274 research outputs found

    Strain elastography for noninvasive assessment of liver fibrosis: A prospective study with histological comparison

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    The aim of this study was to prospectively evaluate the diagnostic performance of strain elastography for the assessment of liver fibrosis in patients with chronic liver disease using Ishak (0–6) histology stage as a reference standard. Ninety-eight consecutive patients with suspected chronic liver disease scheduled for liver biopsy (n = 78) or histologically confirmed cirrhosis (n = 20) were enrolled. Liver fibrosis Index (LF Index) calculated by strain elastography, liver stiffness by transient elastography and serum fibrosis markers (aspartate aminotransferase-to-platelet ratio index and King’s Score) were measured. Spearman’s correlation coefficient between the LF Index, liver stiffness, serum fibrosis markers and fibrosis stage were calculated and compared using areas under the receiver-operating characteristics (AUROCs) curves. Among 73 patients who underwent strain elastography, there was weak correlation between fibrosis stage and the LF Index (Spearman’s: ρ = 0.385 for Ishak score; P = 0.001). Among 52 patients who underwent strain elastography and transient elastography, the AUROC values using LF Index, transient elastography, aspartate aminotransferase-to-platelet ratio index and King’s Score for diagnosing significant fibrosis (Ishak score ≥ 3) were 0.79, 0.87, 0.86 and 0.85, respectively (P < 0.0001) and for diagnosing severe fibrosis/cirrhosis (Ishak score ≥ 5) were 0.83, 0.94, 0.92 and 0.92, respectively (P < 0.0001). When comparing the diagnostic performance using LF Index, transient elastography, aspartate aminotransferase-to-platelet ratio index and King’s Score, transient elastography shows a significantly higher AUROC value than LF Index in detecting severe fibrosis (P = 0.0149). The diagnostic performance of LF Index calculated by strain elastography was not statistically significantly different to the other noninvasive tests for the assessment of significant liver fibrosis but inferior to transient elastography for the assessment of severe fibrosis/cirrhosis

    Reducing the Number of Measurements in Liver Point Shear-Wave Elastography: Factors that Influence the Number and Reliability of Measurements in Assessment of Liver Fibrosis in Clinical Practice

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    PURPOSE: To identify the minimum number of measurements required for the noninvasive assessment of liver fibrosis by using point shear-wave elastography (pSWE) and determine whether the use of a reliability indicator such as interquartile range [IQR]–to-median ratio will affect diagnostic performance. MATERIALS AND METHODS: Ten liver shear-wave velocity (SWV) measurements by pSWE were obtained in 232 participants. Interclass correlation coefficients (ICC) between the median of the first two through the first nine measurements and all 10 measurements were calculated; the minimum number of measurements with ICC greater than 0.95 versus all 10 measurements was determined. The diagnostic performance of the minimum number of measurements and 10 measurements in identifying significant (Ishak stage, ≥3) and severe fibrosis or cirrhosis (Ishak stage, ≥5) was compared by using areas under the receiver operating characteristic curve. These were compared between measurements that demonstrated higher or lower reliability (IQR-to-median ratio of ≤ 30% and IQR-to-median ratio of > 30%, respectively). RESULTS: Compared with 10 measurements, a minimum of six SWV measurements was required. The overall area under the curve for diagnosing significant (areas under the receiver operating characteristic curve, 0.828 vs 0.839; P = .487) and severe fibrosis or cirrhosis (0.953 vs 0.969, respectively; P = .145) did not differ according to number of measurements (six vs 10); a median of six measurements resulted in only limited disagreement (nine of 232 [3.9%]) versus histologic evaluation. When using 10 measurements, higher reliability measurements showed a lower percentage of discordance between pSWE and significant fibrosis and severe fibrosis or cirrhosis (22 [14.7%] and three [2.0%] of 150 cases, respectively) compared with lower reliability measurements (26 [31.7%] and eight [9.8%] of 82 cases, respectively). Significant fibrosis was an independent predictor for lower reliability (hazard ratio, 2.22; P < .020). CONCLUSION: A limited number of SWV measurements (median six vs median 10) were required for the assessment of liver fibrosis by using pSWE. The number of measurements had less influence on the diagnostic accuracy compared with lower reliability measurements

