1,930 research outputs found
Infiltrating ductal carcinoma breast with central necrosis closely mimicking ductal carcinoma in situ (comedo type): a case series
Here we present a series of infiltrative ductal carcinoma breast cases (infiltrative ductal carcinoma with central necrosis) so closely mimicking \u27DCIS with central comedo necrosis\u27 that on initial morphological analysis these foci of tumors were labeled as DCIS (high grade, comedo). However on further histological work up and by using immunohistochemistry (IHC) for myoepithelial markers it was later confirmed that these were foci of infiltrative ductal carcinoma breast with central necrosis. This case series gives the realization that a breast carcinoma may be partly or entirely DCIS like yet invasive. In such a dilemma IHC especially for assessment of myoepithelial lining is very useful to differentiate DCIS comedo from invasive carcinoma with central necrosis
Dolutegravir in pregnant mice is associated with increased rates of fetal defects at therapeutic but not at supratherapeutic levels
BACKGROUND: Dolutegravir (DTG) is a preferred regimen for all people with HIV including pregnant women, but its effects on the fetus are not fully understood. Periconceptional exposure to DTG has been associated with increased rates of neural tube defects (NTDs), although it is unknown whether this is a causal relationship. This has led to uncertainty around the use of DTG in women of reproductive potential. METHODS: Pregnant C57BL/6J mice were randomly allocated to control (water), 1x-DTG (2.5 mg/kg-peak plasma concentration ~3000 ng/ml - therapeutic level), or 5x-DTG (12.5 mg/kg-peak plasma concentration ~12,000 ng/ml - supratherapeutic level), once daily from gestational day 0.5 until sacrifice. DTG was administered with 50 mg/kg tenofovir+33.3 mg/kg emtricitabine. Fetal phenotypes were determined, and maternal and fetal folate levels were quantified by mass-spectrometry. FINDINGS: 352 litters (91 control, 150 1x-DTG, 111 5x-DTG) yielding 2776 fetuses (747 control, 1174 1x-DTG, 855 5x-DTG) were assessed. Litter size and viability rates were similar between groups. Fetal and placenta weights were lower in the 1x-DTG vs. control. Placental weight was higher in the 5x-DTG vs. control. Five NTDs were observed, all in the 1x-DTG group. Fetal defects, including microphthalmia, severe edema, and vascular/bleeding defects were more frequent in the 1x-DTG group. In contrast, defect rates in the 5x-DTG were similar to control. Fetal folate levels were similar between control and 1x-DTG, but were significantly higher in the 5x-DTG group. INTERPRETATION: Our findings support a causal relationship of DTG at therapeutic doses with increased risk for fetal defects, including NTDs at a rate that is similar that reported in the Tsepamo study for women exposed to DTG-based ART from conception. The non-monotonic dose-response relationship between DTG and fetal anomalies could explain the previous lack of fetal toxicity findings from pre-clinical DTG studies. The fetal folate levels suggest that DTG is unlikely to be an inhibitor of folate uptake. FUNDING: This project has been funded with Federal funds from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN275201800001I
In response to the Letter to the Editor by Romach et al. re our publication "Dolutegravir in pregnant mice is associated with increased rates of fetal defects at therapeutic but not at supratherapeutic levels"
Folate deficiency increases the incidence of dolutegravir-associated foetal defects in a mouse pregnancy model
Background: Dolutegravir (DTG) is a recommended first-line regimen for all people with Human Immunodeficiency Virus (HIV) infection. Initial findings from Botswana, a country with no folate fortification program, showed an elevated prevalence of neural tube defects (NTDs) with peri-conceptional exposure to DTG. Here we explore whether a low folate diet influences the risk of DTG-associated foetal anomalies in a mouse model. / Methods: C57BL/6 mice fed a folate-deficient diet for 2 weeks, were mated and then randomly allocated to control (water), or 1xDTG (2.5 mg/kg), or 5xDTG (12.5 mg/kg) both administered orally with 50 mg/kg tenofovir disoproxil fumarate 33.3 mg/kg emtricitabine. Treatment was administered once daily from gestational day (GD) 0.5 to sacrifice (GD15.5). Foetuses were assessed for gross anomalies. Maternal and foetal folate levels were quantified. / Findings: 313 litters (103 control, 106 1xDTG, 104 5xDTG) were assessed. Viability, placental weight, and foetal weight did not differ between groups. NTDs were only observed in the DTG groups (litter rate: 0% control; 1.0% 1xDTG; 1.3% 5xDTG). Tail, abdominal wall, limb, craniofacial, and bleeding defects all occurred at higher rates in the DTG groups versus control. Compared with our previous findings on DTG usage in folate-replete mouse pregnancies, folate deficiency was associated with higher rates of several defects, including NTDs, but in the DTG groups only. We observed a severe left-right asymmetry phenotype that was more frequent in DTG groups than controls. / Interpretation: Maternal folate deficiency may increase the risk for DTG-associated foetal defects. Periconceptional folic acid supplementation could be considered for women with HIV taking DTG during pregnancy, particularly in countries lacking folate fortification programs. / Funding: This project has been funded by Federal funds from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN275201800001I and award #R01HD104553. LS is supported by a Tier 1 Canada Research Chair in Maternal-Child Health and HIV. HM is supported by a Junior Investigator award from the Ontario HIV Treatment Network
Search for Exotic Strange Quark Matter in High Energy Nuclear Reactions
We report on a search for metastable positively and negatively charged states
of strange quark matter in Au+Pb reactions at 11.6 A GeV/c in experiment E864.
