Immune escape mutants of highly pathogenic avian influenza H5N1 selected using polyclonal sera: Identification of key amino acids in the HA protein

Evolution of Avian Influenza (AI) viruses – especially of the Highly Pathogenic Avian Influenza (HPAI) H5N1 subtype – is a major issue for the poultry industry. HPAI H5N1 epidemics are associated with huge economic losses and are sometimes connected to human morbidity and mortality. Vaccination (either as a preventive measure or as a means to control outbreaks) is an approach that splits the scientific community, due to the risk of it being a potential driving force in HPAI evolution through the selection of mutants able to escape vaccination-induced immunity. It is therefore essential to study how mutations are selected due to immune pressure. To this effect, we performed an in vitro selection of mutants from HPAI A/turkey/Turkey/1/05 (H5N1), using immune pressure from homologous polyclonal sera. After 42 rounds of selection, we identified 5 amino acid substitutions in the Haemagglutinin (HA) protein, most of which were located in areas of antigenic importance and suspected to be prone to selection pressure. We report that most of the mutations took place early in the selection process. Finally, our antigenic cartography studies showed that the antigenic distance between the selected isolates and their parent strain increased with passage number

Size distribution and sources of trace metals and n-alkanes in the Athens urban aerosol during summer

Size-resolved, 24-h aerosol samples were collected from June-July 2001 by means of an Andersen high-volume cascade impactor. Sampling was conducted in a central avenue (Patission) characterised by heavy traffic, 21 m above street level, in the Athens city centre. Samples were analysed by atomic absorption spectrometry and gas chromatography to determine the size distribution of nine metallic elements (Cd, Pb, V, Ni, Mn, Cr, Cu, Fe, Al) and n-alkanes (with carbon numbers in the range 18-35). The aerosol mass median diameter (MMD) was calculated by means of probit analysis on the cumulative mass concentration size distribution for each metals and n-alkane. The total n-alkane mass concentration (TNA) in total suspended particles (TSP) ranged from 72 to 1506 ng m-3 while the total metal concentration ranged from 5.6 to 28.6 μg m-3. The results showed that metals such as Cd, V and Ni are characterised by a MMD <1 μm, while the MMD for Pb and Mn are ∼1 μm. Such metals are generally considered to have anthropogenic emission sources. Other metals such as Al, Fe, Cu and Cr were found to have MMD=2-6 μm, which generally originate from soil dust or mechanical abrasion processes. The Carbon number profile of n-alkane compounds showed a strong anthropogenic source with only a minor biogenic influence. The concentration of most n-alkanes was characterised by high variability during the sampling period, in contrast to the concentration of most trace metals. Most n-alkanes had a unimodal size distribution with MMD=1-2 μm similar to those of some trace metals (Pb, Mn), which originate mostly from vehicle emissions. This is a strong indication that these species have a common source. Finally, gas-particle partitioning of n-alkanes was also examined for different particle sizes by means of the relationship between the partition constant Kp and saturation vapour pressure (pL0) as proposed by current sorption models. © 2006 Elsevier Ltd. All rights reserved.Peer reviewe

Size distribution and sources of trace metals and n-alkanes in the Athens urban aerosol during summer

Size-resolved, 24-h aerosol samples were collected from June-July 2001 by means of an Andersen high-volume cascade impactor. Sampling was conducted in a central avenue (Patission) characterised by heavy traffic, 21 in above street level, in the Athens city centre. Samples were analysed by atomic absorption spectrometry and gas chromatography to determine the size distribution of nine metallic elements (Cd, Pb, V, Ni, Mn, Cr, Cu, Fe, Al) and n-alkanes (with carbon numbers in the range 18-35). The aerosol mass median diameter (MMD) was calculated by means of probit analysis on the cumulative mass concentration size distribution for each metals and n-alkane. The total n-alkane mass concentration (TNA) in total suspended particles (TSP) ranged from 72 to 1506 ng m(-3) while the total metal concentration ranged from 5.6 to 28.6 mu g m(-3). The results showed that metals such as Cd, V and Ni are characterised by a MMD &lt; 1 mu m, while the MMD for Pb and Mn are similar to 1 mu m. Such metals are generally considered to have anthropogenic emission sources. Other metals such as Al, Fe, Cu and Cr were found to have MMD = 2-6 mu m, which generally originate from soil dust or mechanical abrasion processes. The Carbon number profile of n-alkane compounds showed a strong anthropogenic source with only a minor biogenic influence. The concentration of most n-alkanes was characterised by high variability during the sampling period, in contrast to the concentration of most trace metals. Most n-alkanes had a unimodal size distribution with MMD = 1-2 mu m similar to those of some trace metals (Pb, Mn), which originate mostly from vehicle emissions. This is a strong indication that these species have a common source. Finally, gas-particle partitioning of n-alkanes was also examined for different particle sizes by means of the relationship between the partition constant K-p and saturation vapour pressure (p(L)(0)) as proposed by current sorption models. (c) 2006 Elsevier Ltd. All rights reserved