    Effects of external irradiation of the neck region on intima media thickness of the common carotid artery

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    <p>Abstract</p> <p>Background</p> <p>Several studies have shown that common carotid intima-media thickness (IMT) is increased after radiotherapy (RT) to the head and neck. However, further studies are needed to define the exact mechanism of radiation-induced injury in large vessels, investigate the relationship between radiation dose and large vessel injury and evaluate the rate of progress of atherosclerosis in irradiated vessels.</p> <p>Objectives</p> <p>To investigate whether external irradiation to the carotid area has any effect on IMT of the common carotid artery in a group of patients who received RT vs control group matched for age, gender and race.</p> <p>Methods</p> <p>We studied 19 patients (10 male; 47.8 ± 17.4 years) during a 5-month period (January 2009-July 2009); they had completed RT with a mean of 2.9 years before (range: 1 month-6 years) The mean radiation dose to the neck in the irradiated patients was 41.2 ± 15.6 Gy (range: 25-70 Gy). Common carotid IMT was measured with echo-color Doppler. Nineteen healthy adult patients (10 male; 47.8 ± 17.6) were recruited as a control group.</p> <p>Results</p> <p>IMT was not significantly higher in patients when compared to the control group (0.59 ± 0.16 vs 0.56 ± 0.16 mm, p = 0.4). There was no significant difference between the two groups in relation to the absence (p = 0.7) or presence (p = 0.6) of vascular risk factors. Although the difference did not reach statistical significance (p = 0.1), the irradiated young patients (age ≤ 52 years) had IMT measurements higher (0.54 ± 0.08 mm) than the non-irradiated young patients (0.49 ± 0.14 mm). The mean carotid IMT increased with increasing doses of radiation to the neck (p = 0.04).</p> <p>Conclusion</p> <p>This study shows that increased IMT of the common carotid artery after RT is radiation-dose-related. Therefore it is important to monitor IMT, which can be used as an imaging biomarker for early diagnosis of cerebrovascular disease in patients who have had radiotherapy for treatment of cancer of the head and neck and who are at increased risk for accelerated atherosclerosis in carotid arteries.</p

    Globally prevalent PfMDR1 mutations modulate Plasmodium falciparum susceptibility to artemisinin-based combination therapies

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    Antimalarial chemotherapy, globally reliant on artemisinin-based combination therapies (ACTs), is threatened by the spread of drug resistance in Plasmodium falciparum parasites. Here we use zinc-finger nucleases to genetically modify the multidrug resistance-1 transporter PfMDR1 at amino acids 86 and 184, and demonstrate that the widely prevalent N86Y mutation augments resistance to the ACT partner drug amodiaquine and the former first-line agent chloroquine. In contrast, N86Y increases parasite susceptibility to the partner drugs lumefantrine and mefloquine, and the active artemisinin metabolite dihydroartemisinin. The PfMDR1 N86 plus Y184F isoform moderately reduces piperaquine potency in strains expressing an Asian/African variant of the chloroquine resistance transporter PfCRT. Mutations in both digestive vacuole-resident transporters are thought to differentially regulate ACT drug interactions with host haem, a product of parasite-mediated haemoglobin degradation. Global mapping of these mutations illustrates where the different ACTs could be selectively deployed to optimize treatment based on regional differences in PfMDR1 haplotypes.This work was funded in part by the National Institutes of Health (R01 AI50234, AI124678 and AI109023) and a Burroughs Wellcome Fund Investigator in Pathogenesis of Infectious Diseases award to D.A.F. This research also received funding from the Portuguese Fundacao para a Ciencia e Tecnologia (FCT), cofunded by Programa Operacional Regional do Norte (ON.2-O Novo Norte); from the Quadro de Referencia Estrategico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and from the Projeto Estrategico - LA 26 - 2013-2014 (PEst-C/SAU/LA0026/2013). M.I.V. is the recipient of a postdoctoral fellowship from FCT/Ministerio da Ciencia e Ensino Superior, Portugal-MCES (SFRH/BPD/76614/2011). A.M.L. was supported by an Australian National Health and Medical Research Council (NHMRC) Overseas Biomedical Fellowship (585519). R.E.M. was supported by an NHMRC RD Wright Biomedical Fellowship (1053082). A.C.U. was supported by an Irving scholarship from Columbia University. We thank Dr Andrea Ecker for her help with plasmid design and Pedro Ferreira for his expert help with Fig. 6.info:eu-repo/semantics/publishedVersio

