Are mutations in MAPT associated with GGT type III? Forrest, S. L.; Halliday, G. M.; Shepherd, C. E. ...
Neuropathology and applied neurobiology,
June 2020, 2020-Jun, 2020-06-00, 20200601, Volume:
46, Issue:
4
Journal Article
Multiple endocrine neoplasia type 2A (MEN 2A) is a dominantly inherited cancer syndrome that affects tissues derived from neural ectoderm. It is characterized by medullary thyroid carcinoma (MTC) and ...phaeochromocytoma. The MEN2A gene has recently been localized by a combination of genetic and physical mapping techniques to a 480-kilobase region in chromosome 10q11.2 (refs 2,3). The DNA segment encompasses the RET proto-oncogene, a receptor tyrosine kinase gene expressed in MTC and phaeochromocytoma and at lower levels in normal human thyroid. This suggested RET as a candidate for the MEN2A gene. We have identified missense mutations of the RET proto-oncogene in 20 of 23 apparently distinct MEN 2A families, but not in 23 normal controls. Further, 19 of these 20 mutations affect the same conserved cysteine residue at the boundary of the RET extracellular and transmembrane domains.
Advances in immunology, immuno-oncology, drug discovery and vaccine development demand improvements in the capabilities of flow cytometry to allow it to measure more protein markers per cell at ...multiple timepoints. However, the size of panels of fluorophore markers is limited by overlaps in fluorescence-emission spectra, and flow cytometers typically perform cell measurements at one timepoint. Here we describe multi-pass high-dimensional flow cytometry, a method leveraging cellular barcoding via microparticles emitting near-infrared laser light to track and repeatedly measure each cell using more markers and fewer colours. By using live human peripheral blood mononuclear cells, we show that the method enables the time-resolved characterization of the same cells before and after stimulation, their analysis via a 10-marker panel with minimal compensation for spectral spillover and their deep immunophenotyping via a 32-marker panel, where the same cells are analysed in 3 back-to-back cycles with 10-13 markers per cycle, reducing overall spillover and simplifying marker-panel design. Cellular barcoding in flow cytometry extends the utility of the technique for high-dimensional multi-pass single-cell analyses.
New cancer therapies and jaw necrosis Patel, V; Kelleher, M; Sproat, C ...
British dental journal,
2015-Sep-11, Volume:
219, Issue:
5
Journal Article
Peer reviewed
Osteonecrosis of the jaw (ONJ) has a number of causes, the most familiar being radiation or bisphosphonate induced. Various other novel anti-neoplastic and bone-targeting therapies that can also ...cause jaw necrosis have recently become available. This has led to the suggested acronym MRONJ for medication-related osteonecrosis of the jaw. This article summarises the available information on these drugs and their implications for the dental surgeon.
Thirteen families have been described with an autosomal dominantly inherited
dementia named frontotemporal dementia and parkinsonism linked to chromosome
17 (FTDP-17), historically termed Pick's
...disease. Most FTDP-17 cases show neuronal and/or glial inclusions
that stain positively with antibodies raised against the microtubule-associated
protein Tau, although the Tau pathology varies considerably in both its quantity
(or severity) and characteristics,. Previous studies have mapped the FTDP-17 locus to a 2-centimorgan
region on chromosome 17q21.11; the tau gene also lies within this region.
We have now sequenced tau in FTDP-17 families and identified three
missense mutations (G272V, P301L and R406W) and three mutations in the 5′
splice site of exon 10. The splice-site mutations all destabilize a potential
stem-loop structure which is probably involved in regulating the alternative
splicing of exon10 (ref. 13). This causes more
frequent usage of the 5′ splice site and an increased proportion of
tau transcripts that include exon 10. The increase in exon 10+
messenger RNA will increase the proportion of Tau containing four
microtubule-binding repeats, which is consistent with the neuropathology described
in several families with FTDP-17 (refs 12, 14).
