354 research outputs found
Evaluation Of Autoantibodies To Paraneoplastic Antigens As Early Detection Biomarkers For High-Grade Serous Ovarian Cancer
The majority of ovarian cancer cases are diagnosed at an advanced stage metastatic disease with poor prognosis due to non-specific symptoms and lack of early detection methods. This study evaluates autoantibodies against tumor antigens to identify candidate biomarkers for the early detection of ovarian tumors in high-risk women. Paraneoplastic antigens are associated with autoimmune diseases termed paraneoplastic neurological syndromes (PNSs), which develop when the unregulated immune response against a tumor also targets healthy cells. Notably, a set of antibodies is found in PNS patients with ovarian cancer, identifying highly immunogenic antigens in the tumor. In this dissertation work, we have detected paraneoplastic antibodies present in the sera of patients with high-grade serous ovarian cancer (HGSOC) using line blots, western blots, and ELISA. A panel of five paraneoplastic antigens (HARS, TRIM21, COR, CDR2, CDR2L) along with 2 established tumor antigens (NY-ESO-1, p53) were purified from E. coli for screening on western blot and ELISA. Screening was performed with a patient serum set consisting of: 50 late stage HGSOC, 14 early stage HGSOC, 50 benign ovarian cyst, and 50 healthy volunteer samples. On western blot, the paraneoplastic antigen with the best performance was TRIM21with 35% sensitivity. Combining TRIM21 with p53 and NYESO-1 yielded a sensitivity of 60% with 90% specificity. In the early stage HGSOC sample set, HARS demonstrated 31% sensitivity individually, and 46% sensitivity with 98% specificity when combined with p53 and NYESO-1. The identified markers will were tested in an independent validation serum set consisting of n=150 samples. The work in this dissertation identified the paraneoplastic antigen TRIM21 that can enhance autoantibody biomarker panels for the early detection of HGSOC
Barriers and facilitators to access and care in services for children with autism spectrum disorder in Newfoundland
This thesis uses thematic analysis and a Complex Cultural Nesting theory to assess the perspectives of parents of children with autism spectrum disorder as well as the service providers as they try to navigate through the healthcare and education system in Newfoundland, Canada. These journeys were explored through interviews with a range of participants in a one to one setting, thus providing rich and specific experiential data. The main barriers discovered were frustrations in the diagnostic process, difficulty accessing and understanding services within the healthcare and education systems, and struggles with the applied behavioural analysis therapy. Main facilitators included having a knowledgeable and supportive family physician, family support, and service provider communication and collaboration. Major recommendations focus on increasing the number of experienced providers in the province and increasing specific autism training for service providers (in the healthcare and education system)
Serotonin in the inferior colliculus fluctuates with behavioral state and environmental stimuli
Neuromodulation by serotonin (5-HT) could link behavioral state and environmental events with sensory processing. Within the auditory system, the presence of 5-HT alters the activity of neurons in the inferior colliculus (IC), but the conditions that influence 5-HT neurotransmission in this region of the brain are unknown. We used in vivo voltammetry to measure extracellular 5-HT in the IC of behaving mice to address this issue. Extracellular 5-HT increased with the recovery from anesthesia, suggesting that the
neuromodulation of auditory processing is correlated with the level of behavioral arousal. Awake mice were further exposed to auditory (broadband noise), visual (light) or olfactory (2,5-dihydro-2,4,5-trimethylthiazoline, TMT) stimuli, presented with food or confined in a small arena. Only the auditory stimulus or restricted movement increased the concentration of extracellular 5-HT in the IC. Changes occurred within minutes of stimulus onset, with the auditory stimulus increasing extracellular 5-HT by an average of 5% and restricted movement increasing it by an average of 14%. These findings suggest that the neuromodulation of auditory processing by 5-HT is a dynamic process that is dependent on internal state and behavioral conditions
Listening to your partner: serotonin increases male responsiveness to female vocal signals in mice
The context surrounding vocal communication can have a strong influence on how vocal signals are perceived. The serotonergic system is well-positioned for modulating the perception of communication signals according to context, because serotonergic neurons are responsive to social context, influence social behavior, and innervate auditory regions. Animals like lab mice can be excellent models for exploring how serotonin affects the primary neural systems involved in vocal perception, including within central auditory regions like the inferior colliculus (IC). Within the IC, serotonergic activity reflects not only the presence of a conspecific, but also the valence of a given social interaction. To assess whether serotonin can influence the perception of vocal signals in male mice, we manipulated serotonin systemically with an injection of its precursor 5-HTP, and locally in the IC with an infusion of fenfluramine, a serotonin reuptake blocker. Mice then participated in a behavioral assay in which males suppress their ultrasonic vocalizations (USVs) in response to the playback of female broadband vocalizations (BBVs), used in defensive aggression by females when interacting with males. Both 5-HTP and fenfluramine increased the suppression of USVs during BBV playback relative to controls. 5-HTP additionally decreased the baseline production of a specific type of USV and male investigation, but neither drug treatment strongly affected male digging or grooming. These findings show that serotonin modifies behavioral responses to vocal signals in mice, in part by acting in auditory brain regions, and suggest that mouse vocal behavior can serve as a useful model for exploring the mechanisms of context in human communication