    The EFSUMB Guidelines and Recommendations for the Clinical Practice of Elastography in Non-Hepatic Applications: Update 2018

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    This manuscript describes the use of ultrasound elastography, with the exception of liver applications, and represents an update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography

    Subjects with Molecularly Defined Familial Hypercholesterolemia or Familial Defective apoB-100 Are Not Being Adequately Treated

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    To study whether subjects with a molecular genetic diagnosis of familial hypercholesterolemia (FH) or familial defective apoB-100 (FDB) are being adequately treated.A questionnaire regarding medical history was sent to 2611 subjects who had been provided with a molecular genetic diagnosis of FH or FDB, and a blood sample was obtained for lipid measurements.956 (36.6%) of the 2611 subjects participated. The mean age for starting lipid-lowering therapy was 33.4 (±12.1) years. Among those below 18 years of age, only 20.4% were on lipid-lowering drugs, whereas 89.1% of those aged 18 and above were on lipid-lowering drugs. The mean levels of total serum cholesterol and LDL-cholesterol were 5.7 (±1.5) mmol/l and 3.9 (±1.3) mmol/l, respectively. Among those who were on lipid-lowering drugs, 29.0% and 12.2% had levels of LDL cholesterol below 3.0 mmol/l and 2.6 mmol/l, respectively. Only 47.3% of the 956 subjects were considered as being adequately treated largely due to a failure to titrate their drug regimens. From the use of cholesterol-years score, lipid-lowering therapy must start before the age of 20 in order to prevent the subjects from contracting premature coronary heart disease.The majority of FH/FDB subjects are being diagnosed late in life and are not being adequately treated. In order to prevent them from contracting premature coronary heart disease, it is key that levels of LDL cholesterol are normalized from a young age and that sufficient doses of lipid-lowering drugs are being used

    Hexahydroquinolines are antimalarial candidates with potent blood-stage and transmission-blocking activity

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    Hexahydroquinolines are antimalarial candidates with potent blood-stage and transmission-blocking activityAntimalarial compounds with dual therapeutic and transmission-blocking activity are desired as high-value partners for combination therapies. Here, we report the identification and characterization of hexahydroquinolines (HHQs) that show low nanomolar potency against both pathogenic and transmissible intra-erythrocytic forms of the malaria parasite Plasmodium falciparum. This activity translates into potent transmission-blocking potential, as shown by in vitro male gamete formation assays and reduced oocyst infection and prevalence in Anopheles mosquitoes. In vivo studies illustrated the ability of lead HHQs to suppress Plasmodium berghei blood-stage parasite proliferation. Resistance selection studies, confirmed by CRISPR-Cas9-based gene editing, identified the digestive vacuole membrane-spanning transporter PfMDR1 (P. falciparum multidrug resistance gene-1) as a determinant of parasite resistance to HHQs. Haemoglobin and haem fractionation assays suggest a mode of action that results in reduced haemozoin levels and might involve inhibition of host haemoglobin uptake into intra-erythrocytic parasites. Furthermore, parasites resistant to HHQs displayed increased susceptibility to several first-line antimalarial drugs, including lumefantrine, confirming that HHQs have a different mode of action to other antimalarials drugs for which PfMDR1 is known to confer resistance. This work evokes therapeutic strategies that combine opposing selective pressures on this parasite transporter as an approach to countering the emergence and transmission of multidrug-resistant P. falciparum malaria.The authors thank T.T. Diagana (Novartis Institute for Tropical Diseases, Singapore) for provision of the compounds, the Red Cross (Australia and the USA) for the provision of human blood for cell cultures, and G. Stevenson for assistance with the triaging of compounds following screening. The authors acknowledge the Bill and Melinda Gates Foundation (grant OPP1040399 to D.A.F. and V.M.A. and grant OPP1054480 to E.A.W. and D.A.F.), the National Institutes of Health (grant R01 AI103058 to E.A.W. and D.A.F., grant R01 AI50234 to D.A.F, and R01 AI110329 to T.J.E.), the Australian Research Council (LP120200557 to V.M.A.) and the Medicines for Malaria Venture for their continued support. P.E.F. and M.I.V. are supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER).info:eu-repo/semantics/publishedVersio

