586 research outputs found
Loci de rasgos binarios que influyen en la expresión del comportamiento higiénico de las abejas melíferas
This study was conducted to detect binary trait loci (BTLs) that influence the expression of hygienic behavior of individual honey bee workers and to locate genetic markers that are associated to these BTLs on a genetic map derived from bees that perform hygienic behavior of a backcross colony. Samples of workers that perform hygienic behavior and workers that not perform hygienic behavior that were used as controls were collected from the colony.Este estudio se realizó, para detectar loci de rasgos binarios (BTL) que influyen en la expresión del comportamiento higiénico de abejas obreras y para localizar marcadores genéticos asociados a estos BTL en un mapa de ligamiento. Se recolectaron abejas que realizaron el comportamiento higiénico y abejas que no realizaron el comportamiento higiénico de una colonia producto de una retrocruza. Se construyó, un mapa genético utilizando marcadores AFLP generados a partir del ADN de las abejas que realizaron el comportamiento higiénico
Genomic correlates of recombination rate and its variability across eight recombination maps in the western honey bee (Apis mellifera L.)
Background: Meiotic recombination has traditionally been explained based on the structural requirement to stabilize homologous chromosome pairs to ensure their proper meiotic segregation. Competing hypotheses seek to explain the emerging findings of significant heterogeneity in recombination rates within and between genomes, but intraspecific comparisons of genome-wide recombination patterns are rare. The honey bee (Apis mellifera) exhibits the highest rate of genomic recombination among multicellular animals with about five cross-over events per chromatid. Results: Here, we present a comparative analysis of recombination rates across eight genetic linkage maps of the honey bee genome to investigate which genomic sequence features are correlated with recombination rate and with its variation across the eight data sets, ranging in average marker spacing ranging from 1 Mbp to 120 kbp. Overall, we found that GC content explained best the variation in local recombination rate along chromosomes at the analyzed 100 kbp scale. In contrast, variation among the different maps was correlated to the abundance of microsatellites and several specific tri- and tetra-nucleotides. Conclusions: The combined evidence from eight medium-scale recombination maps of the honey bee genome suggests that recombination rate variation in this highly recombining genome might be due to the DNA configuration instead of distinct sequence motifs. However, more fine-scale analyses are needed. The empirical basis of eight differing genetic maps allowed for robust conclusions about the correlates of the local recombination rates and enabled the study of the relation between DNA features and variability in local recombination rates, which is particularly relevant in the honey bee genome with its exceptionally high recombination rate. © 2014 Ross et al
THERAPY WITH ADULT BONE MARROW-DERIVED MESENCHYMAL STEM CELLS AMELIORATES DOXORUBICIN-INDUCED CARDIOMYOPATHY
TGF-β1 enhances cardiomyogenic differentiation of skeletal muscle-derived adult primitive cells
The optimal medium for cardiac differentiation of adult primitive cells remains to be established. We quantitatively compared the efficacy of IGF-1, dynorphin B, insulin, oxytocin, bFGF, and TGF-beta1 in inducing cardiomyogenic differentiation. Adult mouse skeletal muscle-derived Sca1+/CD45-/c-kit-/Thy-1+ (SM+) and Sca1-/CD45-/c-kit-/Thy-1+ (SM-) cells were cultured in basic medium (BM; DMEM, FBS, IGF-1, dynorphin B) alone and BM supplemented with insulin, oxytocin, bFGF, or TGF-beta1. Cardiac differentiation was evaluated by the expression of cardiac-specific markers at the mRNA (qRT-PCR) and protein (immunocytochemistry) levels. BM+TGF-beta1 upregulated mRNA expression of Nkx2.5 and GATA-4 after 4 days and Myl2 after 9 days. After 30 days, BM+TGF-beta1 induced the greatest extent of cardiac differentiation (by morphology and expression of cardiac markers) in SM- cells. We conclude that TGF-beta1 enhances cardiomyogenic differentiation in skeletal muscle-derived adult primitive cells. This strategy may be utilized to induce cardiac differentiation as well as to examine the cardiomyogenic potential of adult tissue-derived stem/progenitor cells
Plasmapheresis to remove amyloid fibrin(ogen) particles for treating the post‐COVID‐19 condition
Background
The post‐COVID‐19 condition (PCC) consists of a wide array of symptoms including fatigue and impaired daily living. People seek a wide variety of approaches to help them recover.
