3,937 research outputs found
DNA methylation biomarkers for esophageal adenocarcinoma and precursor disease
Esophageal adenocarcinoma has one of the poorest outcomes of all solid tumors, attributable, at least in part, to lack of an early stage diagnostic test. Aberrant methylation is an early and frequent event in carcinogenesis providing an opportunity for early cancer detection. The overall aim of this thesis is to identify and validate regions of aberrant methylation as a biomarker for early detection of esophageal adenocarcinoma and the dysplastic stages of its precursor disease, Barrett’s esophagus. By using well-classified patient data and stringent, quality controlled biospecimen selection for training and validation cohorts, I found regions of diseaseassociated aberrant methylation that are novel for esophageal carcinogenesis. With comprehensive technical and independent validation by targeted amplicon sequencing and whole genome methylation profiling of a large external validation cohort, I demonstrated potential utility of these target regions for identification of intervention requiring disease. For subsequent blood investigation, all target regions are unmethylated in peripheral blood from healthy patients and amplification assays for targeted sequencing are suitable for degraded, shorter fragments of cell-free circulating DNA in blood. I proposed a panel of three methylation biomarkers (TUBA3FP, VANGL2, ARL10) for identification of intervention requiring disease, reporting 100% sensitivity and 84.6% specificity and demonstrated biomarker application for prediction of disease progression as well as utility for monitoring disease status with treatment. I was also able to show utility for predicting the necessity of treatment for low-grade dysplasia, which is controversial in guidelines worldwide. By performing genome-wide methylation and expression profiling, as well as cancer-associated mutation screening on single tissue biopsies from all stages of the metaplasia-dysplasiaadenocarcinoma sequence, I was able to gain a more complete understanding of the genetic and epigenetic changes occurring in esophageal adenocarcinogenesis. The research presented in this thesis demonstrates that I have been able to propose potentially clinically valuable methylation biomarkers for the detection of intervention-requiring disease, with potential application for non-invasive, high-risk population screening for identification of esophageal adenocarcinoma at an early, treatable stage
Rival Male Relatedness Does Not Affect Ejaculate Allocation as Predicted by Sperm Competition Theory
When females are sexually promiscuous, the intensity of sperm competition for males depends on how many partners females mate with. To maximize fitness, males should adjust their copulatory investment in relation to this intensity. However, fitness costs associated with sperm competition may not only depend on how many males a female has mated with, but also how related rival males are. According to theoretical predictions, males should adjust their copulatory investment in response to the relatedness of their male rival, and transfer more sperm to females that have first mated with a non-sibling male than females that have mated to a related male. Here, for the first time, we empirically test this theory using the Australian field cricket Teleogryllus oceanicus. We expose male crickets to sperm competition from either a full sibling or non-sibling male, by using both the presence of a rival male and the rival male's actual competing ejaculate as cues. Contrary to predictions, we find that males do not adjust ejaculates in response to the relatedness of their male rival. Instead, males with both full-sibling and non-sibling rivals allocate sperm of similar quality to females. This lack of kin biased behaviour is independent of any potentially confounding effect of strong competition between close relatives; kin biased behaviour was absent irrespective of whether males were raised in full sibling or mixed relatedness groups
Selective ALDH3A1 Inhibition by Benzimidazole Analogues Increase Mafosfamide Sensitivity in Cancer Cells
Aldehyde dehydrogenase enzymes irreversibly
oxidize aldehydes generated
from metabolism of amino acids, fatty acids, food, smoke, additives,
and xenobiotic drugs. Cyclophosphamide is one such xenobiotic used
in cancer therapies. Upon activation, cyclophosphamide forms an intermediate,
aldophosphamide, which can be detoxified to carboxyphosphamide by
aldehyde dehydrogenases (ALDH), especially ALDH1A1 and ALDH3A1. Consequently,
selective inhibition of ALDH3A1 could increase chemosensitivity toward
cyclophosphamide in ALDH3A1 expressing tumors. Here, we report detailed
kinetics and structural characterization of a highly selective submicromolar
inhibitor of ALDH3A1, 1-[(4-fluorophenyl)sulfonyl]-2-methyl-1H-benzimidazole (CB7, IC50 of 0.2
μM). CB7 does not inhibit ALDH1A1, ALDH1A2, ALDH1A3,
ALDH1B1, or ALDH2 activity. Structural, kinetics, and mutagenesis
studies show that CB7 binds to the aldehyde binding pocket
of ALDH3A1. ALDH3A1-expressing lung adenocarcinoma and glioblastoma
cell lines are sensitized toward mafosfamide (MF) treatment in the
presence analogues of CB7, whereas primary lung fibroblasts
lacking ALDH3A1 expression, are not
Current State of Preeclampsia Mouse Models: Approaches, Relevance, and Standardization
Preeclampsia (PE) is a multisystemic, pregnancy-specific disorder and a leading cause of maternal and fetal death. PE is also associated with an increased risk for chronic morbidities later in life for mother and offspring. Abnormal placentation or placental function has been well-established as central to the genesis of PE; yet much remains to be determined about the factors involved in the development of this condition. Despite decades of investigation and many clinical trials, the only definitive treatment is parturition. To better understand the condition and identify potential targets preclinically, many approaches to simulate PE in mice have been developed and include mixed mouse strain crosses, genetic overexpression and knockout, exogenous agent administration, surgical manipulation, systemic adenoviral infection, and trophoblast-specific gene transfer. These models have been useful to investigate how biological perturbations identified in human PE are involved in the generation of PE-like symptoms and have improved the understanding of the molecular mechanisms underpinning the human condition. However, these approaches were characterized by a wide variety of physiological endpoints, which can make it difficult to compare effects across models and many of these approaches have aspects that lack physiological relevance to this human disorder and may interfere with therapeutic development. This report provides a comprehensive review of mouse models that exhibit PE-like symptoms and a proposed standardization of physiological characteristics for analysis in murine models of PE
Neuron numbers increase in the human amygdala from birth to adulthood, but not in autism.
