New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Content and performance of the MiniMUGA genotyping array: A new tool to improve rigor and reproducibility in mouse research

The laboratory mouse is the most widely used animal model for biomedical research, due in part to its well-annotated genome, wealth of genetic resources, and the ability to precisely manipulate its genome. Despite the importance of genetics for mouse research, genetic quality control (QC) is not standardized, in part due to the lack of cost-effective, informative, and robust platforms. Genotyping arrays are standard tools for mouse research and remain an attractive alternative even in the era of high-throughput whole-genome sequencing. Here, we describe the content and performance of a new iteration of the Mouse Universal Genotyping Array (MUGA), MiniMUGA, an array-based genetic QC platform with over 11,000 probes. In addition to robust discrimination between most classical and wild-derived laboratory strains, MiniMUGA was designed to contain features not available in other platforms: (1) chromosomal sex determination, (2) discrimination between substrains from multiple commercial vendors, (3) diagnostic SNPs for popular laboratory strains, (4) detection of constructs used in genetically engineered mice, and (5) an easy-to-interpret report summarizing these results. In-depth annotation of all probes should facilitate custom analyses by individual researchers. To determine the performance of MiniMUGA, we genotyped 6899 samples from a wide variety of genetic backgrounds. The performance of MiniMUGA compares favorably with three previous iterations of the MUGA family of arrays, both in discrimination capabilities and robustness. We have generated publicly available consensus genotypes for 241 inbred strains including classical, wild-derived, and recombinant inbred lines. Here, we also report the detection of a substantial number of XO and XXY individuals across a variety of sample types, new markers that expand the utility of reduced complexity crosses to genetic backgrounds other than C57BL/6, and the robust detection of 17 genetic constructs. We provide preliminary evidence that the array can be used to identify both partial sex chromosome duplication and mosaicism, and that diagnostic SNPs can be used to determine how long inbred mice have been bred independently from the relevant main stock. We conclude that MiniMUGA is a valuable platform for genetic QC, and an important new tool to increase the rigor and reproducibility of mouse research

The presenting features of brain tumours: a review of 200 cases

Objective: To determine the presenting features of brain tumours in children. Design: Retrospective case note review. Setting: Paediatric and neurosurgical services at the Wessex Neurology Centre and Southampton General Hospital, UK. Patients: 200 patients presenting with a CNS tumour between 1988 and 2001. Results: The commonest first presenting symptoms were headache (41%), vomiting (12%), unsteadiness (11%), visual difficulties (10%), educational or behavioural problems (10%), and seizures (9%). The commonest symptoms occurring at any time were headache (56%), vomiting (51%), educational or behavioural problems (44%), unsteadiness (40%), and visual difficulties (38%). Neurological signs were present at diagnosis in 88%: 38% had papilloedema, 49% cranial nerve abnormalities, 48% cerebellar signs, 27% long tract signs, 11% somatosensory abnormalities, and 12% a reduced level of consciousness. The median symptom interval was 2.5 months (range 1 day to 120 months). A short symptom interval was significantly associated with high grade tumours and patient age of 3 years or younger. Conclusions: The well known predominance of headache in children with CNS tumours is confirmed. Visual, behavioural, and educational symptoms were also prominent. With the exception of seizures, every initial symptom was accompanied by other symptoms or signs by the time of diagnosis. Questions about visual symptoms and educational or behavioural difficulties, as well as the more widely recognised symptoms of raised intracranial pressure and motor dysfunction, are important in the diagnosis of brain tumours, as are vision assessment and the appropriate plotting of growth and head siz

EGFR signaling suppresses type 1 cytokine-induced T-cell attracting chemokine secretion in head and neck cancer

Experimental cancer immunology and therap

Altered swallowing biomechanics in people with moderate-severe obstructive sleep apnea

Published online:September 1, 2021Study Objectives: Dysphagia is a common but under-recognized complication of obstructive sleep apnea (OSA). However, the mechanisms remain poorly described. Accordingly, the aim of this study was to assess swallowing symptoms and use high-resolution pharyngeal manometry to quantify swallowing biomechanics in patients with moderate-severe OSA. Methods: Nineteen adults (4 female; mean (range) age, 46 ± 26-68 years) with moderate-severe OSA underwent high-resolution pharyngeal manometry testing with 5-, 10-, and 20-mL volumes of thin and extremely thick liquids. Data were compared with 19 age- and sex-matched healthy controls (mean (range) age, 46 ± 27-68 years). Symptomatic dysphagia was assessed using the Sydney Swallow Questionnaire. Swallow metrics were analyzed using the online application swallowgateway.com. General linear mixed model analysis was performed to investigate potential differences between people with moderate-severe OSA and controls. Data presented are means [95% confidence intervals]. Results: Twenty-six percent (5 of 19) of the OSA group but none of the controls reported symptomatic dysphagia (Sydney Swallow Questionnaire > 234). Compared with healthy controls, the OSA group had increased upper esophageal sphincter relaxation pressure (−2 [−1] vs 2 [1] mm Hg, F = 32.1, P < .0001), reduced upper esophageal sphincter opening (6 vs 5 mS, F = 23.6, P < .0001), and increased hypopharyngeal intrabolus pressure (2 [1] vs 7 [1] mm Hg, F = 19.0, P < .05). Additionally, upper pharyngeal pressures were higher, particularly at the velopharynx (88 [12] vs 144 [12] mm Hg⋅cm⋅s, F = 69.6, P < .0001). Conclusions: High-resolution pharyngeal manometry identified altered swallowing biomechanics in people with moderate-severe OSA, which is consistent with a subclinical presentation. Potential contributing mechanisms include upper esophageal sphincter dysfunction with associated upstream changes of increased hypopharyngeal distension pressure and velopharyngeal contractility.Mistyka S. Schar, Taher I. Omari, Charmaine M. Woods, Lara F. Ferris, Sebastian H. Doeltgen, Kurt Lushington, Anna Kontos, Theodore Athanasiadis, Charles Cock, Ching-Li Chai Coetzer, Danny J. Eckert, Eng H. Oo