Search

The blood–brain barrier (BBB) protects the central nervous system from toxins and pathogens in the blood by regulating permeation of molecules through the barrier interface. In vitro BBB models described to date reproduce some aspects of BBB functionality, but also suffer from incomplete phenotypic expression of brain endothelial traits, difficulty in reproducibility and fabrication, or overall cost. To address these limitations, a 3D BBB model based on a hybrid paper/nanofiber scaffold is described. The cell culture platform utilizes lens paper as a framework to accommodate 3D culture of astrocytes. An electrospun nanofiber layer is coated onto one face of the paper to mimic the basement membrane and support growth of an organized 2D layer of endothelial cells (ECs). Human induced pluripotent stem cell‐derived ECs and astrocytes are co‐cultured to develop a human BBB model. Morphological and spatial organization of model are validated with confocal microscopy. Measurements of transendothelial resistance and permeability demonstrate the BBB model develops a high‐quality barrier and responds to hyperosmolar treatments. RNA‐sequencing shows introduction of astrocytes both regulates EC tight junction proteins and improves endothelial phenotypes related to vasculogenesis. This model shows promise as a model platform for future in vitro studies of the BBB. [ABSTRACT FROM AUTHOR]

Many anticarcinogenic drugs kill tumour cells by inducing apoptosis. We examined the effects of hydrogen peroxide (H2O2) on arsenic trioxide (As2O3)-induced cell killing. Low concentrations of H2O2 (200 μmol/l) inhibited the ability of As2O3 to induce apoptosis in the Burkitt's lymphoma cell line Raji. H2O2 altered the form of cell death from apoptosis to pyknosis/ necrosis and also lowered the degree of cell killing by As2O3. H2O2 was capable of preventing caspase-3 activation induced by As2O3 in Raji cells. Incubation of cells with a phosphoinositide-3 kinase (PI-3K) inhibitor, wortmannin (100 nmol/l), blocked the effects of H2O2 on As2O2-induced caspase-3 activation. In addition, the PI-3K inhibitor partially blocked the effects of H2O2 on up-regulation of Bcl-2 and Bcl-X1. protein expression, down-regulation of Bax protein expression, and phosphorylation of Bcl-2 and IκBα. This investigation demonstrated for the first time that low concentrations of H2O2 provide protection against the in vivo of As2O3- induced apoptosis. PI-3K plays a crucial role in enhancing cell survival during H2O2, inhibiting As2O3-induced apoptosis in the Burkitt's lymphoma cells. As2O3-induced cancer cell apoptosis may be enhanced by certain antioxidants in the treatment protocol. [ABSTRACT FROM AUTHOR]

Keratinocyte culture is a necessary and widely used tool in a variety of experimental dermatological and biomedical studies. Literature search has revealed a variety of different protocols of human primary keratinocyte isolation and culture. Therefore, the aim of this paper was to review and summarize current trends in human primary keratinocyte culture techniques. We present data on the most popular and effective methods of human keratinocyte isolation and cultivation obtained from screening of 945 papers published during the last 10 years. [ABSTRACT FROM AUTHOR]

The article presents a list of papers that are to be published in future issues of the European Journal of Biochemistry. Some of the articles are: Properties and Reconstruction of a Cytochrome Oxidase Deficient in Subunit III by T. Pentillä The Effects of Octylglucoside on the Interactions of Chloroplast Coupling factor 1 (CF1) With Adenine Nucleotides by U. Pick and S. Bassilian; Localization of Ellipticine Derivatives Interacting With Membranes. A Fluoroscence-Quenching Study by F. Terce, J.-F. Tocanne and G. Laneelle; and Improved Purification and Further Characterization of Acetyl-CoA Carboxylase From Cultures of Cells of Parsley by B. Egin-Bühler and J. Ebel.

Using cell suspensions, a method was elaborated to isolate high-molecular-weight genomic deoxyribonucleic acid (DNA; 65 MDa or more) from members of the Betulaceae: Alnus incana (L.) Moench, Alnus glutinosa (L.) Gaertn. and Betula papyrifera Marsh. The method was also effective for isolation of DNA from callus cells. Based on the chemical lysis of protoplasts, this procedure yielded 130 μg (callus) to 250 μg (cell suspension) of DNA (g fresh cells)-1 with a ratio A260/A280 of 1.7-2.0. The purified DNA obtained, formed distinct bands when restricted fragments were electrophoresed. Among the 10 endonucleases used for restriction analysis of Alnus glutinosa, Alnus incana and Betula papyrifera genomes, PvuII (EC 3.1.23.33) was unique in giving identical patterns for the two Alnus species. An unusual pattern occurred when AI-2 DNA was restricted with Ava II (EC 3.1.23.4). It formed a ladder with a repeating fragment unit of 181 base pairs long. With the enzymes tested, no differences in restriction patterns were observed among clones of Alnus incana (AI-2 vs AI-2), Betula papyrifera (BP-4 vs BP-8) and subclones of Alnus glutinosa AG-I (PLF1709 vs LF1709), suggesting genetic stability of the Betulaceae cultures. [ABSTRACT FROM AUTHOR]

In vitro reconstruction of highly mature engineered heart tissues (EHTs) is attempted for the selection of cardiotoxic drugs suitable for individual patients before administration. Mechanical contractile force generated in the EHTs is known to be a critical indicator for evaluating the EHT response. However, measuring contractile force requires anchoring the EHT in a tailored force‐sensing cell culture chamber, causing technical difficulties in the stable evaluation of contractile force in long‐term culture. This paper proposes a hydrogel‐sheathed human induced pluripotent stem cell (hiPSC)‐derived heart microtissue (H3M) that can provide an anchor‐free contractile force measurement platform in commonly used multi‐well plates. The contractile force associated with tissue formation and drug response is calculated by motion tracking and finite element analysis on the bending angle of the hydrogel sheath. From the experiment of the drug response, H3M is an excellent drug screening platform with high sensitivity and early testing capability compared to conventionally anchored EHT. This unique platform would be useful and versatile for regenerative therapy and drug discovery research in EHT. [ABSTRACT FROM AUTHOR]

