123 research outputs found
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In vivo detection of γ-glutamyl-transferase up-regulation in glioma using hyperpolarized γ-glutamyl-[1-13C]glycine.
Glutathione (GSH) is often upregulated in cancer, where it serves to mitigate oxidative stress. γ-glutamyl-transferase (GGT) is a key enzyme in GSH homeostasis, and compared to normal brain its expression is elevated in tumors, including in primary glioblastoma. GGT is therefore an attractive imaging target for detection of glioblastoma. The goal of our study was to assess the value of hyperpolarized (HP) γ-glutamyl-[1-13C]glycine for non-invasive imaging of glioblastoma. Nude rats bearing orthotopic U87 glioblastoma and healthy controls were investigated. Imaging was performed by injecting HP γ-glutamyl-[1-13C]glycine and acquiring dynamic 13C data on a preclinical 3T MR scanner. The signal-to-noise (SNR) ratios of γ-glutamyl-[1-13C]glycine and its product [1-13C]glycine were evaluated. Comparison of control and tumor-bearing rats showed no difference in γ-glutamyl-[1-13C]glycine SNR, pointing to similar delivery to tumor and normal brain. In contrast, [1-13C]glycine SNR was significantly higher in tumor-bearing rats compared to controls, and in tumor regions compared to normal-appearing brain. Importantly, higher [1-13C]glycine was associated with higher GGT expression and higher GSH levels in tumor tissue compared to normal brain. Collectively, this study demonstrates, to our knowledge for the first time, the feasibility of using HP γ-glutamyl-[1-13C]glycine to monitor GGT expression in the brain and thus to detect glioblastoma
Determinants of perceived quality of obstetric care in rural Tanzania: a cross-sectional study
Patients’ reported opinions of the health system need to be understood in order to provide patient-centered care. We investigated determinants of women’s ratings of the quality of care during their most recent facility delivery. We conducted a census of all deliveries in the 6 weeks to 12 months preceding the survey, in villages served by 24 primary care clinics in rural Pwani Region, Tanzania. Women who had delivered children in a study facility were included in this analysis (n = 855). We interviewed women about demographic and obstetric factors and the quality of their obstetric care using a structured questionnaire. We created a composite index of perceived quality from six quality questions. We also assessed the functioning of the local health clinic using structured surveys. We used a multi-level model to analyze factors associated with women’s rating of the quality of care during delivery. 14% of respondents rated the overall quality of care received during delivery as excellent. Women who listened to the radio daily reported lower quality composite scores (β: -0.99, p < 0.001). Women who reported receiving more services in ANC had higher quality scores (β: 0.46, p = 0.001), as did women receiving more delivery services (β: 0.55, p < 0.001). Women who reported disrespect and abuse during delivery had significantly lower quality scores (β: -4.13, p < 0.001). A woman’s expectations and prior and current experiences influence her perception of the quality of care she received. Health facility characteristics did not influence ratings of overall quality. Focusing on improving the process rather than inputs of service delivery during ANC visits and delivery may increase perceived quality of delivery care in low-resource settings. Trial registration:
ISRCTN1710776
Vaccine hesitancy among healthcare workers in Europe: A qualitative study.
Healthcare workers (HCWs) are often referred to as the most trusted source of vaccine-related information for their patients. However, the evidence suggests that a number of HCWs are vaccine-hesitant. This study consists of 65 semi-structured interviews with vaccine providers in Croatia, France, Greece, and Romania to investigate concerns HCWs might have about vaccination. The results revealed that vaccine hesitancy is present in all four countries among vaccine providers. The most important concern across all countries was the fear of vaccine side effects. New vaccines were singled out due to perceived lack of testing for vaccine safety and efficacy. Furthermore, while high trust in health authorities was expressed by HCWs, there was also strong mistrust of pharmaceutical companies due to perceived financial interests and lack of communication about side effects. The notion that it is a doctor's responsibility to respond to hesitant patients was reported in all countries. Concerns were also seen to be country- and context-specific. Strategies to improve confidence in vaccines should be adapted to the specific political, social, cultural and economic context of countries. Furthermore, while most interventions focus on education and improving information about vaccine safety, effectiveness, or the need for vaccines, concerns raised in this study identify other determinants of hesitancy that need addressing. The representativeness of the views of the interviewed HCWs must be interpreted with caution. This a qualitative study with a small sample size that included geographical areas where vaccination uptake was lower or where hesitancy was more prevalent and it reflects individual participants' beliefs and attitudes toward the topic. As HCWs have the potential of influencing patient vaccination uptake, it is crucial to improve their confidence in vaccination and engage them in activities targeting vaccine hesitancy among their patients
First gene-edited calf with reduced susceptibility to a major viral pathogen
Bovine viral diarrhea virus (BVDV) is one of the most important viruses affecting the health and well-being of bovine species throughout the world. Here, we used CRISPR-mediated homology-directed repair and somatic cell nuclear transfer to produce a live calf with a six amino acid substitution in the BVDV binding domain of bovine CD46. The result was a gene-edited calf with dramatically reduced susceptibility to infection as measured by reduced clinical signs and the lack of viral infection in white blood cells. The edited calf has no off-target edits and appears normal and healthy at 20 months of age without obvious adverse effects from the on-target edit. This precision bred, proof-of-concept animal provides the first evidence that intentional genome alterations in the CD46 gene may reduce the burden of BVDV-associated diseases in cattle and is consistent with our stepwise, in vitro and ex vivo experiments with cell lines and matched fetal clones
Imaging Renal Urea Handling in Rats at Millimeter Resolution using Hyperpolarized Magnetic Resonance Relaxometry
\textit{In vivo} spin spin relaxation time () heterogeneity of
hyperpolarized \textsuperscript{13}C urea in the rat kidney was investigated.
