from the IMAGINE ID study. IMAGINE ID participants have intellectual disabilities due to genetic anomalies confirmed by National Health Service Regional Genetic Centre laboratories. The mental health and behaviour of participants was examined with the Development and Well‐being Assessment and the Strengths and Difficulties Questionnaire. Results Children with XXYY experienced significantly more frequent and intense temper outbursts than the control group. Conclusion Our results suggest that temper outbursts may be specifically associated with the XXYY phenotype. These problems have a significant impact on the daily lives of boys with XXYY and their families. It is crucial to ensure that families are well supported to manage these difficulties

    Childhood cognitive development in 22q11.2 deletion syndrome: case–control study

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    Background 22q11.2 deletion syndrome (22q11.2DS) is associated with a high risk of childhood as well as adult psychiatric disorders, in particular schizophrenia. Childhood cognitive deterioration in 22q11.2DS has previously been reported, but only in studies lacking a control sample. Aims To compare cognitive trajectories in children with 22q11.2DS and unaffected control siblings. Method A longitudinal study of neurocognitive functioning (IQ, executive function, processing speed and attention) was conducted in children with 22q11.2DS (n = 75, mean age time 1 (T1) 9.9, time 2 (T2) 12.5) and control siblings (n = 33, mean age T1 10.6, T2 13.4). Results Children with 22q11.2DS exhibited deficits in all cognitive domains. However, mean scores did not indicate deterioration. When individual trajectories were examined, some participants showed significant decline over time, but the prevalence was similar for 22q11.2DS and control siblings. Findings are more likely to reflect normal developmental fluctuation than a 22q11.2DS-specific abnormality. Conclusions Childhood cognitive deterioration is not associated with 22q11.2DS. Contrary to previous suggestions, we believe it is premature to recommend repeated monitoring of cognitive function to identifying individual children with 22q11.2DS at high risk of developing schizophrenia

    The effect of ozone exposure on the release of eicosanoids in guinea-pig BAL fluid in relation to cellular damage and inflammation

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    The observed effects after ozone exposure strongly depend on ozone concentration and exposure time. We hypothesized that depending on the O3 exposure protocol, mainly either an oxidant damage or an inflammation will determine the O3 toxicity. We compared two different ozone exposure protocols: an acute exposure (3 ppm 2 h) for studying the oxidant damage and an exposure (1 ppm 12 h) where an inflammatory component is also probably involved. We measured LDH activity and protein and albumin exudation as markers for cellular damage. After the acute exposure an increase in LDH activity was measured and after exposure to 1 ppm ozone for 12 h the exudation of protein and albumin was also enhanced. The histological examinations showed a neutrophilic inflammatory response only after exposure to 1 ppm ozone for 12 h. The acute exposure protocol resulted in an increased release of PGE2, PGD2, PGF2α and 6-ketoPGF1α whereas exposure to 1 ppm ozone for 12 h led to an additional release of LTB4. No effects were measured on the release of TxB2 and LTC4/D4/E4. These changed amounts of eicosanoids will probably contribute to the ozone-induced lung function changes

    Monitoring recently acquired HIV infections in Amsterdam, The Netherlands:The attribution of test locations

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    Background:  Surveillance of recent HIV infections (RHI) using an avidity assay has been implemented at Dutch sexual health centres (SHC) since 2014, but data on RHI diagnosed at other test locations is lacking. Setting:  Implementation of the avidity assay in HIV treatment clinics for the purpose of studying RHI among HIV patients tested at different test locations. Methods: We retrospectively tested leftover specimens from newly diagnosed HIV patients in care in 2013–2015 in Amsterdam. Avidity Index (AI) values ≤0.80 indicated recent infection (acquired ≤6 months prior to diagnosis), and AI > 0.80 indicated established infection (acquired >6 months prior to diagnosis). An algorithm for RHI was applied to correct for false recency. Recency based on this algorithm was compared with recency based on epidemiological data only. Multivariable logistic regression analysis was used to identify factors associated with RHI among men who have sex with men (MSM).Results: We tested 447 specimens with avidity; 72% from MSM. Proportions of RHI were 20% among MSM and 10% among heterosexuals. SHC showed highest proportions of RHI (27%), followed by GPs (15%), hospitals (5%), and other/unknown locations (11%) (p < 0.001). Test location was the only factor associated with RHI among MSM. A higher proportion of RHI was found based on epidemiological data compared to avidity testing combined with the RHI algorithm. Conclusion:  SHC identify more RHI infections compared to other test locations, as they serve high-risk populations and offer frequent HIV testing. Using avidity-testing for surveillance purposes may help targeting prevention programs, but the assay lacks robustness and its added value may decline with improved, repeat HIV testing and data collection
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