Performance of Tablet Splitters, Crushers, and Grinders in Relation to Personalised Medication with Tablets

Swallowing problems and the required dose adaptations needed to obtain optimal pharmacotherapy may be a hurdle in the use of tablets in daily clinical practice. Tablet splitting, crushing, or grinding is often applied to personalise medication, especially for the elderly and children. In this study, the performance of different types of (commercially available) devices was studied. Included were splitters, screwcap crushers, manual grinders, and electric grinders. Unscored tablets without active ingredient were prepared, with a diameter of 9 and 13 mm and a hardness of 100–220 N. Tablets were split into two parts and the difference in weight was measured. The time needed to pulverise the tablets (crush time) was recorded. The residue remaining in the device (loss) was measured. The powder was sieved to obtain a particle fraction >600 µm and <600 µm. The median particle size and particle size distribution of the later fraction were determined using laser diffraction analysis. Splitting tablets into two equal parts appeared to be difficult with the devices tested. Most screwcap grinders yielded a coarse powder containing larger chunks. Manual and especially electric grinders produced a finer powder, making it suitable for administration via an enteral feeding tube as well as for use in individualised preparations such as capsules. In conclusion, for domestic and incidental use, a screwcap crusher may provide sufficient size reduction, while for the more demanding regular use in hospitals and nursing residences, a manual or electric grinder is preferred

Export of functional Streptomyces coelicolor alditol oxidase to the periplasm or cell surface of Escherichia coli and its application in whole-cell biocatalysis

Streptomyces coelicolor A3(2) alditol oxidase (AldO) is a soluble monomeric flavoprotein in which the flavin cofactor is covalently linked to the polypeptide chain. AldO displays high reactivity towards different polyols such as xylitol and sorbitol. These characteristics make AldO industrially relevant, but full biotechnological exploitation of this enzyme is at present restricted by laborious and costly purification steps. To eliminate the need for enzyme purification, this study describes a whole-cell AldO biocatalyst system. To this end, we have directed AldO to the periplasm or cell surface of Escherichia coli. For periplasmic export, AldO was fused to endogenous E. coli signal sequences known to direct their passenger proteins into the SecB, signal recognition particle (SRP), or Twin-arginine translocation (Tat) pathway. In addition, AldO was fused to an ice nucleation protein (INP)-based anchoring motif for surface display. The results show that Tat-exported AldO and INP-surface-displayed AldO are active. The Tat-based system was successfully employed in converting xylitol by whole cells, whereas the use of the INP-based system was most likely restricted by lipopolysaccharide LPS in wild-type cells. It is anticipated that these whole-cell systems will be a valuable tool for further biological and industrial exploitation of AldO and other cofactor-containing enzymes.

Carboxylic ester hydrolases from hyperthermophiles

Carboxylic ester hydrolyzing enzymes constitute a large group of enzymes that are able to catalyze the hydrolysis, synthesis or transesterification of an ester bond. They can be found in all three domains of life, including the group of hyperthermophilic bacteria and archaea. Esterases from the latter group often exhibit a high intrinsic stability, which makes them of interest them for various biotechnological applications. In this review, we aim to give an overview of all characterized carboxylic ester hydrolases from hyperthermophilic microorganisms and provide details on their substrate specificity, kinetics, optimal catalytic conditions, and stability. Approaches for the discovery of new carboxylic ester hydrolases are described. Special attention is given to the currently characterized hyperthermophilic enzymes with respect to their biochemical properties, 3D structure, and classification

Novel tools for extraction and validation of disease-related mutations applied to Fabry disease.

Contains fulltext : 87210.pdf (publisher's version ) (Closed access)Genetic disorders are often caused by nonsynonymous nucleotide changes in one or more genes associated with the disease. Specific amino acid changes, however, can lead to large variability of phenotypic expression. For many genetic disorders this results in an increasing amount of publications describing phenotype-associated mutations in disorder-related genes. Keeping up with this stream of publications is essential for molecular diagnostics and translational research purposes but often impossible due to time constraints: there are simply too many articles to read. To help solve this problem, we have created Mutator, an automated method to extract mutations from full-text articles. Extracted mutations are crossreferenced to sequence data and a scoring method is applied to distinguish false-positives. To analyze stored and new mutation data for their (potential) effect we have developed Validator, a Web-based tool specifically designed for DNA diagnostics. Fabry disease, a monogenetic gene disorder of the GLA gene, was used as a test case. A structure-based sequence alignment of the alpha-amylase superfamily was used to validate results. We have compared our data with existing Fabry mutation data sets obtained from the HGMD and Swiss-Prot databases. Compared to these data sets, Mutator extracted 30% additional mutations from the literature.1 september 201

Rewriting the Script: The Story of Vitamin C and the Epigenome

Vitamin C is a vital micronutrient in the maintenance of numerous cellular functions and the development of mammalian systems. Vitamin C predominantly exists physiologically as the ascorbate anion, an antioxidant classically linked to the prevention of scurvy. Current research has shown that ascorbate plays an additional role critical in DNA demethylation by acting as a cofactor for the ten-eleven translocation (TET) family of methylcytosine dioxygenase enzymes. TET enzymes hydroxylate 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), an epigenetic marker whose further processing results in cleavage of the methylated cytosine and subsequent repair via the base excision repair pathway, resulting in completion of active DNA demethylation. Recent work has also speculated ascorbate’s role in mediating histone demethylation dynamics via Jumonji C domain (JmjC) demethylase enzymes belonging to the same enzyme family as TET dioxygenases. Although these roles in demethylation are of principal importance, the need for ascorbate initially evolved in early photosynthetic eukaryotes who required a reducing agent to protect themselves from photodamage generated by the chloroplast, a role that ultimately affected the evolutionary paths of insects and herbivorous animals. Altogether, the wide-reaching functions of ascorbate play a critical role in the maintenance of mammalian demethylation dynamics and organismal development