Human Platelet Lysate for Good Manufacturing Practice-Compliant Cell Production

Numerous cell-based therapeutics are currently being tested in clinical trials. Human platelet lysate (HPL) is a valuable alternative to fetal bovine serum as a cell culture medium supplement for a variety of different cell types. HPL as a raw material permits animal serum-free cell propagation with highly efficient stimulation of cell proliferation, enabling humanized manufacturing of cell therapeutics within a reasonable timeframe. Providers of HPL have to consider dedicated quality issues regarding identity, purity, potency, traceability and safety. Release criteria have to be defined, characterizing the suitability of HPL batches for the support of a specific cell culture. Fresh or expired platelet concentrates from healthy blood donors are the starting material for HPL preparation, according to regulatory requirements. Pooling of individual platelet lysate units into one HPL batch can balance donor variation with regard to essential platelet-derived growth factors and cytokines. The increasingly applied pathogen reduction technologies will further increase HPL safety. In this review article, aspects and regulatory requirements of whole blood donation and details of human platelet lysate manufacturing are presented. International guidelines for raw materials are discussed, and defined quality controls, as well as release criteria for safe and GMP-compliant HPL production, are summarized.     

The inhibition by naphthoquinones and anthraquinones of 2-amino-3-methylimidazo[4,5-f ]quinoline metabolic activation to a mutagen: a structure-activity relationship study

 Nine naphthoquinones, 19 anthraquinones, and nine structurally related monoketonic compounds such as anthrone, xanthone, etc., inhibited mutagenicity induced by 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in Salmonella typhimurium TA 98 in the presence of rat liver S9 with distinct structure-activity relationships. A carbonyl function was a prerequisite for antimutagenicity while, in general, anthraquinones (IC₅₀ values: 2.3–>213 nmol/ml top agar) were more potent antimutagens than structurally related monoketonic compounds (IC₅₀ values: 25.3–94.9 nmol/ml top agar) and naphthoquinones (IC₅₀ values: 3.7–90.7 nmol/ml top agar). The parent compounds and methyl substituted derivatives were already the most potent while introduction of polar substituents such as COOH and SO₃H considerably reduced antimutagenicity. Introduction of OH functions had equivocal effects: with increasing numbers, antimutagenic potencies were concomitantly reduced; however, anthraflavic acid, chrysazin, quinizarin, and especially 5,8-dihydroxy-1,4-naphthoquinone were more potent than the parent compounds. The patterns of inhibition by quinones of 7-ethoxyresorufin-O-dealkylase activities in rat liver microsomes, linked to cytochrome P-450-dependent oxidation of IQ to N-hydroxy-IQ (N-OH-IQ), were in general identical with those obtained in the Salmonella/reversion assay except for chrysophanic acid, emodin, and some naphthoquinones which were very potent in this assay (IC₅₀: 0.20–45.0 μM). On the other hand, mutagenicity of N-OH-IQ in S. typhimurium TA 98NR was not inhibited by nonpolar quinones (except 1,4-naphthoquinone) but rather by polar compounds and especially by hydroxyquinones (IC₅₀ values: 5.3–106.7 nmol/ml top agar or not reached). Inhibition of mutagenic activities of IQ, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-6-methyldipyrido[1,2-a:3′,2′-d]imidazole, and 3-amino-1-methyl-5H-pyrido[4,3-b]indole by chrysazin, chrysophanic acid, physicon, and purpurin varied, but no clearcut structure-activity relationships of the mutagens were observed. Received: 29 May 1998     

Economic Design And Control of Monitoring Mechanisms in Automated Production Systems

Monitoring production processes to assure product quality has been a major managerial and control problem. These processes are subject to shifts to “out-of-control” states, resulting in the production of defective items. Inspection as well as restoration capabilities are necessary to provide early detection and correction of these shifts in the process. This paper considers the costs of different policies for providing these detection and restoration capabilities. These policies amount to periodic or continuous inspection of the production process with perfect information, and continuous or periodic availability of maintenance facilities. The optimal operation of each policy is studied. Comparative analyses are conducted with different specifications of key parameters such as the rate of shift of the process and the cost of producing defective items. These analyses enable the derivation of the optimal policy when only ranges of the values of these parameters are known.     