We have sampled approximately six billion 10% most central Au+Pb interactions
and have observed no strangelet states (baryon number A < 100 droplets of
strange quark matter). We thus set upper limits on the production of these
exotic states at the level of 1-6 x 10^{-8} per central collision. These limits
are the best and most model independent for this colliding system. We discuss
the implications of our results on strangelet production mechanisms, and also
on the stability question of strange quark matter.Comment: 21 pages, 9 figures, to be published in Nuclear Physics A (Carl Dover
memorial edition
Waiting time distribution in public health care: empirics and theory
Excessive waiting times for elective surgery have been a long-standing concern in many national healthcare systems in the OECD. How do the hospital admission patterns that generate waiting lists affect different patients? What are the hospitals characteristics that determine waiting times? By developing a model of healthcare provision and analysing empirically the entire waiting time distribution we attempt to shed some light on those issues. We first build a theoretical model that describes the optimal waiting time distribution for capacity constraint hospitals. Secondly, employing duration analysis, we obtain empirical representations of that distribution across hospitals in the UK from 1997–2005. We observe important differences on the ‘scale’ and on the ‘shape’ of admission rates. Scale refers to how quickly patients are treated and shape represents trade-offs across duration-treatment profiles. By fitting the theoretical to the empirical distributions we estimate the main structural parameters of the model and are able to closely identify the main drivers of these empirical differences. We find that the level of resources allocated to elective surgery (budget and physical capacity), which determines how constrained the hospital is, explains differences in scale. Changes in benefits and costs structures of healthcare provision, which relate, respectively, to the desire to prioritise patients by duration and the reduction in costs due to delayed treatment, determine the shape, affecting short and long duration patients differently
Measuring persistent and transient energy efficiency in the US
The promotion of US energy efficiency policy is seen as a very important activity. Generally, the level of energy efficiency of a country or state is approximated by energy intensity, commonly calculated as the ratio of energy use to GDP. However, energy intensity is not an accurate proxy for energy efficiency given that changes in energy intensity are a function of changes in several factors including the structure of the economy, climate, efficiency in the use of resources, behaviour and technical change. The aim of this paper is to measure persistent and transient energy efficiency for the whole economy of 49 states in the US using a stochastic frontier energy demand approach. A total US energy demand frontier function is estimated using panel data for 49 states over the period 1995 to 2009 using two panel data models: the Mundlak version of the random effects model (which estimates the persistent part of the energy efficiency) and the true random effects model (which estimates the transient part of the energy efficiency). The analysis confirms that energy intensity is not a good indicator of energy efficiency, whereas, by controlling for a range of economic and other factors, the measures of energy efficiency obtained via the approach adopted here are. Moreover, the estimates show that although for some states energy intensity might give a reasonable indication of a state’s relative energy efficiency, this is not the case for all states.ISSN:1570-646XISSN:1570-647
Insights into the regulation of DMSP synthesis in the diatom Thalassiosira pseudonana through APR activity, proteomics and gene expression analyses on cells acclimating to changes in salinity, light and nitrogen
Despite the importance of dimethylsulphoniopropionate (DMSP) in the global sulphur cycle and climate regulation, the biological pathways underpinning its synthesis in marine phytoplankton remain poorly understood. The intracellular concentration of DMSP increases with increased salinity, increased light intensity and nitrogen starvation in the diatom Thalassiosira pseudonana. We used these conditions to investigate DMSP synthesis at the cellular level via analysis of enzyme activity, gene expression and proteome comparison. The activity of the key sulphur assimilatory enzyme, adenosine 5′- phosphosulphate reductase was not coordinated with increasing intracellular DMSP concentration. Under all three treatments coordination in the expression of sulphur assimilation genes was limited to increases in sulphite reductase transcripts. Similarly, proteomic 2D gel analysis only revealed an increase in phosphoenolpyruvate carboxylase following increases in DMSP concentration. Our findings suggest that increased sulphur assimilation might not be required for increased DMSP synthesis, instead the availability of carbon and nitrogen substrates may be important in the regulation of this pathway. This contrasts with the regulation of sulphur metabolism in higher plants, which generally involves upregulation of several sulphur assimilatory enzymes. In T. pseudonana changes relating to sulphur metabolism were specific to the individual treatments and, given that little coordination was seen in transcript and protein responses across the three growth conditions, different patterns of regulation might be responsible for the increase in DMSP concentration seen under each treatment
Folic acid supplementation in postmenopausal women with hot flushes: phase III randomised double-blind placebo-controlled trial
Objective
To assess whether folic acid supplementation ameliorates hot flushes.
