283 research outputs found

    Nanoparticle-based 3D membrane for impedimetric biosensor applications

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    This paper reports on a comparison between nano-ZnO/CuO and nano-ZnO nitrocellulose membrane biosensors, both of which were fabricated using a simple and inexpensive sonication technique. To produce the nano-ZnO/CuO membranes, the technique involved sonication of 1% (w/v) ZnO and 1% (w/v) CuO nano-crystal colloidal suspensions, with a volume ratio of 1:2. The membranes were analysed by scanning electron microscopy and energy-dispersive spectroscopy, which showed the gradated distribution of nanoparticles in the membrane. Impedance spectroscopy demonstrated that the sonication resulted in a greater than two-fold enhancement of the output signal. Changes in impedance phase values, at a frequency of 100 Hz, were used to establish dose dependent responses for C-reactive protein (CRP). Limits of detection of 27 pg/mL for the 1% (w/v) nano-ZnO and 16 pg/mL for the 1% (w/v) nano-ZnO/CuO nitrocellulose membrane biosensors were demonstrated

    A genome-wide association study of the frailty index highlights brain pathways in ageing

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    Frailty is a common geriatric syndrome and strongly associated with disability, mortality and hospitalization. Frailty is commonly measured using the frailty index (FI), based on the accumulation of a number of health deficits during the life course. The mechanisms underlying FI are multifactorial and not well understood, but a genetic basis has been suggested with heritability estimates between 30 and 45%. Understanding the genetic determinants and biological mechanisms underpinning FI may help to delay or even prevent frailty. We performed a genome-wide association study (GWAS) meta-analysis of a frailty index in European descent UK Biobank participants (n = 164,610, 60–70 years) and Swedish TwinGene participants (n = 10,616, 41–87 years). FI calculation was based on 49 or 44 self-reported items on symptoms, disabilities and diagnosed diseases for UK Biobank and TwinGene, respectively. 14 loci were associated with the FI (p < 5*10−8). Many FI-associated loci have established associations with traits such as body mass index, cardiovascular disease, smoking, HLA proteins, depression and neuroticism; however, one appears to be novel. The estimated single nucleotide polymorphism (SNP) heritability of the FI was 11% (0.11, SE 0.005). In enrichment analysis, genes expressed in the frontal cortex and hippocampus were significantly downregulated (adjusted p < 0.05). We also used Mendelian randomization to identify modifiable traits and exposures that may affect frailty risk, with a higher educational attainment genetic risk score being associated with a lower degree of frailty. Risk of frailty is influenced by many genetic factors, including well-known disease risk factors and mental health, with particular emphasis on pathways in the brain

    Circulating Tumor Cell Transcriptomics as Biopsy Surrogates in Metastatic Breast Cancer

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    BACKGROUND Metastatic breast cancer (MBC) and the circulating tumor cells (CTCs) leading to macrometastases are inherently different than primary breast cancer. We evaluated whether whole transcriptome RNA-Seq of CTCs isolated via an epitope-independent approach may serve as a surrogate for biopsies of macrometastases. METHODS We performed RNA-Seq on fresh metastatic tumor biopsies, CTCs, and peripheral blood (PB) from 19 newly diagnosed MBC patients. CTCs were harvested using the ANGLE Parsortix microfluidics system to isolate cells based on size and deformability, independent of a priori knowledge of cell surface marker expression. RESULTS Gene expression separated CTCs, metastatic biopsies, and PB into distinct groups despite heterogeneity between patients and sample types. CTCs showed higher expression of immune oncology targets compared with corresponding metastases and PB. Predictive biomarker (n = 64) expression was highly concordant for CTCs and metastases. Repeat observation data post-treatment demonstrated changes in the activation of different biological pathways. Somatic single nucleotide variant analysis showed increasing mutational complexity over time. CONCLUSION We demonstrate that RNA-Seq of CTCs could serve as a surrogate biomarker for breast cancer macrometastasis and yield clinically relevant insights into disease biology and clinically actionable targets

    Offspring's Leukocyte Telomere Length, Paternal Age, and Telomere Elongation in Sperm