Electrical conductivity is of great significance to cardiac tissue engineering and permits the use of electrical stimulation in mimicking cardiac pacing. The development of biomaterials for tissue engineering can incorporate physical properties that are uncommon to standard cell culture and can facilitate improved cardiomyocyte function. In this review, the PICOT question asks, "How has the application of external electrical stimulation in conductive scaffolds for tissue engineering affected cardiomyocyte behavior in in vitro cell culture?" The Preferred Reporting Items for Systematic Reviews and Meta‐Analysis guidelines, with predetermined inclusion and quality appraisal criteria, were used to assess publications from PubMed, Web of Science, and Scopus. Results revealed carbon nanotubes to be the most common conductive agent in biomaterials and rodent‐sourced cell types as the most common cardiomyocytes used. To assess cardiomyocytes, immunofluorescence was used most often, utilizing proteins, such as connexin 43, cardiac α‐actinin, and cardiac troponins. It was determined that the modal average stimulation protocol comprised 1–3 V square biphasic 50‐ms pulses at 1 Hz, applied toward the end of cell culture. The addition of electrical stimulation to in vitro culture has exemplified it as a powerful tool for cardiac tissue engineering and brings researchers closer to creating optimal artificial cardiac tissue constructs. [ABSTRACT FROM AUTHOR]

Cell culture‐conditioned medium (CCM) is a valuable source of extracellular vesicles (EVs) for basic scientific, therapeutic and diagnostic applications. Cell culturing parameters affect the biochemical composition, release and possibly the function of CCM‐derived EVs (CCM‐EV). The CCM‐EV task force of the Rigor and Standardization Subcommittee of the International Society for Extracellular Vesicles aims to identify relevant cell culturing parameters, describe their effects based on current knowledge, recommend reporting parameters and identify outstanding questions. While some recommendations are valid for all cell types, cell‐specific recommendations may need to be established for non‐mammalian sources, such as bacteria, yeast and plant cells. Current progress towards these goals is summarized in this perspective paper, along with a checklist to facilitate transparent reporting of cell culturing parameters to improve the reproducibility of CCM‐EV research. [ABSTRACT FROM AUTHOR]

The wide variety of cell and tissue culture systems used to study and engineer tendons can make it difficult to choose the best approach and "optimal" culture conditions to test a given hypothesis. Therefore, a breakout session was organized at the 2022 ORS Tendon Section Meeting that focused on establishing a set of guidelines for conducting cell and tissue culture studies of tendon. This paper summarizes the outcomes of that discussion and presents recommendations for future studies. In the case of studying tendon cell behavior, cell and tissue culture systems are reductionist models in which the culture conditions should be strictly defined to approximate the in vivo condition as closely as possible. In contrast, for tissue engineering tendon replacements, the culture conditions do not need to replicate native tendon, but the outcome measures for success should be narrowly defined for the specific clinical application. Common recommendations for both applications are that researchers should perform a baseline phenotypic characterization of the cells that are ultimately used for experimentation. For models of tendon cell behavior, culture conditions should be well justified by existing literature and meticulously reported, tissue explant viability should be assessed, and comparisons to in vivo conditions should be made to determine baseline physiological relevance. For tissue engineering applications, the functional/structural/compositional outcome targets should be defined by the specific tendons they seek to replace, with key biologic and material properties prioritized for construct assessment. Lastly, when engineering tendon replacements, researchers should utilize clinically approved cGMP materials to facilitate clinical translation. [ABSTRACT FROM AUTHOR]

Hollow fibre membrane bioreactors (HFMBs) have been shown to overcome the diffusion limitation of nutrients (e.g., glucose) from the hollow fibres (lumens) to the porous regions of a scaffold (extracapillary space). However, direct monitoring of glucose diffusion inside the HFMBs is almost impossible because of their small size; thus, various computational modelling frameworks have been developed in the past. These models have defined that the glucose diffusivity in the cell culture medium used in the HFMBs was similar to the diffusivity in water. Similarly, other assumptions have been made that do not represent the nutrient transport processes in the HFMB accurately. In addressing these issues, a mathematical model is presented in this paper, where we employ experimentally deduced effective glucose diffusivities of tissue engineering membranes and scaffolds with and without cells along with glucose diffusivity in cell culture medium. The governing equations are non‐dimensionalized, simplified and solved numerically. The results demonstrate the roles of various dimensionless numbers (e.g., Péclet and Damköhler numbers) and non‐dimensional groups of variables on determining the glucose concentration especially in the scaffold region. The result of this study is expected to help optimize designs of HFMB as well as carry out more accurate scaling analyses. [ABSTRACT FROM AUTHOR]

Raman spectroscopy has found widespread usage in monitoring cell culture processes both in research and practical applications. However, commonly, preprocessing methods, spectral regions, and modeling parameters have been chosen based on experience or trial‐and‐error strategies. These choices can significantly impact the performance of the models. There is an urgent need for a simple, effective, and automated approach to determine a suitable procedure for constructing accurate models. This paper introduces the adoption of a design of experiment (DoE) method to optimize partial least squares models for measuring the concentration of different components in cell culture bioreactors. The experimental implementation utilized the orthogonal test table L25(56). Within this framework, five factors were identified as control variables for the DoE method: the window width of Savitzky–Golay smoothing, the baseline correction method, the order of preprocessing steps, spectral regions, and the number of latent variables. The evaluation method for the model was considered as a factor subject to noise. The optimal combination of levels was determined through the signal‐to‐noise ratio response table employing Taguchi analysis. The effectiveness of this approach was validated through two cases, involving different cultivation scales, different Raman spectrometers, and different analytical components. The results consistently demonstrated that the proposed approach closely approximated the global optimum, regardless of data set size, predictive components, or the brand of Raman spectrometer. The performance of models recommended by the DoE strategy consistently surpassed those built using raw data, underscoring the reliability of models generated through this approach. When compared to exhaustive all‐combination experiments, the DoE approach significantly reduces calculation times, making it highly practical for the implementation of Raman spectroscopy in bioprocess monitoring. [ABSTRACT FROM AUTHOR]

A challenge in the pandemic era is to implement effective but flexible practical teaching for biological sciences courses. Such teaching needs to deliver conceptual, analytical and practical skills training while having the option to rapidly respond to health and safety issues, local regulations, staff and student concerns. In this paper, we describe a set of cell biology practicals (mini‐project) that meets many of these requirements and provides flexibility in providing skills training both through online and in practical laboratory environments. We have used a human adenocarcinoma cell line A431 stably transfected with a fluorescent cell cycle reporter as a biological model to deliver training through discrete work packages encompassing cell culture, fluorescence microscopy, biochemistry and statistics. How such work packages can be modified to, an online format either partially or completely is also described. Furthermore, the activities can be adapted for teaching both undergraduate and postgraduate level courses to ensure effective skills training which is applicable to a wide range of biological degree programs and levels of study. [ABSTRACT FROM AUTHOR]

