81 research outputs found
Optic nerve thinning and neurosensory retinal degeneration in the rTg4510 mouse model of frontotemporal dementia
Visual impairments, such as difficulties in reading and finding objects, perceiving depth and structure from motion,
and impaired stereopsis, have been reported in tauopathy disorders, such as frontotemporal dementia (FTD). These
impairments however have been previously attributed to cortical pathologies rather than changes in the neurosensory
retina or the optic nerve. Here, we examined tau pathology in the neurosensory retina of the rTg(tauP301L)4510
mouse model of FTD. Optic nerve pathology in mice was also assessed using MRI, and corresponding measurements
taken in a cohort of five FTD sufferers and five healthy controls. rTg(tauP301L)4510 mice were imaged (T2-weighted
MRI) prior to being terminally anesthetized and eyes and brains removed for immunohistochemical and histological
analysis. Central and peripheral retinal labelling of tau and phosphorylated tau (pTau) was quantified and retinal layer
thicknesses and cell numbers assessed. MR volumetric changes of specific brain regions and the optic nerve were
compared to tau accumulation and cell loss in the visual pathway. In addition, the optic nerves of a cohort of healthy
controls and behavioural variant FTD patients, were segmented from T1- and T2-weighted images for volumetric study.
Accumulation of tau and pTau were observed in both the central and peripheral retinal ganglion cell (RGC), inner
plexiform and inner nuclear layers of the neurosensory retina of rTg(tauP301L)4510 mice. This pathology was
associated with reduced nuclear density (− 24.9 ± 3.4%) of the central RGC layer, and a reduced volume (− 19.3 ± 4.6%)
and elevated T2 signal (+ 27.1 ± 1.8%) in the optic nerve of the transgenic mice. Significant atrophy of the cortex
(containing the visual cortex) was observed but not in other area associated with visual processing, e.g. the lateral
geniculate nucleus or superior colliculus. Atrophic changes in optic nerve volume were similarly observed in FTD
patients (− 36.6 ± 2.6%). The association between tau-induced changes in the neurosensory retina and reduced optic
nerve volume in mice, combined with the observation of optic nerve atrophy in clinical FTD suggests that ophthalmic
tau pathology may also exist in the eyes of FTD patients. If tau pathology and neurodegeneration in the retina were to
reflect the degree of cortical tau burden, then cost-effective and non-invasive imaging of the neurosensory retina
could provide valuable biomarkers in tauopathy. Further work should aim to validate whether these observations are
fully translatable to a clinical scenario, which would recommend follow-up retinal and optic nerve examination in FT
The Waddlia Genome: A Window into Chlamydial Biology
Growing evidence suggests that a novel member of the Chlamydiales order, Waddlia chondrophila, is a potential agent of miscarriage in humans and abortion in ruminants. Due to the lack of genetic tools to manipulate chlamydia, genomic analysis is proving to be the most incisive tool in stimulating investigations into the biology of these obligate intracellular bacteria. 454/Roche and Solexa/Illumina technologies were thus used to sequence and assemble de novo the full genome of the first representative of the Waddliaceae family, W. chondrophila. The bacteria possesses a 2′116′312bp chromosome and a 15′593 bp low-copy number plasmid that might integrate into the bacterial chromosome. The Waddlia genome displays numerous repeated sequences indicating different genome dynamics from classical chlamydia which almost completely lack repetitive elements. Moreover, W. chondrophila exhibits many virulence factors also present in classical chlamydia, including a functional type III secretion system, but also a large complement of specific factors for resistance to host or environmental stresses. Large families of outer membrane proteins were identified indicating that these highly immunogenic proteins are not Chlamydiaceae specific and might have been present in their last common ancestor. Enhanced metabolic capability for the synthesis of nucleotides, amino acids, lipids and other co-factors suggests that the common ancestor of the modern Chlamydiales may have been less dependent on their eukaryotic host. The fine-detailed analysis of biosynthetic pathways brings us closer to possibly developing a synthetic medium to grow W. chondrophila, a critical step in the development of genetic tools. As a whole, the availability of the W. chondrophila genome opens new possibilities in Chlamydiales research, providing new insights into the evolution of members of the order Chlamydiales and the biology of the Waddliaceae
Scapular winging: anatomical review, diagnosis, and treatments
Scapular winging is a rare debilitating condition that leads to limited functional activity of the upper extremity. It is the result of numerous causes, including traumatic, iatrogenic, and idiopathic processes that most often result in nerve injury and paralysis of either the serratus anterior, trapezius, or rhomboid muscles. Diagnosis is easily made upon visible inspection of the scapula, with serratus anterior paralysis resulting in medial winging of the scapula. This is in contrast to the lateral winging generated by trapezius and rhomboid paralysis. Most cases of serratus anterior paralysis spontaneously resolve within 24 months, while conservative treatment of trapezius paralysis is less effective. A conservative course of treatment is usually followed for rhomboid paralysis. To allow time for spontaneous recovery, a 6–24 month course of conservative treatment is often recommended, after which if there is no recovery, patients become candidates for corrective surgery
Call Cultures in Orang-Utans?
BACKGROUND:
Several studies suggested great ape cultures, arguing that human cumulative culture presumably evolved from such a foundation. These focused on conspicuous behaviours, and showed rich geographic variation, which could not be attributed to known ecological or genetic differences. Although geographic variation within call types (accents) has previously been reported for orang-utans and other primate species, we examine geographic variation in the presence/absence of discrete call types (dialects). Because orang-utans have been shown to have geographic variation that is not completely explicable by genetic or ecological factors we hypothesized that this will be similar in the call domain and predict that discrete call type variation between populations will be found.