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    Leukocyte telomere length (LTL) is a complex genetic trait. It shortens with age and is associated with a host of aging-related disorders. Recent studies have observed that offspring of older fathers have longer LTLs. We explored the relation between paternal age and offspring's LTLs in 4 different cohorts. Moreover, we examined the potential cause of the paternal age on offspring's LTL by delineating telomere parameters in sperm donors. We measured LTL by Southern blots in Caucasian men and women (n=3365), aged 18–94 years, from the Offspring of the Framingham Heart Study (Framingham Offspring), the NHLBI Family Heart Study (NHLBI-Heart), the Longitudinal Study of Aging Danish Twins (Danish Twins), and the UK Adult Twin Registry (UK Twins). Using Southern blots, Q-FISH, and flow-FISH, we also measured telomere parameters in sperm from 46 young (<30 years) and older (>50 years) donors. Paternal age had an independent effect, expressed by a longer LTL in males of the Framingham Offspring and Danish Twins, males and females of the NHLBI-Heart, and females of UK Twins. For every additional year of paternal age, LTL in offspring increased at a magnitude ranging from half to more than twice of the annual attrition in LTL with age. Moreover, sperm telomere length analyses were compatible with the emergence in older men of a subset of sperm with elongated telomeres. Paternal age exerts a considerable effect on the offspring's LTL, a phenomenon which might relate to telomere elongation in sperm from older men. The implications of this effect deserve detailed study

    SIK2 inhibition enhances PARP inhibitor activity synergistically in ovarian and triple-negative breast cancers

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    Poly(ADP-ribose) polymerase inhibitors (PARP inhibitors) have had an increasing role in the treatment of ovarian and breast cancers. PARP inhibitors are selectively active in cells with homologous recombination DNA repair deficiency caused by mutations in BRCA1/2 and other DNA repair pathway genes. Cancers with homologous recombination DNA repair proficiency respond poorly to PARP inhibitors. Cancers that initially respond to PARP inhibitors eventually develop drug resistance. We have identified salt-inducible kinase 2 (SIK2) inhibitors, ARN3236 and ARN3261, which decreased DNA double-strand break (DSB) repair functions and produced synthetic lethality with multiple PARP inhibitors in both homologous recombination DNA repair deficiency and proficiency cancer cells. SIK2 is required for centrosome splitting and PI3K activation and regulates cancer cell proliferation, metastasis, and sensitivity to chemotherapy. Here, we showed that SIK2 inhibitors sensitized ovarian and triple-negative breast cancer (TNBC) cells and xenografts to PARP inhibitors. SIK2 inhibitors decreased PARP enzyme activity and phosphorylation of class-IIa histone deacetylases (HDAC4/5/7). Furthermore, SIK2 inhibitors abolished class-IIa HDAC4/5/7–associated transcriptional activity of myocyte enhancer factor-2D (MEF2D), decreasing MEF2D binding to regulatory regions with high chromatin accessibility in FANCD2, EXO1, and XRCC4 genes, resulting in repression of their functions in the DNA DSB repair pathway. The combination of PARP inhibitors and SIK2 inhibitors provides a therapeutic strategy to enhance PARP inhibitor sensitivity for ovarian cancer and TNBC

    Targeting Protein Homeostasis in Sporadic Inclusion Body Myositis

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    Sporadic inclusion body myositis (sIBM) is the commonest severe myopathy in patients over age 50. Previous therapeutic trials have targeted the inflammatory features of sIBM, but all have failed. Since protein dyshomeostasis may also play a role in sIBM, we tested the effects of targeting this feature of the disease. Using rat myoblast cultures, we found that up-regulation of the heat shock response with Arimoclomol reduced key pathological markers of sIBM in vitro. Furthermore, in mutant valosin-containing protein VCP mice, which develop an inclusion body myopathy (IBM), treatment with Arimoclomol ameliorated disease pathology and improved muscle function. We therefore evaluated the safety and tolerability of Arimoclomol in an investigator-lead, randomised, double-blind, placebo-controlled, proof-of-concept patient trial and gathered exploratory efficacy data which showed that Arimoclomol was safe and well tolerated. Although Arimoclomol improved some IBM-like pathology in vitro and in vivo in the mutant VCP mouse, we did not see statistically significant evidence of efficacy in this proof of concept patient trial

    Impact on birth weight and child growth of Participatory Learning and Action women's groups with and without transfers of food or cash during pregnancy: Findings of the low birth weight South Asia cluster-randomised controlled trial (LBWSAT) in Nepal.

