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This paper presents the influence of pH on the activity and stability of an extracellular chitin deacetylase produced by Absidia orchidis. It showed the highest activity at pH 4.0 and was most stable at pH 9.5. In addition, there was pH deactivation that could be described by first-order irreversible kinetics. The pH deactivation rate constant changed linearly with pH in the range from 4.0 to 9.0. [ABSTRACT FROM AUTHOR]

The aim of the presented work was to evaluate the effect of modification of titanium dioxide nanoparticles with noble metals and their oxides on selected mammalian cells. The in vitro cytotoxicity studies of titanium dioxide (TiO2) nanoparticles modified with Au, Ag, Pd, Ag2O, and PdO with reference to the unmodified TiO2 nanoparticles were presented. The evaluation of cytotoxic activity of the tested nanocomposite particles was carried out using three cell lines: Caco‐2 colorectal epithelial adenocarcinoma cells, BJ normal human skin fibroblasts, and L929 mouse fibroblasts. The in vitro studies included determination of cell viability after 24 and 48 hours of exposure to the nanocomposite particles, using the MTT assay, as well as flow cytometry with Annexin V‐FITC staining. Our results indicate that irrespectively of the kind of cell line and assay used, nanoparticles of unmodified titanium dioxide as well as those with addition of gold and palladium have a slight impact on cell viability at the investigated concentration range (10‐200 μg/mL). Nanoparticles with addition of silver (Ag and Ag2O), were found to have significantly higher toxic effect, the level of which varied depending on the cell line and assay used. [ABSTRACT FROM AUTHOR]

Objective: With a microcomputed tomography (microCT) imaging device, we aimed to quantitatively evaluate root canal fillings after commonly used endodontic procedures and also tested the suitability of microCT for this purpose. Materials and Methods: Eighty single roots were instrumented and obturated with gutta-percha and Tubli-Seal. They were divided into 4 groups of 20. The Hand groups were instrumented with hand files and filled with thermoplastic (Th) compaction and cold lateral (CL) condensation, i.e. Hand-Th and Hand-CL, respectively. The Rot groups, i.e. Rot-Th and Rot-CL, were instrumented with a rotary ProFile system and filled as above. The roots were scanned and 3-dimensional (3D) visualization was obtained. The number, size, percentage of volume and distribution of voids at the filling/dentine interface (i-voids) and voids surrounded by filling material (s-voids) were measured. Results: Canal fillings differed significantly with regard to the size of both types of voids and the average number of i-voids. All canals presented a low volume of voids. The highest percentage (0.69%) was found for i-voids in the Hand-CL group, while the lowest volume (0.11% for s-voids and 0.14% for i-voids) was in the Hand-Th canals. Apically, in the last 3 mm, i-voids were observed mainly in the Th groups, and s-voids occurred mostly in the coronal part of the canal filling in all cases. Conclusion: MicroCT was a useful tool for 3D quantitative evaluations of these root canal fillings. None of the root canal instrumentation and filling methods ensured void-free obturation. CL condensation produced mainly i-voids. With Th compaction, internal s-voids were particularly common, but there were mainly i-voids in the apical part. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Determination of the plasma amino acid (AA) levels in Huntington's disease (HD) can make it possible to find the metabolic markers used in early diagnosis. The aim of the presented study was to determine the AA profile in plasma samples from HD patients and presymptomatic carriers, compared to healthy subjects. The AA profile was analyzed with HPLC. The study concerned 59 participants: 30 subjects with abnormal CAG repeats expansion (>36) in the HTT gene, and 29 healthy subjects. Each participant was analyzed with regard to the parameters characterizing the metabolic state and protein metabolism, such as: urea, creatinine, glucose, total protein, TSH (thyroid-stimulating hormone), cortisol, ESR (erythrocyte sedimentation rate), and CRP (C-reactive protein). Simple statistical comparisons showed 5 AA to be significantly lower in the HD group, compared to the control group, i.e.: Asn, His, Leu, Ser, Thr. Creatinine and creatinine clirens were found to be lower in the HD group, compared to controls, while ESR was noticed to be higher. As a result of Canonical Discriminant Analysis, 5 of all AA assayed (Leu, Gln, Asn, Ser and Lys) were selected as variables that allow distinguishing between HD patients and healthy subjects with 75% of correctness. Concerning AA profile and biochemical markers, Canonical Discriminant Analysis detected a panel of variables (Ser, Asn, Gln, Orn, Pro, Arg, Met, Cit, Val, TSH, glucose, urea, creatinine clirens, total protein, cortisol, CRP) distinguishing HD from the control group, with 90% of correctness. Among all the parameters tested, Asn and Ser were revealed in all statistical analyses and could be considered as potential plasma HD biomarkers.