    Azithromycin-chloroquine and the intermittent preventive treatment of malaria in pregnancy

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    In the high malaria-transmission settings of sub-Saharan Africa, malaria in pregnancy is an important cause of maternal, perinatal and neonatal morbidity. Intermittent preventive treatment of malaria in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) reduces the incidence of low birth-weight, pre-term delivery, intrauterine growth-retardation and maternal anaemia. However, the public health benefits of IPTp are declining due to SP resistance. The combination of azithromycin and chloroquine is a potential alternative to SP for IPTp. This review summarizes key in vitro and in vivo evidence of azithromycin and chloroquine activity against Plasmodium falciparum and Plasmodium vivax, as well as the anticipated secondary benefits that may result from their combined use in IPTp, including the cure and prevention of many sexually transmitted diseases. Drug costs and the necessity for external financing are discussed along with a range of issues related to drug resistance and surveillance. Several scientific and programmatic questions of interest to policymakers and programme managers are also presented that would need to be addressed before azithromycin-chloroquine could be adopted for use in IPTp

    The Tyrphostin Agent AG490 Prevents and Reverses Type 1 Diabetes in NOD Mice

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    <div><h3>Background</h3><p>Recent studies in the NOD (non-obese diabetic) mouse model of type 1 diabetes (T1D) support the notion that tyrosine kinase inhibitors have the potential for modulating disease development. However, the therapeutic effects of AG490 on the development of T1D are unknown.</p> <h3>Materials and Methods</h3><p>Female NOD mice were treated with AG490 (i.p, 1 mg/mouse) or DMSO starting at either 4 or 8 week of age, for five consecutive week, then once per week for 5 additional week. Analyses for the development and/or reversal of diabetes, insulitis, adoptive transfer, and other mechanistic studies were performed.</p> <h3>Results</h3><p>AG490 significantly inhibited the development of T1D (p = 0.02, p = 0.005; at two different time points). Monotherapy of newly diagnosed diabetic NOD mice with AG490 markedly resulted in disease remission in treated animals (n = 23) in comparision to the absolute inability (0%; 0/10, p = 0.003, Log-rank test) of DMSO and sustained eugluycemia was maintained for several months following drug withdrawal. Interestingly, adoptive transfer of splenocytes from AG490 treated NOD mice failed to transfer diabetes to recipient NOD.<em>Scid</em> mice. CD4 T-cells as well as bone marrow derived dendritic cells (BMDCs) from AG490 treated mice, showed higher expression of Foxp3 (p<0.004) and lower expression of co-stimulatory molecules, respectively. Screening of the mouse immune response gene arrary indicates that expression of costimulaotry molecule Ctla4 was upregulated in CD4+ T-cell in NOD mice treated with AG490, suggesting that AG490 is not a negative regulator of the immune system.</p> <h3>Conclusion</h3><p>The use of such agents, given their extensive safety profiles, provides a strong foundation for their translation to humans with or at increased risk for the disease.</p> </div
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