561 research outputs found
Lack of benefits for prevention of cardiovascular disease with aspirin therapy in type 2 diabetic patients - a longitudinal observational study
<p>Abstract</p> <p>Background</p> <p>The risk-benefit ratio of aspirin therapy in prevention of cardiovascular disease (CVD) remains contentious, especially in type 2 diabetes. This study examined the benefit and harm of low-dose aspirin (daily dose < 300 mg) in patients with type 2 diabetes.</p> <p>Methods</p> <p>This is a longitudinal observational study with primary and secondary prevention cohorts based on history of CVD at enrolment. We compared the occurrence of primary composite (non-fatal myocardial infarction or stroke and vascular death) and secondary endpoints (upper GI bleeding and haemorrhagic stroke) between aspirin users and non-users between January 1995 and July 2005.</p> <p>Results</p> <p>Of the 6,454 patients (mean follow-up: median [IQR]: 4.7 [4.4] years), usage of aspirin was 18% (n = 1,034) in the primary prevention cohort (n = 5731) and 81% (n = 585) in the secondary prevention cohort (n = 723). After adjustment for covariates, in the primary prevention cohort, aspirin use was associated with a hazard-ratio of 2.07 (95% CI: 1.66, 2.59, p < 0.001) for primary endpoint. There was no difference in CVD event rate in the secondary prevention cohort. Overall, aspirin use was associated with a hazard-ratio of 2.2 (1.53, 3.15, p < 0.001) of GI bleeding and 1.71 (1.00, 2.95, p = 0.051) of haemorrhagic stroke. The absolute risk of aspirin-related GI bleeding was 10.7 events per 1,000 person-years of treatment.</p> <p>Conclusion</p> <p>In Chinese type 2 diabetic patients, low dose aspirin was associated with a paradoxical increase in CVD risk in primary prevention and did not confer benefits in secondary prevention. In addition, the risk of GI bleeding in aspirin users was rather high.</p
SPARC independent drug delivery and antitumour effects of nab-paclitaxel in genetically engineered mice.
DESIGN: Pharmacokinetic and pharmacodynamic parameters of cremophor-paclitaxel, nab-paclitaxel (human-albumin-bound paclitaxel, Abraxane) and a novel mouse-albumin-bound paclitaxel (m-nab-paclitaxel) were evaluated in genetically engineered mouse models (GEMMs) by liquid chromatography-tandem mass spectrometry (LC-MS/MS), histological and biochemical analysis. Preclinical evaluation of m-nab-paclitaxel included assessment by three-dimensional high-resolution ultrasound and molecular analysis in a novel secreted protein acidic and rich in cysteine (SPARC)-deficient GEMM of pancreatic ductal adenocarcinoma (PDA). RESULTS: nab-Paclitaxel exerted its antitumoural effects in a dose-dependent manner and was associated with less toxicity compared with cremophor-paclitaxel. SPARC nullizygosity in a GEMM of PDA, Kras(G12D);p53(flox/-);p48Cre (KPfC), resulted in desmoplastic ductal pancreas tumours with impaired collagen maturation. Paclitaxel concentrations were significantly decreased in SPARC null plasma samples and tissues when administered as low-dose m-nab-paclitaxel. At the maximally tolerated dose, SPARC deficiency did not affect the intratumoural paclitaxel concentration, stromal deposition and the immediate therapeutic response. CONCLUSIONS: nab-Paclitaxel accumulates and acts in a dose-dependent manner. The interaction of plasma SPARC and albumin-bound drugs is observed at low doses of nab-paclitaxel but is saturated at therapeutic doses in murine tumours. Thus, this study provides important information for future preclinical and clinical trials in PDA using nab-paclitaxel in combination with novel experimental and targeted agents
Expansion of a novel endogenous retrovirus throughout the pericentromeres of modern humans
Abstract
Background
Approximately 8% of the human genome consists of sequences of retroviral origin, a result of ancestral infections of the germ line over millions of years of evolution. The most recent of these infections is attributed to members of the human endogenous retrovirus type-K (HERV-K) (HML-2) family. We recently reported that a previously undetected, large group of HERV-K (HML-2) proviruses, which are descendants of the ancestral K111 infection, are spread throughout human centromeres.
Results
Studying the genomes of certain cell lines and the DNA of healthy individuals that seemingly lack K111, we discover new HERV-K (HML-2) members hidden in pericentromeres of several human chromosomes. All are related through a common ancestor, termed K222, which is a virus that infected the germ line approximately 25 million years ago. K222 exists as a single copy in the genomes of baboons and high order primates, but not New World monkeys, suggesting that progenitor K222 infected the primate germ line after the split between New and Old World monkeys. K222 exists in modern humans at multiple loci spread across the pericentromeres of nine chromosomes, indicating it was amplified during the evolution of modern humans.
Conclusions
Copying of K222 may have occurred through recombination of the pericentromeres of different chromosomes during human evolution. Evidence of recombination between K111 and K222 suggests that these retroviral sequences have been templates for frequent cross-over events during the process of centromere recombination in humans.http://deepblue.lib.umich.edu/bitstream/2027.42/111301/1/13059_2015_Article_641.pd
Hyaluronan impairs vascular function and drug delivery in a mouse model of pancreatic cancer.
