1,046 research outputs found

    Inhalable neutralizing antibodies – promising approach to combating respiratory viral infections

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    Monoclonal antibodies represent an exciting class of therapeutics against respiratory viral infections. Notwithstanding their specificity and affinity, the conventional parenteral administration is suboptimal in delivering antibodies for neutralizing activity in the airways due to the poor distribution of macromolecules to the respiratory tract. Inhaled therapy is a promising approach to overcome this hurdle in a noninvasive manner, while advances in antibody engineering have led to the development of unique antibody formats which exhibit properties desirable for inhalation. In this Opinion, we examine the major challenges surrounding the development of inhaled antibodies, identify knowledge gaps that need to be addressed and provide strategies from a drug delivery perspective to enhance the efficacy and safety of neutralizing antibodies against respiratory viral infections

    Structural analysis and corrosion studies on an ISO 5832-9 biomedical alloy with TiO2 sol–gel layers

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    The aim of this study was to demonstrate the relationship between the structural and corrosion properties of an ISO 5832-9 biomedical alloy modified with titanium dioxide (TiO2) layers. These layers were obtained via the sol–gel method by acid-catalyzed hydrolysis of titanium isopropoxide in isopropanol solution. To obtain TiO2 layers with different structural properties, the coated samples were annealed at temperatures of 200, 300, 400, 450, 500, 600 and 800 C for 2 h. For all the prepared samples, accelerated corrosion measurements were performed in Tyrode’s physiological solution using electrochemical methods. The most important corrosion parameters were determined: corrosion potential, polarization resistance, corrosion rate, breakdown and repassivation potentials. Corrosion damage was analyzed using scanning electron microscopy. Structural analysis was carried out for selected TiO2 coatings annealed at 200, 400, 600 and 800 C. In addition, the morphology, chemical composition, crystallinity, thickness and density of the deposited TiO2 layers were determined using suitable electron and X-ray measurement methods. It was shown that the structure and character of interactions between substrate and deposited TiO2 layers depended on annealing temperature. All the obtained TiO2 coatings exhibit anticorrosion properties, but these properties are related to the crystalline structure and character of substrate–layer interaction. From the point of view of corrosion, the best TiO2 sol–gel coatings for stainless steel intended for biomedical applications seem to be those obtained at 400 C.This study was supported by Grant No. N N507 501339 of the National Science Centre. The authors wish to express their thanks to J. Borowski (MEDGAL, Poland) for the Rex 734 alloy

    Structural and bonding transformation of Al0.67CrCoCuFeNi high-entropy alloys during quenching

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    Structural and bonding transformation of the Al0.67CrCoFeNi high-entropy alloys (HEA) during&nbsp;quenching&nbsp;is investigated by molecular dynamics simulations. At a high cooling rate, some short-ranged ordered clusters, such as FCC, HCP and BCC&nbsp;crystalline&nbsp;clusters are already present in the almost amorphous HEAs. When the cooling rate decreases, the atoms become packed more orderly and ultimately form a nano-polycrystalline structure dominated by FCC structures. The BCC structures appear only as an intermediate state acting on the course of&nbsp;crystallization, while the HCP structure can be viewed as the precursor of the malposed FCC structure due to the identical first neighbor distances. In liquid HEAs, the low-symmetry and low-coordination bond pairs, either transform to high-symmetry and high-coordination 1551 bond pairs, or transform to 1(5,4)41 bond pairs for FCC structure and 1661 bond pairs for an HCP structure, depending on the cooling rates. This study will contribute to a better understanding of the essential phase change in HEAs.</p

    Sensorineural hearing loss after concurrent chemoradiotherapy in nasopharyngeal cancer patients

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    <p>Abstract</p> <p>Background</p> <p>Sensorineural hearing loss (SNHL) is one of the major long term side effects from radiation therapy (RT) in nasopharyngeal cancer (NPC) patients. This study aims to review the incidences of SNHL when treating with different radiation techniques. The additional objective is to determine the relationship of the SNHL with the radiation doses delivered to the inner ear.</p> <p>Methods</p> <p>A retrospective cohort study of 134 individual ears from 68 NPC patients, treated with conventional RT and IMRT in combination with chemotherapy from 2004-2008 was performed. Dosimetric data of the cochlea were analyzed. Significant SNHL was defined as > 15 dB increase in bone conduction threshold at 4 kHz and PTA (pure tone average of 0.5, 1, 2 kHz). Relative risk (RR) was used to determine the associated factors with the hearing threshold changes at 4 kHz and PTA.</p> <p>Results</p> <p>Median audiological follow up time was 14 months. The incidence of high frequency (4 kHz) SNHL was 44% for the whole group (48.75% in the conventional RT, 37% with IMRT). Internal auditory canal mean dose of > 50 Gy had shown a trend to increase the risk of high frequency SNHL (RR 2.02 with 95% CI 1.01-4.03, p = 0.047).</p> <p>Conclusion</p> <p>IMRT and radiation dose limitation to the inner ear appeared to decrease SNHL.</p