Ginger and its derivatives have been shown to be effective in the prevention and treatment of cancer. We undertook a systematic review to answer the question of whether ginger has a role in modifying the biomarkers of cancer in cell culture conditions and on colorectal cancer in randomized clinical trials. We performed a comprehensive search of the literature from Scopus, Embase, Web of Science, PubMed, Cochrane central register of controlled trials, and Cochrane database of systematic reviews. At first, all 12 papers studied the effect of ginger or its derivatives on cell culture conditions. The results of cell culture studies show that ginger has a powerful role in inducing apoptosis. In the second part, five studies of clinical trials were analyzed. By analyzing antitumor markers of clinical trials, ginger increased some anticancer markers but performed poorly in inducing some anticancer markers. This systematic review showed that the consumption of ginger extract has the potential to prevent and treat colorectal cancer but this ability is weak. [ABSTRACT FROM AUTHOR]

In the last four decades, several researchers worldwide have routinely and meticulously exercised cell culture experiments in two‐dimensional (2D) platforms. Using traditionally existing 2D models, the therapeutic efficacy of drugs has been inappropriately validated due to the failure in generating the precise therapeutic response. Fortunately, a 3D model addresses the foregoing limitations by recapitulating the in vivo environment. In this context, one has to contemplate the design of an appropriate scaffold for favoring the organization of cell microenvironment. Instituting pertinent model on the platter will pave way for a precise mimicking of in vivo conditions. It is because animal cells in scaffolds oblige spontaneous formation of 3D colonies that molecularly, phenotypically, and histologically resemble the native environment. The 3D culture provides insight into the biochemical aspects of cell–cell communication, plasticity, cell division, cytoskeletal reorganization, signaling mechanisms, differentiation, and cell death. Focusing on these criteria, this paper discusses in detail, the diversification of polymeric scaffolds based on their available resources. The paper also reviews the well‐founded and latest techniques of scaffold fabrication, and their applications pertaining to tissue engineering, drug screening, and tumor model development. [ABSTRACT FROM AUTHOR]

Disruption of the blood–brain barrier (BBB) leads to various neurovascular diseases. Development of therapeutics required to cross the BBB is difficult due to a lack of relevant in vitro models. We have developed a three‐dimensional (3D) microfluidic BBB chip (BBBC) to study cell interactions in the brain microvasculature and to test drug candidates of neurovascular diseases. We isolated primary brain microvascular endothelial cells (ECs), pericytes, and astrocytes from neonatal rats and cocultured them in the BBBC. To mimic the 3D in vivo BBB structure, we used type I collagen hydrogel to pattern the microchannel via viscous finger patterning technique to create a matrix. ECs, astrocytes, and pericytes were cocultured in the collagen matrix. The fluid flow in the BBBC was controlled by a pump‐free strategy utilizing gravity as driving force and resistance in a paper‐based flow resistor. The primary cells cultured in the BBBC expressed high levels of junction proteins and formed a tight endothelial barrier layer. Addition of tumor necrosis factor alpha to recapitulate neuroinflammatory conditions compromised the BBB functionality. To mitigate the neuroinflammatory stimulus, we treated the BBB model with the glucocorticoid drug dexamethasone, and observed protection of the BBB. This BBBC represents a new simple, cost‐effective, and scalable in vitro platform for validating therapeutic drugs targeting neuroinflammatory conditions. [ABSTRACT FROM AUTHOR]

Three‐dimensional (3D) organoids are an innovative approach to obtain an in vitro model for ex vivo studies to overcome the limitations of monolayer cell culture and reduce the use of animal models. An organoid of skeletal muscle requires the presence of the extracellular matrix to represent a functional muscle in vitro, which is why decellularized tissue is an optimal choice. Various muscles have been considered to produce a muscle organoid, most from rodents or small animals, and only recently some studies have been reported on the muscles of large animals. This work presents a muscular organoid produced from the bovine diaphragm, which has a peculiar multilayered structure with different fibre orientations depending on the considered area. This paper analyses the anatomical structure of the bovine diaphragm, selects the most appropriate portion, and presents a decellularization protocol for a multilayered muscle. In addition, a preliminary test of recellularization with primary bovine myocytes was presented with the future aim of obtaining a 3D muscle allogenic organoid, completely bovine‐derived. The results demonstrate that the dorsal portion of bovine diaphragm presents a regular alternation of muscular and fibrous layers and that the complete decellularization does not affect the biocompatibility. These results provide a strong foundation for the potential application of this portion of tissue as a scaffold for in vitro studies of muscle organoids. [ABSTRACT FROM AUTHOR]

Background: Stem/progenitor cells from human exfoliated deciduous teeth (SHED) show remarkable pluripotent, regenerative, and immunological capacities. During in vivo regenerative processes, there could be the presence of SHED in the surrounding inflammatory microenvironment, through toll‐like receptors (TLRs). Aim: The aim of this paper was to present a characteristic TLR expression profile on SHED for the first time. Design: Cells were harvested from extracted primary teeth (n = 10), anti‐STRO‐1 immunomagnetically sorted and cultivated, through colony‐forming units (CFUs). SHED were examined for mesenchymal stem/progenitor cell traits, including the expression of clusters of differentiation (CDs) 14, 34, 45, 73, 90, 105, and 146, and their multilineage differentiation aptitude. TLRs 1–10 expression was investigated for SHED in uninflamed and inflamed (25 ng/mL IL‐1β, 103 U/mL IFN‐γ, 50 ng/mL TNF‐α, and 3 × 103 U/mL IFN‐α; SHED‐i) microenvironmental conditions. Results: SHED were negative for CDs 14, 34, and 45, but were positive for CDs 73, 90, 105, and 146, and demonstrated characteristic multilineage differentiation. In an uninflamed microenvironment, SHED expressed TLRs 1, 2, 3, 4, 6, 8, 9, and 10. The inflammatory microenvironment downregulated TLR7 significantly on gene level and upregulated TLR8 on gene and protein levels (p <.05; Wilcoxon signed‐rank test). Conclusion: There appears to be a unique TLR expression profile on SHED, which could modulate their immunological and regenerative abilities in oral tissue engineering approaches. [ABSTRACT FROM AUTHOR]