The formation of oil/water (O/W) nano-emulsions suitable for cosmeceutical application was studied. Nano-emulsions were prepared by using phase inversion composition (PIC) method, one of the low-energy emulsification methods. The process consist of stepwise water addition to oil/surfactant mixture, at T = 25°C. Caprylic/capric triglycerides (GTCC), propylene glycol dicaprylate/dicaprate (PC) and oleic acid (OA) were applied as an oil phase. Polysorbate 80 was used as the surfactant. Kinetic stability of the nano-emulsions was analyzed by measuring droplet size as a function of time for different oil/surfactant ratio. The particles size distribution was analyzed by means DLS measurement technique (Dynamic Light Scattering), using Zetasizer Nano ZS (Malvern Instruments, UK). One of triterpenoic acid, practically non-water soluble substance was selected as an active and incorporated into the stable formulation. The obtained results proved that the nanoemulsion NE-T80-GTCC-20:80 based on caprylic/capric triglycerides with the oil/surfactant ratio O/S = 2 0:80 and the droplet size r = 25 nm was the most stable one and additionally showed the highest solubilisation capacity for the triterpene.

High-performance liquid chromatography (HPLC) is a technique most frequently used for the assessment of biologically active peptides. Owing to the ionic character of these compounds, they may also be separated and assayed using capillary electrophoresis (CE), which offers very high efficiency, short analysis time and low consumption of reagents, and is used increasingly more often. The paper describes the combination of HPLC and CE in order to increase the efficiency of the separation of complex mixture of peptides (active substance and its related impurities). The developed two-dimensional HPLC-CE technique was employed for the analysis of the impurities of octreotide, a cyclic octapeptide used in therapy. Because distinct separation mechanisms are used, the two-dimensional technique ensures higher separation efficiency and a more comprehensive impurity profile of the medicinal product than either of the techniques used separately.

Dentists at work are susceptible to the development of health disorders. Bad working habits, repetitive tasks and uncomfortable posture contribute to musculoskeletal disorders (MSDs), stress and loss of production. The paper deals with the assessment of health status among dentists in Poland regarding the symptoms of musculoskeletal pain. The survey was conducted among 220 dentists. The questionnaire was concerned with demographic details, work duration and acquired specialization, organization and methods of work in the surgery, and also disorders connected with the musculoskeletal system and physical prophylactic activity. It was found that over 92% of the surveyed dentists experienced MSDs, especially in the neck (47%) and lower back (35%). More than 29% of the dentists experienced trouble with fingers, 23% with hip, whereas 20% demonstrated problems in the midback, and also in the shoulders (20%). Pain in the wrists was reported by 18.3%, and pain in the knees, feet or elbows by 15-16% of respondents. Statistical dependence was shown between the years of practice and the period of time when disorders occurred. Moreover, significance relationships were found between MSDs and both standing work position and non-use of rest breaks. It was concluded that limited ergonomics in the work environment of dentists results in MSDs, and its prevalence is very high. The symptoms of MSDs increased with the number of years of practice.

Currently, glutamine is thought to be conditionally indispensable amino acid. However, the use of glutamine in clinical practice encounters serious problems related to its limited solubility and instability in water solutions. Therefore, glutamine-containing dipeptides, which have better solubility and stability in the solution, have been introduced into the medical practice. High concentration of L-alanyl-L-glutamine in the medicinal product and thermal sterilization during the manufacturing process are the reasons of many impurities formation--the products of deamidation, racemization, cyclization etc.. The purpose of the study was to develop a single step CE method that could be applied in the purity control of L-alanyl-L-glutamine containing parenteral infusions instead of three routinely used LC methods. After systematic optimization separation conditions were selected: 100 mM borate buffer at pH 8.5 with 0.4 mM diaminopropane as EOF modifier. The method developed allows the separation and determination of the main component and the related impurities. The results show that the method is suitable for quality control of glutamine dipeptide solutions offering some advantages over routinely used LC methods.