    A population study on the association between leisure time physical activity and self-rated health among diabetics in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>There is strong evidence for the beneficial effects of physical activity in diabetes. There has been little research demonstrating a dose-response relationship between physical activity and self-rated health in diabetics. The aim of this study was to explore the dose-response association between leisure time physical activity and self-rated health among diabetics in Taiwan.</p> <p>Methods</p> <p>Data came from the 2001 Taiwan National Health Interview Survey (NHIS). Inclusion criteria were a physician confirmed diagnosis of diabetes mellitus and age 18 years and above (n = 797). Self-rated health was assessed by the question "In general, would you say that your health is excellent, very good, good, fair, or poor?" Individuals with a self perceived health status of good, very good, or excellent were considered to have positive health status.</p> <p>Results</p> <p>In the full model, the odds ratio (OR) for positive health was 2.51(95% CI = 1.53-4.13), 1.62(95% CI = 0.93-2.84), and 1.35(95% CI = 0.77-2.37), for those with a total weekly energy expenditure of ≥ 1000 kcal, between 500 and 999 kcal, and between 1 and 499 kcal, respectively, compared to inactive individuals. Those with duration over 10 years (OR = 0.53, 95%CI = 0.30-0.94), heart disease (OR = 0.50, 95%CI = 0.30-0.85), and dyslipidemia (OR = 0.65, 95% CI = 0.43-0.98) were less likely to have positive health than their counterparts. After stratified participants by duration, those with a duration of diabetes < 6 years, the adjusted OR for positive health was 1.95(95% CI = 1.02-3.72), 1.22(95% CI = 0.59-2.52), and 1.19(95% CI = 0.58-2.41) for those with a total weekly energy expenditure of ≥ 1000 kcal, between 500 and 999 kcal, and between 1 and 499 kcal, respectively, compared to inactive individuals. In participants with a duration of diabetes ≥ 6 years, total energy expenditure showed a gradient effect on self-perceived positive health. The adjusted OR for positive health was 3.45(95% CI = 1.53-7.79), 2.77(95% CI = 1.11-6.92), and 1.90(95% CI = 0.73-4.94) for those with a total weekly energy expenditure of ≥ 1000 kcal, between 500 and 999 kcal, and between 1 and 499 kcal, respectively, compared to inactive individuals.</p> <p>Conclusions</p> <p>Our results highlight that regular leisure activity with an energy expenditure ≧ 500 kcal per week is associated with better self-rated health for those with longstanding diabetes.</p

    Decrease in the production of beta-amyloid by berberine inhibition of the expression of beta-secretase in HEK293 cells

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    <p>Abstract</p> <p>Background</p> <p>Berberine (BER), the major alkaloidal component of <it>Rhizoma coptidis</it>, has multiple pharmacological effects including inhibition of acetylcholinesterase, reduction of cholesterol and glucose levels, anti-inflammatory, neuroprotective and neurotrophic effects. It has also been demonstrated that BER can reduce the production of beta-amyloid<sub>40/42</sub>, which plays a critical and primary role in the pathogenesis of Alzheimer's disease. However, the mechanism by which it accomplishes this remains unclear.</p> <p>Results</p> <p>Here, we report that BER could not only significantly decrease the production of beta-amyloid<sub>40/42 </sub>and the expression of beta-secretase (BACE), but was also able to activate the extracellular signal-regulated kinase1/2 (ERK1/2) pathway in a dose- and time-dependent manner in HEK293 cells stably transfected with APP695 containing the Swedish mutation. We also find that U0126, an antagonist of the ERK1/2 pathway, could abolish (1) the activation activity of BER on the ERK1/2 pathway and (2) the inhibition activity of BER on the production of beta-amyloid<sub>40/42 </sub>and the expression of BACE.</p> <p>Conclusion</p> <p>Our data indicate that BER decreases the production of beta-amyloid<sub>40/42 </sub>by inhibiting the expression of BACE via activation of the ERK1/2 pathway.</p
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