Recently published international guidelines recommended using the stimulated thyroglobulin (sTg) post-radioactive iodine (RAI) ablation, in conjunction with tumour stage, as a risk stratification ...factor. The choice of cut-off values for sTg, namely 1 and 10 ng/ml, was, however, largely based on the functional sensitivities of the assays used, with relatively few published data addressing the prognostic impact of alternative cut-off values. Our study aims to provide data on the prognostic value of sTg at different levels of sensitivities and specificities.
We conducted a retrospective review of all adult cases of differentiated thyroid carcinoma receiving RAI ablation at our centre from 2008 to 2010. All patients had sTg measured at around 6 months post-ablation. The functional sensitivity of our assay was 0.5 ng/ml. The outcome was adverse clinical event, defined as cancer-related death, persistent macroscopic disease demonstrable on imaging (including radioisotope scan) and/or receiving further treatment for persistent or recurrent disease. A receiver operating characteristic (ROC) analysis was carried out.
We identified 140 patients treated in the review period, with 106 of them suitable for further analysis. The reasons for exclusion included the presence of anti-thyroglobulin antibodies and medullary or anaplastic histological subtypes. Most (54.7%) had intermediate-risk disease as per the American Thyroid Association classification (2009). The median follow-up duration was 6.4 years; the minimum, excluding deaths, was 5.0 years. ROC analysis showed that the optimal cut-off value of sTg for predicting adverse clinical events was >1.0 ng/ml, associated with a sensitivity of 90.9%, a specificity of 81.0%, a positive predictive value of 55.6% and a negative predictive value of 97.1%.
Based on ROC analysis of sensitivities and specificities, our data showed that a post-ablation sTg value of 1 ng/ml is the optimal cut-off in prognostication of adverse clinical events.
•Previous studies dichotomised thyroglobulin levels into detectable or undetectable.•Receiver operating characteristic analysis was carried out.•The most prognostic post-ablation stimulated thyroglobulin level was >1.0 ng/ml.•This level was an independent prognostic factor in multivariate analysis.•Our results validated the cut-off levels recommended in recent guidelines.
Numerous families exhibiting both frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) have been described, and although many of these have been shown to harbour a repeat expansion ...in
C9ORF72
, several
C9ORF72
-negative FTD-ALS families remain. We performed neuropathological and genetic analysis of a large European Australian kindred (Aus-12) with autosomal dominant inheritance of dementia and/or ALS. Affected Aus-12 members developed either ALS or dementia; some of those with dementia also had ALS and/or extrapyramidal features. Neuropathology was most consistent with frontotemporal lobar degeneration with type B TDP pathology, but with additional phosphorylated tau pathology consistent with corticobasal degeneration. Aus-12 DNA samples were negative for mutations in all known dementia and ALS genes, including
C9ORF72
and
FUS
. Genome-wide linkage analysis provided highly suggestive evidence (maximum multipoint LOD score of 2.9) of a locus on chromosome 16p12.1–16q12.2. Affected individuals shared a chromosome 16 haplotype flanked by D16S3103 and D16S489, spanning 37.9 Mb, with a smaller suggestive disease haplotype spanning 24.4 Mb defined by recombination in an elderly unaffected individual. Importantly, this smaller region does not overlap with
FUS
. Whole-exome sequencing identified four variants present in the maximal critical region that segregate with disease. Linkage analysis incorporating these variants generated a maximum multipoint LOD score of 3.0. These results support the identification of a locus on chromosome 16p12.1–16q12.2 responsible for an unusual cluster of neurodegenerative phenotypes. This region overlaps with a separate locus on 16q12.1–q12.2 reported in an independent ALS family, indicating that this region may harbour a second major locus for FTD-ALS.
Two-photon polymerization has enabled precise microfabrication of three-dimensional structures with applications spanning from photonic microdevices, drug delivery systems, and cellular scaffolds. We ...present two-photon collagen crosslinking (2P-CXL) of intact corneal tissue using riboflavin and femtosecond laser irradiation. Collagen fiber orientations and photobleaching were characterized by second harmonic generation and two-photon fluorescence imaging, respectively. Measurement of local changes in longitudinal mechanical moduli with confocal Brillouin microscopy enabled the visualization of the cross-linked pattern without perturbation of the surrounding non-irradiated regions. 2P-CXL induced stiffening was comparable to that achieved with conventional one-photon CXL. Our results demonstrate the ability to selectively stiffen biological tissue
at high resolution with broad implications in ophthalmology, laser surgery, and tissue engineering.