Cardiovascular Risk and Serum Hyaluronic Acid: A Preliminary Study in a Healthy Population of Low/Intermediate Risk

Background: Hyaluronic acid (HA) has been found to be an important trigger of atherosclerosis. In this study, we investigate the possible association of serum HA with cardiovascular disease risk in a population of low/intermediate risk for cardiovascular events. Methods: We enrolled 200 subjects with low/intermediate risk for developing cardiovascular disease. High specific C-reactive protein (hsCRP) was used as an indicator of preclinical atherosclerosis. The Framingham score was used to calculate the cardiovascular risk. Results: Participants with dyslipidemia had significantly higher levels of serum HA than those without dyslipidemia (t-test, P = 0.05), higher levels of hsCRP (Kruskal–Wallis test, P = 0.04), and higher cardiovascular risk according to the Framingham score (Kruskal–Wallis test, P = 0.05). Serum HA concentration correlated significantly with the Framingham score for risk for coronary heart disease over the next 10 years (Spearman r = 0.152, P = 0.02). Diabetic volunteers had significantly higher HA than those without diabetes (t-test, P = 0.02). Participants with metabolic syndrome had higher serum HA levels and higher hsCRP (Kruskal–Wallis test, P = 0.01) compared to volunteers without metabolic syndrome (t-test, P = 0.03). Conclusions: Serum HA should be explored as an early marker of atheromatosis and cardiovascular risk. © 2016 Wiley Periodicals, Inc

Role of vaccination-induced immunity and antigenic distance in the transmission of highly pathogenic avian influenza H5N1.

Highly pathogenic avian influenza (HPAI) H5N1 epidemics in poultry causehuge economic losses as well as sporadic human morbidity and mortality.Vaccination in poultry has often been reported as being ineffective in preventingtransmission and as a potential driving force in the selection of immuneescape mutants.We conducted transmission experiments to evaluate the transmissiondynamics of HPAI H5N1 strains in chickens vaccinated with high andlow doses of immune escape mutants we have previously selected, and analysedthe data using mathematical models. Remarkably, we demonstratethat the effect of antigenic distances between the vaccine and challenge strainsused in this study is too small to influence the transmission dynamics of thestrains used. This is because the effect of a sufficient vaccine dose on antibodylevels against the challenge viruses is large enough to compensate for anydecrease in antibody titres due to antigenic differences between vaccine andchallenge strains. Our results showthat at least under experimental conditions,vaccination will remain effective even after antigenic changes as may becaused by the initial selection in vaccinated birds

Hyaluronic acid and hyaluronidase as possible novel urine biomarkers for the diagnosis of prostate cancer

The goal of the study is to examine the possible use of HA (hyaluronic acid) and HAase (hyaluronidase) as novel urine biomarkers for the early diagnosis for prostate cancer (Pca). After a prostatic massage, the urine of 118 high-risk patients for Pca was collected, and the patients were submitted to ultrasound-guided transrectal biopsy. HA and HAase were detected and analyzed with Enzyme-Linked Immunosorbent Assay, and a statistical analysis of the urine levels of the two biomarkers according to the histology results was performed. HAase and HA were independently associated with Pca, and both HAase and HA showed significant predictive ability for prostate cancer. With an optimal cut-off point of 183.71 HAase had 70% sensitivity maintaining at the same time a 55.2% specificity, while the optimal cut-off point for HA was 50.13 with 65% sensitivity and 53.9% specificity. Patients with HAase more than 183.71 ng/ml had 3.67 times greater likelihood for prostate cancer and Patients with HA more than 50.13 ng/ml had 2.31 times greater likelihood for prostate cancer. The need of novel biomarkers that will improve the efficacy of PSA is urgent. HAase and HA showed significant predictive ability for prostate cancer and were independently associated with Pca, and greater levels were associated with greater odds for prostate cancer. To Our Knowledge, this is the first study referring to the detection of HAase and HA as potential urine biomarkers for the early diagnosis of Pca. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

Role of vaccination-induced immunity and antigenic distance in the transmission of highly pathogenic avian influenza H5N1.