Electron microscopy studies of amphiphilic self-assemblies on vitreous ice

The structure of self-assemblies of amphiphiles formed at the air–aqueous solution interface can be determined by cryo transmission electron microscopy (Cryo-TEM). The method is based on fast vitrification of the thin layer of aqueous solution covered with amphiphilic monolayer by plunging the specimen into liquid ethane at its freezing point. During the process of fast cooling the aggregates maintain their two-dimensional crystalline integrity and structure, as demonstrated by comparative studies involving grazing incidence X-ray diffraction (GID) at the air-solution interface, and the Cryo-TEM measurements of the same amphiphilic systems on vitreous ice. Bright-field and dark-field images from the Cryo-TEM observations provide more detailed information than from epifluorescence and Brewster angle microscopy. Furthermore, the electron diffraction patterns have the additional advantage that they allow structural characterization of the crystallites almost at a molecular level, and furnish data on micro twinning and defects occurring between crystalline domains. Cryo-TEM has been applied to elucidate the structure of 2-D and 3-D self-aggregates of amphiphilic alcohols, acids and their cadmium salts, bola-amphiphiles and mixed monolayers. Epitaxial crystallization of hexagonal ice underneath the monolayer of long chain alcohol was also directly demonstrated by this method.     

A mathematical programming model for global plant location problems: Analysis and insights

In this paper, we study the design of global facility networks. We present a mixed integer programming model that captures essential design trade-offs for such networks and explicitly incorporates government subsidies, trade tariffs and taxation issues. The resulting formulation can be solved for reasonable size problems with commercially available mathematical programming software. Focusing on special cases of the problem enables us to provide useful insights on preferable international facility networks for various environments. We demonstrate the pervasive, and often dominating, effects of subsidized financing, tariffs, regional trade rules and taxation in shaping the manufacturing and distribution network of global firms.     

ω‐Phthalimidoalkyl Aryl Ureas as Potent and Selective Inhibitors of Cholesterol Esterase

Cholesterol esterase (CEase), a serine hydrolase thought to be involved in atherogenesis and thus coronary heart disease, is considered as a target for inhibitor development. We investigated recombinant human and murine CEases with a new fluorometric assay in a structure–activity relationship study of a small library of ω‐phthalimidoalkyl aryl ureas. The urea motif with an attached 3,5‐bis(trifluoromethyl)phenyl group and the aromatic character of the ω‐phthalimide residue were most important for inhibitory activity. In addition, an alkyl chain composed of three or four methylene groups, connecting the urea and phthalimide moieties, was found to be an optimal spacer for inhibitors. The so‐optimized compounds 2 [1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐(3‐(1,3‐dioxoisoindolin‐2‐yl)propyl)urea] and 21 [1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐(4‐(1,3‐dioxoisoindolin‐2‐yl)butyl)urea] exhibited dissociation constants (K_i) of 1–19 μm on the two CEases and showed either a competitive ( 2 on the human enzyme and 21 on the murine enzyme) or a noncompetitive mode of inhibition. Two related serine hydrolases—monoacylglycerol lipase and fatty acid amide hydrolase—were inhibited by ω‐phthalimidoalkyl aryl ureas to a lesser extent.     

FSCOAL—Parallel simultaneous fuzzy co‐clustering and learning

A model‐based co‐clustering divides the data based on two main axes and simultaneously trains a supervised model for each co‐cluster using all other input features. For example, in the rating prediction task of recommender system, the main two axes are items and users. In each co‐cluster, we train a regression model for predicting the rating based on other features such as user's characteristics (e.g., gender), item's characteristics (e.g., genre), contextual features (e.g., location), and so on. In reality, users and items do not necessarily belong to a single co‐cluster, but rather can be associated with several co‐clusters. We extend the model‐based co‐clustering to support fuzzy co‐clustering. In this setting, each item–user pair is associated to every co‐cluster with some membership grade. This grade indicates the level of relevance of the item–user pair to the co‐cluster. Furthermore, we propose a distributed algorithm, based on a map‐reduce approach, to handle big datasets. Evaluating the fuzzy co‐clustering algorithm on three datasets shows a significant improvement comparing with a regular co‐clustering algorithm. In addition, a map‐reduce version of the fuzzy co‐clustering algorithm significantly reduces the runtime.     