Remarkably little is known about the postnatal cellular development of the human amygdala. It plays a central role in mediating emotional behavior and has an unusually protracted development well into adulthood, increasing in size by 40% from youth to adulthood. Variation from this typical neurodevelopmental trajectory could have profound implications on normal emotional development. We report the results of a stereological analysis of the number of neurons in amygdala nuclei of 52 human brains ranging from 2 to 48 years of age [24 neurotypical and 28 autism spectrum disorder (ASD)]. In neurotypical development, the number of mature neurons in the basal and accessory basal nuclei increases from childhood to adulthood, coinciding with a decrease of immature neurons within the paralaminar nucleus. Individuals with ASD, in contrast, show an initial excess of amygdala neurons during childhood, followed by a reduction in adulthood across nuclei. We propose that there is a long-term contribution of mature neurons from the paralaminar nucleus to other nuclei of the neurotypical human amygdala and that this growth trajectory may be altered in ASD, potentially underlying the volumetric changes detected in ASD and other neurodevelopmental or neuropsychiatric disorders
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Cutibacterium (formerly Propionibacterium) acnes clavicular infection.
Cutibacterium (formerly Propionibacterium) acnes13, 16 is a slow growing, gram-positive bacteria that is naturally found in higher concentrations as skin flora on the chest and back, as well as in other areas with greater numbers of hair follicles.25, 37 Most of the reported cases of C. acnes shoulder girdle infection follow arthroplasty surgery,18, 20, 26, 27, 32, 35 which then often requires debridement, administration of intravenous antibiotics, and surgical revision of the implanted device.12, 15, 21, 28-30 In a recent study, 56% of 193 shoulder revisions had a positive culture, 70% of which grew C. acnes.30 Despite the relatively common presumed association of C. acnes humeral osteomyelitis with prosthetic infection, infection of the scapula or clavicle secondary to C. acnes is rare.4, 23, 36 Osteomyelitis of the clavicle involving any organism is also an uncommon event that can arise spontaneously via presumed hematogenous spread, or secondary to open fractures or internal fixation.6, 33 The most commonly found organism in clavicular osteomyelitis is Staphylococcus aureus.9 We here report two cases of clavicular infection secondary to C. acnes that were not associated with implants
Health Management: Occupational Therapy’s Key Role in Educating Clients About Reliable Online Health Information
Background: Only 12% of Americans possess proficient health literacy skills. Among those with the lowest health literacy are individuals with chronic health conditions. Occupational therapists are well prepared to assist these clients with health literacy, given our roles in teaching new health management skills and health promotion.
Methods: An educational course was designed and taught to over 100 individuals and caregivers with chronic health conditions to assist in finding and determining trustworthy health information online. An author designed pre postsurvey was used to evaluate effectiveness.
Results: There was a significant pre-post change in four categories: finding quality health information online (M = 0.703), judging trustworthiness of online health information (M = 0.624), understanding health information (M = 0.489), and retrieving information using email alerts (M = 0.826).
Conclusion: The ability to find and evaluate health information online empowers clients to fully participate in medical care. Evidence shows that this skill can be efficiently taught to clients or client groups for improved health management. Providing training in finding trustworthy health information online is a skill that occupational therapists can successfully teach in conjunction with overall health management skills for improved occupational participation
Differential Indicators of Diabetes-Induced Oxidative Stress in New Zealand White Rabbits: Role of Dietary Vitamin E Supplementation
Determination of reliable bioindicators of diabetes-induced oxidative
stress and the role of dietary vitamin E supplementation
were investigated. Blood (plasma) chemistries, lipid peroxidation
(LPO), and antioxidant enzyme activities were measured over
12 weeks in New Zealand White rabbits (control, diabetic, and diabetic +
vitamin E). Cholesterol and triglyceride levels did not correlate
with diabetic state. PlasmaLPOwas influenced by diabetes and
positively correlated with glucose concentration only, not cholesterol
or triglycerides. Liver glutathione peroxidase (GPX) activity
negatively correlated with glucose and triglyceride levels. Plasma
and erythrocyte GPX activities positively correlated with glucose,
cholesterol, and triglyceride concentrations. Liver superoxide dismutase
activity positively correlated with glucose and cholesterol
concentration. Vitamin E reduced plasma LPO, but did not affect
the diabetic state. Thus, plasmaLPOwas the most reliable indicator
of diabetes-induced oxidative stress. Antioxidant enzyme activities
and types of reactive oxygen species generated were tissue dependent.
Diabetes-induced oxidative stress is diminished by vitamin E
supplementation
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