Selective quenching of the vascular hyperpolarized \textsuperscript{13}C signal
with a macromolecular relaxation agent revealed that a long- component of
the \textsuperscript{13}C urea signal originated from the renal extravascular
space, thus allowing the vascular and renal filtrate contrast agent pools of
the \textsuperscript{13}C urea to be distinguished via multi-exponential
analysis. The response to induced diuresis and antidiuresis was performed
with two imaging agents: hyperpolarized \textsuperscript{13}C urea and a
control agent hyperpolarized
bis-1,1-(hydroxymethyl)-1-\textsuperscript{13}C-cyclopropane-.
Large increases in the inner-medullar and papilla were observed with the
former agent and not the latter during antidiuresis suggesting that
relaxometry may be used to monitor the inner-medullary urea transporter (UT)-A1
and UT-A3 mediated urea concentrating process. Two high resolution imaging
techniques - multiple echo time averaging and ultra-long echo time sub-2 mm
resolution 3D imaging - were developed to exploit the particularly long
relaxation times observed
GOALS-JWST: Small neutral grains and enhanced 3.3 micron PAH emission in the Seyfert galaxy NGC 7469
We present James Webb Space Telescope (JWST) Near Infrared Spectrograph
(NIRSpec) integral-field spectroscopy of the nearby luminous infrared galaxy,
NGC 7469. We take advantage of the high spatial/spectral resolution and
wavelength coverage of JWST /NIRSpec to study the 3.3 um neutral polycyclic
aromatic hydrocarbon (PAH) grain emission on ~60 pc scales. We find a clear
change in the average grain properties between the star-forming ring and the
central AGN. Regions in the vicinity of the AGN, with [NeIII]/[NeII]>0.25, tend
to have larger grain sizes and lower aliphatic-to-aromatic (3.4/3.3) ratios
indicating that smaller grains are preferentially removed by photo-destruction
in the vicinity of the AGN. We find an overall suppression of the total PAH
emission relative to the ionized gas in the central 1 kpc region of the AGN in
NGC 7469 compared to what has been observed with Spitzer on 3 kpc scales.
However, the fractional 3.3 um to total PAH power is enhanced in the starburst
ring, possibly due to a variety of physical effects on sub-kpc scales,
including recurrent fluorescence of small grains or multiple photon absorption
by large grains. Finally, the IFU data show that while the 3.3 um PAH-derived
star formation rate (SFR) in the ring is 8% higher than that inferred from the
[NeII] and [NeIII] emission lines, the integrated SFR derived from the 3.3 um
feature would be underestimated by a factor of two due to the deficit of PAHs
around the AGN, as might occur if a composite system like NGC 7469 were to be
observed at high-redshift.Comment: 14 pages, 5 figures, 2 tables, Submitted to ApJ
Convergent genetic and expression data implicate immunity in Alzheimer's disease
Background
Late–onset Alzheimer's disease (AD) is heritable with 20 genes showing genome wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease we extended these genetic data in a pathway analysis.
Methods
The ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain.
Results
ALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (p = 3.27×10-12 after multiple testing correction for pathways), regulation of endocytosis (p = 1.31×10-11), cholesterol transport (p = 2.96 × 10-9) and proteasome-ubiquitin activity (p = 1.34×10-6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected p 0.002 – 0.05).
Conclusions
The immune response, regulation of endocytosis, cholesterol transport and protein ubiquitination represent prime targets for AD therapeutics
Post-Operative Functional Outcomes in Early Age Onset Rectal Cancer
Background: Impairment of bowel, urogenital and fertility-related function in patients treated for rectal cancer is common. While the rate of rectal cancer in the young (<50 years) is rising, there is little data on functional outcomes in this group. Methods: The REACCT international collaborative database was reviewed and data on eligible patients analysed. Inclusion criteria comprised patients with a histologically confirmed rectal cancer, <50 years of age at time of diagnosis and with documented follow-up including functional outcomes. Results: A total of 1428 (n=1428) patients met the eligibility criteria and were included in the final analysis. Metastatic disease was present at diagnosis in 13%. Of these, 40% received neoadjuvant therapy and 50% adjuvant chemotherapy. The incidence of post-operative major morbidity was 10%. A defunctioning stoma was placed for 621 patients (43%); 534 of these proceeded to elective restoration of bowel continuity. The median follow-up time was 42 months. Of this cohort, a total of 415 (29%) reported persistent impairment of functional outcomes, the most frequent of which was bowel dysfunction (16%), followed by bladder dysfunction (7%), sexual dysfunction (4.5%) and infertility (1%). Conclusion: A substantial proportion of patients with early-onset rectal cancer who undergo surgery report persistent impairment of functional status. Patients should be involved in the discussion regarding their treatment options and potential impact on quality of life. Functional outcomes should be routinely recorded as part of follow up alongside oncological parameters
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
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