A new belief, arising from a few laboratory studies, is that 'microclots' cause the symptoms of PCC. This belief has been extended outside these studies, suggesting that to recover people need plasmapheresis (an expensive process where blood is filtered outside the body). We appraised the laboratory studies, and it was clear that the term 'microclots' is incorrect to describe the phenomenon being described. The particles are amyloid and include fibrin(ogen); amyloid is not a part of a thrombus which is a mix of fibrin mesh and platelets. Initial acute COVID‐19 infection is associated with clotting abnormalities; this review concerns amyloid fibrin(ogen) particles in PCC only.
We have reported here our appraisal of laboratory studies investigating the presence of amyloid fibrin(ogen) particles in PCC, and of evidence that plasmapheresis may be an effective therapy to remove amyloid fibrin(ogen) particles for treating PCC.
Objectives
Laboratory studies review
To summarize and appraise the research reports on amyloid fibrin(ogen) particles related to PCC.
Randomized controlled trials review
To assess the evidence of the safety and efficacy of plasmapheresis to remove amyloid fibrin(ogen) particles in individuals with PCC from randomized controlled trials.
Search methods
Laboratory studies review
We searched for all relevant laboratory studies up to 27 October 2022 using a comprehensive search strategy which included the search terms ‘COVID’, ‘amyloid’, ‘fibrin’, ‘fibrinogen’.
Randomized controlled trials review
We searched the following databases on 21 October 2022: Cochrane COVID‐19 Study Register; MEDLINE (Ovid); Embase (Ovid); and BIOSIS Previews (Web of Science). We also searched the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov for trials in progress.
Selection criteria
Laboratory studies review
Laboratory studies that investigate the presence of amyloid fibrin(ogen) particles in plasma samples from patients with PCC were eligible. This included studies with or without controls.
Randomized controlled trials review
Studies were eligible if they were of randomized controlled design and investigated the effectiveness or safety of plasmapheresis for removing amyloid fibrin(ogen) particles for treating PCC.
Data collection and analysis
Two review authors applied study inclusion criteria to identify eligible studies and extracted data.
Laboratory studies review
We assessed the risk of bias of included studies using pre‐developed methods for laboratory studies. We planned to perform synthesis without meta‐analysis (SWiM) as described in our protocol.
Randomized controlled trials review
We planned that if we identified any eligible studies, we would assess risk of bias and report results with 95% confidence intervals. The primary outcome was recovery, measured using the Post‐COVID‐19 Functional Status Scale (absence of symptoms related to the illness, ability to do usual daily activities, and a return to a previous state of health and mind).
Main results
Laboratory studies review
We identified five laboratory studies. Amyloid fibrin(ogen) particles were identified in participants across all studies, including those with PCC, healthy individuals, and those with diabetes. The results of three studies were based on visual images of amyloid fibrin(ogen) particles, which did not quantify the amount or size of the particles identified. Formal risk of bias assessment showed concerns in how the studies were conducted and reported. This means the results were insufficient to support the belief that amyloid fibrin(ogen) particles are associated with PCC, or to determine whether there is a difference in the amount or size of amyloid fibrin(ogen) particles in the plasma of people with PCC compared to healthy controls.
Randomized controlled trials review
We identified no trials meeting our inclusion criteria.