Highly pathogenic avian influenza (HPAI) H5N1 epidemics in poultry cause<br/>huge economic losses as well as sporadic human morbidity and mortality.<br/>Vaccination in poultry has often been reported as being ineffective in preventing<br/>transmission and as a potential driving force in the selection of immune<br/>escape mutants.We conducted transmission experiments to evaluate the transmission<br/>dynamics of HPAI H5N1 strains in chickens vaccinated with high and<br/>low doses of immune escape mutants we have previously selected, and analysed<br/>the data using mathematical models. Remarkably, we demonstrate<br/>that the effect of antigenic distances between the vaccine and challenge strains<br/>used in this study is too small to influence the transmission dynamics of the<br/>strains used. This is because the effect of a sufficient vaccine dose on antibody<br/>levels against the challenge viruses is large enough to compensate for any<br/>decrease in antibody titres due to antigenic differences between vaccine and<br/>challenge strains. Our results showthat at least under experimental conditions,<br/>vaccination will remain effective even after antigenic changes as may be<br/>caused by the initial selection in vaccinated birds

Treatment with cinacalcet in hemodialysis patients with severe secondary hyperparathyroidism, influences bone mineral metabolism and anemia parameters

Background: Due to the premium rate of Chronic Kidney Disease, we have increased our knowledge with respect to diagnosis and treatment of Bone Mineral Disease (BMD) in End-Stage Renal Disease (ESRD). Currently, various treatment options are available. The medication used for Secondary Hyper-Parathyroidism gives promising results in the regulation of Ca, P and Parathormone levels, improving the quality of life. The aim of the present study was to investigate the relation of cinacalcet administration to not only parathormone, Ca and P but also to anemia parameters such as hematocrit and hemoglobin. Materials and Methods: A retrospective observational study was conducted in a Chronic Hemodialysis Unit. One-hundred ESRD patients were recruited for twenty-four months and were evaluated on a monthly rate. Biochemical parameters were related to medication prescribed and the prognostic value was estimated. Cinacalcet was administered to 43 out of 100 patients in a dose of 30-120 mg. Results: Significant differences were observed in PTH, Ca and P levels with respect to Cinacalcet administration. Ca levels appeared to be higher at 30mg as compared to 60mg cinacalcet. Furthermore, a decreasing age-dependent pattern was observed with respect to cinacalcet dosage. A positive correlation was observed between dry weight (DW) and cinacalcet dose. Finally, a positive correlation between Hematocrit and Hemoglobin and cinacalcet was manifested. Conclusions: Cinacalcet, is a potential cardiovascular and bone protective agent, which is approved for use in ESRD patients to assist SHPT. A novel information was obtained from this study, regarding the improvement of the control of anemia. © 2020 Bentham Science Publishers

Alpha 2-adrenergic receptors decrease DNA replication and cell proliferation and induce neurite outgrowth in transfected rat pheochromocytoma cells

Alpha 2-adrenergic receptors (α2-ARs) have a widespread distribution in the central nervous system (CNS) and affect a number of biochemical and behavioral functions, including stimulation of prefrontal cortex (PFC) and cognitive function. In addition to its role as a classical neurotransmitter, norepinephrine (NE) has been recently shown to exert an important influence on the plasticity in areas of the brain where neurogenesis persists in the adult, notably the subgranular zone (SGZ) within the dentate gyrus of the hippocampus and the olfactory bulb (OB). In regulating adult neurogenesis, the noradrenergic system is functionally integrated with chronic stress and depression. Chronic stress, depression, or depletion of NE in vivo suppress, and antidepressant treatments induce hippocampal neurogenesis by down- or upregulating, respectively, cell proliferation. In the present study we show that α2-AR subtypes promote the differentiation rather than cell proliferation of PC12 cells. It is conceivable that α2-ARs might contribute neurotrophic actions in vivo synergistically or in permutation with other neurotrophic factors. © 2006 New York Academy of Sciences

Detecting Novel Urine Biomarkers for the Early Diagnosis of Prostate Cancer: Platelet Derived Growth Factor-BB as a Possible New Target

Introduction: Although the prostate specific antigen revolutionized the diagnosis of prostate cancer (PCa), it has its limitations. We prospectively examined the potential use of the platelet-derived growth factor-BB (PDGF-BB) as a urine biomarker for the early diagnosis of PCa. Materials and Methods: The urine samples of 118 patients were collected after a prostatic massage and all the patients subsequently underwent ultrasound-guided transrectal biopsy. PDGF-BB was detected in the urine by enzyme-linked immunosorbent assay. Results: Patients with PCa had greater levels of prostate specific antigen and PDGF-BB. Receiver operating characteristic curve analysis showed that the optimal cut-of of PDGF-BB for the prediction of PCa was 1,504.9 with a sensitivity of 60% and a specificity of 51.3%. For a 100 unit increase in PDGF-BB, the likelihood for PCa increased about 4%. Conclusion: PDGF-BB showed a significant predictive ability for PCa. Detection of PDGF-BB in urine with Elisa was easy and improved our diagnostic accuracy in the diagnosis of PCa. © 2018 2018 The Author(s) Published by S. Karger AG, Basel