Design
Double-blind, placebo-controlled randomised trial.
Setting
Nine hospitals in England.
Population
Postmenopausal women experiencing ≥50 hot flushes weekly.
Methods
Women (n = 164) were randomly assigned in a 1:1 ratio to receive folic acid 5 mg tablet or placebo daily for 12 weeks. Participants recorded frequency and severity of hot flushes in a Sloan Diary daily and completed Greene Climacteric and Utian Quality of Life (UQoL) Scales at 4-week intervals.
Main outcome measures
The change in daily Hot Flush Score at week 12 from randomisation based on Sloan Diary Composite Score B calculation.
Results
Data of 143 (87%) women were available for the primary outcome. The mean change (SD) in Hot Flush Score at week 12 was −6.98 (10.30) and −4.57 (9.46) for folic acid and placebo group, respectively. The difference between groups in the mean change was −2.41 (95% CI −5.68 to 0.87) (P = 0.149) and in the adjusted mean change −2.61 (95% CI −5.72 to 0.49) (P = 0.098). Analysis of secondary outcomes indicated an increased benefit in the folic acid group regarding changes in total and emotional UQoL scores at week 8 when compared with placebo. The difference in the mean change from baseline was 5.22 (95% CI 1.16–9.28) and 1.88 (95% CI 0.23–3.52) for total and emotional score, respectively.
Conclusions
The study was not able to demonstrate that folic acid had a statistically significant greater benefit in reducing Hot Flush Score over 12 weeks in postmenopausal women when compared with placebo.
Tweetable abstract
Folic acid may ameliorate hot flushes in postmenopausal women but confirmation is required from a larger study
Pharmacological screening using an FXN-EGFP cellular genomic reporter assay for the therapy of Friedreich ataxia
Copyright @ 2013 Li et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Friedreich ataxia (FRDA) is an autosomal recessive disorder characterized by neurodegeneration and cardiomyopathy. The presence of a GAA trinucleotide repeat expansion in the first intron of the FXN gene results in the inhibition of gene expression and an insufficiency of the mitochondrial protein frataxin. There is a correlation between expansion length, the amount of residual frataxin and the severity of disease. As the coding sequence is unaltered, pharmacological up-regulation of FXN expression may restore frataxin to therapeutic levels. To facilitate screening of compounds that modulate FXN expression in a physiologically relevant manner, we established a cellular genomic reporter assay consisting of a stable human cell line containing an FXN-EGFP fusion construct, in which the EGFP gene is fused in-frame with the entire normal human FXN gene present on a BAC clone. The cell line was used to establish a fluorometric cellular assay for use in high throughput screening (HTS) procedures. A small chemical library containing FDA-approved compounds and natural extracts was screened and analyzed. Compound hits identified by HTS were further evaluated by flow cytometry in the cellular genomic reporter assay. The effects on FXN mRNA and frataxin protein levels were measured in lymphoblast and fibroblast cell lines derived from individuals with FRDA and in a humanized GAA repeat expansion mouse model of FRDA. Compounds that were established to increase FXN gene expression and frataxin levels included several anti-cancer agents, the iron-chelator deferiprone and the phytoalexin resveratrol.Muscular Dystrophy Association (USA), the National Health and Medical Research Council (Australia), the Friedreich’s Ataxia Research Alliance (USA), the Brockhoff Foundation (Australia), the Friedreich Ataxia Research Association (Australasia), Seek A Miracle (USA) and the Victorian Government’s Operational Infrastructure Support Program
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