OBJECTIVE: Pancreatic ductal adenocarcinoma (PDA) is characterised by stromal desmoplasia and vascular dysfunction, which critically impair drug delivery. This study examines the role of an abundant extracellular matrix component, the megadalton glycosaminoglycan hyaluronan (HA), as a novel therapeutic target in PDA. METHODS: Using a genetically engineered mouse model of PDA, the authors enzymatically depleted HA by a clinically formulated PEGylated human recombinant PH20 hyaluronidase (PEGPH20) and examined tumour perfusion, vascular permeability and drug delivery. The preclinical utility of PEGPH20 in combination with gemcitabine was assessed by short-term and survival studies. RESULTS: PEGPH20 rapidly and sustainably depleted HA, inducing the re-expansion of PDA blood vessels and increasing the intratumoral delivery of two chemotherapeutic agents, doxorubicin and gemcitabine. Moreover, PEGPH20 triggered fenestrations and interendothelial junctional gaps in PDA tumour endothelia and promoted a tumour-specific increase in macromolecular permeability. Finally, combination therapy with PEGPH20 and gemcitabine led to inhibition of PDA tumour growth and prolonged survival over gemcitabine monotherapy, suggesting immediate clinical utility. CONCLUSIONS: The authors demonstrate that HA impedes the intratumoral vasculature in PDA and propose that its enzymatic depletion be explored as a means to improve drug delivery and response in patients with pancreatic cancer
The inwardly rectifying K+ channel KIR7.1 controls uterine excitability throughout pregnancy
Abnormal uterine activity in pregnancy causes a range of important clinical disorders, including preterm birth, dysfunctional labour and post-partum haemorrhage. Uterine contractile patterns are controlled by the generation of complex electrical signals at the myometrial smooth muscle plasma membrane. To identify novel targets to treat conditions associated with uterine dysfunction, we undertook a genome-wide screen of potassium channels that are enriched in myometrial smooth muscle. Computational modelling identified Kir7.1 as potentially important in regulating uterine excitability during pregnancy. We demonstrate Kir7.1 current hyper-polarizes uterine myocytes and promotes quiescence during gestation. Labour is associated with a decline, but not loss, of Kir7.1 expression. Knockdown of Kir7.1 by lentiviral expression of miRNA was sufficient to increase uterine contractile force and duration significantly. Conversely, overexpression of Kir7.1 inhibited uterine contractility. Finally, we demonstrate that the Kir7.1 inhibitor VU590 as well as novel derivative compounds induces profound, long-lasting contractions in mouse and human myometrium; the activity of these inhibitors exceeds that of other uterotonic drugs. We conclude Kir7.1 regulates the transition from quiescence to contractions in the pregnant uterus and may be a target for therapies to control uterine contractility
A detailed Hapmap of the Sitosterolemia locus spanning 69 kb; differences between Caucasians and African-Americans
BACKGROUND: Sitosterolemia is an autosomal recessive disorder that maps to the sitosterolemia locus, STSL, on human chromosome 2p21. Two genes, ABCG5 and ABCG8, comprise the STSL and mutations in either cause sitosterolemia. ABCG5 and ABCG8 are thought to have evolved by gene duplication event and are arranged in a head-to-head configuration. We report here a detailed characterization of the STSL in Caucasian and African-American cohorts. METHODS: Caucasian and African-American DNA samples were genotypes for polymorphisms at the STSL locus and haplotype structures determined for this locus RESULTS: In the Caucasian population, 13 variant single nucleotide polymorphisms (SNPs) were identified and resulting in 24 different haplotypes, compared to 11 SNPs in African-Americans resulting in 40 haplotypes. Three polymorphisms in ABCG8 were unique to the Caucasian population (E238L, INT10-50 and G575R), whereas one variant (A259V) was unique to the African-American population. Allele frequencies of SNPs varied also between these populations. CONCLUSION: We confirmed that despite their close proximity to each other, significantly more variations are present in ABCG8 compared to ABCG5. Pairwise D' values showed wide ranges of variation, indicating some of the SNPs were in strong linkage disequilibrium (LD) and some were not. LD was more prevalent in Caucasians than in African-Americans, as would be expected. These data will be useful in analyzing the proposed role of STSL in processes ranging from responsiveness to cholesterol-lowering drugs to selective sterol absorption
Interaction of short modified peptides deriving from glycoprotein gp36 of feline immunodeficiency virus with phospholipid membranes
A tryptophan-rich octapeptide, C8 (Ac-Trp-Glu-Asp-Trp-Val-Gly-Trp-Ile-NH2), modelled on the membrane-proximal external region of the feline immunodeficiency virus (FIV) gp36 glycoprotein ectodomain, exhibits potent antiviral activity against FIV. A mechanism has been proposed by which the peptide, being positioned on the surface of the cell membrane, inhibits its fusion with the virus. In the present work, peptide–lipid interactions of C8 with dimyristoyl phosphatidylcholine liposomes are investigated using electron spin resonance spectroscopy of spin-labelled lipids. Three other peptides, obtained from modifications of C8, have also been investigated, in an attempt to clarify the essential molecular features of the interactions involving the tryptophan residues. The results show that C8 adsorbs strongly on the bilayer surface. Membrane binding requires not only the presence of the Trp residues in the sequence, but also their common orientation on one side of the peptide that is engendered by the WX2 WX2 W motif. Membrane interaction correlates closely with peptide antiviral activity, indicating that the membrane is essential in stabilizing the peptide conformation that will be able to inhibit viral infection