Objective: This paper describes the effect of Porphyromonas gingivalis (P gingivalis) lipopolysaccharide (LPS) on the expression of interleukin-6 (IL-6) and C-C motif chemokine ligand 2 (CCL2) in cultured hCMEC/D3 human brain microvascular endothelial cells.Background: P gingivalis is one of the important pathogens in periodontitis, and periodontitis is a risk factor for brain disorders including cerebrovascular diseases and Alzheimer's disease. However, the mechanisms underlying the pathogenesis of P gingivalis-mediated brain diseases are incompletely understood. Effects of P gingivalis LPS on brain endothelial cells are not known well.Methods: The hCMEC/D3 human brain microvascular endothelial cells were cultured and treated with P gingivalis LPS. The expression of IL-6 and CCL2 mRNA and protein was examined using quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Effect of inhibitors of Toll-like receptor (TLR) 2, TLR4, nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) was also investigated. Phosphorylation of NF-κB p65, p38 MAPK and JNK was examined using Western blotting.Results: P gingivalis LPS-induced mRNA and protein expression of IL-6 and CCL2 in hCMEC/D3 cells in a concentration-dependent manner at the concentration of 0.5-50 µg/mL. Maximal mRNA expression of IL-6 and CCL2 was found 2 and 4 hours after stimulation, respectively. Induction of IL-6 and CCL2 by P gingivalis LPS was almost completely inhibited by pretreatment of cells with TLR4 inhibitor but not by TLR2 inhibitor. Treatment of cells with P gingivalis LPS for up to 2 hours induced phosphorylation of NF-κB p65, p38 MAPK and JNK. IL-6 induction was decreased by pretreatment of cells with NF-κB inhibitor SN50 or p38 MAPK inhibitor SB203580, while CCL2 induction was reduced by SN50 or JNK inhibitor SP600125.Conclusions: IL-6 and CCL2 produced upon P gingivalis LPS stimulation may contribute to the inflammatory reactions in brain endothelial cells and subsequent neurological disorders such as cerebrovascular and Alzheimer's diseases. [ABSTRACT FROM AUTHOR]

Functional microfluidic particle reactors (MPRs), prepared with microfluidic emulsions with biomaterials as the templates, can directly encapsulate bioactive substances to achieve different biomedical applications. Different types of MPRs (such as single structure MPRs, mixed structure MPRs, and all‐aqueous structure MPRs) have multifarious functions owing to the prominent interface characteristics endowed by emulsion templates with exquisite controlled fluid components and interface structures, as well as functional biomaterials with attractive properties. Notably, the constructed MPRs are endowed with better controllability, biocompatibility, and injectability with the significant advances in the burgeoning droplet microfluidic technology and material science. This contributes to the improvement of the flexibility and degree of freedom of the MPRs supporting cell and drug‐related biomedical applications (such as 3D cell culture, cell/drug delivery, and controlled drug release), leading to more effective diagnosis and treatment. In this paper, the correlation between the particle structure, determined by optimizing emulsion template fluid components and interfacial complexity, and the interface characteristics of the MPRs are primarily investigated. Next, the interface characteristics of the MPRs expanded by functional biomaterials are reviewed, as well as the distinct properties of MPRs in the biomedical applications related to cells and drugs. Finally, the existing challenges and future perspectives are discussed to improve the unique interface characteristics of MPRs in broader biomedical applications. [ABSTRACT FROM AUTHOR]

Plasma‐treated water solutions (PTWS) allow the delivery of reactive oxygen and nitrogen species (RONS) to cells and tissues for different purposes. The mechanism of RONS formation has been clearly modelled in simple liquids like water, by assuming a plasma‐driven process independent from the liquid. PTWS for biological experiments, however, are often produced from solutions of complex composition, where the formation mechanism of RONS is far from being understood. In this paper, we describe how water, phosphate‐buffered saline solution and two cell culture media were plasma‐treated in different conditions to demonstrate how the different composition of the liquids affects the formation of stable RONS (H2O2 and NO2−) in the resulting PTWS, especially when aromatic organic molecules are present. [ABSTRACT FROM AUTHOR]

With the steady advancement of medicine and the healthcare industry, the demand for recombinant biotherapeutics drugs and vaccines has increased in the last two decades. This has put substantial pressure on the biopharma industry to meet the increasing need for treatment of prevailing and new diseases. Different technologies and bioreactor designs have been developed over the years to ensure safe and economical manufacturing of biopharmaceutical products by attaining high cell densities and longevities for extended periods of time. Bioreactors are the backbone of the bioprocessing industry albeit each bioreactor design has its advantages and disadvantages. A comprehensive design suitable for wide varieties of cell lines to produce high‐yielding products with the lowest cost and risk in the shortest span of time is sought. This paper focuses on evaluating the engineering aspects of currently available bioreactor designs and their suitability for mammalian cell cultures. [ABSTRACT FROM AUTHOR]

Biodegradable ϕ4 mm tubular porous poly(ε‐caprolactone)/poly(L‐lactide‐co‐ε‐caprolactone) (PCL/PLCL) scaffolds are fabricated successfully via one‐step microcellular supercritical carbon dioxide foaming process. The effect of blending ratio on the rheology, pore structures, mechanical property, wettability, and biocompatibility of PCL/PLCL blends tubular scaffold are reported. Rheological results show that PCL matrix and PLCL dispersed phase has good compatibility. The melt strength of PCL can be enhanced obviously by adding PLCL. With an increase of PLCL content from 10 to 30 wt%, the pore size increases from 7.6 to 24.9 μm due to the homogeneous nucleation effect. The maximum open‐cell content can reach 77% for PCL/PLCL foamed sample. Cyclical tensile and compliance tests show that few content of dispersed PLCL (10–20 wt%) improves the flexibility and recoverability. Cell viability results demonstrate that human umbilical vein endothelial cells (HUVECs) cultured on all PCL/PLCL porous scaffolds exhibit a typical spindle‐like cell morphology. Moreover, HUVECs have a higher density and spreading areas on surface of 10% PLCL scaffold. The results gathered in this paper may open a new perspective for the fabrication of small‐diameter vascular tissue engineering scaffold. [ABSTRACT FROM AUTHOR]

Numerous traditional adhesives have good adhesion in dry environments. However, non‐environmental‐friendliness and poor water resistance largely limit their practical applications. To prepare biocompatible adhesives with strong water resistance and adhesion strength, in this paper, catechol‐functionalized cellulose‐based adhesive polymers are synthesized by grafting N‐(3,4‐dihydroxyphenethyl)methacrylamide and methyl methacrylate onto cellulose chain through atom transfer radical polymerization (ATRP). The successful synthesis of the catechol‐functionalized cellulose‐based adhesive polymers is confirmed by FTIR and 1H NMR. The different characteristics of the adhesive polymers, such as thermal stability, swelling ratio, biocompatibility, and adhesion strength are investigated. Strong water resistance on various substrates is realized in underwater environment for the catechol‐functionalized cellulose‐based adhesive with addition of Fe3+. The adhesion strength and thermal stability are enhanced when the catechol content is increased. The adhesive with catechol content of 25.4% shows the adhesion strength of 0.45 MPa for iron substrate in underwater environment. In addition, the adhesive with addition of Fe3+ exhibits excellent adhesion in dry environment, with maximum adhesion strength of 3.50 MPa for iron substrate. The cell culture test shows that the adhesive polymers have excellent biocompatibility. The biocompatible adhesives with strong water resistance have potential application in electronic, wood, and building fields. [ABSTRACT FROM AUTHOR]