Authors' conclusions
In the absence of reliable research showing that amyloid fibrin(ogen) particles contribute to the pathophysiology of PCC, there is no rationale for plasmapheresis to remove amyloid fibrin(ogen) particles in PCC. Plasmapheresis for this indication should not be used outside the context of a well‐conducted randomized controlled trial
A Search for Parent-of-Origin Effects on Honey Bee Gene Expression
Parent-specific gene expression (PSGE) is little known outside of mammals and plants. PSGE occurs when the expression level of a gene depends on whether an allele was inherited from the mother or the father. Kin selection theory predicts that there should be extensive PSGE in social insects because social insect parents can gain inclusive fitness benefits by silencing parental alleles in female offspring. We searched for evidence of PSGE in honey bees using transcriptomes from reciprocal crosses between European and Africanized strains. We found 46 transcripts with significant parent-of-origin effects on gene expression, many of which overexpressed the maternal allele. Interestingly, we also found a large proportion of genes showing a bias toward maternal alleles in only one of the reciprocal crosses. These results indicate that PSGE may occur in social insects. The nonreciprocal effects could be largely driven by hybrid incompatibility between these strains. Future work will help to determine if these are indeed parent-of-origin effects that can modulate inclusive fitness benefits
The allure of otherness: transnational cult film fandom and the exoticist assumption
Academic scholarship addressing transnational cult fandom, particularly Western cult fans forming attachments to films outside their cultures, has frequently addressed the issue of exoticism. Much attention has been paid to how Western fans are problematically drawn to artefacts outside of their own cultures because of exotic qualities, resulting in a shallow and often condescending appreciation of such films. In this article, I critique a number of such articles for merely assuming such processes without proffering sufficient supporting evidence. In fact, I argue that a number of such exotic-oriented critiques of transnational cultism are actually guilty of practising what they preach against: an insufficient contextualization of fandom and a tendency to downplay the messiness of empirical data in favour of generalized abstractions. Further, I argue that the constant critique of fans as avoiding contextualization has not only been overstated but stringently used as a yardstick to denigrate fan engagements with texts as improper. As such, fans are often ‘othered’ within such articles, a process mirroring the ways they are accused of othering distant cultural artefacts
A protocol for a randomised clinical trial of the effect of providing feedback on inhaler technique and adherence from an electronic device in patients with poorly controlled severe asthma.
INTRODUCTION: In clinical practice, it is difficult to distinguish between patients with refractory asthma from those with poorly controlled asthma, where symptoms persist due to poor adherence, inadequate inhaler technique or comorbid diseases. We designed an audio recording device which, when attached to an inhaler, objectively identifies the time and technique of inhaler use, thereby assessing both aspects of adherence. This study will test the hypothesis that feedback on these two aspects of adherence when passed on to patients improves adherence and helps clinicians distinguish refractory from difficult-to-control asthma.
METHODS: This is a single, blind, prospective, randomised, clinical trial performed at 5 research centres. Patients with partially controlled or uncontrolled severe asthma who have also had at least one severe asthma exacerbation in the prior year are eligible to participate. The effect of two types of nurse-delivered education interventions to promote adherence and inhaler technique will be assessed. The active group will receive feedback on their inhaler technique and adherence from the new device over a 3-month period. The control group will also receive training in inhaler technique and strategies to promote adherence, but no feedback from the device. The primary outcome is the difference in actual adherence, a measure that incorporates time and technique of inhaler use between groups at the end of the third month. Secondary outcomes include the number of patients who remain refractory despite good adherence, and differences in the components of adherence after the intervention. Data will be analysed on an intention-to-treat and a per-protocol basis. The sample size is 220 subjects (110 in each group), and loss to follow-up is estimated at 10% which will allow results to show a 10% difference (0.8 power) in adherence between group means with a type I error probability of 0.05.
TRIAL REGISTRATION NUMBER: NCT01529697; Pre-results
Potential health impacts of heavy metals on HIV-infected population in USA.
Noninfectious comorbidities such as cardiovascular diseases have become increasingly prevalent and occur earlier in life in persons with HIV infection. Despite the emerging body of literature linking environmental exposures to chronic disease outcomes in the general population, the impacts of environmental exposures have received little attention in HIV-infected population. The aim of this study is to investigate whether individuals living with HIV have elevated prevalence of heavy metals compared to non-HIV infected individuals in United States. We used the National Health and Nutrition Examination Survey (NHANES) 2003-2010 to compare exposures to heavy metals including cadmium, lead, and total mercury in HIV infected and non-HIV infected subjects. In this cross-sectional study, we found that HIV-infected individuals had higher concentrations of all heavy metals than the non-HIV infected group. In a multivariate linear regression model, HIV status was significantly associated with increased blood cadmium (p=0.03) after adjusting for age, sex, race, education, poverty income ratio, and smoking. However, HIV status was not statistically associated with lead or mercury levels after adjusting for the same covariates. Our findings suggest that HIV-infected patients might be significantly more exposed to cadmium compared to non-HIV infected individuals which could contribute to higher prevalence of chronic diseases among HIV-infected subjects. Further research is warranted to identify sources of exposure and to understand more about specific health outcomes
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