METHODOLOGY/PRINCIPAL FINDINGS:
We examined long-term behavioural data from five orang-utan populations and collected fecal samples for genetic analyses. We show that there is geographic variation in the presence of discrete types of calls. In exactly the same behavioural context (nest building and infant retrieval), individuals in different wild populations customarily emit either qualitatively different calls or calls in some but not in others. By comparing patterns in call-type and genetic similarity, we suggest that the observed variation is not likely to be explained by genetic or ecological differences.
CONCLUSION/SIGNIFICANCE:
These results are consistent with the potential presence of 'call cultures' and suggest that wild orang-utans possess the ability to invent arbitrary calls, which spread through social learning. These findings differ substantially from those that have been reported for primates before. First, the results reported here are on dialect and not on accent. Second, this study presents cases of production learning whereas most primate studies on vocal learning were cases of contextual learning. We conclude with speculating on how these findings might assist in bridging the gap between vocal communication in non-human primates and human speech
Regulatory (pan-)genome of an obligate intracellular pathogen in the PVC superphylum.
Like other obligate intracellular bacteria, the Chlamydiae feature a compact regulatory genome that remains uncharted owing to poor genetic tractability. Exploiting the reduced number of transcription factors (TFs) encoded in the chlamydial (pan-)genome as a model for TF control supporting the intracellular lifestyle, we determined the conserved landscape of TF specificities by ChIP-Seq (chromatin immunoprecipitation-sequencing) in the chlamydial pathogen Waddlia chondrophila. Among 10 conserved TFs, Euo emerged as a master TF targeting >100 promoters through conserved residues in a DNA excisionase-like winged helix-turn-helix-like (wHTH) fold. Minimal target (Euo) boxes were found in conserved developmentally-regulated genes governing vertical genome transmission (cytokinesis and DNA replication) and genome plasticity (transposases). Our ChIP-Seq analysis with intracellular bacteria not only reveals that global TF regulation is maintained in the reduced regulatory genomes of Chlamydiae, but also predicts that master TFs interpret genomic information in the obligate intracellular α-proteobacteria, including the rickettsiae, from which modern day mitochondria evolved
Effect of skilled and unskilled training on nerve regeneration and functional recovery
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
External quality assessment of SARS-CoV-2-sequencing: An ESGMD-SSM pilot trial across 15 European laboratories
Objective: This first pilot on external quality assessment (EQA) of SARS-CoV-2 whole genome sequencing, initiated by the ESCMID Study Group for Genomic and Molecular Diagnostics (ESGMD) and Swiss Society for Microbiology (SSM), aims to build a framework between laboratories in order to improve pathogen surveillance sequencing.Methods: Ten samples with varying viral loads were sent out to 15 clinical laboratories who had free choice of sequencing methods and bioinformatic analyses. The key aspects on which the individual centres were compared on were identification of 1) SNPs and indels, 2) Pango lineages, and 3) clusters between samples.Results: The participating laboratories used a wide array of methods and analysis pipelines. Most were able to generate whole genomes for all samples. Genomes were sequenced to varying depth (up to 100-fold difference across centres). There was a very good consensus regarding the majority of reporting criteria, but there were a few discrepancies in lineage and cluster assignment. Additionally, there were inconsistencies in variant calling. The main reasons for discrepancies were missing data, bioinformatic choices, and interpretation of data.Conclusions: The pilot EQA was an overall success. It was able to show the high quality of participating labs and provide valuable feedback in cases where problems occurred, thereby improving the sequencing setup of laboratories. A larger follow-up EQA should, however, improve on defining the variables and format of the report. Additionally, contamination and/or minority variants should be a further aspect of assessment.</p
5-Methyltetrahydrofolate-homocysteine methyltransferase gene polymorphism (MTR) and risk of head and neck cancer
Kidney transplantation from elderly donors: a prospective randomized study comparing Celsior and UW solutions.
AIM:
The aim of present study was to assess the effect of Celsior as compared with University of Wisconsin (UW) solution on immediate and long-term function of kidney transplants harvested from elderly donors.
METHODS:
A prospective multicenter randomized study was designed to evaluate the efficacy of Celsior versus UW solution for the clinical preservation of the kidney. Fifty renal transplants were performed from donors over 60 years old. Twenty-five kidneys were stored in Celsior and 25 in UW solution. The groups were comparable with regard to donor and recipient characteristics. Renal function outcomes were compared by evaluating delayed graft function rates, daily urinary output, as well as the evolution of mean serum creatinine at 1, 3, 5, 7, and 15 days.
RESULTS:
The warm ischemia time was 42.4 +/- 11 minutes among Celsior vs 46.9 +/- 17.9 minutes in the UW cohort (P = NS). The cold ischemia time was 18 +/- 4.5 hours in Celsior and 19 +/- 6.5 hours in UW (P = NS). Delayed graft function occurred in 48% of the Celsior group and in 52% of the UW group (P = NS). Mean serum creatinine levels and mean daily urinary output were also similar. One- and 5-year graft survivals of kidneys preserved with Celsior were 91.8% and 79.3% compared with 96% and 87.4% for UW without any significant statistical difference
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