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    BACKGROUND: Undernutrition during pregnancy leads to low birthweight, poor growth and inter-generational undernutrition. We did a non-blinded cluster-randomised controlled trial in the plains districts of Dhanusha and Mahottari, Nepal to assess the impact on birthweight and weight-for-age z-scores among children aged 0-16 months of community-based participatory learning and action (PLA) women's groups, with and without food or cash transfers to pregnant women. METHODS: We randomly allocated 20 clusters per arm to four arms (average population/cluster = 6150). All consenting married women aged 10-49 years, who had not had tubal ligation and whose husbands had not had vasectomy, were monitored for missed menses. Between 29 Dec 2013 and 28 Feb 2015 we recruited 25,092 pregnant women to surveillance and interventions: PLA alone (n = 5626); PLA plus food (10 kg/month of fortified wheat-soya 'Super Cereal', n = 6884); PLA plus cash (NPR750≈US$7.5/month, n = 7272); control (existing government programmes, n = 5310). 539 PLA groups discussed and implemented strategies to improve low birthweight, nutrition in pregnancy and hand washing. Primary outcomes were birthweight within 72 hours of delivery and weight-for-age z-scores at endline (age 0-16 months). Only children born to permanent residents between 4 June 2014 and 20 June 2015 were eligible for intention to treat analyses (n = 10936), while in-migrating women and children born before interventions had been running for 16 weeks were excluded. Trial status: completed. RESULTS: In PLA plus food/cash arms, 94-97% of pregnant women attended groups and received a mean of four transfers over their pregnancies. In the PLA only arm, 49% of pregnant women attended groups. Due to unrest, the response rate for birthweight was low at 22% (n = 2087), but response rate for endline nutritional and dietary measures exceeded 83% (n = 9242). Compared to the control arm (n = 464), mean birthweight was significantly higher in the PLA plus food arm by 78·0 g (95% CI 13·9, 142·0; n = 626) and not significantly higher in PLA only and PLA plus cash arms by 28·9 g (95% CI -37·7, 95·4; n = 488) and 50·5 g (95% CI -15·0, 116·1; n = 509) respectively. Mean weight-for-age z-scores of children aged 0-16 months (average age 9 months) sampled cross-sectionally at endpoint, were not significantly different from those in the control arm (n = 2091). Differences in weight for-age z-score were as follows: PLA only -0·026 (95% CI -0·117, 0·065; n = 2095); PLA plus cash -0·045 (95% CI -0·133, 0·044; n = 2545); PLA plus food -0·033 (95% CI -0·121, 0·056; n = 2507). Amongst many secondary outcomes tested, compared with control, more institutional deliveries (OR: 1.46 95% CI 1.03, 2.06; n = 2651) and less colostrum discarding (OR:0.71 95% CI 0.54, 0.93; n = 2548) were found in the PLA plus food arm but not in PLA alone or in PLA plus cash arms. INTERPRETATION: Food supplements in pregnancy with PLA women's groups increased birthweight more than PLA plus cash or PLA alone but differences were not sustained. Nutrition interventions throughout the thousand-day period are recommended. TRIAL REGISTRATION: ISRCTN75964374

    Generation and bioenergetic analysis of cybrids containing mitochondrial DNA from mouse skeletal muscle during aging

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    Mitochondrial respiratory chain defects have been associated with various diseases and normal aging, particularly in tissues with high energy demands including skeletal muscle. Muscle-specific mitochondrial DNA (mtDNA) mutations have also been reported to accumulate with aging. Our understanding of the molecular processes mediating altered mitochondrial gene expression to dysfunction associated with mtDNA mutations in muscle would be greatly enhanced by our ability to transfer muscle mtDNA to established cell lines. Here, we report the successful generation of mouse cybrids carrying skeletal muscle mtDNA. Using this novel approach, we performed bioenergetic analysis of cells bearing mtDNA derived from young and old mouse skeletal muscles. A significant decrease in oxidative phosphorylation coupling and regulation capacity has been observed with cybrids carrying mtDNA from skeletal muscle of old mice. Our results also revealed decrease growth capacity and cell viability associated with the mtDNA derived from muscle of old mice. These findings indicate that a decline in mitochondrial function associated with compromised mtDNA quality during aging leads to a decrease in both the capacity and regulation of oxidative phosphorylation
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