Summary
Background Allopurinol, a common medication for gout treatment, can cause rare but life‐threatening severe cutaneous adverse reactions. A strong pharmacogenetic association of human ...leucocyte antigen (HLA)‐B*58:01 with allopurinol‐induced drug hypersensitivity has been reported, especially in the Han Chinese population.
Objectives To develop a rapid and simple loop‐mediated isothermal amplification (LAMP) assay of HLA‐B*58:01 and evaluate its feasibility in predicting allopurinol‐induced drug hypersensitivity.
Methods Two sets of LAMP primers targeting exons 2 and 3 of HLA‐B*58:01 were designed. DNA extracted from 20 clinical blood samples of patients with gout was used to evaluate the effectiveness of the two LAMP primer sets for the detection of HLA‐B*58:01.
Results The results were compared with routine clinical genotyping methods. All extracted DNA samples tested with the HLA‐B*58:01 LAMP assay showed agreement with the routine genotyping results. No amplifications were observed when unextracted blood samples were tested.
Conclusions The HLA‐B*58:01 LAMP assay was confirmed to be simple, rapid and specific for the detection of HLA‐B*58:01, and therefore of potential value in the diagnosis of allopurinol‐induced hypersensitivity.
What’s already known about this topic?
•
Loop‐mediated isothermal amplification (LAMP) is a rapid test with shorter hands‐on time and assay time than routine genotyping assays.
•
Routine sequence‐specific oligonucleotide and sequence‐specific priming assays for HLA‐B*58:01 screening have high set‐up times and are costly to perform.
What does this study add?
•
This is the first study using LAMP for the detection of HLA‐B*58:01‐associated allopurinol‐induced hypersensitivity.
•
DNA samples, rather than blood samples, must be used as the starting materials for LAMP.
•
LAMP is a cost‐effective test for potential allopurinol‐induced drug hypersensitivity screening.
Previously, we reported elevated levels of the neuron‐specific tropomyosin receptor kinase B (TrkB) transcript, TrkB‐ sarc homology containing (Shc) in the hippocampus of Alzheimer’s disease (AD) ...brains. In this study, we determined how TrkB‐Shc transcripts are increased in AD. Utilizing a TrkB minigene transiently transfected into SHSY5Y cells, we found increased exon 19 inclusion in TrkB minigene transcripts (to generate TrkB‐Shc) following cellular exposure to amyloid beta 1–42 (Αβ42). As this suggested altered TrkB pre‐mRNA splicing in AD, we conducted an in silico screening for putative splice regulatory protein‐binding sites in the intron/exon splice regulatory regions of exons 18 and 19 of the TrkB gene and then assessed their gene expression profiles using a microarray database of control/AD post‐mortem human hippocampal brain tissue. We found significant changes in serine/arginine protein 20 (Srp20) gene expression in AD cases and confirmed this using a second cohort of control/AD. In vitro, we found increased Srp20 mRNA levels in SHSY5Y cells treated with Αβ42 fibrils. Moreover, Srp20 over‐expression was found to increase exon 19 inclusion in TrkB minigene transcripts and ratio of endogenous TrkB‐Shc:TrkB‐TK+ mRNA expression. Conversely, Srp20 expression knockdown produced the opposite effects. Our findings suggest that dysregulation of factors regulating TrkB pre‐mRNA splicing may contribute to gene expression changes that occur in AD.
The TrkB alternative transcript, TrkB‐Shc, is increased in the AD hippocampus. We found that the splicing factor, Srp20, can influence TrkB pre‐mRNA splicing to increase TrkB‐Shc transcript levels. In the AD hippocampus, Srp20 expression is increased. Dysregulation of factors regulating TrkB pre‐mRNA splicing may contribute to gene expression changes that occur in AD, thereby promoting BDNF/TrkB‐TK+ signaling dysfunction and neurodegeneration.
PDF