Service robots in hospitals: new perspectives on niche evolution and technology affordances

Changing demands in society and the limited capabilities of health systems have paved the way for robots to move out of industrial contexts and enter more human-centered environments such as health care. We explore the shared beliefs and concerns of health workers on the introduction of autonomously operating service robots in hospitals or professional care facilities. By means of Q-methodology, a mixed research approach specifically designed for studying subjective thought patterns, we identify five potential end-user niches, each of which perceives different affordances and outcomes from using service robots in their working environment. Our findings allow for better understanding resistance and susceptibility of different users in a hospital and encourage managerial awareness of varying demands, needs, and surrounding conditions that a service robot must contend with. We also discuss general insights into presenting the Q-methodology results and how an affordance-based view could inform the adoption, appropriation, and adaptation of emerging technologies.     

Combinatorial PCPs with Short Proofs

The Probabilistically Checkable Proof (PCP) theorem (Arora and Safra in J ACM 45(1):70–122, 1998; Arora et al. in J ACM 45(3):501–555, 1998) asserts the existence of proofs that can be verified by reading a very small part of the proof. Since the discovery of the theorem, there has been a considerable work on improving the theorem in terms of the length of the proofs, culminating in the construction of PCPs of quasi-linear length, by Ben-Sasson and Sudan (SICOMP 38(2):551–607, 2008) and Dinur (J ACM 54(3):241–250, 2007). One common theme in the aforementioned PCP constructions is that they all rely heavily on sophisticated algebraic machinery. The aforementioned work of Dinur (2007) suggested an alternative approach for constructing PCPs, which gives a simpler and arguably more intuitive proof of the PCP theorem using combinatorial techniques. However, this combinatorial construction only yields PCPs of polynomial length and is therefore inferior to the algebraic constructions in this respect. This gives rise to the natural question of whether the proof length of the algebraic constructions can be matched using the combinatorial approach. In this work, we provide a combinatorial construction of PCPs of length \({n\cdot\left(\log n\right)^{O(\log\log n)}}\), coming very close to the state-of-the-art algebraic constructions (whose proof length is \({n\cdot\left(\log n\right)^{O(1)}}\)). To this end, we develop a few generic PCP techniques which may be of independent interest. It should be mentioned that our construction does use low-degree polynomials at one point. However, our use of polynomials is confined to the construction of error-correcting codes with a certain simple multiplication property, and it is conceivable that such codes could be constructed without the use of polynomials. In addition, we provide a variant of the main construction that does not use polynomials at all and has proof length \({n^{4} \cdot\left(\log n\right)^{O(\log\log n)}}\). This is already an improvement over the aforementioned combinatorial construction of Dinur.     

You like it,you learn it: affectivity and learning in competitive social role play gaming

Despite the alleged ability of digital game-based learning (DGBL) to foster positive affect and in turn improve learning, the link between affectivity and learning has not been sufficiently investigated in this field. Regarding learning from team-based games with competitive elements, even less is known about the relationship between competitiveness (as a dispositional trait) and induced positive affect. In this media comparison study with between-subject design, participants (N?=?325; high school and college students) learned about the EU’s policy agenda by means of a debate-based method delivered through one of three educational media: a) through a social role-playing game with competitive elements played on computers, b) through a very similar game played without computers and c) through a non-game workshop. Unlike many previous DGBL studies, this study used participant randomization and strived to address the teacher effect and the length of exposure effect, while also using the same learning materials and a very similar educational method for all three treatments. Both games induced comparatively higher generalized positive affect and flow. Participants also learned more with the games. Positive affect, but not flow, mediated the influence of educational media on learning gains. Participants’ competitiveness was partly related to positive affect and experiencing flow but unrelated to learning gains. These outcomes held both when the game was played using computers, as well as without them. The study indicates that the ability of an educational intervention to instigate positive affect is an important feature that should be considered by educational designers.