With the outbreak of new respiratory viruses and high mortality rates of pulmonary diseases, physiologically relevant models of human respiratory system are urgently needed to study disease pathogenesis, drug efficacy, and pharmaceutics. In this paper, a 3D alveolar barrier model fabricated by printing four human alveolar cell lines, namely, type I and II alveolar cells (NCI‐H1703 and NCI‐H441), lung fibroblasts (MRC5), and lung microvascular endothelial cells (HULEC‐5a) is presented. Automated high‐resolution deposition of alveolar cells by drop‐on‐demand inkjet printing enables to fabricate a three‐layered alveolar barrier model with an unprecedented thickness of ≈10 µm. The results show that the 3D structured model better recapitulate the structure, morphologies, and functions of the lung tissue, compared not only to a conventional 2D cell culture model, as expected, but also a 3D non‐structured model of a homogeneous mixture of the alveolar cells and collagen. Finally, it is demonstrated that this thin multilayered model reproduce practical tissue‐level responses to influenza infection. Drop‐on‐demand inkjet‐printing is an enabling technology for customization, scalable manufacturing, and standardization of their size and growth, and it is believed that this 3D alveolar barrier model can be used as an alternative to traditional test models for pathological and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

New short-lived strains of mice (SAM-P), which have been developed by Takeda et al. (1981), show a defective antibody response to T dependent (TD) antigen in vitro, as demonstrated in the accompanying paper (see page 419). In the present study, we investigated the cellular site of the defect, using a cell culture system. In this paper, it is demonstrated that T-helper (Th) cell activity for the antibody response to TD antigen is impaired, while other cellular immune responses, e.g. mixed leucocyte reaction, cytotoxic T-lymphocyte response, and delayed-type hypersensitivity reaction, are normal. These results suggest that the defect in T-helper subset is limited in helper function for the antibody response, and that the helper function for the cell-mediated immune responses is intact. These two functions of the T-helper subset are apparently regulated in a different manner. The SAM-P strains of mice may thus serve as an appropriate model for studying functional heterogeneity in T-helper/inducer cell subsets. [ABSTRACT FROM AUTHOR]

Liquid marble is a non‐wetting droplet coated with micro‐ or nanometer sized particles and exhibits great versatility as a standalone system. Unique features such as low evaporation rate, low friction, and a porous shell enable it to be a potential tool for gas sensing, cell culture, and drug delivery. With the growing number of interests in these fields, it is important to understand the structure of the liquid marble shell and how it behaves with the variation of the surface tension of the core liquid. This paper investigates the thickness and the mass of liquid marble shell at various surface tension values. Surfactant mediated surface tension reduction allows the encapsulating particles to penetrate more into the core liquid and decreases the shell thickness. The shell thickness decreases significantly with the surface tension, whereas the mass remains almost constant. Interestingly, the trend reverses with further decrease of the surface tension. In this regime, both the thickness and the mass of the shell increase due to interfacial jamming. This work provides a new insight into understanding the contribution of the particle distribution at the shell for the stability and the measurement of the effective surface tension of a liquid marble. [ABSTRACT FROM AUTHOR]

Microspheres applied in medical applications experience explosive development in recent years, such as drug release, cell culture, and bone tissue engineering, etc. However, there are still some bottlenecks both in economy and technology lay that cannot be ignored. For instance, microsphere technology has not been used in cell culture widely because of its uneconomical cost; as the core of drug‐loaded microsphere, targeted microsphere technology is still not mature enough. Besides, the common microsphere fabrication methods: microfluidic or emulsion technology is difficult to guarantee high biocompatibility of microsphere due to utilization of photoinitiator, crosslinking agent, surfactant, and other substances. Therefore, gas‐shearing technology has been proposed to solve these above shortcomings successfully. This paper focuses more on heteromorphic microspheres rather than on single microspheres which begins with a minute introduction of microsphere preparation methods: microfluidic, coaxial electrospray, emulsion, and gas‐shearing technology. Then its medical applications: drug release, cell culture, bone tissue engineering, and hemostasis are discussed in detail. The disadvantages of fabrication methods and bottlenecks for medical applications at present are also stated. At the end, perspectives of microsphere development are put forward. [ABSTRACT FROM AUTHOR]

There is an unmet demand for microfluidics in biomedicine. This paper describes contactless fabrication of microfluidic circuits on standard Petri dishes using just a dispensing needle, syringe pump, three‐way traverse, cell‐culture media, and an immiscible fluorocarbon (FC40). A submerged microjet of FC40 is projected through FC40 and media onto the bottom of a dish, where it washes media away to leave liquid fluorocarbon walls pinned to the substrate by interfacial forces. Such fluid walls can be built into almost any imaginable 2D circuit in minutes, which is exploited to clone cells in a way that beats the Poisson limit, subculture adherent cells, and feed arrays of cells continuously for a week. This general method should have wide application in biomedicine. [ABSTRACT FROM AUTHOR]

Biosurfactants of rhamnolipids have been enthusiastically investigated for substitutes of synthetic agrochemicals against plant pathogens. However, all such studies have been conducted on rhamnolipids with high purity which have limitations due to high costs. This paper focused on the applicability of rhamnolipid-containing cell-free culture broth. It was found that rhamnolipids in cell-free culture broth of Pseudomonas aeruginosa ZJU211 were largely composed of di-rhamnolipid and mono-rhamnolipid with the ratio varying with culture time. After 96 h of fermentation, the mass ratio of di-rhamnolipid over mono-rhamnolipid increased to 2.6:1. Crude rhamnolipids in a form of cell-free culture broth showed high antifungal activity against colony growth and biomass accumulation of seven plant pathogens comprising two Oomycetes, three Ascomycota and two Mucor spp. fungi, among which three plant pathogens were firstly reported in this paper showing inhibition to rhamnolipids. Particularly, rhamnolipids showed potent activity against two Oomycetes that acquire resistance to commercial compound of metalaxyal. Furthermore, di-rhamnolipid was elucidated to dominate the antifungal activity of crude rhamnolipids by in vitro studies. At last, the efficacy and safety of cell-free culture broth was preliminarily illustrated on plants in vivo. So cell-free culture broth as a crude rhamnolipid product could be served as a potential cost-effective and environmental-friendly fungicide in agriculture. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Surfactants are one of the important ingredients of cosmetics. However, their penetration and penetration‐promoting behavior in the skin has not been well understood. Aiming to explore the surfactant penetration in skin, a novel fluorescent surfactant F‐C16, based on sodium fluorescein, was synthesized in this paper. F‐C16 has a fluorescence maxima (λem) of around 530 nm, and its fluorescence increased with the polarity of solvent. It possesses good emulsifying properties and low cytotoxicity. Hence, it can be used as a quickly detected indicator for surfactants in cosmetics. As demonstrated by this fluorescent surfactant, it was found that the surfactants can penetrate well into skin and cells. It seems that surfactants in cosmetics can enter the cells and reach the dermal layer of skin. [ABSTRACT FROM AUTHOR]

