Microengineered systems with iPSC-derived cardiac and hepatic cells to evaluate drug adverse effects

Hepatic and cardiac drug adverse effects are among the leading causes of attrition in drug development programs, in part due to predictive failures of current animal or in vitro models. Hepatocytes and cardiomyocytes differentiated from human induced pluripotent stem cells (iPSCs) hold promise for predicting clinical drug effects, given their human-specific properties and their ability to harbor genetically determined characteristics that underlie inter-individual variations in drug response. Currently, the fetal-like properties and heterogeneity of hepatocytes and cardiomyocytes differentiated from iPSCs make them physiologically different from their counterparts isolated from primary tissues and limit their use for predicting clinical drug effects. To address this hurdle, there have been ongoing advances in differentiation and maturation protocols to improve the quality and use of iPSC-differentiated lineages. Among these are in vitro hepatic and cardiac cellular microsystems that can further enhance the physiology of cultured cells, can be used to better predict drug adverse effects, and investigate drug metabolism, pharmacokinetics, and pharmacodynamics to facilitate successful drug development. In this article, we discuss how cellular microsystems can establish microenvironments for these applications and propose how they could be used for potentially controlling the differentiation of hepatocytes or cardiomyocytes. The physiological relevance of cells is enhanced in cellular microsystems by simulating properties of tissue microenvironments, such as structural dimensionality, media flow, microfluidic control of media composition, and co-cultures with interacting cell types. Recent studies demonstrated that these properties also affect iPSC differentiations and we further elaborate on how they could control differentiation efficiency in microengineered devices. In summary, we describe recent advances in the field of cellular microsystems that can control the differentiation and maturation of hepatocytes and cardiomyocytes for drug evaluation. We also propose how future research with iPSCs within engineered microenvironments could enable their differentiation for scalable evaluations of drug effects.     

Molecular cloning and chromosomal localization of a sarco/endoplasmic reticulum-type Ca2(+)-ATPase of Drosophila melanogaster

We report here the characterization of a Drosophila melanogaster cDNA that encodes a sarco/endoplasmic reticulum-type Ca2(+)-ATPase. Previously we amplified the phosphorylation site - FITC-binding site fragment of this cDNA by Polymerase Chain Reaction utilizing homology primers (Váradi, A., Gilmore-Hebert, M. and Benz, E. J. Jr. (1989) FEBS Letters 258 203-207) and in the present work we used this fragment as probe for isolation of a cDNA clone with the intire coding region. The isolated 3.3 kb clone has been sequenced and the primary structure of the encoded protein has been deduced. It consists of 1002 amino acids with all the characteristic features of the P-type ATPases. It shows 67-71% amino acid identity and an apparently identical hydropathy profile with the mammalian sarco/endoplasmic reticulum-type Ca2(+)-ATPases. On basis of sequence similarity we suggest that the first transmembrane segment of sarco/endoplasmic reticulum type Ca2(+)-ATPases may be responsible for targeting of these transport proteins into the organellar membrane. The gene of this sarco/endoplasmic reticulum-type Ca2(+)-ATPase has been mapped on the right arm of chromosome 2, in section 60A.     

Erythropoietin is a novel therapeutic option in the treatment of anemia caused by small cell lung cancer

Anemia is very common among patients with malignant tumors, due to the disease and chemotherapy. Anemia decreases the patient's quality of life. Erythropoietin therapy is accessible in Hungary for the treatment of chemotherapy-induced anemia in patients suffering from small cell lung cancer. In our case report we present the case of a 62-year-old female small cell lung cancer patient with severe anemia, treated by erythropoietin-beta. The erythropoietin treatment provided the possibility of effective chemo- and radiotherapy. The patient's quality of life greatly improved due to the lack of the symptoms of anemia. The adequate use of erythropoietin is of great help to the physician in the management of small cell lung cancer patients, by improving the quality of life.     

Monthly incidence of Theileria cervi and seroconversion to Babesia odocoilei in white-tailed deer (Odocoileus virginianus) in Texas.