Car Cabin Filters as Sampling Devices to Study Bioaerosols Using eDNA and Microbiological Methods
The aim of this study was to examine whether bioaerosols could be isolated and quantified from used car cabin filters. Car cabin filters are widely available and can provide a vast untapped resource for sampling of bioaerosols in areas with enhanced air pollution. We developed a test system where we exposed car cabin filters to birch pollen under compressed air to represent airflow onto the filter. The flow of pollen within the test system was confirmed by microscopy and real-time PCR. Testing of extraction methods was performed on the most prevalent types of filters in UK cars and confirmed it was possible to extract and quantify viable fungi, birch pollen or proteins from car filters. The main challenge of their use is envisaged to be the lack of temporal resolution as car cabin filters are not routinely changed at intervals greater than 1 year; however, the systematic recording of the different routes driven during the sampling interval has been enabled through the common use of GPS, smartphones or similar technologies. Car filters therefore provide substantial possibilities to monitor exposure of harmful bioaerosols in the polluted traffic regions defined by the road network. This method could also be applied to studying allergen exposure associated with bioaerosols and their delivery into the human respiratory system. These findings demonstrate that car cabin filters have the potential to be used to isolate and quantify a range of bioaerosols including pollen and fungi, as well as fractions of bioaerosols, such as proteins
Morphologic change in rabbit femoral arteries induced by storage at four degrees Celsius and by subsequent reperfusion
AbstractPurpose: Cold-stored arteries function well as microvascular autografts, but little is known of the morphologic changes that occur in them during cold storage or of further changes during reperfusion.Methods: In part A of the study, rabbit femoral arteries were stored at 4° C for up to 6 months. In part B rabbit femoral arteries were stored at 4° C for up to 6 months, inserted as end-to-end autografts into contralateral femoral arteries, and reperfused for 24 hours. Tissue was examined by histologic study, transmission and scanning electron microscopy, histochemical study, immunohistochemical study, and tissue culture.Results: Cell viability declined gradually at 4° C, so that by 4 weeks no viable cells remained. However, the extracellular framework and elastic lamellae remain intact. If cold-stored arteries are reinserted as autografts for 24 hours, this accelerates breakdown of necrotic cells and reduces the thickness of the medial wall and internal elastic lamina but does not alter the extracellular framework.Conclusions: Cold storage results in acellular vascular grafts with intact extracellular frameworks. After 24 hours reperfusion there is no major change to the extracellular framework. (J VASC SURG 1995;22:769-79.
Going beyond richness: Modelling the BEF relationship using species identity, evenness, richness and species interactions via the DImodels R package, and a comparison with traditional approaches
BEF studies aim at understanding how ecosystems respond to a gradient of
species diversity. Diversity-Interactions models are suitable for analysing the
BEF relationship. These models relate an ecosystem function response of a
community to the identity of the species in the community, their evenness
(proportions) and interactions. The no. of species in the community (richness)
is also implicitly modelled through this approach. It is common in BEF studies
to model an ecosystem function as a function of richness; while this can
uncover trends in the BEF relationship, by definition, species diversity is
much broader than richness alone, and important patterns in the BEF
relationship may remain hidden. We compare DI models to traditional modelling
approaches to highlight the advantages of using a multi-dimensional definition
of species diversity. DI models can capture variation due to species
identities, species proportions and species interactions, in addition to
richness effects. We also introduce the DImodels R package for implementing DI
models. Through worked examples, we show that using DI models can lead to
considerably improved model fit over other methods. Collapsing the multiple
dimensions of species diversity to a single dimension (such as richness) can
result in valuable ecological information being lost. Predicting from a DI
model is not limited to the study design points, the model can extrapolate to
predict for any species composition and proportions. Overall, DI models lead to
enhanced inference compared to other approaches. Expressing the BEF
relationship as a function of richness alone can be useful to capture overall
trends, however, there are multiple ways to quantify the species diversity of a
community. DI modelling provides a framework to test the multiple aspects of
species diversity and facilitates uncovering a deeper ecological understanding
of the BEF relationship
Activation of mTORC1 and c-Jun by Prohibitin1 loss in Schwann cells may link mitochondrial dysfunction to demyelination.
Schwann cell (SC) mitochondria are quickly emerging as an important regulator of myelin maintenance in the peripheral nervous system (PNS). However, the mechanisms underlying demyelination in the context of mitochondrial dysfunction in the PNS are incompletely understood. We recently showed that conditional ablation of the mitochondrial protein Prohibitin 1 (PHB1) in SCs causes a severe and fast progressing demyelinating peripheral neuropathy in mice, but the mechanism that causes failure of myelin maintenance remained unknown. Here, we report that mTORC1 and c-Jun are continuously activated in the absence of Phb1, likely as part of the SC response to mitochondrial damage. Moreover, we demonstrate that these pathways are involved in the demyelination process, and that inhibition of mTORC1 using rapamycin partially rescues the demyelinating pathology. Therefore, we propose that mTORC1 and c-Jun may play a critical role as executioners of demyelination in the context of perturbations to SC mitochondria
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