When evaluating new bioactive glass compositions for their suitability as a biomaterial, one of the first steps is the study of their behavior in contact with aqueous solutions. Ion release, pH changes, and apatite precipitation are investigated during immersion experiments, and a wide variety of solutions is used, including simulated body fluid, Tris buffer solution, various cell culture medium formulations or deionized water. This paper reviews the different parameters used for immersion experiments on bioactive glasses. Results show that, depending on solution composition, pH, and buffering capacity, the experimental outcome is likely to vary. In addition, bioactive glass particle size and solution volume/glass surface area ratio affect the resulting ion concentration in solution, and, thus, the rate at which apatite is formed. It is, therefore, important to consider these effects when planning experiments, interpreting results or comparing the results of experiments performed in different laboratories. [ABSTRACT FROM AUTHOR]

Significant and continual improvements in upstream processing for biologics have resulted in challenges for downstream processing, both primary recovery and purification (1). Given the high cell densities achievable in both microbial and mammalian cell culture processes, primary recovery can be a significant bottleneck in both clinical and commercial manufacturing. The combination of increased product titer and low viability leads to significant relative increases in the levels of process impurities such as lipids, intracellular proteins and nucleic acid versus the product. In addition, cell culture media components such as soy and yeast hydrolysates have been widely applied to achieve the cell culture densities needed for higher titers (2,3). Many of the process impurities can be negatively charged at harvest pH and can form colloids during the cell culture and harvest processes. The wide size distribution of these particles and the potential for additional particles to be generated by shear forces within a centrifuge may result in insufficient clarification to prevent fouling of subsequent filters. The other residual process impurities can lead to precipitation and increased turbidity during processing and even interference with the performance of the capturing chromatographic step. Primary recovery also poses significant challenges owing to the necessity to execute in an expedient manner to minimize both product degradation and bioburden concerns. Both microfiltration and centrifugation coupled with depth filtration have been employed successfully as primary recovery processing steps. Advances in the design and application of membrane technology for microfiltration and dead-end filtration have contributed to significant improvements in process performance and integration, in some cases allowing for a combination of multiple unit operations in a given step. Although these advances have increased productivity and reliability, the net result is that optimization of primary recovery processes has become substantially more complicated. Ironically, the application of classical chemical engineering approaches to overcome issues in primary recovery and purification (e.g., turbidity and trace impurity removal) are just recently gaining attention (4). Some of these techniques (e.g., membrane cascades, pretreatment, precipitation, and the use of affinity tags) are now seen almost as disruptive technologies (5). This paper will review the current and potential future state of research on primary recovery, including relevant papers presented at the 234th American Chemical Society (ACS) National Meeting in Boston. [ABSTRACT FROM AUTHOR]

The first paper in this series reported that it was possible to reconstitute the response of low concentrations of mouse spleen lymphocytes to concanavalin A (Con A) by adding small numbers of peritoneal exudate cells (PEC) to the cultures. In this paper it is shown that the role of the PEC in this system can be partially replaced by conditioned medium (CM) prepared from PEC cultures or completely replaced by CM taken from lymphocytes cultured at optimal concentration. These CM were inactive unless fresh Con A was added to the assay cultures. Activity was present in CM which was incubated with lymphocytes or PEC for the shortest possible time but maximal activity was found after 24 hr of incubation. Activity was also found in CM prepared in the absence of Con A. Only in the case of lymphocytes cultured at optimal concentration for 24 hr was there substantially more activity in the CM thus prepared if Con A was present. PEC preparations depleted of T lymphocytes produced as much activity in CM as the untreated control. CM produced by PEC was less sensitive to heat treatment or to freezing and thawing than that produced by lymphocyte cultures. [ABSTRACT FROM AUTHOR]

This paper describes in detail the processing path leading to successful phase images stitching in digital holographic microscope for the extension of the field of view. It applies FIJI Grid/Collection Stitching Plugin, which is a general tool for images stitching, non‐specific for phase images. The FIJI plugin is extensively supported by aberration and phase offset correction. Comparative analysis of different aberration correction methods and data processing strategies is presented, together with the critical analysis of their applicability. The proposed processing path provides good background for statistical phase analysis of cell cultures and digital phase pathology. [ABSTRACT FROM AUTHOR]

Immortalized or continuous cell lines are invaluable tools in basic and preclinical research. However, the widespread use of misidentified cell lines is a serious threat to scientific reproducibility. Based on the experiences of mandatory cell line authentication at the International Journal of Cancer (IJC), we provide an overview of the issues pertinent to misidentified cell lines and discuss available solutions. We also summarize the lessons learned, revealing that at least 5% of the human cell lines used in manuscripts considered for peer review are misidentified. About 4% of the considered manuscripts are rejected for severe cell line problems, and most are subsequently published in other journals. In order to diminish such malpractice and its consequences for the scientific record, we postulate that strict multi‐layered quality control is essential. Besides journals and publishers, we encourage scientists, research institutions, and funders to take action on the matter and revise their respective policies. Hence, we provide concrete recommendations on introducing regular authentication schemes and staff training, and discuss future steps for enhancing good cell culture practices. [ABSTRACT FROM AUTHOR]