Monthly monitoring of fawns collected from an area in Texas endemic for Theileria cervi and Babesia odocoilei showed that transmission of T. cervi occurred during July and August, a time period consistent with the occurrence of Amblyomma americanum. Seroconversion to B. odocoilei occurred during October to December and possibly continued through January and February. The time of seroconversion was more suggestive of transmission of B. odocoilei by Ixodes scapularis than by Amblyomma americanum.     

Identification of airborne propagules of the Gibberella fujikuroi species complex during maize production

The airborne dispersal of the anamorphs of the Gibberella fujikuroi species complex was studied under pre- and postharvest maize (corn) production conditions using a 3-stage Andersen sampler. The aim of this study was to identify and analyse the size distribution of such species in air samples. Differences were observed between the concentration of large- and small-sized propagules (identified as aggregates and single microconidia, respectively), but the difference was only significant during a high concentration period (October 2007, P = 0.009). No correlation was found between the concentration of fusaria found at different sampling heights (10 and 150 cm above ground level). Fusarium isolates were collected and identified based on morphological characters and using species-specific PCR assays. The PCR analysis confirmed morphological identification of F. verticillioides, F. proliferatum and F. subglutinans. High concentrations were found during the maize harvest, loading and corn shelling. Our results showed that the monitoring of F. verticillioides should be performed at a single sampling height.     

Comparison of serotonin agonistic and antagonistic activities of a new antidepressant agent Trelibet (EGYT-475) and its metabolite EGYT-2760 on isolated rat fundus.

The effects of Trelibet (EGYT-475, N-benzyl-piperazine-picolinyl-fumarate) and its active metabolite (EGYT-2760, N-benzyl-piperazine) on the serotoninergic responses of rat stomach fundus were investigated and compared with those of MCPP (m-chlorophenyl-piperazine) which is the common metabolite of the arylpiperazine antidepressants Trazodone and Etoperidone. The contraction inhibitory potencies of the agents were determined on the equipotent contractions (EC50) to serotonin (5-HT) and prostaglandin F2 alpha (PGF2 alpha). Isotonic contractile responses to 5-HT were not affected by EGYT-475, however, both EGYT-2760 and MCPP produced concentration related and reversible inhibition of the serotoninergic responses. The IC50 values for EGYT-2760 and MCPP were 40.5 +/- 7.5 mumol/l and 125 +/- 35 nmol/l, respectively. The inhibition was selective for the serotoninergic responses, as the equipotent responses to PGF2 alpha were not affected. EGYT-2760 and MCPP displayed not only 5-HT antagonistic, but also partial agonistic activities on the rat fundus preparation. Maximum contractile response of the fundus preparation to MCPP was approximately 25%, to EGYT-2760 was 10% of the maximum response to 5-HT.     

Prenatal fate of parthenogenetic cells in mouse aggregation chimaeras

Parthenogenetically activated BCF1 and fertilized BALB/c embryos were aggregated to form chimaeras. The fate of the parthenogenetic component was followed in the conceptus during the second half of gestation. The results indicate an early strong selection against parthenogenetic cells in the extra-embryonal part, which is presumably complete by term, and a weaker selective process in the embryo. During early development, parthenogenetic cells have nearly normal developmental potency in the embryo, which allows their balanced contribution in the chimaeras on day 12. Later, this contribution declines significantly resulting in an unbalanced relation to the advantage of the fertilized counterpart. From the results, we suggest that gametic imprinting may play a role not only in the key steps of preimplantation and early postimplantation development, but later in cell and tissue differentiation.     

Efficiency clustering for low-density microarrays and its application to QPCR

Background  

Pathway-targeted or low-density arrays are used more and more frequently in biomedical research, particularly those arrays that are based on quantitative real-time PCR. Typical QPCR arrays contain 96-1024 primer pairs or probes, and they bring with it the promise of being able to reliably measure differences in target levels without the need to establish absolute standard curves for each and every target. To achieve reliable quantification all primer pairs or array probes must perform with the same efficiency.