Digital IAPT: the effectiveness & cost-effectiveness of internet-delivered interventions for depression and anxiety disorders in the Improving Access to Psychological Therapies programme: study protocol for a randomised control trial
BACKGROUND: Depression and anxiety are common mental health disorders worldwide. The UK's Improving Access to Psychological Therapies (IAPT) programme is part of the National Health Service (NHS) designed to provide a stepped care approach to treating people with anxiety and depressive disorders. Cognitive Behavioural Therapy (CBT) is widely used, with computerised and internet-delivered cognitive behavioural therapy (cCBT and iCBT, respectively) being a suitable IAPT approved treatment alternative for step 2, low- intensity treatment. iCBT has accumulated a large empirical base for treating depression and anxiety disorders. However, the cost-effectiveness and impact of these interventions in the longer-term is not routinely assessed by IAPT services. The current study aims to evaluate the clinical and cost-effectiveness of internet-delivered interventions for symptoms of depression and anxiety disorders in IAPT. METHODS: The study is a parallel-groups, randomised controlled trial examining the effectiveness and cost-effectiveness of iCBT interventions for depression and anxiety disorders, against a waitlist control group. The iCBT treatments are of 8 weeks duration and will be supported by regular post-session feedback by Psychological Wellbeing Practitioners. Assessments will be conducted at baseline, during, and at the end of the 8-week treatment and at 3, 6, 9, and 12-month follow-up. A diagnostic interview will be employed at baseline and 3-month follow-up. Participants in the waitlist control group will complete measures at baseline and week 8, at which point they will receive access to the treatment. All adult users of the Berkshire NHS Trust IAPT Talking Therapies Step 2 services will be approached to participate and measured against set eligibility criteria. Primary outcome measures will assess anxiety and depressive symptoms using the GAD-7 and PHQ-9, respectively. Secondary outcome measures will allow for the evaluation of long-term outcomes, mediators and moderators of outcome, and cost-effectiveness of treatment. Analysis will be conducted on a per protocol and intention-to-treat basis. DISCUSSION: This study seeks to evaluate the immediate and longer-term impact, as well as the cost effectiveness of internet-delivered interventions for depression and anxiety. This study will contribute to the already established literature on internet-delivered interventions worldwide. The study has the potential to show how iCBT can enhance service provision, and the findings will likely be generalisable to other health services. TRIAL REGISTRATION: Current Controlled Trials ISRCTN ISRCTN91967124. DOI: https://doi.org/10.1186/ISRCTN91967124 . Web: http://www.isrctn.com/ISRCTN91967124 . Clinicaltrials.gov : NCT03188575. Trial registration date: June 8, 2017 (prospectively registered)
Exogenous Administration of Recombinant MIF at Physiological Concentrations Failed to Attenuate Infarct Size in a Langendorff Perfused Isolated Mouse Heart Model
Trends and predictions of malnutrition and obesity in 204 countries and territories: an analysis of the Global Burden of Disease Study 2019.
BackgroundMalnutrition and obesity are interdependent pathologies along the same spectrum. We examined global trends and projections of disability-adjusted life years (DALYs) and deaths from malnutrition and obesity until 2030.MethodsUsing data from the 2019 Global Burden of Disease study involving 204 countries and territories, trends in DALYs and deaths were described for obesity and malnutrition from 2000 to 2019, stratified by geographical regions (as defined by WHO) and Socio-Demographic Index (SDI). Malnutrition was defined according to the 10th revision of International Classification of Diseases codes for nutritional deficiencies, stratified by malnutrition type. Obesity was measured via body mass index (BMI) using metrics related to national and subnational estimates, defined as BMI ≥25 kg/m2. Countries were stratified into low, low-middle, middle, high-middle, and high SDI bands. Regression models were constructed to predict DALYs and mortality up to 2030. Association between age-standardised prevalence of the diseases and mortality was also assessed.FindingsIn 2019, age-standardised malnutrition-related DALYs was 680 (95% UI: 507-895) per 100,000 population. DALY rates decreased from 2000 to 2019 (-2.86% annually), projected to fall 8.4% from 2020 to 2030. Africa and low SDI countries observed highest malnutrition-related DALYs. Age-standardised obesity-related DALY estimates were 1933 (95% UI: 1277-2640). Obesity-related DALYs rose 0.48% annually from 2000 to 2019, predicted to increase by 39.8% from 2020 to 2030. Highest obesity-related DALYs were in Eastern Mediterranean and middle SDI countries.InterpretationThe ever-increasing obesity burden, on the backdrop of curbing the malnutrition burden, is predicted to rise further.FundingNone
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