A representative photomicrograph of GFAP and DAPI stained astrocytes in primary mixed brain cell cultures. See paper in this issue by Nishikimi et al. (pp. 389‐403). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Microscopy is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: BACKGROUND: Compared with other methods, the stationary liquid mass balance method for oxygen uptake rate (OUR) determination offers advantages in terms of estimation accuracy and reduction of stress. However, the need for sophisticated instrumentation, like mass flow controllers and gas analysers, has historically limited wider implementation of such a method. In this paper, a new simplified method based on inexpensive valves for the continuous estimation of OUR in animal cell cultures is evaluated. The determination of OUR values is based on accurate operation of the dissolved oxygen (DO) control loop and monitoring of its internal variables. RESULTS: The method developed was tested empirically in 2 L bioreactor HEK293 batch cultures. OUR profiles obtained by a dynamic method, global mass balance method and the developed simplified method were monitored and compared. The results show how OUR profile obtained with the proposed method better follows the off‐line cell density determination. The OUR estimation frequency was also increased, improving the method capabilities and applications. The theoretical rationale of the method was extended to the sensitivity analysis which was analytically and numerically approached. CONCLUSIONS: The results showed the proposed method to be not only cheap, but also a reliable alternative to monitor the metabolic activity in bioreactors in many biotechnological processes, being a useful tool for high cell density culture strategies implementation based on OUR monitoring. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: The case of cultured red blood cells (RBCs) currently being grown in a laboratory for future use in human transfusion raises questions about the ontological status of such products of modern biotechnology. This paper presents results from a six‐year ethnographic study involving interviews, focus groups and other forms of engagement with the scientific research team and other stakeholders, including public groups, which sought to understand respondents’ reactions to cultured RBCs. These cells, derived from stem cell technology, have the potential to address the global shortage of donated blood. How these blood cells are situated within the spectrum of ‘natural’ to ‘synthetic’ will shape expectations and acceptance of this product, both within the scientific community and by wider publics: these blood cells are both novel and yet, at the same time, very familiar. Drawing on discussions related to classification and ‘anchoring’, we examine the contrasting discourses offered by our respondents on whether these blood cells are ‘natural’ or not and consider the impact that naming might have on both their future regulation and the eventual uptake of cultured RBCs by society. [ABSTRACT FROM AUTHOR]

Cryogels are macroporous materials that display remarkable properties, such as high pore interconnection, large surface to volume ratio, and high mechanical stability, making them good candidates for 3D cell culture. However, shaping cryogels remains challenging because of the harsh conditions of synthesis at temperatures as low as -80 °C. In this paper, a solution for the 3D printing of functionalized cryogels is proposed. A microfabricated dispensing probe allowing the last second mixing of cryogel precursors as well as control of the temperature of the extruded material during printing is presented. This dispensing tool allows multilayer 3D printing of cryogels with on demand local pore size change through the control in temperature of the dispensed solution. Moreover, thanks to advanced functionalization of the scaffold, cells can be cultured in 3D within the printed scaffold and exhibited spreading. The ability to tune the pore size of the printed cryogels allows to select during printing where cells will get seeded. [ABSTRACT FROM AUTHOR]

ABSTRACT: Advances in mechanobiology have evolved through insights from multiple disciplines including structural engineering, biomechanics, vascular biology, and orthopaedics. In this paper, we reviewed the impact of key reports related to the study of applied loads on tissues and cells and the resulting signal transduction pathways. We addressed how technology has helped advance the burgeoning field of mechanobiology (over 33,600 publications from 1970 to 2016). We analyzed the impact of critical ideas and then determined how these concepts influenced the mechanobiology field by looking at the citation frequency of these reports as well as tracking how the overall number of citations within the field changed over time. These data allowed us to understand how a key publication, idea, or technology guided or enabled the field. Initial observations of how forces acted on bone and soft tissues stimulated the development of computational solutions defining how forces affect tissue modeling and remodeling. Enabling technologies, such as cell and tissue stretching, compression, and shear stress devices, allowed more researchers to explore how deformation and fluid flow affect cells. Observation of the cell as a tensegrity structure and advanced methods to study genetic regulation in cells further advanced knowledge of specific mechanisms of mechanotransduction. The future of the field will involve developing gene and drug therapies to simulate or augment beneficial load regimens in patients and in mechanically conditioning organs for implantation. Here, we addressed a history of the field, but we limited our discussions to advances in musculoskeletal mechanobiology, primarily in bone, tendon, and ligament tissues. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:605–619, 2018. [ABSTRACT FROM AUTHOR]

Single-cell biology provides insights into some of the most fundamental processes in biology and promotes the understanding of life's mysteries. As the technologies to study single-cells expand, they will require sophisticated analytical tools to make sense of various behaviors and components of single-cells as well as their relations in the adherent tissue culture. In this paper, we revealed cell heterogeneity and uncovered the connections between cell adhesion strength and cell viability at single-cell resolution by extracting single adherent cells of interest from a standard tissue culture by using a microfluidic chip-based live single-cell extractor (LSCE). We believe that this method will provide a valuable new tool for single-cell biology. [ABSTRACT FROM AUTHOR]

ABSTRACT Following the Process Analytical Technology (PAT) of the Food and Drug Administration (FDA), drug manufacturers are encouraged to develop innovative techniques in order to monitor and understand their processes in a better way. Within this framework, it has been demonstrated that Raman spectroscopy coupled with chemometric tools allow to predict critical parameters of mammalian cell cultures in-line and in real time. However, the development of robust and predictive regression models clearly requires many batches in order to take into account inter-batch variability and enhance models accuracy. Nevertheless, this heavy procedure has to be repeated for every new line of cell culture involving many resources. This is why we propose in this paper to develop global regression models taking into account different cell lines. Such models are finally transferred to any culture of the cells involved. This article first demonstrates the feasibility of developing regression models, not only for mammalian cell lines (CHO and HeLa cell cultures), but also for insect cell lines (Sf9 cell cultures). Then global regression models are generated, based on CHO cells, HeLa cells, and Sf9 cells. Finally, these models are evaluated considering a fourth cell line(HEK cells). In addition to suitable predictions of glucose and lactate concentration of HEK cell cultures, we expose that by adding a single HEK-cell culture to the calibration set, the predictive ability of the regression models are substantially increased. In this way, we demonstrate that using global models, it is not necessary to consider many cultures of a new cell line in order to obtain accurate models. Biotechnol. Bioeng. 2017;114: 2550-2559. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Empiric antibiotic therapy in suspected prosthetic joint infection should cover likely pathogens while avoiding overly broad‐spectrum antibiotics. We analysed individual patient data from a large prospective cohort study (Prosthetic Joint Infection in Australia and New Zealand, Observational (PIANO)) and found that causative organisms vary with the presentation type, with early post‐operative infections more likely to be polymicrobial (41%) compared with late acute infections (10%). We thus propose empirical regimens tailored to the presentation type and presence or absence of sepsis. [ABSTRACT FROM AUTHOR]

The embryo‐like structures (embryoids) constructed by aggregating embryonic stem cells (ESCs) and trophoblast stem cells (TSCs) have provided revolutionary tools for studying the intricate interaction between embryonic and extra‐embryonic tissues during early embryonic development, which has been achieved in mice. However, due to the opposite dependence on some signalling pathways for in vitro culture of human ESCs (hESCs) and TSCs (hTSCs), particularly WNT and TGFβ signalling pathways, which limits the construction of human post‐implantation embryoids by aggregating hESCs and hTSCs. To overcome this challenge, here, by screening 1639 chemicals, we found that an inhibitor of integrated stress response, ISRIB, can replace WNT agonists and TGFβ inhibitors to maintain the stemness and differentiation capacity of hTSCs. Thus, we developed an ISRIB‐dependent in vitro culture medium for hTSCs, namely nTSM. Furthermore, we demonstrated that ISRIB could also maintain the hESC stemness. Using a 3D co‐culture system (hESCs and hTSCs aggregate, ETA), we demonstrated that a 1:1 mixture of hESC culture medium (ESM) and nTSM improved the cell proliferation and organisation of both hESC‐ and hTSC‐compartments and the lumenogenesis of hESC‐compartment in ETAs. Overall, our study provided an ISRIB‐dependent system for co‐culturing hESCs and hTSCs, which facilitated the construction of human embryoids by aggregating hESCs and hTSCs. [ABSTRACT FROM AUTHOR]

Background and Aims: Natural products are widely used in the pharmaceutical and cosmetics industries due to their high‐value bioactive compounds, which make for "greener" and more environmentally friendly ingredients. These natural compounds are also considered a safer alternative to antibiotics, which may result in antibiotic resistance as well as unfavorable side effects. The development of cosmeceuticals, which combine the cosmetic and pharmaceutical fields to create skincare products with therapeutic value, has increased the demand for unique natural resources. The objective of this review is to discuss the biological properties of extracts derived from larvae of the black soldier fly (BSF; Hermetia illucens), the appropriate extraction methods, and the potential of this insect as a novel active ingredient in the formulation of new cosmeceutical products. This review also addresses the biological actions of compounds originating from the BSF, and the possible association between the diets of BSF larvae and their subsequent bioactive composition. Methods: A literature search was conducted using PubMed and Google Scholar to identify and evaluate the various biological properties of the BSF. Results: One such natural resource that may be useful in the cosmeceutical field is the BSF, a versatile insect with numerous potential applications due to its nutrient content and scavenging behavior. Previous research has also shown that the BSF has several biological properties, including antimicrobial, antioxidant, anti‐inflammatory, and wound healing effects. Conclusion: Given the range of biological activities and metabolites possessed by the BSF, this insect may have the cosmeceutical potential to treat a number of skin pathologies. [ABSTRACT FROM AUTHOR]

Cellular phenotypes and functional responses are modulated by the signals present in their microenvironment, including extracellular matrix (ECM) proteins, tissue mechanical properties, soluble signals and nutrients, and cell–cell interactions. To better recapitulate and analyze these complex signals within the framework of more physiologically relevant culture models, high throughput culture platforms can be transformative. High throughput methodologies enable scientists to extract increasingly robust and broad datasets from individual experiments, screen large numbers of conditions for potential hits, better qualify and predict responses for preclinical applications, and reduce reliance on animal studies. High throughput cell culture systems require uniformity, assay miniaturization, specific target identification, and process simplification. In this review, we detail the various techniques that researchers have used to face these challenges and explore cellular responses in a high throughput manner. We highlight several common approaches including two‐dimensional multiwell microplates, microarrays, and microfluidic cell culture systems as well as unencapsulated and encapsulated three‐dimensional high throughput cell culture systems, featuring multiwell microplates, micromolds, microwells, microarrays, granular hydrogels, and cell‐encapsulated microgels. We also discuss current applications of these high throughput technologies, namely stem cell sourcing, drug discovery and predictive toxicology, and personalized medicine, along with emerging opportunities and future impact areas. [ABSTRACT FROM AUTHOR]

This paper summarizes studies on antibody formation in the bone marrow and the suppressive effects of intravenous immunization with allogeneic blood cells on T-cell function in mice. The latter studies were extended by employing the limiting dilution culture system developed in Ivan Lefkovits' laboratory and implemented in collaboration with Lucien Aarden. Thereby, the functional data were complemented with frequencies of alloantigen-activated helper (Th) and suppressor T cells after intravenous alloimmunization. These results led the Rotterdam group to studies on the prevention of rejection of the foetal‘allograft’. Th cells are central in foetal allograft rejection and pregnancy success. Characteristic for human pregnancy is the production of the glycoprotein chorionic gonadotropin (hCG) hormone. The in vivo liberated peptide fragments originating from nicking of the sequence MTRVLQGVLPALPQ in theβ-chain of hCG were considered for their immunoregulating capacity related to pregnancy success. These peptides– prepared synthetically– (MTR, MTRV, LQG, LQGV, VLPALP and others) indeed showed a remarkable spectrum of biological effects (e.g. modulation of angiogenesis, inhibition of septic shock syndrome, prevention of diabetes and reduction of ischaemia-reperfusion damage). The paper interprets and generalizes these findings and projects them into various research directions, especially towards the proteomics framework studies built up in Ivan Lefkovits' laboratory in the nineties. During the time period, when Ivan spent a mini-sabbatical in Rotterdam (months after closing down the BII) more detailed discussions were intiated. This paper is meant to keep the discussions between the involved research groups going on. [ABSTRACT FROM AUTHOR]

This paper uses an empirical case study to present a new way of thinking about the dynamics of multicultural relationships within organizations. The paper initially uses subcultural analysis to identify how doctors became clinical directors and how their culture emerged as they learned to cope with problems of external adaptation and internal integration. Clinical directors were unique in working within and between the medical and managerial cultures, mediating the process of cultural learning and balancing the multicultural dynamics of the organization. They sustained this dynamic by becoming 'cultural chameleons' in both the medical and managerial cultures. It is also argued that clinical directors formed a 'cell culture' rather than a 'subculture' as they developed directly from the medical culture but emerged as different from it. The conclusions reveal how the empirical data describe a complex and dynamic pattern of multicultural relationships that are more interdependent than hierarchical. Consequently an alternative concept of cultural coconstitutionality is used to describe how these three cultures exist alongside each other in a relationship of asymmetric complementarity. [ABSTRACT FROM AUTHOR]